Author
SCHUMACHER, T - SOUTH DAKOTA STATE UNIV. | |
Lindstrom, Michael | |
BLECHA, M - SOUTH DAKOTA STATE UNIV. | |
COGO, N - FA/UFRGS, BRAZIL | |
CLAY, D - SOUTH DAKOTA STATE UNIV. | |
BLEAKLEY, B - SOUTH DAKOTA STATE UNIV. |
Submitted to: Clean Water Clean Environment 21st Century Conference Proceedings
Publication Type: Proceedings Publication Acceptance Date: 3/8/1995 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Row crop production after CRP will require management practices that control soil erosion and reduce surface runoff to minimize surface water contamination. The establishment of no-till into killed sod is one practice that may prolong the benefits of grass on soil structure and on soil carbon/nitrogen dynamics. A study was conducted to examine the tillage system effects on soil loss, surface runoff, and microbial activity. Treatments established into alfalfa (Medicago sativa L.) - bromegrass (Bromus inermis Leyss.) sod included moldboard plow, chisel plow and no-till in the spring of 1990. In each subsequent year through 1993 another no-till treatment was started. Continuous corn (Zea mays L.) was grown on all plots. Corn yields were not significantly different among till age treatments. The grass check and all no-till treatments had essentially no water runoff or soil erosion. The moldboard plow treatment was highly erodible. Four years of moldboard plowing reduced microbial activity and the corresponding mineralization potentials of nitrogen and carbon. This was probably related to extensive mineralization of easily oxidizable organic matter at the start of this treatment. No-till into sod appears to be an acceptable option for minimizing soil degradation and for reducing nitrate losses in surface runoff after CRP contracts expire. Our study showed that surface cover is very critical to reduce surface runoff and sediment load from the field. This is true even if extensive macropores have been established from the ten years of grass. Extensive residue on the soil surface prevents sealing of macropores and therefore reduces surface runoff and potential contamination of surface water supplies. |