| Popis: |
Infiltration and runoff are important processes that affect the efficiency of center-pivot irrigation systems. No-till planting systems potentially influence the hydraulic properties of soils and the soil surface conditions. The result of long-term use of no-till could be higher infiltration and lower runoff of rainfall and irrigation. This potential was investigated at four center-pivot irrigated fields at two locations in central Nebraska. At each location, we have paired center-pivot fields, one that has been no-till planted for over seven years and one that uses two to three tillage operations per year for seedbed preparation and cultivation. At three positions in each field, we established micro-runoff plots. These plots were bordered by galvanized steel borders. The plot dimensions are 0.76 m wide and 1.83 m long. One of the tilled fields had only plot, span 3, cultivated in the fall due to corn being too high. Once span 3 data were removed, hydraulic conductivity was significantly higher for no-till at both sites with 6.18 and 8.21 cm/h for no-till and 3.89 and 2.82 cm/h for tilled. However, runoff data between sites were inconsistent. Although, water content at the time of rainfall events was not considered, no-till appears to increase the infiltration into the soil. |
