| Title: | Nitrogen and water management strategies to reduce nitrate leaching under irrigated maize. |
| Authors: | Schepers, J.S.
Varvel, G.E.
Watts, D.G.
USDA, ARS |
| Source: | Journal of contaminant hydrology. Dec 1995. v. 20 (3/4), p. 227-239. |
| NALT Subjects: | Zea mays
nitrates
leaching
pollution control
furrow irrigation
center pivot irrigation
fertigation
chlorophyll
meters
nutrient requirements
urea ammonium nitrate
crop yield
research projects
crop rotation
Glycine max
runoff
irrigation requirement
fertilizer requirements
application rate
continuous cropping
anhydrous ammonia |
| Other Subjects: | recovery
surge flow furrow irrigation
fertilizer requirement determination
management systems evaluation area |
| Issue Date: | Dec-1995 |
| Abstract: | 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. |
| URI: | http://hdl.handle.net/10113/17160 |
| Appears in Collections: | USDA Research and Information
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