Author
McCool, Donald | |
MCCLELLAN, RONALD - USDA-NRCS RETIRED | |
RICKMAN, RONALD - USDA-ARS RETIRED | |
MUTCH, PAUL - USDA-ARS RETIRED |
Submitted to: ASAE Annual International Meeting
Publication Type: Proceedings Publication Acceptance Date: 3/29/2002 Publication Date: 5/1/2002 Citation: Mccool, D.K., Mcclellan, R.C., Rickman, R.W., Mutch, P.W. 2002. Residue and crop yield relationships for erosion prediction models. ASAE Annual International Meeting. Interpretive Summary: Crop residue production and the resulting surface cover are very important in preventing both water and wind erosion and ensuring long-term sustainability of the soil resource. Erosion prediction models are used to evaluate and select cropping systems that meet soil, air and water quality goals. These models are highly sensitive to the amount of surface residue, particularly during periods when surface residue may be low, such as seedbed preparation and crop emergence. For most cropland areas, the periods of seedbed preparation and crop emergence generally coincide with those of greatest rainfall amounts and intensities, making these the most critical erosion periods. In the Northwestern Wheat and Range Region (NWRR) of the USA, winter is the period of greatest erosion hazard because most precipitation occurs during winter, soils are weakened by freeze/thaw action, and of the historically productive and profitable practice of producing fall-seeded cereals. In this study, datasets were assembled from various regional sources in order to establish surface residue versus yield relationships for a number of crops currently produced in the NWRR. The NWRR is a unique crop production area with Mediterranean-type climate with wet winters and dry summers with very little precipitation during July and August. After spring rains cease, crops are grown on soil water stored during the previous winter. This influences both vertical root distribution and biomass production. Similar to data from the eastern USA, linear relationships between above ground residue production and crop yield were found for winter and spring cereals and spring legumes. However, the intercept and slope of the linear relationship for the same species were different from those for the eastern USA, reflecting the influence of climate as well as the semi-dwarf cereal varieties that have been developed for the NWRR. These above ground residue versus yield relationships will be used in erosion prediction models such as RUSLE2, and to calibrate crop growth models that are important components of more complex erosion models such as WEPP and WEPS. The study resulted in new and better-substantiated relationships between crop yield and total biomass production crops currently produced in the NWRR. These relationships are important because they provide the databases for using hydrology and erosion models to evaluate cropping systems that meet soil, air and water quality goals for the 4 million hectare of non-irrigated cropland of the region. Technical Abstract: Residue production and the resulting surface cover are very important in developing strategies to prevent or control erosion for long-term sustainability. Erosion prediction models are highly sensitive to the amount of surface residue, particularly during periods when surface residue may be low, such as seedbed preparation and crop emergence. For most cropland areas, the periods of seedbed preparation and crop emergence generally coincide with those of greatest rainfall amounts and intensities, making these the most critical erosion periods. In this study, datasets were assembled from various sources in order to establish surface residue versus yield relationships for a number of crops currently produced in the Northwestern Wheat and Range Region (NWRR) of the USA. The NWRR is a unique crop production area with a Mediterranean-type climate. Winters are wet and summers are dry with very little precipitation during July and August. After spring rains cease, crops are grown on soil water stored during the previous winter. This influences both vertical root distribution and biomass production. Similar to data from the eastern USA, linear relationships between above ground residue production and crop yield were found for winter and spring cereals and spring legumes. However, the intercept and slope of the linear relationship for the same species were different from those for the eastern USA, reflecting the influence of climate as well as the semi-dwarf cereal varieties that have been developed for the NWRR. These above ground residue versus yield relationships will be used in erosion prediction models such as RUSLE2, and to calibrate crop growth models that are important components of more complex erosion models such as WEPP and WEPS. |