Tillage and Cover Crop Management for Soil Water Conservation
1990
Munawar, A. | Blevins, R. L. | Frye, W. W. | Saul, M. R.
The effectiveness of a conservation tillage system depends on the amount and distribution of plant residues left on the soil surface. We determined effects of tillage systems, N fertilizer rates, and cover crop management on soil temperature, soil moisture, and corn (Zea mays L.) yields. Tillage treatments were chisel-plow tillage, conventional tillage (moldboard plowing and disking), disk tillage, and notillage. Nitrogen fertilizer at rates of 0, 75, 150, or 225 kg N ha⁻¹ were broadcast on the soil surface. Rye (Secafe cereale L.) on one-half of each split plot was killed 3 wk before corn planting time, while the other half was allowed to grow until the corn was planted. Corn yields in 1986 were 4.41, 4.03, 3.64, and 2.25 Mg ha⁻¹ for notillage, chisel-plow tillage, disk tillage, and conventional tillage, respectively. The yields were significantly greater with early killed rye (3.85 and 5.05 Mg ha⁻¹ in 1986 and 1987, respectively) than with late-killed rye (3.32 and 4.58 Mg ha⁻¹ in 1986 and 1987, respectively). Soil temperature tended to be slightly higher under the latekilled rye mulch in 1986 with no significant difference in 1985. Soil moisture content was significantly higher for early killed rye treatment in the early part of the season in 1986 because there was less soil moisture depletion due to the growing rye. Published as Journal Paper no. 88-3-290 with approval of the Director of Kentucky Agric. Exp. Stn., Lexington.
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