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【目的】明确长期秸秆还田对白浆土土壤物理性质及水稻产量的影响。【方法】开展秸秆还田长期定位试验。试验设置4个处理,分别为对照(CK),单施秸秆(S),秸秆+化肥(SNPK),单施化肥(NPK)。在2005年后连年处理,并于试验处理前和2010年、2015年试验处理期间调查土壤容重、硬度、孔隙、三相组成以及水稻产量。【结果】白浆土长期秸秆还田有利于水稻产量提高,10年产量平均,秸秆还田配施肥料处理水稻产量比对照和秸秆单独还田处理增产275.70%和133.23%,比单施化肥处理增产14.17%。秸秆还田处理水稻产量在还田第5—10年平均产量比第1—5年有增加趋势;长期秸秆还田可以改善土壤物理性质,降低土壤容重、硬度,还田10年后,秸秆还田配施化肥处理土壤容重低于化肥单施、秸秆单施及对照处理,SNPK处理0—20、20—30 cm土层土壤容重与对照相比分别降低6.34%和10.00%,与还田5年后同类处理相比仍呈下降趋势;秸秆还田配施化肥处理土壤硬度10年后在10、20、30 cm土层与处理前相比分别降低为26.87%、5.68%和4.62%,在20—30 cm土层与对照相比差异显著,还田10年与5年后相比有下降趋势,其他处理变化不明显;还田5年后,秸秆还田配施化肥处理在0—20、20—30、30—40 cm土层土壤固相比例与对照相比分别下降8.82%、8.36%和3.65%,还田10年后分别下降10.87%、10.61%和4.67%,10年后要比5年后下降幅度大,秸秆还田配施化肥比秸秆单施和化肥单施处理下降幅度大;长期秸秆还田可以增加土壤有效孔隙的数量,在处理间和年限间差异极显著,还田10年后,在0—20、20—30、30—40 cm土层秸秆还田配施化肥土壤有效孔隙比对照增加28.86%、63.85%和23.40%,在20—30 cm和30—40 cm土层比化肥单施增加12.55%和62.96%,在0—20、20—30、30—40cm土层比秸秆单施增加19.68%、56.52%和24.46%;与还田5年后相比,土壤有效孔隙度均呈现增加的趋势。【结论】长期秸秆还田可以改善白浆土不良物理性状,降低白浆层的容重、硬度,增加土壤总孔隙度和有效孔隙的比例,提高水稻产量。秸秆还田年限越长改善土壤不良物理性质效果越明显。单独进行秸秆还田改善土壤效果不明显,秸秆还田配施肥料处理效果明显;在不同处理上,秸秆还田配施化肥处理既有改土效果,又可提高水稻产量,而单施化肥和单独秸秆还田均达不到此类效果。
【Objective】 The objective of this study was to clarify the effects of long-term straw returning on soil physical properties and rice yield of albic soil. 【Method】 Carrying out long-term positioning experiment of straw returning. Four treatments were set up as CK, S, SNPK and NPK respectively. Year-on-year after 2005 and soil bulk density, hardness, porosity, three-phase composition, and rice production were investigated before and during the 2010 and 2015 pilot treatments. 【Result】 The results showed that the yield of paddy soil increased with the return of straw to soil over a period of 10 years. The yield of rice with straw returning and fertilization was 275.70% and 133.23% more than that of the control and straw returning alone, Output increased 14.17%. The average yield of straw returning to paddy fields in the 5-10 years after returning straw has an increasing trend compared with the first five years. Long-term straw returning can improve the physical properties of the soil and reduce the bulk density and hardness of the soil. After returning to the soil for 10 years, Compared with the control, soil bulk density of treatments 0-20, 20-30 cm by SNPK decreased by 6.34% and 10.00%, respectively, compared with the control Compared with the same treatment year, the treatment rates of straw returning to the soil were still declining. After 10 years of straw returning to the field with chemical fertilizers, the soil hardness decreased to 26.87%, 5.68% and 4.62% in the 10, 20 and 30 cm soil layers respectively, 20-30 cm soil layer compared with the control significant difference, 10 years after returning and 5 years after a downward trend, the other changes are not obvious; 5 years after returning to the field, straw with fertilizer treatment in the 0-20 , The proportion of soil solid phase in 20-30, 30-40 cm soil layers decreased by 8.82%, 8.36% and 3.65% respectively compared with the control, and decreased by 10.87%, 10.61% and 4.67% respectively after 10 years of returning to the soil. After 10 years After 5 years, the rate of decrease was larger. The straw returning to the field with chemical fertilizers dropped more than that of straw single application and chemical fertilizer alone. The long-term straw returning Increasing the number of effective soil pores showed significant difference between treatments and years. After returning to soil for 10 years, the effective porosity of straw returning to fertilizers was higher in the 0-20, 20-30, 30-40 cm soil layers than in the control 28.86%, 63.85% and 23.40% respectively. Compared with the single fertilizers applied in the 20-30 cm and the 30-40 cm soil layers, the contents increased by 12.55% and 62.96% Increased by 19.68%, 56.52% and 24.46%, respectively. Compared with 5 years after returning to the field, the effective porosity of soil showed an increasing tendency. 【Conclusion】 Long-term straw returning can improve the bad physical properties of albacore soil, reduce the bulk density and hardness of albacore layer, increase the ratio of total soil porosity and effective porosity, and increase the yield of rice. The longer the straw returning to the soil, the better the physical properties of the soil are. The effect of returning straw to soil alone was not obvious and the effect of returning straw to soil with fertilizers was obvious. In different treatments, applying straw to soil with chemical fertilizers not only improved the soil, but also increased the yield of rice. However, Straw alone can not reach such effects.