Browse on keywords: tillage computer model
Search results on 09/26/18
5389. Prato, T., H. Shi, R. Rhew, and M. Brusven. 1989. Soil erosion and nonpoint-source pollution control in an Idaho watershed.. J. Soil Water Cons. 44:323-328.
Offsite economic damage from cropland erosion has been estimated at between $2-6 billion. This study modelled erosion reduction, improvements in surface water quality, and impact on net returns for a watershed near Lapwai, Idaho, using a 1000 acre wheat-pea farm as the prototype. It concluded that total net farm income in the watershed increased 1.5% when average erosion was reduced to T. The study used a GIS system to model the outcomes of farm practice choices. Soil erosion was calculated with the USLE. Water quality impacts were estimated with AGNPS. Eleven resource management systems were modelled for each of the 16 farms in the watershed. The results indicate that minimum tillage with either cross-slope farming or contour farming is the most economically efficient resource management system for reducing erosion. Averaged over all farms, such a system increased annualized net returns by $1.05/ac and $1.38/ac, and reduced erosion by 5.2 T/ac/yr and 5.6 T/ac/yr for the min-til cross-slope and min-til contour systems respectively. To achieve a 70% erosion reduction (equalling 2T), no-till and permanent vegetation were the required systems. Net farm income increased 1.5% when total erosion was reduced 40%, and decreased 35% when erosion was reduced 70%. Total net farm income declined rapidly beyond 40% erosion reduction. Figure 5 shows net income versus erosion reduction.
7693. Yan, Ying. 1989. A model for predicting soil loss ratio and crop production in eastern Washington. M.S. Thesis, Dept. of Agronomy and Soils, WSU, Pullman, WA.
The model (SHUI) predicts soil erosion and crop production under different crop rotation, tillage operation, and crop residue management conditions. It simulates the soil-water budget, crop and root growth, top dry matter production, grain yield, and residue production and loss, and predicts the soil loss ratio. Validation data are included.