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

- Determining the effect of lateral spacing and irrigation amount on the growth, development, and yield of spring wheat.
- Determine the optimum design and management of drip irrigation systems for spring wheat production.
- Excessive spacing between two laterals would not lead to irrigate the furthest row and decrease the grain yield.
- Too small lateral spacing had no effect on increasing the grain yield.
- Increasing water amount could reduce the difference between rows.

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 m3/ha; W2, 4500 m3/ha; W3, 6000 m3/ha; and W4, 7500 m3/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 μmol CO2 m−2 s−1), and aboveground biomass (1670 g/m2) 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.