Advancing Intensive Management of Corn Systems in Minnesota (Rainfed)

Two Global Maize sites exist in Minnesota: 1) a high-productivity, tile-drained, clay loam soil in Waseca, Minnesota (2013 to 2014), and 2) an irrigated sandy soil in Becker, Minnesota (2014). The objective for both is to assess the potential of advanced fertilizer and crop management practices for increasing the yield and N use efficiency of continuous corn.

Timely rainfall in Waseca during 2013 produced corn yields ranging from 193 to 233 bu/A. In comparison, 2014 had excessive rainfall in June (12.9 in.) and dry conditions during the remainder of the season. Corn yields ranged from 92 to 156 bu/A. High-yield management practices, including a longer-season hybrid (104 vs. 99 day) and a greater planting rate (41,000 vs. 36,000 seeds/A), increased corn yield by 18 bu/A in 2013 and 35 bu/A in 2014. Intensive practices also enhanced the efficiency of applied N fertilizer (0.66 vs. 0.71 lb N/bu in 2013; 1.32 vs. 1.74 lb N/bu in 2014). Compared to standard practices, a fertilizer management program that included P and K applications based on grain nutrient removal, surface-dribbled N near the row at planting, and an additional side-dressed 40 lb N/A increased corn yield 23 bu/A in 2013 and 31 bu/A in 2014. Yield increases with advanced fertilizer management were consistent with both standard and high-yield management. These results demonstrate the potential for growers to close the corn yield gap by pairing advanced fertilizer management with intensified cropping systems that include longer-season hybrids and greater planting rates.

In Becker, removing 40% of corn residue prior to tillage in the previous fall, coupled with a longer-season hybrid (103 vs. 97 day) and a greater planting rate (41,000 vs. 36,000 seeds/acre) increased corn yield by 21 bu/A and enhanced N efficiency (1.17 vs. 1.32 lb N/bu). Advanced fertilizer management, including surface-dribbled N near the row at planting and three in-season applications of N rather than two, increased corn yield by an average of 29 bu/A. Coupling advanced fertilizer management with advanced crop management enhanced the efficiency of applied N fertilizer to 1.02 lb N/bu. The results from the first year of this study demonstrate that irrigated continuous corn yields can be increased with changes in residue management, hybrid selection and planting rate. These results also show that advanced fertilizer management based on 4R principles can increase corn yield and N fertilizer efficiency on irrigated sands in both standard and high-yield systems.