2005 Annual Report: Effect of Gypsum on Soybean Yield

Objective

Demonstrate the effect of gypsum as a soil amendment to heavy clay soil in the Missouri river bottom. The goal is to improve drainage resulting in increased yield.

Materials and Methods

Soybeans were planted in plots that had gypsum applied in the spring of 2004. The treatments were 300, 500 and 1,000 pound rates and a control.

Crop Management Info
Planting Date: May 11, 2005
Herbicides: Roundup
Hybrid:Pioneer 93M11
Insecticides: None
Population: 162,000 seeds/acre
Row Width: 30-inch

Demonstration Design
Replications: 5
Design: Randomized Block
Size: 10’ X 40’
Statistics: Analysis of Variance

Results

The effect of gypsum applied in 2004 resulted in no corn yield advantage. This year’s soybean demonstration also indicates there is not a significant yield increase from the gypsum treatments.

Gypsum is typically used in western states to flush sodium through the soil profile. Sodic soils are quite noticeable as a white crust on the soil surface in eastern Colorado, western Kansas and Oklahoma.