Abstract

Successful N management practices for the US Midwest must optimize crop production and minimize NO-N losses from subsurface tile drainage. The objective of this study was to measure the effects of N rate, N application timing, and nitrapyrin [2-chloro-6-(trichlormethyl) pyridine] on corn ( L.) production and NO-N in tile drainage water in a corn-soybean [ (L.) Merr.] rotation in Minnesota. Anhydrous ammonia was applied at 90 and 179 kg ha with nitrapyrin in the fall and at 134 kg ha with and without nitrapyrin in fall and spring. However, drainage water monitoring was only conducted on fall treatments. Over a 5-yr period, 71% of drainage occurred in April through June and <1% occurred from November through March due to frozen soil. Averaged across N treatments and crops, annual drainage ranged from 69 to 380 mm among years. From 2001 through 2003, NO-N concentrations averaged 13.8, 15.6, and 20.0 mg L in corn and 7.3, 8.2, and 12.6 mg L in soybean when 90, 134, and 179 kg N ha was fall applied with nitrapyrin to corn, respectively. Corn grain yields were greater with spring-applied N at 134 kg ha (11.3 Mg ha) than with fall-applied N at 134 and 179 kg ha with nitrapyrin (10.5 and 10.8 Mg ha, respectively), and nitrapyrin did not affect corn production or water quality. Fall application of N is common on cold soils in Minnesota. These data showed that fall application required a greater rate of N to optimize yield than spring and that greater fall rate often increased NO-N concentration and load in tile drainage water.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.