【作者】 苗峰；

【导师】 陈金林；

【作者基本信息】 南京林业大学 ， 土壤学， 2011， 硕士

【摘要】 秸秆还田是我国目前循环经济下处理秸秆的重要途径,随着作物秸秆还田技术的推广与应用,秸秆还田条件下配施氮肥成了现代农业发展的新趋势。本研究通过田间试验,比较研究了秸秆还田下不同氮肥对我国黄淮海平原典型农区作物籽粒产量、产量构成因素、养分吸收状况、土壤速效养分和土壤生物学特性的影响,主要结论如下：1.在相同氮肥用量条件下,秸秆还田有增加小麦籽粒产量的趋势,增产率为6.34%-12.17%,但秸秆还田和不还田处理间没有显著性差异。与不施氮肥相比,氮肥导致籽粒产量的增加主要由于增加单位面积冬小麦穗数所致,但不同施肥量之间籽粒产量没有显著性差异。此外,秸秆还田对冬小麦地上部氮素、磷素和钾素吸收量的增加也有明显促进作用。2.秸秆还田配施氮肥提高了土壤碱解氮和速效钾含量,增加了土壤脲酶活性,提高了土壤硝态氮总量,特别是提高了0-80cm硝态氮含量,减少了80-180cm的硝态氮含量,为作物养分吸收提供了肥力基础。3.不施氮条件下,秸秆还田显著增加了夏玉米籽粒产量。秸秆还田条件下,有机无机氮肥配施处理相对于单施无机氮肥夏玉米籽粒产量有所增加,但未达到显著水平。有机肥施用有助于玉米穗粒数的增加,但对夏玉米百粒重的影响并不明显。有机无机氮肥配施作物氮肥利用率明显高于单施无机氮肥处理,增加率为12.6%-21.7%。有机无机氮肥配施可增加作物氮素、磷素和钾素吸收量,特别是在作物生长后期的增加作用更为明显。4.秸秆还田下有机无机氮肥配施相对于单施无机氮肥处理可明显增加夏玉米生长中期和后期土壤碱解氮、速效磷、速效钾含量。同时,有机无机氮肥配施可明显提高夏玉米乳熟期土壤微生物量氮含量和土壤脲酶活性,促进有机氮向无机氮的转化,为夏玉米产量形成的关键时期提供充足的肥力基础。此外,秸秆还田下有机无机氮肥配施还可促进作物对土壤硝态氮的吸收,降低了土壤深层硝态氮含量,减少土壤氮素的淋失,防止环境污染。更多还原

【Abstract】 In China, straw-return is a main and popular way for dealing with straw under the concept of circular economy. With the popularization and development of straw-return techniques, straw-return with nitrogen (N) fertilization became the new trend of such practices. In this study, field experiments were conducted to investigate the influence of different treatments of straw-return coupled with N fertilization on grain yield, typical factors of crop yield components, nutrient uptake processes, soil available nutrients and biological characteristics in the Huang-Huai-Hai Plain. Main conclusions were drawn as follows:1. Straw-return greatly increased wheat yield under the same condition of N fertilization, but the difference between treatments with or without straw-return was not significant. Compared with no N fertilization, the increase in wheat yield with chemical fertilization mainly due to the increase in wheat panicles per unit area, but there was no significant difference between these grain yields. Overall, straw-return could enhance the yield by a rate of 6.34%-12.17%. In addition, straw-return obviously improved the crop uptake of N, phosphorus (P) and potassium (K) during the growth of winter wheat.2. Straw-return with N fertilization increased the content of soil alkali-hydro N and available K, and increased the soil urease activity and the soil nitrate content, especially in the depth of 0-80cm, and reduced nitrate concentration in the depth of 80-180cm, which provides the fertility basis for crop nutrient uptake. In addition, straw-return reduced soil available P content, and also demonstrated the trend of reducing the soil microbial biomass N.3. In no fertilization conditions, straw-return significantly increased summer corn yield. In straw-return conditions, the summer corn grain yield increased under the the application of organic-inorganic fertilizer, in comparison with the application of chemical fertilizers, but the difference did not achieve a significant level. Organic fertilizer application improved corn grain numbers, but it did not impact 100 kernel weight of summer corn. The crop N use efficiency in organic fertilizer treatments was significantly higher than that in the chemical fertilizer treatments by a rate of 12.6-21.7%. Meanwhile, N fertilization increased the crop uptake of N, P and K, especially at the late period of crop growth.4. In the straw-return conditions, the organic-inorganic fertilizer, comparing with the chemical fertilizer obviously increased the content of soil available nutrients as N, P, K, during the period of the middle and late summer maize growth. Meanwhile, the organic-inorganic fertilizer obviously increased the soil microbial biomass N and urease activity in the milk stage of summer corn, and improved the transformation of inorganic N to its organic species, which provided ample fertility basis for the key period of summer corn yield formation. Besides, in the straw-return conditions, the organic-inorganic fertilizer can promote the crop absorption of soil NO3-N and reduce its translocation and accumulation in the deeper soil layers, which reduced the nitrate leaching and thus lessen environmental pollution.更多还原