|LENSSEN, ANDREW - Iowa State University|
|Jabro, Jalal "jay"|
|Stevens, William - Bart|
Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/15/2018
Publication Date: 9/27/2018
Citation: Lenssen, A.W., Sainju, U.M., Allen, B.L., Jabro, J.D., Stevens, W.B. 2018. Dryland corn production and water use affected by tillage and crop management intensity. Agronomy Journal. 110:2439-2446. https://doi.org/10.2134/agronj2018.04.0267.
Interpretive Summary: Farmers in the semi-arid northern Great Plains have traditionally grown dryland spring wheat every other year separated by a fallow year when no crop is grown. Adoption of no-till practices, which conserve soil water more effectively than conventional tillage, has contributed to the elimination of the fallow period resulting in the production of a cash crop every year. Farmers are now looking for ways to diversify their crop rotations to enhance soil quality, reduce chemical inputs and manage risk associated with variable commodity prices. Limited precipitation and a short growing season have prevented dryland farmers in eastern Montana from growing corn in the past. The recent development of corn hybrids that are more drought tolerant and mature more quickly have made corn more attractive as a rotation crop but farmers need information about best management practices for the northern Great Plains. Factors such as seeding rate, residue management, planting date and fertilizer placement can be varied to better control weeds or to optimize crop yields. ARS scientists in Sidney, MT examined the effects of some of these practices under both tilled and no-till management for dryland corn from 2005 to 2010. They found that corn yield averaged 2965 kilograms per hectare (46 bushels per acre) overall and was 18% higher with no-till than with conventional tillage. However, it was also noted that practices intended to reduce weed competition, such as a higher seeding rate and higher wheat stubble, reduced corn yield in both tillage systems by about 11% compared to conventional practices. Interestingly, soil water storage and soil water use were about the same regardless of which management system was employed. These results suggest that corn is a potential alternative crop that may help diversify dryland wheat systems in the northern Great Plains, especially when grown using no-till practices and proper seeding rates.
Technical Abstract: Management strategies to enhance dryland corn (Zea mays L.) production and soil water use are lacking. We evaluated the effect of tillage and weed management practice on the growth, yield, and water use of dryland corn in crop rotation from 2005 to 2010 in the northern Great Plains. Tillage systems were no-tillage (NT) and conventional tillage (CT) and weed management were traditional (conventional seeding rates, early planting, broadcast N fertilization, and reduced stubble height) and improved (variable seeding rates, delayed planting, banded N fertilization, and increased stubble height) practices. Corn plant stand was greater for CT than NT in 3 out of 6 yr and greater for the improved than the traditional practice in 4 out of 6 yr. Seed number and grain yield were greater for NT than CT in 4 out of 6 yr. Ear number was greater for the traditional than the improved practice in 1 out of 6 yr. Biomass was greater for NT than CT in 1 out of 6 yr and greater for NT than CT in the traditional practice. Corn plant height, seed weight, and harvest index as well as preplant and postharvest soil water, water use, and water-use efficiency (WUE) were not influenced by treatments, but varied with years. Corn yield increased for NT compared to CT during years with below-average precipitation due to increased seed number and by reducing seeding rate and stubble height. No-tillage with reduced seeding rate and stubble height can enhance dryland corn production without affecting soil water.