Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/9/2000
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Starter fertilizer with three levels of nitrogen were applied to soybeans in corn-soybean rotation under conventional and ridge tillage and in a corn-soybeans-wheat-alfalfa rotation under conventional tillage. Our hypothesis was that low levels of starter nitrogen fertilizer may be beneficial under the cooler wetter conditions of the northern Corn Belt. Starter nitrogen significantly increased yield under each tillage and rotation. Accounting for the cost of the fertilizer, starter nitrogen increased net returns $12 to $52 per hectare, without a protein or oil premium. Starter nitrogen increased soybean protein content under the corn-soybeans-wheat-alfalfa rotation and significantly reduced protein content under the ridge tilled corn-soybean rotation. Starter nitrogen also significantly decreased oil content under each tillage and rotation. If premiums were paid based on oil and protein content, starter nitrogen could reduce net returns $12 per hectare under ridge tillage while increasing net returns $32 to $54 per hectare under conventional tillage. Tillage and rotation had no significant impact on soybean yield or oil content, however the corn-soybeans-wheat-alfalfa rotation had significantly higher protein levels. Premiums based on oil and protein content could add $4 to $15 per hectare to soybean net returns in the corn-soybean-wheat- alfalfa rotation compared to the corn-soybean rotation.