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Tillage and Nutrient Source Effects on Water Quality and Corn Grain Yield from a Flat Landscape
Author(s) -
Thoma David P.,
Gupta Satish C.,
Strock Jeffrey S.,
Moncrief John F.
Publication year - 2005
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2004.0200
Subject(s) - tillage , environmental science , agronomy , yield (engineering) , nutrient , water quality , grain yield , agricultural engineering , biology , ecology , materials science , engineering , metallurgy
Beneficial effects of leaving residue at the soil surface are well documented for steep lands, but not for flat lands that are drained with surface inlets and tile lines. This study quantified the effects of tillage and nutrient source on tile line and surface inlet water quality under continuous corn ( Zea mays L.) from relatively flat lands (<3%). Tillage treatments were either fall chisel or moldboard plow. Nutrient sources were either fall injected liquid hog manure or spring incorporated urea. The experiment was on a Webster–Canisteo clay loam (Typic Endoaquolls) at Lamberton, MN. Surface inlet runoff was analyzed for flow, total solids, NO 3 –N, NH 4 –N, dissolved P, and total P. Tile line effluent was analyzed for flow, NO 3 –N, and NH 4 –N. In four years of rainstorm and snowmelt events there were few significant differences ( p < 0.10) in water quality of surface inlet or tile drainage between treatments. Residue cover minimally reduced soil erosion during both snowmelt and rainfall runoff events. There was a slight reduction in mineral N losses via surface inlets from manure treatments. There was also a slight decrease ( p = 0.025) in corn grain yield from chisel‐plow plots (9.7 Mg ha −1 ) compared with moldboard‐plow plots (10.1 Mg ha −1 ). Chisel plowing (approximately 30% residue cover) alone is not sufficient to reduce nonpoint source sediment pollution from these poorly drained flat lands to the extent (40% reduction) desired by regulatory agencies.