【作者】 黄梅；

【导师】 黄璜；

【作者基本信息】 湖南农业大学 ， 生态学， 2003， 硕士

【摘要】 本研究提出了一种新型的生态农业模式——免耕稻-鸭生态种养模式，并在湖南农业大学植物标本园和湖南宁乡迥龙铺两地同时对免耕的湿地稻-鸭复合生态系统土壤环境、植株性状、生态效益和社会经济效益进行了研究，旨在为全面系统地评价免耕稻-鸭复合生态系统提供理论依据，为免耕稻-鸭生态种养这一新型的生态农业模式的推广应用奠定坚实的理论基础。 本试验研究包括四个方面的内容：(1)构建了免耕稻-鸭复合生态种养模式；(2)研究该体系对土壤环境的影响；(3)研究该体系对植株性状的影响；(4)研究该系统的生态效益、经济效益、社会效益。主要研究结果如下： 1 免耕稻-鸭复合生态系统对土壤环境的影响 免耕稻-鸭复合生态系统与常规翻耕相比，0～5cm土层土壤容重降低了2％，非毛管孔隙度增加了3.28％；5～15cm土层土壤容重变化不大，非毛管孔隙度增加了1.1％，说明免耕养鸭有利于改善土壤的物理性状。土壤养分库数量在0～5cm土层有不同程度的增加，有机质两地平均增加了8.8g／kg，全氮增加了0.53g／kg，碱解氮增加了77.0mg／kg，增加幅度分别达17.9％、23.76％、44.41％，说明免耕养鸭有利于这些养分的增加，对土壤中速效磷、速效钾的分析表明养鸭有利于土壤中速效磷、速效钾的增加，而免耕则对两者影响不大；5～15cm土壤的肥力变化缺乏明显的规律性，说明免耕养鸭能提高土壤表层肥力水平，而对中下层土壤肥力影响不明显。免耕养鸭与常规翻耕相比，氧化还原电位提高了18.4mV，还原物质总量减少83％，有利于土壤氧化还原状态的改善。以上结果说明免耕稻-鸭复合生态系统全面提高了土壤环境质量。 2 免耕稻-鸭复合生态系统对水稻植株的影响 免耕稻-鸭复合生态系统有利于提高水稻生长前中期的叶面积指数、干物重以及水稻根系的活力，后期由于免耕不动土，影响了根系下扎，根系有早衰现象，叶面积指数也受到影响，但后期这三项指标与常规翻耕比仍然处于优势。水稻植株茎叶氮、磷、钾含量在齐穗期以前也表现出免耕养鸭处理的优势，齐穗期后，则翻耕略高于免耕。穗粒性状考查表明，免耕稻-鸭复合系统水稻的有效穗数、每穗总粒数、结实率都得到了提高，理论产量每公顷增加了197kg，实际产量每公顷增加了141k8，增产幅度分别达2.5％、2.3％，产量增加显著。 3 免耕稻-鸭复合系统的综合效益研究 免耕稻-鸭复合生态系统具有强大的生态功能，产生了较好的生态效益：免耕的稻鸭复合生态系统利用鸭子除虫、除病、除草，不施农药和除草剂也能获得明显的防治病虫草害的效果，而且保护了天敌，防治效果稳定，大大减少了对农田生态环境的污染；而且免耕养鸭处理降低了晚稻甲烷排放高峰--分蘖盛期排放通量的40.4％，整个生育期排放总量降低了28.8％，这对于改善全球的温室气体效应具有重大意义；免耕稻一鸭复合生态系统在早稻生长后期不断水，不晒田，发挥了稻田生态系统集雨蓄水的作用，每公顷可节约灌溉用水1300 ms。经济效益方面，免耕养鸭增产显著，每公顷增加纯收入4390元，节约农药、除草剂以及机耕费用920元，产投比比对照增加了将近60地免耕抛秧养鸭极大地缓和了农忙时期机耕、畜力和劳力紧张强度，降低了农民的劳动强度，对提高农民种粮积极性有很大现实意义，同时生产了无公害农产品，满足了消费者对绿色食品的需求，产生了较好的社会效益。 综合以上结果表明，免耕稻一鸭复合生态系统将兔耕与养鸭有机地结合起来，全面提高了土壤环境质量，改善了水稻植株性状，增加产量、提高稻田的产出和效率、降低成本，还为社会提供了优质的生态米、生态鸭、生态蛋，同时能降低农田污染、减少甲烷排放，节约灌溉用水，生态效益显著。实验证明兔耕稻一鸭复合生态系统是经济效益、生态效益、社会效益的最佳结合，将成为一种很有发展潜力的生态农业模式。更多还原

【Abstract】 This research put forward a new ecological agriculture mode -Rice-Duck ecological management with no-tillage, and studied soil environment, plant characteristics, ecological benefits, social and economical benefits of Rice-Duck Complex Ecosystem with no-tillage in the Hunan Agriculture University and Huilongpu Town of NingXiang at the same time. It aimed at affording scientific basis for comprehensive assessment of this new ecological agriculture mode and establishing solid theoretical foundation for extending it.Study contents of this experiment included: (1) Constructing Rice-Duck Complex Ecosystem mode with no-tillage; (2) Study on impact of this system on soil environment; (3) Study on impact of this system on plant character; (4) Study on ecological benefits, social and economical benefits of this system. Main results for this study are as follows:1. The influence of Rice-Duck Complex Ecosystem with no-tillage upon soil environmentsCompared with tillage(CK), soil bulk density decreased by 2%, soil non-capillary increased 3.28% in 0~5cm soil layer, hi 5~15cm soil layer, soil bulk density have no change and soil non-capillary increased by 1.1%. It showed no-tillage duck-raising was beneficial to improving soil physical characteristics; The contents of soil nutrient increased in 0~5cm soil layer in various degree, compared with CK: organic matter, total N, available N increase 8.8 g/kg, 0.53 g/kg, 77.0 mg/kg, reaching 17.9%, 23.76%, 44.41%, it showed no-tillage duck-raising was beneficial to improving these nutrients; The analyzing of available P, available K showed, duck-raising was beneficial to increasing available P, available K, but no-tillage have no effects on them. The changes of soil nutrients in 5-15cm soil layer didn’t show any regular changes, so no-tillage duck-raising can increase the soil fertility of surface layer, but have no effects on middle and lower layer. Eh increased 18.4mv, SRS decrease 83%, resulting in improving of Redox status. The results hereinbefore showed no-tillage duck-raising improved the soil environment obviously.2. The influence of Rice-Duck Complex Ecosystem with no-tillage upon plant characteristicsThe Rice-Duck Complex Ecosystem with no-tillage is beneficial to increasing the paddy’s LAI, dry matter weight ,and the a-NA oxidation ability of rice root in the earlierterm and midterm of growth period ,in the latter term, because no tillage resulted in premature senility of rice root, the LAI was affected, but this three were all not in inferior position compared with tillage. The nutrient content of rice plant body increased before heading stage, but decreased after heading stage because of premature senility of rice root, affecting absorption of N, P, K nutrient for paddy. The comparisons of yield characters showed, the effective panicles, total grains per panicle, seed-setting percentage increased, compared with tillage, theory yield, actual yield increased 2.5%, 2.3%, the increment of yield reaching significant level.3. The study on comprehensive benefits of rice-duck complex ecosystem with no-tillageRice-duck complex ecosystem with no-tillage has strong ecological function, producing great ecological benefits: because of duck’s eating and moving about at the field, it can control plant diseases and insect pests and weeds effectively by not using pesticide and herbicide, and because it protects the natural enemy, the effects are very stable, cutting down the pollution to the cropland ecosystem greatly. Furthermore, the fluxes of methane emission of late rice in full tillering stage of paddy decrease 22.5%, the total methane emission decreased 40.5% from full tillering stage to boot stage compared with tillage. It can reduce .the globe’s greenhouse effects, producing great ecological significance. Also it can save water resources 1300 m3hm-2 through gathering rainwater and sluice of rice-duck complex ecosystem. As to economical effects, it increased the yield and the net income per ha. 4390 Yuan, decreased the consumption of pesticide, herbici更多还原