Surface seeding irrigated corn

An attachment has been developed for center pivot irrigation systems to surface seed crops, a process called seedigation. Since corn (Zea mays L.) is commonly irrigated in Nebraska, we evaluated seedigation of corn. The effects of five tillage practices and five irrigation treatments on establishment, growth, and yield were determined. We evaluated dryland conditions and four irrigation frequencies: every other day, once/day, twice/day, and three times/day. Tillage practices included: disking prior to conventional planting, disking prior to surface seeding, disking before and after surface seeding, and surface seeding into undisturbed winter wheat, corn, and soybean residues. The establishment of conventionally planted seeds was similar to that when seeds were incorporated by disking after seeding. Establishment was significantly lower when seeds were not incorporated. Establishment was less than 20% when seeding into plots with plant residue cover. Frequent irrigation improved establishment when seeds were not incorporated. Establishment ranged from 34% for the dryland treatment to 69% when irrigated three times/day for plots that were only tilled before seeding. Grain yields were highest for conventionally planted corn. Yields for conventionally planted plots and those disked before and after surface seeding were significantly different in 1986, but not in 1987. Disking after seeding significantly increased yields. Disking before surface seeding produced significantly higher yields than seeding onto soils covered with plant residue. Only plots that were disked before and after seeding were economically comparable to conventional planting. Our results also suggest that tilling corn fields increases establishment of volunteer corn. These results provide initial data to evaluate seedigation for selected conditions. Soils, climatic conditions, management practices, and other factors affect results and additional research is needed to develop these relationships.