GROUNDS

Using Soybeans as Lawn Fertilizer

Imagine… fertilizer that is safe enough to eat (not that we recommend doing so)! Yes, ground soybeans have been found to be an effective turf fertilizer. In 2000, Michigan State University began conducting research on the effectiveness of ground soybean fertilizer as compared with chemical fertilizers. Their studies suggest that soybeans perform equal to or better than chemical fertilizers when appropriate amounts are used. During the grinding process, soybeans are ground into particles of varying sizes. These different particle sizes act as the slow-release mechanism – the larger the particle, the longer it takes to break down – and provide a slow and steady feeding to the lawn.

The obvious advantage to using the soybean fertilizer is that it is completely organic, therefore, it is harmless to people, pets, and other plant material. The Grounds department is particularly interested in this product, especially for use in areas like Family Housing and the child care facilities where large numbers of curious children are present. Another benefit of using an organic fertilizer is that each time it is applied, , the soil is improved or amended. One more advantage is that the fertilizer is produced locally from soybeans grown on Southeastern Michigan farmland. While the cost of soybean fertilizer is roughly three times the cost of standard chemical fertilizer, the department is able to offset the cost by applying two large applications instead of four small applications of chemical fertilizer. Since the soybeans are organic material, they will not burn the grass unlike chemical fertilizers. The labor savings in making two applications instead of four comes close to offsetting the cost increase in the fertilizer.

Phosphorus has been a long time pollutant of the Great Lakes and has become more prevalent due to improper use of lawn fertilizers. Since most existing soils in Southeastern Michigan already have adequate phosphorus levels, there isn’t a need to apply additional phosphorus. Ground soybean fertilizers do not contain phosphorus; thus, they do not contribute to this pollution problem. Of course, before applying any fertilizer, we recommend conducting a soil test to determine which additives should be applied.

The Grounds Department has teamed up with Mike Score from Michigan State University Extension to study the effects of soybean fertilizer along waterways to reduce phosphorus runoff. The School of Music has provided the lawns around their pond as a testing site. We have begun applying soybean fertilizer around the pond and will continue to test the runoff water monthly over the next few years. We anticipate finding reduced phosphorous levels in the runoff water.

Over the next few years, we will use the soybean fertilizer in various areas to evaluate its effectiveness on our campus lawns. If you have any questions regarding the soybean fertilizer, contact Rob Doletzky 764.3422 or send Rob Doletzky (get address) (38.107.191.119).

~Rob Doletzky
Grounds Services