Michigan State University Extension
Ag Experiment Station Special Reports - 03299580
07/28/98
January 1995 Special Report 80
Status and Potential of Michigan Natrual Resources
Michigan Agricultural Experiment Station,Michigan State University
SPECIAL REPORT
Land Resources Lead Author: Delbert L. Mokma
Introduction
Land is one of our most important natural resources. It is virtually the sole source of our sustenance. Land supports the plants and animals that provide our food, fiber and shelter. Land is the reservoir for our water supply and the receptacle for our wastes. Land also provides the minerals we use.
Land is limited in supply. We can not make any more land and there are no areas of land that we have not explored. Therefore, as our population increases, the amount of land per person decreases. This "loss of land" is felt daily as we try to get space in a crowded park, travel busy streets and roads, seek a secluded spot to relax, attend crowded events, look for a parking space or push our way through a crowded store. Our ancestors used and misused land as though the supply were inexhaustible. Our land resources, however, were found to be limited. Certain land uses were overextended and excessive soil erosion and water pollution resulted. We recognize now that we must use our land resources in ways that are sustainable through time.
We do not have enough land to do with it as we wish. Economics and social pressures restrict how land is used. As restrictions increase, our view of land changes. In the future, we will view land less as a commodity that can be freely traded and more as a public resource that must be utilized and maintained for the good of all. We need to consider how best to use our limited land resources today so future generations will have adequate land resources to sustain them through the future.
Land is an intermediate good. Demands for land are really demands for the goods and services that land provides and supports. The demands for land and changes in ownership vary across the state. They tend to concentrate in urban areas, areas with increasing recreation demands and areas near surface waters. We have limited choices-probably more limited than we realize_given our limited land resources, current land uses and population growth. We must make choices among land uses.
Land resources, as used in this report, include soil resources, topography, climate, mineral resources and current land uses. Mineral resources are further discussed in SAPMINR Special Report 81. Water resources are important to use of our land resources and are discussed in SAPMINR Special Report 79.
Soil Resources
Soil is the collection of natural bodies in the earth's crust. Soils have depth as well as width and length. Soils differ because of five factors: parent materials; topography, including soil drainage; organisms, including plants and animals; climate; and length of time of weathering. Soils are products of these factors, so wherever the factors are the same, the soils will be similar. Each group of natural bodies that have similar physical, chemical, mineralogical and biological properties is a soil series. Each soil series is named for a town or other geographical feature near the place where the soil series was first recognized. More than 475 soil series have been recognized in Michigan.
Parent Material
Parent material is the unconsolidated mass from which soil forms. It affects the textural, chemical and mineralogical composition of the soil. Parent material is the most important factor in determining the kind of soil that forms. In Michigan, nearly all parent materials were deposited by glaciers or glacial meltwaters. Though most of the parent materials are of glacial origin, their properties vary greatly, even within small areas, depending on how the materials were deposited. The soil mantle ranges from a few inches to more than 100 feet in thickness.
Glacial till was deposited directly by glaciers with minimal water action. It is a mixture of particles of various sizes. The small pebbles in glacial till have sharp corners, indicating that they were not worn by water.
Outwash material was deposited by running water from melting glaciers. The size of the particles depends on the velocity of the stream that carried the material. As it slowed down, the water deposited the coarser particles while the finer particles-such as very fine sand, silt and clay-stayed in suspension. As a result, outwash deposits tend to have layers of particles of similar size, such as sand, gravel or other coarse particles. The pebbles in outwash material have rounded corners, indicating that they were worn by water.
Lacustrine material was deposited from still or ponded glacial meltwater. It consists of fine soil particles-such as very fine sand, silt and clay-that settled out in still or very slowly moving water.
Eolian material was deposited by wind action. It consists of sand deposited on dunes.
Alluvium is material recently deposited by floodwater from streams. This material varies in texture, depending on the speed of the water that deposited it. Organic soils occur as deposits of transformed plant residues. After the glaciers withdrew from the state, water remained standing in depressions. Grasses and sedges grew around the edges of these lakes. When these plants died, their residue did not decompose because the areas were wet. Later, water-tolerant trees grew in some areas. After these trees died, their residues also became part of the organic accumulation. Eventually, the lakes were filled with organic material.
Texture-the relative proportions of sand, silt and clay- affects the amount of water the soil will hold for use by plants (Figure 1) and the permeability of the soil (Figure 2). Clay and organic matter provide the soil with the ability (exchange capacity) to hold nutrients and adsorb materials from the water in the soil. Permeability and exchange capacity determine whether a soil can remove and hold materials from percolating waters to prevent contamination of groundwater. Sandy soils have a rapid or high permeability and a low capacity to adsorb materials. Therefore, soluble compounds such as nitrates and certain pesticides are likely to move through these soils into the groundwater. Loamy and clayey soils have slow permeabilities and high exchange capacities, and soluble compounds are not likely to move through such soils into the groundwater. Sandy soils are more prone to drought than loamy and clayey soils.
Topography
Topography affects soil formation by influencing runoff, erosion, drainage, soil temperature and plant cover. Topography is next in importance to parent material in determining the kind of soil in a given location. It causes erosional and depositional changes and thus alters the influence of the parent material and of time. It alters the effects of climate by influencing runoff, the water table, slope aspect and vegetation. Runoff is greatest on the steeper slopes.
Drainage, through its effect on aeration of the soil, determines the color of the soil. Water and air move freely through well drained soils but slowly through poorly drained soils. In well aerated soils, the iron compounds are oxidized and are red, brown or yellow. In poorly aerated soils, the iron compounds are reduced and are gray, blue or green. Hydric soils, which naturally supported wetland vegetation, are poorly drained and have dull-colored subsoils.
Organisms
Plants, animals, insects, bacteria and fungi are important in the formation of soils. Additions of organic matter and nitrogen in the soil, gains or losses in plant nutrients, and alterations in soil structure and porosity are among the changes caused by living organisms. Plant life is also capable of altering minerals.
Plant remains accumulate on the soil surface, decay and eventually become organic matter. Roots of plants provide channels for downward movement of water through the soil and also add organic matter as they decay. Bacteria in the soil help to break down the organic matter so that the nutrients can be used by growing plants and the decomposed organic materials can improve soil structure and adsorb nutrients.
Most soils in Michigan formed under trees, but some soils, especially in the southwestern part of the state, formed under grasses. Topsoil formed under trees is thin, usually light- colored and low in organic matter. Topsoil formed under grass is normally thick, dark-colored and high in organic matter.
Climate
Climate plays an important role in soil development. Temperature and rainfall are major components of climate. Climate determines the kinds of plant and animal life on and in the soil and the amount of water available for the weathering of minerals and the translocation of soil material. Greater rainfall can cause increased leaching of soluble components of soil or more translocation of non-soluble soil materials deeper in the soil profile. Through its influence on soil temperature, climate also determines the rate of chemical reactions in the soil. The climate in Michigan is predominantly cool and humid, though not uniform in all parts of the state. Presumably, it is similar to that under which the soils formed.
Time
Some soils form rapidly; others form slowly. Generally, development of distinct soil layers, called horizons, takes a long time. The degree of profile development commonly reflects the length of time that the parent material has been in place. The soils in Michigan range from young to mature. Most of the soils that formed in glacial deposits have been exposed to the soil-forming factors long enough for distinct horizons to develop. Some soils forming in recent alluvium or eolian material, however, have not been in place long enough for the development of distinct horizons.
Soil-Forming Processes
Several processes were involved in the formation of horizons in Michigan soils. The processes are: accumulation of organic matter; leaching of carbonates (lime) and other bases; reduction and movement of iron; formation and translocation of silicate clay minerals; and translocation of aluminum, iron and humus.
As organic matter accumulates at the surface, an A horizon forms. The A and E (eluvial) horizons are mixed into a plow layer, or Ap horizon, if the soil is plowed. The surface layer of soils in Michigan ranges from low to high in organic matter content.
Carbonates and other bases have been leached from the upper horizons of most soils. The leaching of bases generally precedes the translocation of silicate clay minerals, and aluminum, iron and humus complexes.
The reduction and movement of iron is evident in somewhat poorly and poorly drained soils. A gray subsoil indicates the reduction and loss of iron.
The translocation of clay minerals has contributed to horizon development in many soils. An eluviated, or leached, E horizon typically is lower in clay content and lighter in color than the illuviated B horizon. The B horizon typically has an accumulation of clay in the form of clay films in pores or on faces of peds (units of structure such as aggregates). These soils were probably leached of carbonates and soluble salts to a considerable extent before the silicate clay minerals were translocated.
In many soils in the northern part of Michigan, aluminum, iron and humus have been translocated from the surface layer to the B horizon. This accumulation increases the water- and nutrient-holding capacities of these soils. The state soil, Kalkaska sand, has this accumulation of aluminum, iron and humus.
Michigan is covered with soils that vary widely in thickness, color, texture, and chemical and mineralogical composition. These soils differ in their potential to support plants and animals. They also differ in their ability to support buildings and to treat or hold wastes. The quantity and quality of our water supply vary with soil and landscape properties. For more detailed soils information, see the Soil Association Map of Michigan (E-1550) or soil surveys of individual counties, which are available from local Soil Conservation Service and Michigan State University Extension offices.
States that have loess (wind-deposited silt) deposits (e.g., Illinois, Iowa, Wisconsin) have soils with greater water-holding capacity than most Michigan soils. In addition, Michigan has a large acreage of sandy soils. These soil factors put Michigan at a comparative disadvantage for crop production compared with those states.
Topography
In the eastern portion of the Upper Peninsula, the terrain varies from nearly level to gently rolling and elevations generally range from 600 to 1,000 feet above sea level (Eichenlaub et al., 1990) (Figure 3). In the western portion of the Upper Peninsula, elevations exceed 1,600 feet. The highest point in the state, in Baraga County, rises to about 1,980 feet.
In the Lower Peninsula the terrain varies from nearly level, such as in the Saginaw Lowland, to the gently rolling hills of the southeastern and southwestern portions of the Lower Peninsula (Eichenlaub et al., 1990). Elevations are generally between 800 and 1,000 feet. Higher elevations occur in the northern portion of the Lower Peninsula, reaching a maximum of 1,725 feet in Osceola County near Cadillac. Sand dunes along Lake Michigan rise nearly 400 feet above mean lake level.
Topography plays a role in the production of agricultural commodities in the state. Areas with higher elevations tend to have shorter growing seasons. The nearly level areas permit intensive cropping (row crops) with little erosion. The gently rolling hills in the southwestern and western portion of the Lower Peninsula provide cold air drainage for commercial fruit production.
Topography is also important for recreational activities in the state. Hilly topography is ideal for downhill skiing and tobogganing. The approximately 3,200 miles of Great Lakes shoreline and hilly topography attract a large, year-round tourist business.
Climate
The climate of Michigan varies from location to location. Michigan's climate is greatly influenced by the Great Lakes. Climate consists of moisture, solar radiation, temperature and wind.
Precipitation (both rainfall and snowfall) ranges between 26 and 40 inches per year (Eichenlaub et al., 1990). Most parts of the state receive 30 to 34 inches. The smallest amount of annual precipitation occurs near Saginaw Bay (Figure 4). The largest amounts of precipitation occur in the southwestern part of the Lower Peninsula and the western portion of the Upper Peninsula. Southwestern lower Michigan is nearest the Gulf of Mexico, the source of moist air for much of the state's rain and snow. In the western Upper Peninsula, snowfall created by cold air crossing the relatively warmer surface of Lake Superior contributes greatly to that area's total precipitation. The dry, cold air picks up moisture and heat. As the warmer, moist air moves over the colder land, it deposits moisture in the form of snow.
Snowfall totals (Figure 5) vary widely from about 30 inches in the Detroit area to more than 200 inches on the Keweenaw Peninsula of the Upper Peninsula (Eichenlaub et al., 1990). Lake proximity influences snowfall distribution. Lake-effect snow extends inland about 30 to 40 miles. Most snowbelts occur on the east side of Lake Michigan and the south side of Lake Superior.
The state's latitude determines the amounts and seasonal contrasts of incoming solar radiation (Eichenlaub et al., 1990). Solar radiation is the source of energy for heating the earth, evaporating water and photosynthesis. Average daily solar radiation (Figure 6) for six locations in Michigan was determined by the National Climatic Data Center and cooperating agencies using a regression model. At Sault Ste. Marie, the most northern of the six locations, day length varies from about 8 hours and 32 minutes to about 15 hours and 49 minutes. At Detroit, the most southerly location, day length varies from about 9 hours and 4 minutes to about 15 hours and 17 minutes. The relatively longer day lengths are important in total energy accumulation, especially for plants that respond to photoperiod for their stages of development.
The amount of sunshine reaching the land surface and plants varies slightly in Michigan (Figure 7). Summers are relatively sunny, whereas winters are relatively cloudy. This contrast in cloudiness or sunshine influences plant growth. Generally, sunshine is less and cloudiness greater in more northern parts of the state throughout the year, except in spring (Eichenlaub et al., 1990).
The average annual daily mean temperature (Figure 8) varies from about 39 degrees Fahrenheit in the western portion of the Upper Peninsula to about 50 degrees Fahrenheit in the southeastern portion of the state (Eichenlaub et al., 1990). The Great Lakes moderate the weather. Cold air passing over an unfrozen lake in the winter is warmed, while hot air passing over a lake in the summer is cooled. The latter effect is less significant. The effect of the Great Lakes on the annual average daily mean temperature, therefore, is to increase it.
The length of time between the last spring frost and the first fall frost generally limits agricultural production in Michigan (Eichenlaub et al., 1990). The shortest average growing season occurs in the northern portion of the Lower Peninsula, away from the influence of the Great Lakes (Figure 9). Lake proximity, latitude and local topography influence the length of the growing season. The 32 degree Fahrenheit threshold is important for many agronomic crops, though for some crops the 28 degree Fahrenheit threshold (Figure 10) is more critical. These crops, such as tree fruit (the fruit but not the blossoms), are able to withstand freezing temperatures but not temperatures below 28 degrees Fahrenheit. The number of growing degree-days is an indicator of the amount of energy available for biological activity (plant growth and maturity, pest development, diseases, etc.). The number of growing degree-days (base 50 degrees Fahrenheit) varies from about 1,200 at Whitefish Point in the Upper Peninsula to nearly 3,100 at Dearborn and Kalamazoo in the southern Lower Peninsula (Figure 11). Areas located south of Michigan (e.g., Ohio, Indiana and Illinois) have a longer frost-free period and a greater number of growing degree-days, which give them a comparative advantage over Michigan for crop production.
The modification of the climate by the Great Lakes, especially Lake Michigan, is important to fruit production. The lake effect helps delay fruit tree bloom in the spring and lessens the possibility of frost damage. The lake-effect snow provides moisture for the fruit trees as well as insulation for their root systems. The combination of lake-moderated climate, hilly topography and loamy soils from Grand Traverse Bay southward to the Indiana state line makes the area ideal for fruit production. The combination of soil resources, topography and climatic conditions gives Michigan a comparative advantage for many crops, especially fruits and vegetables. The modified climate is also important to the tourist business. The cooler temperatures and sunny days provide an opportunity for an enjoyable summer vacation. The increased snowfall makes the area suitable for downhill skiing, tobogganing, cross-country skiing and snowmobiling.
Wind direction and speed are highly variable in Michigan (Figure 12). Michigan lies within the belt of westerlies and winds generally prevail from this direction (Eichenlaub et al., 1990). During the summer, winds are predominantly from the southwest; during the winter, winds prevail from the west or northwest.
Current Land Uses
Michigan has more than 36 million acres of land and more than 10,000 inland lakes that have a surface area of at least 5 acres. These lakes are distributed throughout 81 of the 83 counties in the state. The inland lakes and ponds have a total area of 1,276,200 acres (1987 National Resources Inventory). The greatest acreage is in the Upper Peninsula (481,600 acres); the least, in the southern Lower Peninsula (357,000 acres). The state has more than 3,200 miles of Great Lakes coastline; Alaska is the only state that has a longer coastline. More than 36,000 miles of rivers and streams flow to the Great Lakes, providing some of the best sport fishing in the country. For further detail on fisheries and boating, see SAPMINR Special Reports 74 and 77, respectively.
The Great Lakes contain 95 percent of the surface freshwater in the United States and 18 percent of the world's freshwater supply. The quality of water in these lakes depends on how we use our land resources. Industrial wastes, septage and other wastes have polluted the Great Lakes since the 1800s. Direct dumping, dumping into tributaries and air transport of chemicals have polluted the lakes. Pollutants have limited the amount of fish a person can safely consume.
No place in Michigan is more than 85 miles from one of the Great Lakes. This abundance of water makes the state attractive for many land uses, especially recreational uses. The long Great Lakes coastline, inland lakes and rivers make Michigan attractive to boaters_Michigan has more registered boats than any other state. For a more detailed discussion of Michigan's water resources, see SAPMINR Special Report 79.
Land use varies across Michigan. In this report, land uses were summarized by the Michigan Department of Natural Resources (MDNR) regions (Figure 13). Because the land resources in the seven southeastern counties of the northern Lower Peninsula are different from those in the remainder of the region, an east central (EC) subregion was distinguished within the northern Lower Peninsula. The total surface areas of the four regions are: Upper Peninsula, 10.18 million acres; northern Lower Peninsula, 10.24 million acres; east central, 3.21 million acres; and southern Lower Peninsula, 13.83 million acres.
Forestland was the dominant land use in Michigan in 1987 (Figure 14). More than half of the Upper Peninsula and the northern Lower Peninsula were used for forest purposes, whereas cropland was the dominant land use in the east central subregion and the southern Lower Peninsula. About half of the state is forestland when national forestlands (2.8 million acres) (Wells and Eidelson, 1991) are combined with state and private forestlands (15.5 million acres) (1987 National Resources Inventory). More than one-quarter of the state is used for crop production.
Urban and Built-Up Land
Urban and built-up land covers about 5.5 percent of the state; two-thirds of it is in the southern Lower Peninsula, which also has the greatest acreage of cropland. The area of urban and built-up land continues to increase (Figure 15). The greatest increase in acreage occurred in the southern Lower Peninsula, where the greatest number of people live (see SAPMINR Special Report 69). Continued expansion of urban land uses will most likely be at the expense of farmland.
Seasonal and recreational properties are significant components of urban and built-up land use. Data on acreages of these properties are not available, so the number of houses will be used to indicate the trend in this land use for the future. The number of seasonal and recreational houses in 1990 was the greatest since 1950 (Figure 16) (Census of Housing, 1950, 1960, 1970, 1980; Census of Population and Housing, 1990). The northern Lower Peninsula has the greatest number of seasonal houses. In each region, the number of seasonal houses decreased between 1960 and 1970. In the Upper Peninsula and the northern Lower Peninsula, the number of houses has more than tripled since 1950. In the east central subregion, the number of seasonal and recreational houses has more than doubled since 1950. In the southern Lower Peninsula, the number has increased since 1970 but the number is less than that in 1960. Many seasonal and recreational houses have been converted to year-round houses for retirement. The acreages of land for seasonal and recreational houses are likely to be greater than those for primary houses because people desire more space and more natural settings. The construction of houses and roads destroys wildlife habitat, thereby impacting wildlife populations (see SAPMINR Special Report 75 for more information on wildlife).
Public Lands
The large acreage of federal and state lands in Michigan provides many recreation opportunities (Figure 17). About 86 percent of these lands is in national and state forests. The remainder is used for parks, lakeshores, recreation areas, wildlife refuges, wildlife areas, boating and fishing sites, military facilities and the Soo Locks. (The P.B. Wurtsmith and K.I. Sawyer Air Force bases were not included because they are closed or scheduled to close.) Michigan's acreage of federal lands (3.16 million acres in 1992) and state lands (4.45 million acres in 1989) is greater than that in the other Great Lakes states. This acreage and the lake-modified climate give Michigan a comparative advantage for tourism dollars in this region. About 92 percent of the federal and state lands are located in the Upper Peninsula (53 percent) and the northern Lower Peninsula (39 percent).
The acreage of federal lands in the northern Lower Peninsula has increased 24.6 percent since 1958, while the acreage in the Upper Peninsula and the southern Lower Peninsula increased 9.1 and 7.1 percent, respectively (Figure 18). In the east central subregion, the acreage increased from about 2,000 acres in 1958 to about 11,000 acres in 1967, but since then has decreased to about 9,000 acres. Approximately 50,000 acres changed ownership from non-federal to federal land in Michigan between 1982 and 1987. The relative amount of land owned by the federal government is inversely related to the acres of prime farmland (defined below) or high quality soil for crop production (Figure 19). The acreage of federal lands is expected to remain the same or increase slightly in the future.
Forestlands
In 1987, Michigan had a total of about 18.3 million acres of forestland; this total makes up about half of the 36.4 million acres of land in the state. The acreages of private, state and national forestland are about 11.6 million, 3.9 million and 2.8 million acres, respectively. Michigan has the nation's largest state forest system. The four national forests in the state are the second largest state total east of the Rocky Mountains.
The Upper Peninsula has the largest acreage of private and state forestland, with the northern Lower Peninsula a close second (Figure 20). The acreage of private and state forestland has increased slightly since 1977. The greatest increase has been in the northern Lower Peninsula. For more detailed information on forest resources, see SAPMINR Special Reports 71, 72 and 73.
Farmland
Land in farms has decreased in all regions of the state since 1944 (Figure 21). The most rapid shift in land out of agriculture has occurred in the Upper Peninsula. The Upper Peninsula had about 67 percent less land in farms in 1992 than it had in 1964. Acreage in farms in the northern Lower Peninsula and the southern Lower Peninsula declined 60 and 40 percent, respectively. The acreage of farmland in the east central subregion declined only 27 percent. Former farmland has now been converted to urban uses and forestland and other uses. Between 1982 and 1992, farmland in the state decreased by about 854,200 acres, whereas urban land increased by about 461,300 acres and forestland increased by about 236,800 acres. Therefore, more than one-fifth, or about 156,100 acres, were converted to other uses that are not well defined. Included are areas that are in various stages of forest succession since being abandoned as farmland.
Agriculture and the related food industry represent a significant portion of Michigan's economy. In 1989-91, gross farm income averaged about $3.7 billion annually (Michigan Agricultural Statistics Service, 1993). Both crops and livestock are important sources of income to Michigan farmers, with total cash receipts of nearly $3.1 billion in 1991. Total crop receipts were somewhat greater than total livestock and products receipts. Fruits and vegetables account for 23 percent of the total crop receipts, while using only about 4 percent of the cropland. For more details on Michigan's agriculture and food industry, see Status and Potential of Michigan Agriculture (SAPMA) Special Report 32.
In the 1970s and early 1980s, concern over the loss of farmland in Michigan and elsewhere in the nation was high (e.g., Anonymous, 1973b, 1976, 1985; Barlowe, 1981). In these studies, projections based on the rates of decline then suggested that Michigan could have as little as 2.5 million to 4.4 million acres in farmland in the year 2000. In 1992, the land in farms was 10.1 million acres. It is highly unlikely that the acreage of farmland will decline as projected. The area in 1992 is 12.2 percent larger than the 9 million acres projected to exist in 1985 (Anonymous, 1973a) and 26.2 percent larger than projected acreage needed in the year 2000 to produce the necessary food and fiber. These data do not necessarily indicate that the concerns over loss of farmland were unfounded_rather, they could indicate that Michigan citizens recognized the importance of preserving farmland and worked together to reduce the rate of conversion of farmland to urban and built-up land in the state. Between 1974 and 1982, the area of land in farms increased slightly (Figure 21). In the east central subregion, the acreage of farmland increased again between 1987 and 1992. Western Michigan, however, has been identified as one of 12 agricultural regions in the United States that are threatened by urban encroachment.
Prime farmland has the soil quality, growing season and moisture supply needed to economically produce sustained high yields of crops when treated and managed according to acceptable farming methods. Prime farmland may now be cropland, pasture, forestland or other land, but not urban or built-up land. This resource is valuable not only to the agricultural community, but to all citizens of Michigan. Of the approximately 7.6 million acres of prime farmland in the state, about 84 percent occurs in the southern Lower Peninsula and the east central portion of the Lower Peninsula. A slight loss of prime farmland occurred between 1982 and 1987 (less than 4 percent). Only about 5.8 million acres (about 76 percent) of this prime farmland are used for cropland. The remaining 1.8 million acres are being used for pasture or forestland and could be converted to crop production in the future if the need arises. This, of course, would reduce the area of prime farmland available for those other uses.
In 1974, Michigan enacted the Farmland and Open Space Preservation Act (P.A. 116 of 1974). As of January 7, 1993, more than 4.5 million acres of farmland had been contracted under the act. Fewer than 4,000 acres of open space had been contracted under the act. The greatest acreage was in the southern Lower Peninsula (61.8 percent); the least was in the Upper Peninsula (2.2 percent). The northern Lower Peninsula has about 7.6 percent of the land contracted under the act, and the east central subregion has about 28.4 percent. The acreage of farmland under contract in Michigan today is greater than that projected to remain in farmland by the year 2000 (Anonymous, 1973b, 1976; Barlowe, 1981).
Cropland
Total cropland decreased in all three regions of Michigan from 1944 to 1992 (Figure 21). The Upper Peninsula has less than half of the cropland it had in 1944 (51 percent decrease). The acreage of cropland in the northern Lower Peninsula, the southern Lower Peninsula and the east central regions declined 40, 28 and 7 percent, respectively.
The acreage of harvested cropland in the state in 1992 was 6.6 million acres (0.4 million acres more than in 1987). This acreage is 37.5 percent greater than that (4.8 million acres) projected to exist in 1985 (Anonymous, 1973a) and 40.4 or 88.6 percent greater than that (4.7 or 3.5 million acres) projected to remain in the year 2000 (Anonymous, 1973b; Barlowe, 1981).
The total cropland to total farmland ratio has increased since 1944 in all regions of the state (Figure 22). This increase indicates that there is less farmland available that could be converted to cropland in the future. It also indicates that the areas no longer counted as farmland may have had above average acreages of non-cropland. If a larger acreage of cropland is needed in the future, land will have to be converted from other uses, most likely forestland. The increase in the ratio also indicates there is less land in permanent vegetation that wildlife could use for food and cover. (For more information on wildlife, see SAPMINR Special Report 75.)
Fruits and Vegetables
Michigan is one of the nation's major fruit-producing states, largely because of Lake Michigan's moderating influence on the weather of the western parts of the state. The fruit belt extends along the western coast of the Lower Peninsula from Grand Traverse Bay southward to the Indiana state line, where the lake effect is strongest. Michigan is the leading producer of tart cherries (73 percent) and blueberries (30 percent) (Michigan Agricultural Statistics Service, 1993). Michigan is also among the leading producers of apples, sweet cherries, grapes, prunes and plums. The acreage of land in orchards decreased from 1964 to 1982 in the southern Lower Peninsula, where the majority of fruit is grown, and in the east central subregion (Figure 23). The northern Lower Peninsula and the Upper Peninsula had fewer acres in orchards in 1987 than in 1964, but the decrease was much less than that in the southern Lower Peninsula and more variable with time. The acres in blueberries have nearly doubled in the past 20 years (Michigan Department of Agriculture, 1993).
Michigan is also a major vegetable-producing state. It leads the nation in the production of cucumbers for pickles (19 percent) and is a leading producer of asparagus, snap beans, celery, carrots and fresh market cucumbers (Michigan Agricultural Statistics Service, 1993). Vegetable production is concentrated in the southern Lower Peninsula. The variation in total acreage of land used for vegetables has differed among MDNR regions (Figure 24). The southern Lower Peninsula had at least 46 percent more acres in vegetables in 1992 than in 1964. The east central subregion had about 9,300 acres less in 1992 than in 1964 but about 6,000 acres more than in 1982. The acreage of vegetables in the northern Lower Peninsula was about 8,800 acres greater in 1992 than in 1964. In the Upper Peninsula, the acreage in vegetables decreased more than 62 percent between 1964 and 1992. The greatest decrease took place between 1969 and 1974; since 1974, the acreage has increased.
Irrigated Land
Irrigation has increased dramatically since 1964, especially in the Lower Peninsula (Figure 25). In the Upper Peninsula and the northern Lower Peninsula, the acreage of irrigated land decreased between 1982 and 1987 but has increased since 1987. In the east central and the southern Lower Peninsula, where about 93 percent of the irrigated land is located, the acreage continues to increase. This increase in irrigation has helped offset the reduction in cropland acreage. Between 1982 and 1992, the state's irrigated acreage increased 28.7 percent. If this increase continues during the next decade, irrigated land would increase by 57 percent between 1982 and 2002_less than a doubling of irrigated land between 1980 and 2000 as predicted by Bartholic et al. (1983).
Soil Erosion
Since 1964, the types of crops grown have changed considerably (Figure 26). The acreage of row crops-corn, soybeans, sorghum, dry beans, sugar beets and potatoes- increased until 1978 in the Upper Peninsula and until 1982 in the northern Lower Peninsula, the east central and the southern Lower Peninsula, and then decreased. Acreage in small grains-wheat, oats, barley and rye-has decreased slightly and is at the lowest since 1964. In all regions, the acreage in hay decreased from 1964 until 1974 and then increased. In the Upper Peninsula, hay land has decreased since 1978, but in the Lower Peninsula regions, hay land increased from 1982 to 1992 after decreasing from 1978 to 1982. The trend in hay acreage reflects the decrease in livestock numbers and the increase in horse numbers. The acreage of all types of pasture has decreased in all three regions since 1964. This decrease reflects the decrease in livestock numbers and the change from raising livestock on pasture to raising them in feedlots. The loss in acreage of cropland and the increase in acreage of row crops have been at the expense of pastureland.
The change in types of crops grown could be of concern to environmental quality. Soil erosion by water and wind continues today and will continue in the future as long as soil is exposed to the erosive power of water and wind. Soil is exposed not only by cultivation, but also by removal of vegetation during development of areas for non-agricultural uses. Greater amounts of erosion usually occur from cropland than from pasture, hay land or forestland because of the exposed soil surface. The decrease in pasture, hay and small grains and the increase in row crops could increase soil erosion by water and wind. However, the estimated acres of land that are eroding by water and wind have decreased in all regions since 1977 (Figure 27) (1987 National Resources Inventory). The estimated amount of eroded soil (in tons) decreased in the Upper Peninsula and the northern Lower Peninsula but increased in the east central subregion and the southern Lower Peninsula (Figure 28). Much of this eroded soil material reached our surface waters, decreasing their quality. Conservation treatment to reduce soil erosion to or below tolerable amounts is needed on about 15.2 million acres of crop-, pasture- and forestland (1987 National Resources Inventory). The percentage of each of these three uses that requires conservation treatment varies from region to region (Figure 29). Conservation plans have been developed for about 650,000 acres (more than 85 percent) of the approximately 750,000 acres of highly erodible land used for cropland in Michigan. Farmers have implemented the conservation plans on about 473,000 acres (more than 60 percent) of highly erodible lands. Conservation plans must be prepared and implemented on the remaining highly erodible lands by December 31, 1994, as mandated by the Food Security Act of 1985 (P.L. 99-198) and amended by the Food, Agriculture, Conservation and Trade Act of 1990 (P.L. 101-624). If conservation plans are not implemented, farmers will lose their eligibility for USDA benefits. Lands in addition to highly erodible lands that contribute to degradation of water quality may also be placed in the Conservation Reserve Program (CRP) because they occur in the Great Lakes region.
Since 1986, farmers in Michigan have enrolled about 332,850 acres in the Conservation Reserve Program (nationally the total is 35 million acres). This program, a provision of the Food Security Act of 1985, was designed to retire highly erodible land and other environmentally fragile cropland from production for a period of at least 10 years. In 1995, the earliest of those CRP contracts will expire. Will federal policymakers approve a continuation of the program to keep these and other fragile CRP lands out of production? Will farmers convert their CRP lands to cropland? Some lands that have been planted to soil-conserving grass or trees will not be converted, but other lands will be converted as the contracts expire. This could increase the amount of soil erosion, unless the farmers acquire and follow conservation plans designed to protect these lands. The permanent vegetation provided by the Conservation Reserve Program is also beneficial to wildlife. Therefore, converting CRP lands to cropland will affect wildlife negatively.
Conservation tillage, including no-till, has greatly helped reduce erosion from land used for row crops. Conservation tillage reduces soil erosion but may increase the use of pesticides to produce high yields. In 1992, about 1.01 million acres of crops were planted using no-till in Michigan. In this cropping system, crops are planted in the residues of the previous crop without first plowing and preparing a clean seed bed. The residues are left on the soil surface to protect the soil against water and wind erosion. More than three-fourths of the no-till acreage was used to plant corn and soybeans, row crops that are susceptible to erosion. No-till is the most effective conservation measure farmers can use to control erosion and protect water quality.
Cover crops can reduce erosion with minimal reduction in crop yields. Cover crops are planted when a crop is reaching maturity or after a crop has been harvested. They provide vegetative cover for the soil during late fall, winter and early spring, when most soils are exposed to the full forces of water and wind. Vegetative cover absorbs the energy of water and wind and holds soil in place.
Fertilizer Usage
Fertilizer usage can affect environmental quality. Between 1975 and 1985, total fertilizer use in Michigan increased (Figure 30) (TVA, 1992). During that decade, fertilizer use per cropland acre increased slightly from 328 to 359 pounds per acre. In 1985, total fertilizer consumption reached a maximum of 1,470,000 tons, but it has since fluctuated between 1,158,000 and 1,279,000 tons. The rate of fertilizer application increased to 393 pounds per acre in 1990.
Nutrient use per acre decreased in the mid-1970s, when energy costs were high, but has increased since (Figure 31). Phosphorus usage has decreased since 1980, perhaps in recognition that additional phosphorus is not beneficial on many cropland acres. Nitrogen and potassium use steadily increased during the 1980s but has leveled off in the past few years. Good nutrient management is based on knowing what nutrient levels are present in the soil. In 1990, approximately 79,000 soil samples were collected from cropland in Michigan. Assuming that one-third of the cropland acreage is sampled each year, then one soil sample was taken for each 27 acres. Farmers are recommended to collect one sample to represent 10 acres. This would suggest that some farmers are not sampling and testing their soils or are not sampling on a regular basis. Some farmers, however, are sampling and testing more frequently and more intensively.
Farm fields are usually composed of more than one soil. These soils may have different capacities to retain nutrients or pesticides and may transmit water at different rates. Also, farm fields may have been managed differently in the past. These variations have presented problems to farmers as they applied fertilizers and pesticides. Uniform application of these materials may result in inappropriate management for some areas of a field. Site-specific management permits farmers to vary the application of fertilizers and pesticides within a field according to plant requirements and the soil's capacity to retain these chemicals. This will minimize the movement of these chemicals to groundwaters.
Waste Management
Of the large amounts of wastes generated in Michigan annually, a significant proportion are organic materials (i.e., materials primarily of biological origin). The U.S. Department of Agriculture (USDA, 1978) has grouped many organic materials that are or could be applied to cropland into the following categories:
1. Animal manure - feces and urine excreted by cattle, horses, sheep, goats, swine and poultry, with any accompanying bedding or litter.
2. Crop residues and green manures - the stems, leaves, roots, chaff, composted yard wastes and other plant parts remaining after crops are grazed or harvested; and plant material that is green and growing to maturity that is incorporated into the soil.
3. Human wastes - various forms of organic materials containing human feces and urine, such as night soil, septage, sewage wastewater and sewage sludge.
4. Food processing wastes - organic byproducts from the fruit, vegetable, seafood, sugar, fats, oils and dairy food processing industries. 5. Industrial organic wastes - byproducts from paper and allied products; fermentation, including phar- maceutical and food additives; soap and detergent; alcoholic fermentation, including distilleries, wineries and malt beverage industries; meat packing and related industries, including those producing pet food, seafood and poultry products; leather tanning and finishing; organic fiber processing; petroleum refining and related industries; and milling.
6. Logging and wood manufacturing residues - waste debris in forests after logging, such as limbs, leaves, needles, diseased/decayed wood; manufacturing residues, such as chips, bark, sawdust, etc.
7. Municipal refuse - the organic portion of collectable solid wastes generated by households, institutions, offices, commercial and industrial premises, and collected in the streets of urban areas.
An estimate of the annual production of these organic materials in the United States is given in Table 1. If one excludes crop residues, which largely remain on the cropland where they are produced, the two largest quantities of organic materials produced that must be managed in our society are animal manure and municipal solid waste (MSW). As with crop residues, a large part of logging residues remain on the land where they were produced. Much lower quantities of industrial organics, human wastes and food processing byproducts are produced.
The use of each type of organic material on cropland and forestland in 1978 as a source of plant nutrients or as an organic matter amendment is also given in Table 1. As the table shows, about 90 percent of the animal manure, 68 percent of crop residues, 23 percent of human wastes (i.e., sewage sludge and septage) and about 13 percent of the food processing byproducts were being used on land. Only about 1 percent of the MSW was estimated as being returned to agricultural land. The USDA predicted that the probability for increased use of these organic materials on land in the future is very low for logging residues, medium for sewage sludge/septage and low for the other categories. Soil has long been known as nature's most effective decontaminating facility, but it is essential that additions of wastes do not exceed the soil's capacity to treat the wastes.
While agriculture has been challenged recently to manage animal manure nutrients better than it has in the past, management of the two major municipal waste streams-sewage sludge and MSW_has reached a critical stage (Parr and Hornick, 1993). Production of sewage sludge in the United States has increased to 5.9 million dry tons/year (U.S. EPA, 1993), and MSW has increased to about 196 million tons/year (U.S. EPA, 1992). As shown in Figure 32, approximately 68 percent of MSW is made up of organic residuals, including paper and paperboard, yard trimmings, food garbage and wood materials.
Interest in recycling more of these two municipal waste streams has been increasing because of the escalating costs of landfilling and incinerating. For sewage sludge, the percentage applied to land for beneficial reuse increased from 23 percent in 1978 (Table 1) to 36 percent in 1990 (U.S. EPA, 1993). For MSW, composting is currently being viewed as a means of treating the organic portions of this waste stream prior to beneficial reuse.
The total potential supply of compost that could be produced annually from sewage sludge, horticultural/silvicultural residues and animal manure was estimated to be 51 million tons/year, which included 30 million tons for MSW, 15 million tons for horticultural waste, and 3 million tons each for sewage sludge and animal manure (Slivka et al., 1992). In contrast, the potential demand for compost was estimated to be about 500 million tons/year. These relative quantities of production and application/utilization are shown in Figure 33. Potential utilization of compost products is predominantly on agricultural land, with 86 percent on cropland, 10 percent on forestland and 2 percent for sod production. Other potential applications- which include landscaping, topsoil, bagged/retail products, landfill final cover, container and field nurseries, and surface mine reclamation_will contribute less than 2 percent to the potential demand/utilization of compost. Therefore, cropland and forestland can play a significant role in helping our society utilize the soil resource to manage its organic waste streams, not only nationally but also here in Michigan.
Application of organic waste residuals to land in Michigan provides a major waste management option for municipalities and businesses. Most of the animal manure produced in Michigan is returned to cropland. Based on animal numbers, the estimated annual production for 1990 was approximately 18.5 million tons. The numbers of cattle and poultry in Michigan are projected to increase in the near future (Ferris, 1992), so more animal manure will be produced and applied on cropland. Estimates of crop residues and green manures and of logging and wood manufacturing residues are not readily available for Michigan, but we assume that proportions of these two categories of organic materials comparable to the USDA estimate (Table 1) will be utilized on Michigan's land resources.
Most septage (pumpings from septic tanks) has traditionally been applied to land, although some county health departments are requiring haulers to dispose of septage into municipal wastewater treatment plants. In 1990, the MDNR estimated that approximately 299,000 dry tons/year of sewage sludge was being produced in Michigan and about 21 percent (61,800 dry tons/year) was being applied to cropland and forestland. This percentage is lower than the national average of 36 percent recently estimated by the U.S. Environmental Protection Agency (U.S. EPA, 1993). Some increase in land application has occurred in Michigan since 1990, but the fact that more than 50 percent of the sludge continues to be produced in the Detroit metropolitan area is an obstacle to land application because of the distance between where the sludge is generated and available cropland and the difficulty of crossing political boundaries. Nevertheless, land application of sewage sludge in Michigan is the primary waste management option selected by about 80 percent of the more than 200 sewage wastewater treatment plants in Michigan.
Very little MSW finds its way to the land surface. The majority of MSW in Michigan (about 60 percent) goes to landfills (Steuteville, 1994). In December 1993, Michigan had about 11,000 acres of active and closed landfills. The number of landfills in the state decreased 6 percent, from 71 in 1990 (Glenn and Riggle, 1991) to 67 in 1992 (Steuteville and Goldstein, 1993). Nationally, the number of landfills decreased about 15 percent. With the recent ban on yard wastes in landfills, increased amounts of organic residuals are expected to be composted and then returned to the land. For some communities not wanting to compost, yard waste materials may be put through grinders or chippers and applied directly to land.
Estimating the quantity of MSW organic materials that might be recycled to land is difficult. The characterization of MSW by the U.S. EPA (1992) suggested that per capita generation in 1990 was 4.3 pounds/day (or 1,570 pounds/year) and projected to be 4.5 pounds/day (or 1,640 pounds/year) by the year 2000. For a Michigan population of 9,312,000 in 1990 (see SAPMINR Special Report 69), this would be about 7,310,000 tons of MSW per year, and for a projected population of 10,300,000 in 2010, the quantity of MSW could be expected to be about 8,450,000 tons per year.
Several recreational activities generate organic wastes that must be managed in an environmentally sound manner. Human wastes and garbage are produced in our parks (for more information on camping, trails and dispersed recreation, see SAPMINR Special Report 78) and by boating (for more information on boating see SAPMINR Special Report 77). The fishing industry, especially sport fishing, produces large amounts of fish residues that must be managed (for more information on fisheries, see SAPMINR Special Report 74). The paper industry also produces organic wastes, some of which are returned to land. Management of these wastes is a key to the continuation of these activities.
When the application of organic waste residuals to cropland is being considered as a waste management option, the potential benefits and hazards to the soil-plant system will be important to farmers who may be asked to accept these materials. Waste residuals can provide one or more of the following potential benefits for crop production: 1. Essential plant nutrients (biofertilizers).
2. Organic matter (soil amendments).
3. Ag lime substitute (soil pH maintenance).
4. Water (supplemental irrigation).
Application of organic waste materials to cropland as a source of nutrients and organic matter provides one of the best alternatives for waste management available to our society. Quantities of the major organic waste streams can be compared to commercial fertilizer as a potential source of plant nutrients (Table 2). Animal manure provides the greatest potential for replacing fertilizer nutrients on cropland. The potential nutrient value of MSW was estimated on the basis of population, the U.S. EPA per capita MSW generation rate, and the MSW nutrient content suggested by Parr and Hornick (1993). Though a significant quantity of nutrients may be present in MSW, this potential is still largely unavailable for beneficial reuse. At present, the quantity of MSW nutrients being applied to cropland and forestland is probably less than the quantity of sewage sludge nutrients being recycled to cropland.
Potential hazards of applying organic materials to the soil-plant system for crop production include (Jacobs, 1990): 1. Poor management of nutrients.
2. Additions of undesirable trace elements and trace organic chemicals.
3. Pathogens (i.e., disease-causing organisms).
4. Creation of soil physical problems.
Addition of trace elements or organic chemicals is not expected to be a problem with the various types of organic materials listed above, though sewage sludges and MSW will need to be monitored regularly for trace elements because of the potential for introducing these from public collection systems. Some industrial organic waste streams may have higher-than-background levels of some elements because of their manufacturing processes.
Animal manure and human wastes must be properly managed to avoid any transmission of pathogens that could cause animal or human health problems. Some care may also be needed when handling plant materials to avoid introducing plant pathogens to soil-plant systems that could reduce crop yields. Care must be taken during land application of residuals so as not to damage soil structure by compaction due to the heavy weight of application equipment when soil conditions are too moist. Additional soil physical problems can be encountered with wastewater applications, such as high BOD (biochemical oxygen demand), excess water that prevents adequate soil aeration and increases the risk of runoff/erosion, and excess salts that can cause dispersion of soil colloids.
The greatest potential hazard in the application of organic materials to land, however, is improper nutrient management that can result in pollution of water resources, particularly with nitrogen (N) and phosphorus (P). Excess nitrate can contaminate groundwater. Excess phosphorus may accumulate in surface soils, increasing the risk of phosphorus runoff/erosion losses to surface water. In addition, odors and fly problems can occur if the application of these organic materials are not managed properly. The application of most organic materials to land in Michigan (i.e., categories 3-7 above) is regulated by the MDNR to minimize environmental degradation. An inventory of waste products in Michigan that can be applied to land (similar to that for Maine in Seekins, 1986; and Seekins and Mattei, 1990), can help waste generators (which include consumers) and potential utilizers (i.e., farmers) recognize that many of these residuals have resource value. Agriculture can play a significant role in organic waste management in our society and help the citizens of Michigan manage their waste residuals in an environmentally responsible manner.
Wetlands
Wetlands are valuable land resources in Michigan. Wetlands are defined as those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. They can provide wildlife habitat, improve water quality, provide recreational activities, act as water storage areas during flooding, and minimize bank and shoreline erosion along rivers and lakes. It was estimated that in about 1780, Michigan had about 11.2 million acres of wetlands but in about 1980, only about 5.6 million acres remained (Dahl, 1990). This loss of wetlands resulted from drainage for crop production and development for urban uses. Some wetlands are also being threatened by vegetative takeover. Purple loosestrife (Lythrum salicaria L.) has invaded some wetlands, suppressed the resident plant community, and altered the structure and function of the wetlands. The resulting monoculture eliminates many natural foods and much cover essential to wetland wildlife.
The 1780 acreage estimate can be questioned because a large acreage has been converted to uses that prevent us from determining the type of vegetation that was naturally growing on many sites 200 years ago. The acreage of hydric soils, which are developed under sufficiently wet conditions to support the growth and regeneration of hydrophytic vegetation, would give a good estimation of the amount of wetlands in the state then. That estimate_10.6 million acres, made from the Soil Conservation Service Statsgo data (Figure 34)_compares favorably with the 11.2 million acres of wetlands (Dahl, 1990). An estimate of the acreage of wetlands existing in Michigan today may be obtained from the 1987 National Resources Inventory. About 3 million acres of non-federal flooded flats, marshes, swamps and bogs were included in the inventory. Federal lands were not included in the inventory and significant expanses of wetlands are included in national forests and wildlife refuges, so the estimate of about 5.6 million acres (Dahl, 1990) appears to be accurate.
The current U.S. wetlands policy of "no net loss of wetlands" is an attempt to stop the continuing reduction in wetlands acreage. This policy allows for trading constructed wetlands for natural wetlands. Not all natural wetlands are identical, however. The function and value of individual wetland areas should be considered when determining whether a constructed wetland may be traded for a natural wetland. It is not clear that all types of natural wetlands can be constructed. When mitigation takes place, the acreage of wetlands usually increases, but is the constructed wetland required to perform the same functions as the natural wetland? If this is not required, there is in effect a loss of wetlands functions, even though there is an increase in the total acreage of wetlands.
Another policy question is: Should all wetlands be protected at the expense of certain upland habitats? Upland habitats also perform unique functions and are not identical to other upland habitats. We should not wait to protect these habitats until they are in danger of extinction.
Golf
Golfing is a form of recreation rapidly growing in popularity. In Michigan, golfers can play courses designed by some of the world's foremost golf course architects, including Jack Nicklaus, Arnold Palmer, William Newcomb, Robert Trent Jones and Donald Ross. Michigan has some of the best golf courses in the nation. In 1990, four courses were listed among "America's 75 Best Public Courses," an increase from two in 1984 (Tarde, 1984; Whitten, 1990). Three golf courses were listed among "America's 100 Greatest Golf Courses" in 1993 (Whitten, 1993).
The number of public golf holes has increased since 1986 in all regions of Michigan (Figure 35). The number of holes has increased more in the southern Lower Peninsula (623) than in the other regions (99 in the Upper Peninsula, 531 in northern Lower Peninsula and 153 in the east central subregion). Michigan ranks second in the nation behind Florida in the number of public golf holes. The number of public golf courses increased more in the southern Lower Peninsula (81) than in the northern Lower Peninsula (49), the east central subregion (15) and the Upper Peninsula (6) since 1986. In 1989, golf courses (total property) occupied 261,032 acres in Michigan (Trendfacts Research, 1989). About 31.9 acres were associated with each of the 8,181 holes. Since 1986, the acreage of public golf courses has increased by over 3,100 acres in the Upper Peninsula, almost 17,000 acres in the northern Lower Peninsula, almost 4,900 acres in east central subregion and almost 20,000 in the southern Lower Peninsula (Figure 36).
Sandy soils dominate in the northern Lower Peninsula region. Fertilizers and pesticides applied to maintain courses in this region could find their way to groundwaters. Irrigation waters may exacerbate the movement of these soluble materials through the soil. Care in the amounts and the timing of applications is necessary to prevent groundwater contamination.
Mines, Quarries and Pits
Extractive industries are not extensive in Michigan. In 1992, the state had about 128,600 acres of strip mines, quarries, sand and gravel pits, and borrow pits (SCS, 1982). Though these uses do not affect large areas, they do affect the surrounding area. Four extractive industries are directly related to land resources: peat, construction sand and gravel, industrial sand and clay production. Data on the acreage of each of these four industries are not available, so production data are presented to indicate their trends.
Peat
Organic soils are abundant in Michigan. About one of every eight acres-about 4.53 million acres-is organic soil. Peat mining (Figure 37) is a major use of organic soil resources. Peat mining occurred on an estimated 1,000 acres in 1992 (assuming one acre-foot is harvested annually). Michigan has fallen to second place behind Florida in peat production. These two states accounted for about 64 percent of the U.S. production in 1992. The Great Lakes states, including Michigan, produced about 35 percent of the national production, with other Midwest states producing about 10 percent.
In 1992, peat was being mined in nine counties in Michigan. Sanilac is the leading county in peat production. Peat was also harvested in Allegan, Eaton, Ingham, Mecosta, Monroe, Oakland, St. Joseph and Shiawassee counties. More than 90 percent of the peat harvested in Michigan is sold for soil improvement; most of the remainder is sold for potting soil.
Organic soils are hydric soils_the equivalent of wetlands. With the wetlands legislation, the peat harvesting industry may rapidly decline. The decline in Michigan peat production since 1988 (Figure 37) may be at least partially related to this.
Sand and Gravel
Sand and gravel mining is another consumptive use of land resources (Figure 38). Michigan is the second leading state in the production of construction sand and gravel, behind California. Most counties in Michigan have had at least one sand and gravel mining operation. In 1991, 314 operations were located in 72 of Michigan's 83 counties.
Michigan is also the second leading state in the production of industrial sand (Figure 38), behind Illinois. The leading counties in sand production, based on value, are Muskegon, Ottawa, Van Buren, Wayne and Wexford. Dune sand is ideal for foundry castings, making Michigan's dunes the target of industrial sand producers. The destruction of dunes will be reduced with the passage of the Sand Dune Protection and Management Act of 1977.
Clay
Clay production (Figure 39) occurred in four counties- Alpena, Shiawassee, Monroe and Wayne. Michigan is fourth in the nation in common clay production. Most of the clay produced in the state is captive production by cement companies; the remainder is used in pottery and brick manufacturing. For more information on Michigan's non-renewable resources, see SAPMINR Special Report 81.
Legislation
Legislation at the national level (Section 404 of the Clean Water Act; the Swampbuster provision of the 1985 Food Security Act, as amended: Emergency Wetlands Resources Act, P.L. 99-645 in 1986) and the state level (Goemaere-Anderson Wetland Protection Act, P.A. 203 of 1979) protect Michigan's wetlands from further development. The state of Michigan has acquired many wetland areas-about 11,224 acres (MDNR, 1993)-with waterfowl stamp revenues and the Michigan Natural Resource Trust Fund.
Surface waters of Michigan are protected from sedimentation through the control of accelerated soil erosion by the Erosion and Sedimentation Control Act (P.A. 347 of 1972). The act exempts the earth changes of logging, mining, and plowing, tilling and crop harvest. Most highly erodible lands that will be taken out of crop production will be managed with appropriate conservation practices as mandated by the Food Security Act of 1985 (P.L. 99-198) as amended by the Food, Agriculture, Conservation and Trade Act of 1990 (P.L. 101-624).
The Farmland and Open Space Preservation Act (P.A. 116 of 1974) protects farmland and open space from development. A landowner who enters into a development rights agreement may not construct a building or structure, improve land or extract minerals for 10 years.
The Sand Dune Protection and Management Act of 1977 will protect those unique ecosystems and preserve sand dunes for future generations.
The Subdivision Control Act (P.A. 288 of 1967) regulates the subdivision of land to further the orderly layout and use of land.
Assumptions for the Future
The analysis and projections for the 1990s and early 21st century have several underlying assumptions. These include: - The North American Free Trade Agreement (NAFTA) has been adopted, thereby reducing trade barriers and increasing trade between the United States, Canada and Mexico. Other agreements, such as GATT, will be made with other countries to reduce trade barriers between the United States and those countries.
- Overall economic conditions in the United States- economic growth, unemployment and inflation-will be similar to conditions during the past five years.
- Michigan citizens will demand a greater quantity of high quality water.
- Land use decisions must be environmentally sound.
- Wetlands and sand dunes will continue to be preserved.
- Land resources can not be moved to other locations.
- Irreversible land uses will not be moved to other locations.
- Climatic conditions will be similar to those experienced in the past 50 years.
Projections to the Year 2010
As the population increases, the need for food and fiber will increase. Some increase in food production will come from increases in per acre yield that will result from increases in irrigation (increase in acres); increases in amounts of nutrients applied, both from wastes and fertilizers; and improvements in crop varieties. These increases in production will not be sufficient to meet the increased demand and offset the conversion of farmland to urban land, so some pasture, hay land and forestland will need to be converted to cropland. The amount of land available for farmland and cropland in the year 2010 should be at least 8.5 million and 6.5 million acres, respectively. This should assure that Michigan citizens will have sufficient land for food production to the year 2010, but future generations may not be able to produce enough food if the population continues to grow. Terleckyj and Coleman (1992b) have projected that the number of farm jobs will decrease by about 22 percent and farm earnings will decrease by about 23 percent between 1990 and 2010 in Michigan. On the other hand, the number of private non-farm jobs is projected to increase by about 20 percent and private non-farm earnings to increase by about 47 percent during the same period. These projections would suggest that significant decreases in the acreages of farmland and cropland will occur. Will future consumers have an adequate food supply if these decreases are realized? Farm products will continue to be exported from and imported into Michigan, but other states will also experience decreases in farmland and cropland acreages and face similar challenges to provide an adequate food supply.
Can Michigan's soil resources sustain food, feed and fiber production for future generations? Sustainable agriculture means agricultural systems that provide farmers with a good income, provide consumers with an adequate, safe food supply and have minimal negative impact on the environment. High productivity requires an adequate supply of available nutrients. These nutrients must be sufficient for the desired high yields and be retained in the upper soil horizons or layers to assure they do not leach into groundwaters. Soil erosion must be minimized to prevent the loss of nutrients from the system and the introduction of nutrients to our surface waters. This makes it imperative that all lands that need conservation treatment receive it, not just the highly erodible lands. Cover crops help to reduce soil erosion and take up nutrients that might otherwise leach into the groundwater during the off-season for crop growth.
Crop yield increases depend on adequate supplies of nutrients and water. The nutrients needed to produce sufficient food will come from two sources_fertilizers and wastes. Applications of nutrients must be based on the nutrient levels in the soil and the crop need. If wastes are applied, their nutrient amounts must be subtracted from the amounts of fertilizer nutrients to be applied to prevent loss of nutrients from the root zone to groundwater. During an average year, Michigan's lands, except sandy soils, receive sufficient precipitation to produce high yields. Irrigation is needed to supply water to soils with low available water-holding capacity and at times of insufficient rainfall. Michigan has sufficient water resources of high quality to meet the increasing demands for irrigation to increase food, feed and fiber production in the state.
Productive systems must manage pests at or below economic threshold levels with minimal negative impact on the environment. Use of mechanical methods of pest control is unlikely to increase in the future. Chemical methods of pest control will continue to be used, though changes will occur. Growers will gradually shift from preemergent to postemergent herbicides. Farmers will use integrated pest management practices to determine what pests are present in a field and then apply specific pesticides to control those pests. This will reduce the total amount of pesticides applied, not necessarily the acreage that will be treated nor the number of pesticides applied to a field. The amounts of pesticides applied per acre will also be reduced as growers switch from pesticides, especially herbicides, with low activity (applied at rates of pounds per acre) to those with much higher activities (applied at rates of ounces per acre). Canada has mandated that the amount of pesticides be reduced by 25 percent in the next five years. American farmers may be encouraged by cost savings to scout fields, implement integrated pest management practices and thereby reduce the amounts of pesticides they apply. Reducing the rate of pesticides applied reduces the chance that some of the pesticides will leach to groundwater.
Sandy soils have rapid permeability and low capacity to hold water and adsorb nutrients and pesticides. When used for crop production, these soils require careful management to prevent environmental degradation. With increased concern about environmental quality, it is likely that some crop production will be moved from sandy soils to finer textured soils. This change may require adapting present management systems for sandy soils to systems for high production on finer soils. If high quality farmlands, especially prime farmland, are available for food production and farmers apply needed chemicals at appropriate rates, Michigan's soil resources can sustain food production for future generations.
The adoption of NAFTA will have minimal negative impact on Michigan agriculture. This agreement will allow Michigan farmers to export their crops to Canada and Mexico without import tariffs, thereby possibly increasing exports, especially dry beans. Asparagus and sugar beets have been mentioned as two crops that will likely be negatively affected. One must remember that Mexico also has limited land resources. It must feed its people, also. If Mexico increases its acreages of asparagus and sugarcane, it must decrease production of other crops, and this will allow U.S. and Michigan farmers to export those crops. The 15-year phaseout of tariffs will allow sufficient time for Michigan farmers to adjust their crop acreages to compensate for changes in Mexican production.
The population increase will also increase recreational demands-e.g., hiking, camping, golfing, hunting and fishing. Some of these uses can be achieved through multiple use of some lands-e.g., hunting and hiking_but others require land dedicated only to that use_e.g., golfing. The future needs for most recreational uses are discussed in SAPMINR Special Report 78. The number of public golf holes and courses will continue to increase, but at a slower rate than in the past 10 years. By the year 2010, there will be a predicted 11,000 golf holes on 800 golf courses. This will mean 63,800 acres will be converted from other uses to golf courses. The increase in golfing could be even greater if workers achieve shorter work weeks.
The expansion of urban areas will continue, but the rate of conversion of farmland and forestland to urban land will not increase over the rate at which it has occurred since about 1975. Laws that protect wetlands will continue to be enforced, thereby slowing development. Terleckyj and Coleman (1992a) project the greatest population increases in west central and northern lower Michigan (see also SAPMINR Special Report 69). It is not surprising that northern lower Michigan is projected as a high population growth area_people have been attracted to this area by recreational activities for many years. Seasonal houses will be converted to year-round houses as people retire. As people gain affluence, they will build new seasonal houses. Urban land is expected to increase by about 300,000 acres to about 2,310,000 acres, with the greatest percentage in the west central and northern Lower Peninsula, but the largest acreage will be in southeastern Michigan. Urban development on prime and unique farmland must be minimized to assure future generations they will have sufficient farmland to produce the needed food and fiber at reasonable prices.
Land application of wastes, especially organic wastes, will increase. The recent legislation that restricts disposal of yard wastes (grass clippings and leaves) in landfills will force their disposal on land. The numbers of cattle and poultry in Michigan are projected to increase in the near future (Ferris, 1993). This will mean more animal manure will be produced and disposed of on cropland. For soils to treat these wastes with no negative environmental impact, growers must take into account the nutrients they contain when determining how much fertilizer to apply. Environmentally sound manure management is a key to the growth of the animal industry.The percentage of wastes that will be disposed of in landfills will decrease, and the percentages of waste materials that will be recycled, composted and incinerated will increase. Michigan citizens desire to recycle more, and technology will develop ways to recycle more items. People will be willing to pay a slightly higher (up to 5 percent) price for products made or packaged with recycled or biodegradable materials.
Transportation systems affect the distribution of land uses, especially urban uses. With the completion of the interstate highway system in 1992, highway construction is no longer one of the major factors in conversion of farmland and forestland to urban land. Relocation of portions of existing highways may cause some farmland and forestland to be converted to urban land in those areas. These conversions should be limited in extent.
Continuing Issues
Soil Erosion
Erosion of agricultural and non-agricultural lands continues to threaten our surface waters. Though the acres of land eroding have decreased, the amount of soil eroding has increased, especially in the southern part of Michigan where crop production is the greatest. The Conservation Reserve Program has removed many highly erodible lands from crop production. This program has not only benefited surface water quality but has provided habitat for wildlife. No funds have been allocated to continue the CRP beyond the current contracts. The gains in reduced erosion from these highly erodible lands may be lost if the CRP is not continued and the lands are converted to cropland. The CRP should be continued, and new programs that give farmers incentives to properly use and manage lands are needed.
Urbanization
The conversion of farmland to non-agricultural uses continues to reduce the acreage of land that will be available for food and fiber production in the future. Though the rate of conversion has declined recently, urbanization continues. The estimated acreage of land available for crop production in the year 2010 appears to be sufficient. What will happen beyond 2010? As the population continues to increase, more food will be required. More, not less, land will be required to meet that demand.
Fragmentation of Land Uses
The ownership of land is constantly changing. Some actions create more ownerships; others cause land use changes. Urbanization of farmland may cause fragmentation of agricultural land to the point where, in some areas, a viable agriculture becomes impossible. Farmland is not the only land use negatively affected by fragmentation. Several counties in northern Michigan have significant acreages of forestlands. Because these forestlands are in relatively small woodlots, and are frequently in different ownerships, they are difficult to manage and develop. Tourism and the scenic beauty of the landscape are also affected by fragmentation. Michigan residents must consider the impact of fragmentation in decisions to purchase land and to change land use. The Subdivision Control Act (P.A. 288 of 1967) addresses some of these issues, but additional steps must be taken to overcome the problem of fragmentation.
Agricultural Chemicals
Fertilizers and pesticides have been very instrumental in producing large amounts of food and fiber at low prices. These chemicals are necessary to meet future needs. They should be applied at rates that will not result in leaching to groundwater, and appropriate conservation practices should be used to prevent their movement to surface waters.
Waste Management
Large amounts of wastes have been and will be generated in Michigan. They will need to be managed safely. Waste management is a key to the future of Michigan agriculture and, to a lesser degree, of Michigan industry and recreation. Soil has been effective in decontaminating waste, and land application of wastes is a viable method of waste management. For soils to treat wastes adequately, the application rate must not exceed the soil's ability to treat them. Problems have arisen when application rates have been too high.
Emerging Issues
Incorporating Ecological Relationships in Land Use Decisions
Ecological relationships are the composite of the facilitating and limiting properties of land resources and their interactions. How these principles can be used in making local land use decisions is not obvious. We must develop a better understanding of ecological relationships and their implications for land use planning. Knowledge of these relationships needs to be transferred to land use planners. The protection of wetlands comes at the expense of upland habitats. Some upland habitats are probably more valuable to society than some wetland areas.
Improved Land Resources Data Base and Geographic Information Systems
Land resources data bases must be updated periodically to provide the most current data for decision making, and these data bases must be shared among state, regional and local governmental units. Weightings to permit combining different land resources must be developed to assist land use planners in using all available information in decision making. These weightings are necessary to make maximum use of geographic information systems. Degree of soil limitations for various land uses is provided in modern soil survey reports, but soil potentials for various uses would allow planners to make better decisions.
Integration of Economic and Environmental Decisions
Currently a conflict exists between economic development and environmental considerations. The focus should not be on the conflict, but rather on how to increase the integration between economic development and environmental considerations. Much of our economic planning, decision making and implementation has been quite separate from environmental planning and decision making. Environmentally fragile areas and environmentally resilient areas must be identified and categorized, and environmental limits and tolerances permissible for such areas specified. Effective processes for integrated planning and decision making must be developed.
Wetlands Inventory
Wetlands must be inventoried_not only their location and size, but also their function and value. Such an inventory would be a useful tool in preserving wetlands. Michigan citizens, including developers, should consider the importance of a specific wetland before purchasing a certain piece of property. Those with high value should be purchased by the state, or their development rights purchased, so they will be protected against all future attempts to develop them. The inventory would prepare Michigan for a future Wetlands Reserve Program signup if the state is included in the list of states that receive federal monies to purchase permanent easements from owners of wetlands. Priority will be given to wetlands that will help preserve endangered or threatened species. Because some U.S. legislators are concerned that environmental legislation such as the Clean Water Act will encroach on private rights, the state should purchase the property or the development rights, especially of the high value wetlands. If these important wetlands are allowed to remain in private ownership, they will repeatedly be considered for development. Wetlands that serve special functions, especially those functions that can not be performed by constructed wetlands, should also be purchased, or their development rights purchased, to assure they are protected from future development. Constructed wetlands should be monitored to determine if they perform the functions they were designed to perform. Natural wetlands developed over long periods of time_will the functions of constructed wetlands remain unchanged through time?
Upland Habitat Inventory
Upland habitats should also be inventoried and their locations, sizes and functions recorded. Essential ones should be purchased, or their development rights purchased, to assure their availability for future generations. The upland habitats that are most threatened are those located in the southern Lower Peninsula, where many areas have already been converted to farmland or urban land. Priority should be given to upland habitats that will help preserve endangered or threatened species.
Table 1. Annual production of organic materials in the United States about 1978.
Millions of Portion Current Use
Organic Material Dry Tons of Total on Land
Animal Manure 175.0 21.8% 90%
Crop Residues 431.0 53.7% 68%
Human Wastes 4.4 0.5% 23%
Food Processing 3.2 0.4% 13%
Industrial Organics 8.2 1.0% 3%
Logging/Wood Manuf. 35.7 4.5% 5%
Municipal Solid Waste 145.0 18.1% 1%
Table 2. Estimated nutrients present in organic waste materials compared to fertilizer nutrients sold in Michigan.
Material Amount N P2O5 K2O
tons/year
Animal manure 18,500,000 96,800 56,000 96,400
(wet)
Sewage sludge
Total produced 299,000 8,970 13,100 1,670
(dry)
Land applied 62,000 1,860 2,710 350
(dry)
Municipal solid
waste* 7,310,000 51,200 33,600 26,300
(dry)
Fertilizers** 1,279,000 250,000 122,000 228,000
* Quantity of MSW estimated by using 1990 Michigan population (9,312,000) and U.S. EPA per capita MSW generation rate (4.3 pounds/day or 1,570 pounds/year). **TVA, 1992.
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Figure 1. Available water capacity in upper 36 inches of soil in Michigan.
Figure 2. Soil permeability in Michigan.
Source: Lusch, D.C., and C.P. Rader. 1992, Center for Remote Sensing and Department of Geography, Michigan State University.
Figure 3. Topography in Michigan.
Source: Eichenlaub et al., 1990.
Figure 4. Average annual precipitation (inches) in Michigan, 1951-1980.
Source: Eichenlaub et al., 1990.
Figure 5. Average seasonal snowfall (inches), 1950-51 to 1979-80.
Source: Eichenlaub et al., 1990.
Figure 6. Average daily solar radiation in selected Michigan cities, 1952-1976.
Source: Eichenlaub et al., 1990.
Figure 7. Average monthly sunshine and cloud cover in selected Michigan cities, 1923-1979.
Source: Eichenlaub et al., 1990.
Figure 8. Average annual daily mean temperatures (degrees Fahrenheit), 1951-1980.
Source: Eichenlaub et al., 1990.
Figure 9. Average number of days between last spring and first fall 320F occurrences, 1930-1979.
Source: Eichenlaub et al., 1990.
Figure 10. Average number of days between last spring and first fall 280F occurrences, 1930-1979.
Source: Eichenlaub et al., 1990.
Figure 11. Seasonal (March to October) growing degree-days (base 500F), 1951-1980.
Source: Eichenlaub et al., 1990.
Figure 12. Average annual wind directional frequency and speed.
Source: Eichenlaub et al., 1990.
Figure 13. The three Michigan Department of Natural Resources (MDNR) regions with the east central (EC) subregion of the northern Lower Peninsula.
Figure 14. Proportion of different land uses in the MDNR regions, 1987. Source: Soil Conservation Service, 1987 National Resources Inventory.
Figure 15. Acreage of urban and built-up land in the MDNR regions, 1982-1992.
Source: Soil Conservation Service, 1982, 1987 and 1992 National Resources Inventories.
Figure 16. Number of seasonal and recreational houses in the MDNR regions, 1950-1990.
Source: Department of Commerce, 1950, 1960, 1970 and 1980 Census of Housing and 1990 Census of Population and Housing.
Figure 17. Proportional uses of federal and state lands in the MDNR regions, 1989.
Source: Wells and Eidelson, 1991.
Figure 18. Acreage of federal land in the MDNR regions.
Source: Soil Conservation Service, 1958 and 1967 Conservation Needs Inventory and 1982, 1987 and 1992 National Resources Inventory.
Figure 19. Percentage of total land area in the MDNR regions owned by the federal government in relation to the percentage of prime farmland in each region, 1987.
Source: Soil Conservation Service, 1987 National Resources Inventory.
Figure 20. Acreage of private and state forestland in the MDNR regions.
Source: Soil Conservation Service, 1982, 1987 and 1992 National Resource Inventories.
Figure 21. Acreage of land in farms and total cropland in the MDNR regions.
Source: U.S. Census of Agriculture, 1940, 1944, 1949, 1954, 1959, 1964, 1969, 1974, 1978, 1982, 1987 and 1992.
Figure 22. Ratio of total cropland to farmland in the MDNR regions.
Source: U.S. Census of Agriculture, 1940, 1944, 1949, 1954, 1959, 1964, 1969, 1974, 1978, 1982, 1987 and 1992.
Figure 23. Acreage of orchards in the MDNR regions.
Source: U.S. Census of Agriculture, 1964, 1969, 1974, 1978, 1982, 1987 and 1992.
Figure 24. Acreage of land in vegetables in the MDNR regions.
Source: U.S. Census of Agriculture, 1964, 1969, 1974, 1978, 1982, 1987 and 1992.
Figure 25. Acreage of irrigated land in the MDNR regions.
Source: U.S. Census of Agriculture, 1964, 1969, 1974, 1978, 1982, 1987 and 1992.
Figure 26. Cumulative acreage of row crops, small grains, hay and pasture in the MDNR regions.
Source: U.S. Census of Agriculture, 1964, 1969, 1974, 1978, 1982, 1987 and 1992.
Figure 27. Estimated average annual erosion (acres) in the MDNR regions.
Source: Soil Conservation Service, 1982 and 1987 National Resources Inventories.
Figure 28. Estimated average annual erosion (tons) in the MDNR regions, 1987.
Source: Soil Conservation Service, 1982 and 1987 National Resources Inventories.
Figure 29. Pe