Lateral spacing in drip-irrigated wheat: The effects on soil moisture, yield, and water use efficiency

摘要

This objective of this two-year field study was to determine the effects of lateral spacing and irrigation amount on wheat yield and water use efficiency. The irrigation treatments consisted of three lateral spacings (R1, 0.30 m; R2, 0.60 m; and R3, 0.90 m) and four water amounts (W1, 3000 m(3)/ha; W2, 4500 m(3)/ha; W3, 6000 m(3)/ha; and W4, 7500 m(3)/ha). The plots were irrigated every 10 d during the growing season. The results showed that plant growth and grain yield both decreased as lateral spacing increased. Regardless of the amount of water, the R1 plots exhibited the highest LAI (3.90), leaf Pn (24.5 mu Mol CO2 m(-2) s(-1)), and aboveground biomass (1670 g/m(2)) at flowering. Grain yield was also greater in R1 (8130 kg/ha) than in either R2 (7450 kg/ha) or R3 (5300 kg/ha). Among the R2 plots, grain yield was greater in W3 and W4 than in either W1 or W2. The difference between plants in row 1 and row 2 decreased as the amount of water applied to the R2 plots increased. The R3 treatment significantly reduced plant growth and grain yield; grain yields in R3 did not increase as the amount of irrigation water increased. Among the treatments in this study, R2W3 exhibited the most stable soil moisture content during the wheat growing season, the highest LAI at flowering, and the greatest dry matter accumulation after anthesis. In conclusion, the results of this experiment demonstrate that among the treatments in this study, R2W3 resulted in the most water savings, the highest yield, and the greatest economic benefit. Therefore, R2W3 is a good water saving practice in arid and semi-arid regions areas. (C) 2015 Elsevier B.V. All rights reserved.