Abstract:

In this experiment, the changes of soil physical and chemical properties after applying phosphorus-reducing fertilizer and adding biochar were analyzed, and the characteristics of soil fertility after phosphorus-reducing and carbonizing were discussed. We took the main local variety ‘Xinchun 37’ in the irrigated area of northern Xinjiang as the material, set up 15 different fertilization modes, including 5 phosphate (P₂O₅) levels of P0, P1, P2, P3 and P4 (0, 120, 102, 84 and 66 kg/hm²), and 3 biochar levels of B0, B1 and B2 (0, 22.5 and 30.0 t/hm²). Soil samples were collected at the maturing stage of spring wheat to determine soil available nutrients, total available nutrients, organic matter content, soil water content, pH and EC. The results showed that fertilizer reduction of 45% with low levels of biochar (P4B1) treatment had higher content of alkali-hydrolyzed nitrogen, 68.18% higher than that of control; the conventional phosphate with high quantity of biochar (P1B2) had the highest organic content, 65.14% higher than that of control; phosphate reduction of 30% with low levels of biochar (P3B1) treatment had higher available phosphorus and available potassium content, 48.60% and 22.58% higher than that of control, respectively; however, the application of biochar had no significant effect on soil acidity and alkalinity. Under this experimental condition, the application of biochar could effectively improve the soil nutrient content and soil water-holding capacity, and has no significant effect on alkaline soil pH, causing no damage to alkaline soil. The study provides a theoretical basis for reducing phosphorus, adding biochar and improving soil fertility in the north Xinjiang irrigated area.

Key words: biochar, P fertilizer, available nutrient, organic matter, irrigation area, wheat field