减磷加炭对北疆灌区土壤理化性质的影响

试验通过分析减施磷肥增施生物炭后土壤理化性质的变化,探讨减磷加炭后土壤肥力特性。以北疆灌区小麦主产地奇台当地主推品种‘新春37号’为材料,设15种不同施肥模式,其中磷肥(P₂O₅)设5个水平,分别为P0、P1、P2、P3、P4 (0、120、102、84、66 kg/hm²);配施生物炭设3个水平,分别为B0、B1、B2 (0、22.5、30.0 t/hm²)。于春小麦成熟期采集土样,测定土壤速效养分、有机质含量以及土壤含水量、pH、电导率。结果表明：磷肥减量45%配施低量生物炭(P4B1)处理下碱解氮含量较高,较对照增加68.18%;常规磷肥配施高量生物炭(P1B2)时有机质含量最高,较对照增加65.14%;磷肥减量30%配施低量生物炭(P3B1)处理下速效磷与速效钾含量较高,分别较对照增加48.60%、22.58%;但施加生物炭对土壤酸碱性没有显著影响。本试验条件下,施加生物炭可有效提高土壤养分含量,有效提高土壤持水能力,且对碱性土壤pH无显著影响,不会对碱性土壤造成破坏。为北疆灌区合理减磷加炭,改善土壤肥力提供理论依据。

Effects of Phosphorus Reduction and Biochar Addition on Soil Physical and Chemical Properties in North Xinjiang Irrigated Area

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.