长期秸秆还田和施肥对黑土肥力及玉米产量的影响
Effects of long-term straw returning and fertilization on soil fertility and maize yield in black soil
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摘要: 基于长期定位试验(17年)：不施肥(CK)、单施化肥(NPK)、化肥+秸秆(NPKS)处理，研究了长期秸秆还田对黑土肥力和玉米产量的影响和贡献。结果表明：与2003年初始土壤属性相比，CK处理0~40 cm土壤有机质、全氮、碱解氮、速效磷和速效钾含量均显著下降(P < 0.05)。NPKS处理0~20 cm和20~40 cm土壤有机质、全氮、碱解氮和速效钾含量则分别显著增加了6.6%~16.4%、4.6%~17.3%、8.0%~15.0%和59.4%~61.5%(P < 0.05)。与CK处理相比，NPKS处理0~20 cm和20~40 cm土层土壤容重分别下降了14.8%和4.50%，0~20 cm土层的通气孔隙度增加了43.7%。NPK和NPKS处理的平均产量较CK处理分别增加了54.9%和65.2%，NPKS处理的平均产量比NPK产量增加6.6%(P < 0.05)。0~20 cm土层，土壤有机质和全氮含量对玉米产量的贡献度>30%，而20~40 cm土层土壤碱解氮的贡献度最高达到35.7%。土壤物理属性在0~20 cm土层，土壤毛管孔隙和土壤容重对玉米产量贡献最高; 20~40 cm土层，容重对玉米产量的贡献度最高达到56.9%。因此长期秸秆还田能够显著提高40 cm以上土层土壤的肥力，改善土壤容重和孔隙度，从而间接影响玉米的产量。Abstract:
To investigate the effect and contribution of long-term straw returning on fertility and yield, a long-term experiment (17 years)was selected as following treatments: no fertilizer(CK), chemical fertilizer alone(NPK), and chemical fertilizer plus straw(NPKS).The results showed that the soil organic matter(SOM), total nitrogen (TN), alkaline nitrogen(AN), available phosphorus(AP)and available potassium(AK) contents was significantly decreased in 0~40 cm soil layer in CK treatment compared to those in initial soil(P < 0.05).While the SOM, TN, AN, AP and AK contents in 0~20 and 20~40 cm soil layer was significantly increased by 6.6%~16.4%, 4.6%~17.3%, 8.0%~15.0% and 59.4%~61.5% in the NPKS treatment compared to those in initial soil(P < 0.05).The soil bulk density was significantly decreased by 14.8% and 4.5% in NPKS treatment in 0~20 cm and 20~40 cm soil layers, and the aeration porosity was significantly increased by 43.7% in 0~20 cm soil layer compared to that in CK treatment.The average yield of NPK and NPKS treatments were increased by 54.9% and 65.2%, respectively, compared to CK treatment.And the average yield of NPKS treatment was increased by 6.6% compared to that in NPK treatment(P < 0.05).The SOM and TN in 0~20 cm soil layer could contribute 30% for maize yield, while the AN could contribute 35.7% in 20~40 cm soil layer.Moreover, the soil bulk density and aeration porosity in 0~20 cm soil layer was the most contributor for maize yield, the soil bulk density could contribute 56.9% for maize yield in 20~40 cm soil layer.Therefore, long-term straw returning significantly increases soil fertility and improves soil bulk density and aeration porosity in the 0~40 cm soil layer, thus indirectly affecting maize yield.
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