Image_1_Optimal planting pattern of cotton is regulated by irrigation amount under mulch drip irrigation.pdf

Objective

It is of great importance to explore agronomic management measures for water conservation and cotton yield in arid areas.

Methods

A four–year field experiment was conducted to evaluate cotton yield and soil water consumption under four row spacing configurations (high/low density with 66+10 cm wide, narrow row spacing, RS_66+10H and RS_66+10L; high/low density with 76 cm equal row spacing, RS₇₆H and RS₇₆L) and two irrigation amounts (CI:conventional drip irrigation; LI:limited drip irrigation) during the growing seasons in Shihezi, Xinjiang.

Results

A quadratic relationship was observed between the maximum LAI (LAI_max) and seed yield. Canopy apparent transpiration rate(CAT), daily water consumption intensity (DWCI) and crop evapotranspiration (ET_C) were positively and linearly correlated with LAI. The seed yields, lint yields, and ET_C under CI were 6.6–18.3%,7.1–20.8% and 22.9–32.6%higher than those observed under LI, respectively. The RS_66+10H under CI had the highest seed and lint yields. RS₇₆L had an optimum LAI_max range, which ensured a higher canopy apparent photosynthesis and daily dry matter accumulation and reached the same yield level as RS_66+10H; however, soil water consumption in RS₇₆L was reduced ET_C by 51–60 mm at a depth of 20–60 cm at a radius of 19–38 cm from the cotton row,and water use efficiency increased by 5.6–8.3%compared to RS_66+10H under CI.

Conclusion

A 5.0max<5.5 is optimum for cotton production in northern Xinjiang, and RS₇₆L under CI is recommended for high yield and can further reduce water consumption. Under LI, the seed and lint yield of RS_66+10H were 3.7–6.0% and 4.6–6.9% higher than those of RS₇₆L, respectively. In addition, high-density planting can exploit the potential of soil water to increase cotton yields under water shortage conditions.