Influence of Water and Fertilizer Management on Yield and Water-input Efficiency of Corn1
- F. M. Rhoads,
- R. S. Mansell and
- L. C. Hammond2
Damaging plant water stress develops in corn grown on coarse-textured, low water retaining soils of the south-eastern U.S. during I to 2-week periods without rainfall. However, in most years rainstorms cause leaching of soluble fertilizers from the root zone. This study was conducted to evaluate efficiency of water input in terms of corn grain yield per unit of water, with two fertilizer application methods under three soil-water management systems on a Troup loamy sand (Grossarenic Paleudult). Water management consisted of (a) control — natural rainfall only, (b) trickle irrigation scheduled daily (0.64 cm/day), and (c) trickle irrigation scheduled by tensiometer (1.30 cm/application). Tensiometers were placed in each treatment at six depths between 15 and 150 cm below the soil surface and readings were recorded daily. Methods of applying fertilizers were designated (a) conventional — 1/3 of N and all P and K applied broadcast preplant, and remainder of N applied in two sidedressings; (b) program fertilization — N-P,K applied broadcast small increments (5, 5, 10, 20, 20, 20, and 20%) at 2-week intervals after corn emerged. Average grain yields for the above water management treatments were 2,790, 4,160, and 5,700 kg/ha respectively. Conventional fertilization had an average grain yield of 8,680 kg/ha and program fertilization 4,760 kg/ha. Water-input efficiencies based on grain yields and total water input were 57, 42, and 76 kg/ha/cm for no irrigation, daily irrigation, and tensiometer scheduled irrigation respectively. Highest irrigation water.input efficiency (150 kg/ha/cm) occurred with program fertilization and tensiometer scheduled irrigation. Irrigation water-input efficiency was lowest (10 kg/ha/cm) with corn receiving daily irrigation and conventional fertilization.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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