Foliar Fertilization

In this study, Task Force 2, a blend of N, P, K, boron, cobalt, iron, manganese, molybdenum, and zinc was applied at a rate of 2 qt./acre. The cost was $11/acre.

Omitting the foliar fertilizer from the high-yield protocol resulted in only a 0.6 bu/acre decline in yield. Economic loss when this input was omitted was negligible.

These results are not surprising. Over the nearly 4 decades since a positive yield response of soybean to foliar fertilizer was first reported, yield responses to this input have been rare and negligible.

Take Home Message

These results confirm that application of foliar fertilizer to soybeans late in the season has not and still does not appear to be a viable input for increasing yields in a high-yield environment.

In a blog posted on the MSSOY website, the case is made for applying small amounts of N fertilizer to soybeans at the mid-reproductive stage (R3) when grown in high-yield environments with low residual soil N. Response to this soil-applied N late in the season is not predictable, but it is one possible late-season fertility input that should be considered for Midsouth soybeans that are grown in high-yield environments. Foliar-applied N does not appear to offer the same benefit.

Composed by Larry G. Heatherly, Oct. 2012, larryheatherly@bellsouth.net