通过田间小区试验,研究膜下滴灌条件下农田施用生物炭0 t/hm2(A0)、15 t/hm2(A15)、30 t/hm2(A30)和45 t/hm2(A45)后玉米各生育期土壤含水率、温度和有机质及速效养分含量的变化规律.试验结果表明:在每个生育期,各处理耕层土壤含水率均随生物炭施用量增加呈先增加后减少的趋势,且均高于对照.在玉米拔节期、抽雄期和灌浆期差异性显著,且显著相关,其中A30处理增幅最大,达13.74%;在玉米三叶期和拔节初期,施用生物炭显著提高土壤表层温度,且呈正相关;在抽雄期、灌浆期和成熟期,土壤表层温度依次为A30>A0>A45>A15,与施炭量没有表现出显著相关;耕层土壤有机质和有效磷含量随施炭量增加而显著增加,且均高于对照,与施炭量表现出极显著相关;整个玉米生育期,相比对照A0,处理A15、A30和A45有机质最大增幅分别为:14%、20%和58%,有效磷最大增幅分别为:62%、99%和113%;施用生物炭后,各处理均显著提高了耕层土壤碱解氮和速效钾含量,相比对照A0,处理A15、A30和A45碱解氮的最大增幅分别为13%、17%和10%,速效钾的最大增幅分别为:35%、48%和63%.综上所述,膜下滴灌条件下适量施用生物炭可有效增加耕层土壤含水率、土壤温度和有机质及速效养分,生物炭具有一定的保水、保温、保肥特性,有利于提高土壤水、肥利用率.%Field plot experiments were conducted to study the effects of biochar on the hehavior of soil moisture, temperature, organic matter and available nutrient contents in different growth periods of maize under mulched drip irrigation conditions. The dosages of biochar were set at 0 t/hm2 (A0), 15 t/hm2 (A15), 30 t/hm2 (A30) and 45 t/hm2 (A45), respectively. Results showed that, with the increase of biochar use, soil moisture increased first and then decreased in plough layer during the growth period of maize. Soil moisture in the treatments with biochar were higher than that in control (A0), significant differences were observed in the jointing, tasseling and filling stages of maize and the highest increase rate (13.74%) was found in A30. At three-leaf stage and early jointing stage, biochar application increased the temperature of surface soil layer remarkably. At tasseling, filling and maturity stages, the temperature of surface soil layer followed an order of A30>A0>A45>A15, with no significant correlation to biochar rate. Moreover, organic matter and available phosphorus contents in plough soil layer increased with biochar rate. During the growth period of maize, as compared with control (A0), soil organic matter contents in A15, A30 and A45 increased by 14%, 20% and 58%, while available phosphorus by 62%, 99% and 113%, respectively. The application of biochar significantly increased alkali-hydrolyzable nitrogen and rapidly available potassium contents in plough soil layer. In comparison with control (A0), alkali-hydrolyzable nitrogen of A15, A30 and A45 increased by 13%, 17% and 10%, while rapidly available potassium increased by 35%, 48% and 63%, respectively. In conclusion, biochar use under mulched drip irrigation effectively increased soil moisture, temperature, organic matter and rapidly available nutrients in plough soil layer, which indicate that biochar could maintain soil water-heat-fertility, is of great significance in improving soil water and fertilizer use efficiency.
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