Site Specific Management of Boron in Alfalfa fields

Richard Leep, Peter Jeranyama, Tim Dietz, and James DeYoung

Department of Crop and Soil Sciences

Michigan State University

A study was initiated to evaluate the feasibility of site specific boron application to established alfalfa.  Three dairy farms in Michigan were selected for the study.  The fields were located at the Kellogg Biological Station Dairy farm in Kalamazoo County, the Ken Gasper dairy farm in Ionia County, and the Larry Gingrich dairy farm in Osceola County, Michigan.  Each field of alfalfa was established in 1998.  Soils were tested in the spring of 2000 to determine boron content and applications were made on the basis of boron levels and soil type.  Plots were divided into either site specific applications which were based upon site specific soil tests or whole field management applications based upon the field composite soil test. 

At KBS site specific management of boron was associated with a higher yield response compared with whole field management. Also without boron application in both site specific and whole field management did not result in similar yields to those of boron application (Table 1). All cuttings but the third cutting did not respond to boron management. In this case site specific management at KBS 1 was associated with a higher yield compared with whole field management in the third cutting (Table 2).

At Osceola 1 (established alfalfa), there were no significant differences between whole field and site specific management (Table 3). However, site specific management in either without boron or with boron treatments had significantly higher yields than whole field management (Table 3). Total seasonal yields were higher within site specific management of boron but, individual cuttings were not different from each other (Table 3).

At the Ionia alfalfa field (established alfalfa), site specific management of boron produced significantly higher yields compared with whole field management in the first cutting (Table 4).However, in the second cutting, whole field management had significantly higher yields compared with site specific management. Total season yields were not different among management and boron treatments (Table 4). In the second cutting, whole field management was associated with higher neutral detergent fiber (NDF) concentrations (Table 5). Also,  in the second cutting within whole field management  boron application was associated with a higher NDF concentration compared with without boron treatment (Table 5). In both site specific and whole field management, without boron treatment was associated with a higher crude protein (CP) concentration (Table 5).

In summary, site specific boron application based upon grid sampling fields, shows potential for yield enhancement in established alfalfa in the fields under study.