【作者】 符冠富；

【导师】 章秀福；

【作者基本信息】 中国农业科学院 ， 作物栽培与耕作学， 2007， 硕士

【摘要】 保护性耕作(conservation tillage)是以减轻水土流失和保护土壤与环境为主要目标，采用保护性种植制度和配套栽培技术形成的一套完整的农田保护性耕作技术体系。发展生态农业，实现可持续发展已成我国未来农业发展的主要方向，利用有机肥参与农业生态系统的养分循环、再利用和培肥土壤是实现农业可持续发展的有效措施之一。稻田冬作作为有机肥的主要肥源之一，能改善生态环境、节约能源，是实现南方稻田可持续发展的一项关键性措施。因而充分利用稻田冬季保护性耕作技术，不但能减轻农民负担，还能防治土壤风蚀以及水土养分流失，从而减少农业生产对环境的污染。前人对保护性耕作的研究主要集中在土壤肥力的变化特征以及生态环境保护等方面，而对保护性耕作下水稻生长发育，生理特征以及稻米品质方面的研究比较少，尤其是在水稻抗早衰及稻米品质方面，国内还未见报道。随着时代的发展，水稻高产优质已成为广大农民以及农业专家追求的目标，因而本课题以国稻6号为材料，选用长江中下游比较常见的冬季保护性耕作栽培措施，即稻草覆盖马铃薯前茬处理(T1，2年培肥)、燕麦草前茬处理(T2，1年培肥)、油菜前茬处理(T3，2年培肥)，黑麦草前茬处理(T4，1年培肥)及空闲(CK)并结合有机肥试验(供试品种为籼稻中早22)着重探索保护性耕作下的土壤肥力变化特征及其与水稻叶片衰老、产量以及稻米品质之间的关系。主要结果如下：1、施用有机肥情况下，水稻灌浆期间的土壤蛋白酶，磷酸酶以及过氧化氢酶活性都比较高；和对照处理(CK)相比，有机肥处理在灌浆后期的叶片叶绿素，SOD活性以及可溶性蛋白含量下降比较缓慢，POD含量则上升比较快，与之相对应的MDA含量上升的幅度却比较小，表现出很好的抗衰老特性；相关分析表明，土壤酶活性与叶片衰老特性指标之间存在着显著的相关性。2、秸秆还田对土壤酶活性和稻米综合品质的影响因秸秆还田量和培肥年限而异，秸秆还田量越大土壤酶活性越高，培肥年限越长其土壤酶活性越稳定，并且土壤酶活性与稻米综合品质之间呈显著相关，其中蛋白酶对稻米综合品质影响最大，尤其是在灌浆中后期，土壤蛋白酶活性与稻米综合品质之间呈显著相关或极显著相关。各前茬处理中以T1的培肥效果最好，其土壤酶活性明显高于其他前茬处理，其次是T3，虽然酶活性不高，但比较稳定，有利于稻米品质的形成。稻米综合品质则以T3最高，其质量指数达52.3，其次是T1和T2，分别为51和49，相对于对照处理(CK)均有显著性差异。3、秸秆还田可以提高水稻灌浆后期叶片SOD及POD活性，有效延缓叶绿素以及可溶性蛋白的降解，并抑制MDA的增长。试验中发现土壤酶活性与叶片衰老指标之间普遍存在显著相关性，同样以蛋白酶对叶片衰老影响最大，尤其是在灌浆中后期，蛋白酶活性与叶片衰老指标之间都呈显著相关或极显著相关。试验结果表明T1、T2及T3都能比较好地延缓水稻叶片的衰老，与之相对应的水稻产量也依次达到12.27t／hm~2、12.30t／hm~2以及12.21t／hm~2(相对于对照处理(CK)，均有显著性差异)，相关分析表明它们之间普遍存在着显著相关关系或极显著相关关系。4、在水稻生长上，相对于对照处理(CK)，不同稻作前茬处理对水稻干物重积累、叶面积指数以及叶片比叶重都有很好的促进作用，其中T1的促进效果最好，其次是T2；在生理特性上，T1和T2的水稻根系活力高、叶绿素含量下降缓慢，延缓水稻叶片衰老；在灌浆上表现为起始势大，平均灌浆速率较快，有利于籽粒的充实。更多还原

【Abstract】 Conservation Tillage is a complete cropping system, which adopt conservational crop planting models and techniques to reduce water and soil erosion, protect environment. Ecological agriculture and agricultural sustainable development have become the developmental trend of future agriculture, and it is one of the realization measures to use organic manure participating in the nutrient circulation, resusing and soil fertility improvement in sustainable agriculture. Winter crops are resources of organic manure. Green-cover technique which can improve ecological environments and save energy is an important measure of realizing sustainable development of southern paddyfield. So, fully utilizing the paddyfield winter conservation tillage techniques, not only be able to alleviate the farmers’ burden, but also be able to control the aeolian erosion and nutrient availability loss . The former studies of conservation tillage were mainly focus on the characteristics of soil fertility and ecological environment protection, while the researches of rice growth, physiological characteristics and quality in conservation tillage is still relatively little, especially in the rice senescence and quality which has not been reported so far. With the development of society, the high yield and quality of rice are the goal pursuited by farmers and experts. In order to study the effects of paddy winter conservation tillage on the rice growth, using rice variety guodaoliuhao as materials, we analysed the influence of four winter greencover plant on characteristics of soil fertility, rice senescence and quality with fallow as control(CK).; using early season indica rice of zhongzao22 as material, we studied the effect of organic fertilizer. The four winter green-cover plants are potato covered with straw(T1, fertilization of two years), oatgrass(T2, fertilization of one year), rape(T3, fertilization of two years), ryegrass(T4, fertilization of one year), which are common in Middle and Lower Reaches of the Yangtze River, The results are as follow:1, Compared to the control treatment, the organic significantly improved soil protease, phosphatase and catalase activities; During grain-filling stage, chlorophyll and soluble protein content, SOD activity in the leaves under organic nitrogen treatment decreased slowly, while POD activity increased quickly, MDA content changed little, which showed that organic fertilizer can effectively postpone the senescence of rice; The correlation analysis showed that it was significant correlation between the soil enzyme activities and the leaf senescence characteristics.2, Effects of returning straw on soil enzyme activities and rice integrated quality depends on the weight of straw returning and the fertilization life. There were significantly positive correlations between soil enzyme activities and rice comprehensive quality, with the soil protease activity had the most important effect on comprehensive quality, with significant correlation or very significant correlation in the latter part of grain filling stage especially. Soil enzyme activities in T 1 were higher than the other treatments, followed by T3. However, the activity in T3 is low, but it is stable and advantageous for the development of rice quality. And the comprehensive quality in T3 was the highest at 52.3 of quality index, the next are T1 and T2 with 51 and 49 respectively, and there were significant differences compared to the control treatment (CK).3, Returning straw can increase rice leaf SOD and POD activity, delay the degradation of chlorophyll and soluble protein effectively, and prevent the increasing of the MDA content during the grain filling. The significant correlation was widely found between the soil enzyme activities and leaf senescence in the research and the soil protease activity had the most effect on the leaf senescence, which showed significantly or very significantly correlated between the soil protease activity and leaf senescence in the mist and late grain filling, especially. The results show that T1, T2 and T3 can better delay the rice leaf senescence, and their yield reached 12.27 t/hm~2, 12.30t/hm~2 and 12.21t/hm~2 respectively (Compared to the control treatment (CK), there were significant differences). Correlation analysis showed that there was significant or very significant positive relationship between rice yield and leaf senescence. 4, Compared to the control treatment (CK), different previous crops played a great role in promoting dry weight accumulation, leaf area index and leaf weight of rice, but T1 had the most important effect on the rice growth, followed by T2; The root activities was higher, Chlorophyll content decreased more slowly in T1 and T2 than the other treatments; In grain filling, the initial potential was large and the average grain filling rate was fast, it is helpful to enrich the grain.更多还原