Start Date: 2014
Principal Investigator: Jeff Coulter
Organization: University of Minnesota, Department of Soil, Water, and Climate
Irrigated sands can produce high corn yields but pose economic and environmental challenges with regard to nitrogen (N) management. In 2014, research was established on an irrigated sand in central Minnesota near Becker to assess the potential of advanced fertilizer and crop management practices for increasing the yield and N use efficiency of continuous corn. This study compares two management systems: 1) current farmer practice; and 2) a high-yield system that is also environmentally responsible (ecological intensification). For each system, current university nutrient recommendations are being compared to advanced nutrient management. The performance of each management system and nutrient intensity regime is being evaluated with corn yield and nutrient uptake, N use efficiency, and soil fertility levels (both macro- and micronutrients). This study is a companion to the AFREC-funded high-yield rainfed continuous corn study established at Waseca, MN in 2013. Results from this study will be combined with those from 19 other locations in 9 countries as part of an International Plant Nutrition Institute project, allowing the results from Minnesota to be placed in both U.S. and global contexts.
Establish treatments and manage plots
Manage plots in the fall
Present oral update to AFREC council
Collect soil samples after harvest and analyze
Collect and analyze in-season plant samples
Harvest plots for grain, cob, stover, and analyze plant samples collected at harvest
Present research to farmers and agricultural professionals and Extension meetings
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 bushels/acre and enhanced the efficiency of applied N fertilizer (1.17 vs. 1.32 pounds N/bushel).
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 bushels/acre. Coupling advanced fertilizer management with advanced crop management enhanced the efficiency of applied N fertilizer to 1.02 pounds N/bushel.
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.