Effects of Tillage Systems and Nitrogen Source on Corn Yield

Corn producers in Iowa adopt different tillage systems for commercial fertilizer or liquid swine manure. The cost of commercial nitrogen fertilizers continues to rise due to the increasing cost of natural gas, which is the raw product of commercial nitrogen fertilizers. Liquid swine manure is a good source of nitrogen, phosphorus, and potassium and can be a potentially viable substitute for the more expensive commercial fertilizers. The effects of tillage systems on crop yield are functions of several factors including soil and climatic conditions. Determining the most appropriate combination of tillage systems and nitrogen rates for corn production leads to profitability for corn producers. The objective of this study was to evaluate the responses of corn to three tillage systems and four nitrogen rates of swine manure and commercial nitrogen.