Search National Agricultural Library (NAL) Digital Collections
Showing item 0 of
from your search.
Nitrogen and water management strategies to reduce nitrate leaching under irrigated maize
- Cropping systems that fail to integrate nitrogen (N) water management are frequently associated with elevated concentrations of nitrate-N in soil and groundwater. Examples of poorly integrated management practices are abundant, especially where irrigation is used to minimize the effects of drought and N fertilizer is inexpensive. Two maize fields under improved water and N management practices at the Nebraska Management Systems Evaluation Area (MSEA) project were compared with an adjacent field under conventional furrow irrigation that followed management guidelines mandated by the local Natural Resources District. Surge-flow furrow irrigation with laser grading and a runoff-water recovery system reduced water application by 45-69% compared to conventional furrow irrigation over the three years of this study. Center-pivot sprinkler irrigation reduced water application by 60-72% compared to conventional furrow irrigation. Uniformity of water application was improved with the surge-flow and sprinkler irrigation systems, which made it reasonable to consider adding fertilizer N in the water (fertigation) to meet crop needs. The spoon-feeding strategy, based on chlorophyll meter readings to schedule fertigation, saved 168 kg hat1- N the first year and 105 kg ha-1 N the second year without reducing yields. Near total reliance of fertigation to meet crop N needs resulted in a 15% yield reduction the second year because spatial variability in soil N status made it difficult to collect representative chlorophyll meter data. Plot studies showed chlorophyll meter readings and yields were consistently higher for maize following soybean than where maize was grown in monoculture.
Schepers, J.S. , Varvel, G.E. , Watts, D.G.
meters (equipment) , Zea mays , nitrates , leaching , pollution control , furrow irrigation , center pivot irrigation , fertigation , chlorophyll , nutrient requirements , urea ammonium nitrate , crop yield , research projects , crop rotation , Glycine max , runoff , irrigation requirement , fertilizer requirements , application rate , continuous cropping , anhydrous ammonia
- In the special issue: Integrated nitrogen management in relation to leaching and groundwater quality / edited by R.F. Follett and P.J. Wierenga. Proceedings of a symposium held July 10-16, 1994, Acapulco, Mexico.
- Journal of contaminant hydrology Dec 1995. v. 20 (3/4)
Journal Articles, USDA Authors, Peer-Reviewed
- Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.