【作者】 沈建凯；

【导师】 黄璜；

【作者基本信息】 湖南农业大学 ， 作物信息科学， 2010， 硕士

【摘要】 研究稻鸭生态种养系统杂草的生物多样性,有助了解适度保护农田杂草生物多样性的重要性和潜在的巨大价值,为水稻病虫草害的综合生态防治提供依据；研究稻鸭生态系统的土壤营养特性,有助于了解稻鸭生态种养对土壤养分变化的影响,为稻鸭种养的快速推广提供环境学依据,同时也可为水稻的高产生态栽培提供新的思路。2008年3月-2009年11月采用田间试验,研究了机械直播条件下的稻鸭生态种养系统土壤营养特性和规模化稻鸭生态种养稻田杂草的生物多样性以及病虫害发生特点。主要得到以下结论：1完全稻鸭生态系统土壤营养特性(1)土壤团聚体含量及其养分特征。与水稻单一种植比较,完全稻鸭生态种养系统土壤2-1 mm团聚体增加5.29%,<0.25mm团聚体减少5.17%,>2 mm团聚体减少0.28%。全氮、全磷、全钾和全有机碳在2-1mm团聚体的含量显著增加,<0.25mm团聚体含量减少。与间歇稻鸭生态种养处理比较,完全稻鸭生态种养处理<0.25mm团聚体含量减少2.14%及其全钾含量下降。稻田养鸭有助于土壤大团聚体的形成,增加土壤养分在大团聚体的贮存量。(2)耕层养分特征。完全稻鸭生态种养和水稻单一种植的土壤氮、磷、钾养分的含量均随着耕层深度的增加呈逐渐下降,完全稻鸭生态种养0-5 cm土壤全磷、全钾、速效氮、速效钾和不同活性的有机碳含量增加显著,全氮含量明显下降；5-10 cm全磷、全钾含量减少,而高活性有机碳含量增加。10-15 cm速效氮和速效磷含量略有增加,15-20 cm全钾含量显著增加。说明鸭子的活动和粪便的输入对耕作表层养分影响效果较明显,且不同养分种类不同影响程度存在差异。(3)水稻根区营养。齐穗灌浆期水稻根表速效氮、速效钾、活性有机碳、高活性有机碳和pH值比水稻单一种植处理分别高30.80 mg/kg、17.93 mg、2.17 g/kg、0.56g/kg和0.23个单位,全氮、速效磷和全有机碳分别降低了0.11 g/kg、8.66 mg/kg和0.99g/kg；水稻根际土壤全氮、速效氮、速效钾、全有机碳、活性有机碳、中活性有机碳含量比水稻单一种植处理分别低0.11g/kg、15.13 mg/kg、7.61 mg/kg、2.39 g/kg、2.64 g/kg和0.72 g/kg,速效磷含量升高9.66 mg/kg。表明鸭子在稻田的行走中耕作用改变了土壤速效磷、速效钾、活性有机碳和高活性有机碳在水稻根际和根表的相对集中趋势。(4)有机碳与土壤理化的相关性分析。完全稻鸭生态种养系统土壤全有机碳与土壤全氮、全磷和速效氮含量的变化呈极显著正相关,相关系数分别为0.95、0.95、0.96,回归方程分别为Y=-11.3033+18.61137X,Y=1.454846+26.23002X,Y=-2.83889+0.181469X,经F检验均达到极显著水平。活性有机碳与全钾回归方程Y=39.21046-2.02799X,经F检验达到显著水平；高活性有机碳与速效磷回归方程为Y=17.62807-0.20748X,但F检验不显著。土壤全有机碳与土壤pH、容重呈极显著负线性相关,与总孔隙度呈显著正相关,相关系数分别为-0.85、-0.77、0.77,线性回归方程为Y=59.51093-7.15519X,Y=24.12376-4.27418X,Y=12.79717+0.113266X,经F检验回归均达到显著水平。活性有机碳、中活性有机碳分别与土壤容重呈显著负线性相关,与总孔隙度表现显著正相关。活性有机碳与土壤容重、总孔隙度线性回归方程为Y=26.334110.8307X,Y=-2.36728+0.287014X,F检验均也达到显著水平。说明稻鸭生态种养系统土壤有机碳的变化是土壤理化性状的综合作用结果。2规模稻鸭生态种养系统杂草的生物多样性以及病虫害变化规律(1)杂草群落组成及多样性。规模稻鸭生态种养杂草密度明显降低,水稻分蘖到孕穗期稻田杂草主要是看麦娘、稗草、水花生、狗牙根、鸭舌草和水竹叶组成；抽穗期到成熟期是水竹叶、稗草、狗牙根和水花生组成。水稻分蘖期物种丰富度、Simpon指数、Shannon-Wiener指数略高于水稻单一种植,Pielou指数低于水稻单一种植；孕穗期到成熟期物种丰富度、Simpon指数、Shannon-Wiener指数低于水稻单一种植,Pielou指数显著高于水稻单一种植。规模稻鸭生态种养与常规稻鸭生态种养比较稻田杂草密度、生物量和多样性指数差异不显著,但杂草生物多样性指数略有提高。(2)病虫害发生与发展特点。规模稻鸭生态种养系统水稻二化螟、稻纵卷叶螟、稻飞虱和稻叶蝉平均虫量较水稻单一种植分别下降54.4%、48.8%、73.6%、96.1%,纹枯病和稻瘟病病株率分别降低78.9%和48.5%；较常规稻鸭生态种养水稻二化螟、稻纵卷叶螟、稻飞虱和稻叶蝉量分别下降18.2%、9.5%、7.0%、0.82%,纹枯病病株率降低35.5%,稻瘟病病株率升高8.0%。稻飞虱和二化螟对水稻危害株率比常规稻鸭生态种养分别降低52.9%和6.9%。同时规模稻鸭生态种养系统水稻二化螟、稻纵卷叶螟、稻飞虱虫峰迟现,持续危害时间等特点；纹枯病蔓延危害期缩短10-14天。更多还原

【Abstract】 The research adopted methods of experimental plots and investigation in paddy fields, and maked a study on the physical and chemical characteristics of soil, diversity of weed communities, population dynamics for rice insect pests and diseases, and economical benefits in rice-duck ecological farming ecosystem from 2008 to 2009. The main results were as follows:1. The soil nutrient characteristics in rice-duck ecological farming during growth stage of rice(1) The content of water stable aggregate and nutrient characteristics. Compared with that of sole cropping,2-1 mm water stable aggregate were increased by 5.29% in rice-duck ecological system,<0.25 mm and>2 mm water stable aggregate were decreased by 5.17% and 0.28% respectively. The content of total N, total P, total K and organic carbon were increased markedly in 2-1 mm and 1-0.25 mm water stable aggregate,<0.25 mm water stable aggregate were decreased.(2) Nutrient characteristics of soil profile. The content of N, P and K were decreased from surfance soil to 20 cm soil profile. Ducks moving and inputed dejecta into paddy fields, which influence on the surfance soil nutrient remakedly. The content of total P, total K, available N, available K and active organic carbon were increased markedly in 0-5 cm soil profile, while the content of total N was decreased. In 5-10 cm soil profile, the content of total P, total K were hegher than sole rice cropping, and in 10-15 cm soil profile, the content of available N, available P were incereased, and in 15-20 cm soil profile the content of total K were increased.(3) Nutritional status in the root zone. Available N, available K, active organic carbon, heigh-active organic carbon and pH value of rice root surface soil were increased by 30.80 mg/kg,17.93 mg/kg,2.17 g/kg,0.56 g/kg and 0.23, and total N and available P were decreased by 0.11 g/kg、8.66 mg/kg. The soil total N, available N available K, organic carbon, active organic carbon and mid-active organic carbon in rhizosphere were decreased by 0.11 g/kg,15.13 mg/kg,7.61 mg/kg,2.39 g/kg,2.64 g/kg and 0.72 g/kg, and available P was increased by 9.66 mg/kg. (4) The correlation analysis between organic carbon and soil properties. Soil total N, total P and available N was significantly correlated with Soil total organic carbon (R=0.95, 0.95,0.96), regression equations were Y=-11.3033+18.61137X, Y=1.454846+26.23002X, and Y=-2.83889+0.181469X respectively. The concertration of total K was with active organic carbon the linear regression equation was Y=39.21046-2.02799X. Soil pH value, bulk density and total porosity were significantly correlated with Soil total organic carbon (R=-0.85、-0.77、0.77), regression equations were Y=59.51093-7.15519X, Y=24.12376-4.27418X, Y=12.79717+0.113266X, F value were 10.11,5.90,5.90.2. The biodiversity of weed and population dynamics on rice insect pests and diseases in scale rice-duck ecological farming ecosystem.(1) The composition and diversity of weed communities. The density of weed of the scale rice-duck farming in paddy fields decreased significantly compared with the sole rice cropping. Before the rice booting stage,weed was composed of Mouochoria vaginalis, Echinochhloa crausgalli, Alternanthera philoxeroides, Murdannia triquetra, Cynodon dactylon L and Alopecurus pratensis Linn; From the rice heading stage to ripe stage, weed was composed of Echinochhloa crausgalli, Alternanthera philoxeroides and Cynodon dactylon L. At the rice tillering stage species richness, Simpon index and Shannon-Wiener index of scale rice-duck farming were higher than sole cropping, while Pielou index was lower than sole cropping. From the rice booting stage to rice ripe stage, species richness, Simpon index and Shannon-Wiener index of scale rice-duck farming were lower than that of sole cropping, while Pielou index was significantly higher than that of sole cropping. During the whole rice growing stage, weed density, weed fresh weight and species diversity were not significantly different between the scale rice-duck farming and conventional rice-duck farming,but species diversity of weed had a increasing trend. The scale rice-duck farming changed the structure of weed community and decreased the weed species diversity, which effectively limited weed infestation in paddy fields.(2) Population dynamics on rice insect pests and diseases in scale rice-duck ecological farming ecosystem. In scale rice-duck farming the mean densities of rice stem borers, leaf folder, planthoppers and leafhoppers were decreased by 54.4%,48.8%,73.6% and 96.1% compared with mono-cropping, as well as the rate of diseased plant of rice sheath blights and rice planthopper were decreased by 78.9% and 48.5%; While compared with the conventional rice-duck farming, the average densities of rice stem borer, rice leaf folder, rice planthopper and rice leafhopper was reduced by 18.2%,9.5%,7.0% and 0.82%, and the rate of diseased plant of rice sheath blight were decreased by 35.5%, unfortunately the rate of diseased plant rice blast-infested was increased by 8.0%. In scale rice-duck farming ecosystem, the percentage of infected plants of rice striped stem borer and rice planthopper were 52.9% and 6.9% lower than conventional rice-duck farming. The experiment also shows that the population peak density of rice stem borer, rice leaf folder and planthopper were postponed in scale rice-duck farming field, and infestation period of rice sheath blight was shortened by 10-14 days. The characters of rice in scale_rice-duck farming field were improved in terms of larger number of spikes per plant and kernels per spike, higher 1000-kernel-weight, lower emptiness rate and the highest grain yield. Net profit of scale rice-duck farming treatment increased by 1024.32 yuan/hm2 (4.53%) and 1370.61 yuan/hm2 (71.21%) compared with the conventional rice-duck farming and mono-cropping respectively. The scale rice-duck farming has an good effect on control of rice diseases and pests, and its economic income was increased markedly.更多还原