EFFECTS OF GYPSUM COMBINED WITH DIFFERENT AMOUNTS OF BIOCHEMICAL HUMIC ACID ON SOIL IMPROVEMENT AND COTTON (GOSSYPIUM HIRSUTUM L.) YIELD ON SALINE-ALKALI LAND
Yue Shan, Ge Li, Youshuai Bai, H.B. LIU, J.H. ZHANG, Kou Wei, Q.J. WANG, Lei Cao
Abstract
This study was conducted to investigate the effects of gypsum combined with different amounts of biochemical humic acid (BHA) on the improvement of saline-alkali soil and cotton (Gossypium hirsutum L.) yield under film-mulched drip irrigation in Shaya County, Aksu Prefecture, Xinjiang, China. Using the micro zone test method, taking the single application of gypsum as the control (CK, gypsum 15 tha -1 ), 3 ratios of BHA were applied: A (gypsum 15 tha -1 + BHA 0.35 tha -1 ), B (gypsum 15 tha -1 + BHA 0.75 tha -1 ) and C (gypsum 15 tha -1 + BHA 1.50 tha -1 ). The results showed that the combined application of gypsum and BHA significantly reduced soil pH and electric conductibility, while increased soil porosity. Compared to the control, the large aggregates (>0.25mm) in 0-10 cm and 10-20 cm soil layers of the three treatments increased by 10.00%, 20.33%, 33.68% and 7.39%, 20.61% and 25.00%, respectively. Besides, the content of Na + in topsoil decreased significantly, while the content of Mg 2+ increased obviously. In addition, the cotton yield increased by 5.86%, 12.50% and 18.13%, respectively compared with the control. Considering the yield investment ratio of agricultural production and the comprehensive effect of soil improvement, the combined application mode of gypsum 15 tha -1 + biochemical humic acid 1.50 tha -1 had the best result among all three treatments.