Effect of tillage and furrow irrigation timing on efficiency of preplant irrigation

Abstract

A field study to determine the efficiency of preplant irrigating with furrow irrigation and the effects of tillage and fall or spring application of preplant irrigation on this efficiency was conducted during 1983, 1984, and 1985 at the Texas Agricultural Experiment Station, North Plains Research Field at Etter, Texas on a Sherm, silty clay loam soil. Sorghum residue from the previous crop was shredded, gravimetric soil samples were taken, and five tillage treatments were imposed in the fall. The tillage treatments consisted of various combinations of disking, chiselling, moldboard plowing, and disk bedding. A preplant irrigation was applied in the fall to half of each tillage plot and in the spring to the other half of each plot. Soil samples were taken from each plot one month after the spring preplant irrigation. Sorghum (Sorghum bicolor L. cv. ‘NC 178’) was planted and irrigated similarly on all plots during the growing season. On the average, 237 mm of water were required to irrigate the tillage treatments during fall preplant irrigation and 466 mm were required during spring preplant irrigation. The additional water requirement in the spring was associated with increased water uptake by non-wheel-track furrows. Treatments with chiselling required larger water application during spring preplant irrigation. All treatments had similar soil water contents at planting time. Neither timing of preplant irrigation nor type of tillage had any effect on sorghum grain yield. Therefore, fall preplant irrigation was considerably more efficient than spring preplant irrigation. Averaged over the three years do study and five tillage treatments storage efficiency was 26% for fall application and 17% for springtime.