Soil fertility, tillage, and mulching effects on rainfed maize grown after rice

This paper reports two studies to determine soil-water status and chemical soil properties resulting from three soil management methods and their effects on rainfed maize grown after wetland rice with different tillage methods. Maize response to fertilizer management and mulching was also studied. Experiments were performed on Lipa clay loam with a shallow water table. In the first experiment, nonfertilized and fertilized maize was grown after puddled flooded, nonpuddled nonflooded, and nonpuddled flooded rice. Tillage included no tillage, row tillage, and complete tillage. Nutrient availability in soils was higher after puddled flooded rice than after nonpuddled flooded rice, but the high moisture content and compact soil after puddled flooded rice resulted in poorer maize establishment, growth, and yield. Tillage improved soil aeration, but reduced nutrient availability. Maize yields from plots not tilled after rice harvest were not significantly less than those from tilled plots. Maize responded less to fertilizer applied after puddled flooded than after nonpuddled flooded rice. In the second experiment, the soil in a dried puddled flooded rice field was intensively tilled to a depth of 20 cm. Mulched and unmulched maize was grown at four fertilizer rates, with the fertilizer placed at depths of either 5 or 20 cms. Fertilization and mulching significantly affected lodging, root and top growth, and grain yield. Application of nitrogen and phosphorus greatly increased maize dry matter and grain yield. Deeper fertilizer placement caused roots to grow deeper and to absorb more nutrients and moisture. Mulching reduced top soil moisture loss and resulted in better fertilizer availability and maize yield. Maize plots that received deep-placed 120-26-25 fertilizer and mulch yielded 3,150 kg grain/ha. Seven references (1966-77) are provided.