Abstract:

In response to the coexistence of soil salinization and alkalization in the Hetao irrigation area of Inner Mongolia, this study investigated the comprehensive effects of different types of soil conditioners on salt and alkali reduction under drip irrigation conditions and its impact on sunflower yield in saline-alkali cultivated land. Three representative soil conditioner products (microbial agents, acidic organic conditioner Shidijia, compound conditioner Yibaijia) were selected, and drip irrigation was used as supply method of the water and conditioners. Combined with reasonable fertilization measures, field experiments were conducted to analyze the effects of different types of conditioners on the physicochemical properties of saline-alkali soil and the components of sunflower yield. The results showed that compared with the control, the bulk density, pH, total salt content, and alkalinity of the soil in the 0-60 cm soil layer decreased to varying degrees after the application of soil conditioners. Among them, the treatment with microbial agents showed the most significant decrease in soil bulk density of 1.89%; the treatment with Shidijia showed the most significant decrease in total salt content and alkalinity of 27.06% and 14.02% respectively, and the contents of total nitrogen, available phosphorus and available potassium in the soil increased to varying degrees; the treatment with Yibaijia had the more significant increase in the contents of total nitrogen, available phosphorus, and available potassium in the soil of 21.30%, 36.63% and 14.95% respectively; the dry matter and yield of sunflowers also increased to varying degrees, with an increase in dry matter mass of 6.60% to 25.79% and an increase in yield of 6.77% to 14.08%. The treatment with Shidijia and microbial agents had a more significant yield-increasing effect than Yibaijia. Overall, microbial agents were more conducive to improving soil structure, and acidic organic soil conditioners were more conducive to reducing soil salinization. It is suggested to optimize the combination application strategy based on the composition and performance of conditioners, and soil saline-alkali obstacle types.

Key words: Hetao irrigation area, soil conditioner products, salinization, yield, soil