Effects of poly-γ-glutamic acid on water use efficiency, cotton yield, and fiber quality in the sandy soil of southern Xinjiang, China

The socio-economic development of a country is highly dependent on water availability. Nowadays, increasing water scarcity is a major global challenge. Continuing improvements in water-use efficiency are essential for cotton production sustainability. Reduced irrigation in cotton could be a solution to water shortage in the arid climate without compromising the cotton yield. Therefore, a two-year field study was conducted to assess the effect of two levels of irrigation i.e., 50% and 100% of available water content (AWC) on the yield of four cotton genotypes (CIM-678, CIM-343, CRIS-613, and CYTO-510). The maximum seed cotton yield was observed in CIM-678, which was 2.31 and 2.46 Mg ha−1 under 100% AWC during 2018 and 2019, respectively, and was non-significantly reduced by 7.7 and 8.94%, owing to deficit irrigation. The maximum water use efficiency (WUE) of 0.55 and 0.64 Kg ha−1 mm−1 was observed under 50% AWC in CIM-678, which was significantly higher than WUE at 100% AWC during both years. Leaf area index and physiological parameters such as photosynthesis rate, transpiration rate, and stomatal conductance were not significantly affected by deficit irrigation. So, it was concluded that the reduced irrigation technique performed well without significant yield loss, improve WUE, and saved 37 cm of water that could be used for other crops or to increase the area of the cotton crop.

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Effects of Soil Texture on Soil Leaching and Cotton (Gossypium hirsutum L.) Growth under Combined Irrigation and Drainage

Water ◽

10.3390/w13243614 ◽

2021 ◽

Vol 13 (24) ◽

pp. 3614

Author(s):

Dongwang Wang ◽

Zhenhua Wang ◽

Jinzhu Zhang ◽

Bo Zhou ◽

Tingbo Lv ◽

...

Keyword(s):

Soil Moisture ◽

Water Use Efficiency ◽

Water Use ◽

Sandy Soil ◽

Drip Irrigation ◽

Ph Value ◽

Growth Stages ◽

Clay Loam ◽

Use Efficiency ◽

T1 And T2

To further explore the effects of different soil textures on soil leaching and cotton (Gossypium hirsutum L.) growth using a combined irrigation and drainage technique and provide a theoretical basis for the improvement of saline alkali land in Xinjiang, we used a test pit experiment to test soil moisture, salinity, soil pH, permeability, cotton agronomic characteristics, cotton yield and quality, and water use efficiency in three soil textures (clay, loam, sand soil) under the combined irrigation and drainage (T1) and conventional drip irrigation (T2). We measured the soil moisture content in different soil layers of clay, loam and sandy soil under the T1 and T2 treatments. Clay and loam had better water retention than sandy soil, and the soil moisture under the combined irrigation and drainage treatment was slightly higher than that under conventional drip irrigation. Under T1, the average salt content and pH value in the 0–60 cm soil layer of clay, loam and sandy soil decreased by 14.09%, 14.21% and 12.35%, and 5.02%, 5.85% and 3.27%, respectively, compared with T2. Therefore, T2 reduced the salt content and pH value of shallow soil. Under T1 and T2, the relative permeability coefficient (K/K0) values in different soil textures at different growth stages of cotton were ranked as follows: sandy soil > loam > clay. Under T1, the K/K0 values for different soil textures at different growth stages of cotton were >1; therefore, T1 improved soil permeability. The yield and water use efficiency of seed cotton under T1 and T2 in different soil textures were ranked as follows: loam > clay > sand, and there were significant differences between the different treatments. In loam, the cotton yield and water use efficiency of the combined irrigation and drainage treatment were 6.37% and 13.70% higher than those for conventional drip irrigation treatment, respectively. By combining irrigation and drainage to adjust the soil moisture, salt, pH value and soil permeability of different soil textures, the root growth environment of crops can effectively be improved, which is of great significance to improving the utilization efficiency of water and fertilizer and promoting the growth of cotton.

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