Evaluation of no-tillage crop production with subsurface drip irrigation on soils with compacted layers
1999
Camp, C.R. | Bauer, P.J. | Busscher, W.J.
Subsurface drip irrigation offers many advantages for management of water and nutrients, but its effectiveness may be limited by weather or soil conditions. Solving soil problems, such as compaction, in subsurface drip irrigation systems is understandably difficult using deep tillage. We hypothesized that the need for deep tillage in conservation tillage systems may be reduced if the compacted soil layers are kept moist enough for root growth. A two-year experiment that included wheat, soybean, and cotton under no-tillage culture was conducted with subsurface drip irrigation. The irrigation system had been used for five years before this experiment and provided two irrigation drip line spacings (1 m and 2 m) and three irrigation amounts (6, 9, and 12 mm/application). Irrigated soybean yields were greater than rainfed in one of the two years. No differences in yield occurred among irrigation drip line spacing or irrigation amounts. Also, neither cotton nor wheat yields were increased by irrigation. Observations during the growing seasons, cotton root observations after harvest, and soil strength measurements during the spring indicate that considerable soil compaction occurred at very shallow soil depths (< 5 cm) and restricted root growth. This compaction probably limited the efficacy of subsurface drip irrigation, which was located at the 30-cm depth. Based on these results, it appears that strategies must be developed to reduce soil strength to obtain optimum no-tillage crop production with subsurface drip irrigation on these soils.
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