【作者】 甄若宏；

【导师】 卞新民；

【作者基本信息】 南京农业大学 ， 生态学， 2007， 博士

【摘要】 稻田是最大的人工湿地生态系统,具有多重生态功能,净化污水,美化环境,还是一座巨大的物种基因库。然而现代稻作生产为了片面追求其生产经济效益,对稻田生态系统过度干扰,加大稻田的利用开发程度,导致稻田生产力下降,污染加剧,不能满足当今人们对安全食品的需求。稻鸭共作生态农业模式正是适应农业发展现状而产生的,是以稻作水田为条件,以种稻为中心,家鸭田间网养的自然与人工相配合的生态工程系统,是有效控制常规稻作生态污染的重要技术途径.1、通过田间小区对比试验研究分析了不同稻作模式对水稻植株形态的刺激效应.结果表明,由于鸭子在稻田的活动使水稻植株形态发生了明显的变化,植株碳水化合物含量、植株碳氮比、茎秆干物质输出率都明显增加,而且茎秆基部节间长度明显比对照缩短2.88%,茎粗增加64.90%,茎秆强度和抗倒伏指数也分别提高了11.78%和10.95%,并且稻鸭共作后提高了深层根比例和根系活力,黑根比例降低了16.63%.2、分析了稻田放养鸭子后,不同土壤层次的理化性状、水体性质以及水稻产量构成和品质性状,可知,稻鸭共作处理有效改善了稻田土壤、水体的理化性状,与对照处理相比,土壤表层容重降低5.30%,总孔隙度提高2.52%,非毛管孔隙度提高19.03%,土壤表层的有机质、碱解氮、速效磷、速效钾比未放鸭的对照处理也分别提高了6.41%、9.74%、5.24%和5.17%,水体中的总氮、总磷和总钾比对照区分别增加9.31%、16.46%和16.42%,说明鸭子在田间的活动不仅有效刺激土壤养分释放,也明显改善了土壤结构,以及鸭子的排泄物等优质有机肥的还田,从而显著提高了稻田土壤、水体养分含量,也明显改善了水稻产量组成及品质指标,稻鸭共作处理的穗长比对照处理增加了1.41%,经济系数升高5.48%。通过稻米品质指标分析表明,与对照处理相比,出糙率、精米率和整精米率分别提高了3.21%、4.82%、3.49%,垩白粒率降低了26.17%,垩白度降低了32.56%,稻米直链淀粉含量降低4.03%,胶稠度提高了9.06%,稻米清蛋白和谷蛋白含量分别增加了12.12%和13.35%。3、通过鸭子在稻田生态位的添加,系统研究了稻鸭共作对稻田病虫草的生态控制效应.结果表明:稻鸭共作对杂草的防除效应达到96.1%,降低了稻田杂草的发生种类,但Pielou均匀度指数显著提高;稻鸭共作对稻飞虱具有明显的生物控制效应,防治效果达到65.49%;稻鸭共作因鸭子对蜘蛛的捕食,降低了稻田蜘蛛的数量,而因稻田稻飞虱数量的明显减少,从而显著提高了稻田蜘蛛与稻飞虱的比例;鸭子对稻纵卷叶螟和二化螟有一定的控制效应,但控制能力随着水稻株高的增加而逐渐下降;鸭子的践踏、采食等活动特性并未控制住纹枯病的发生,只能减轻纹枯病的发病程度;稻鸭共作对稻瘟病也有明显的抑制作用,防治效果达到57.02%.由灰飞虱传毒危害的水稻条纹叶枯病是近年来在我国部分稻作区严重发生的病毒病害,稻鸭共作以及秧田期覆盖防虫网、栽后大田稻鸭共作处理对灰飞虱有显著的控制效应,因此也显著降低了两处理在水稻整个生长期间条纹叶枯病的发病率;稻鸭共作处理对条纹叶枯病的防效为79.44%,略高于常规稻作78.82%的防效,而秧田期覆盖防虫网、栽后大田稻鸭共作处理对稻田灰飞虱和条纹叶枯病的防治效果最好,防效超过94.01%.4、轻型机械栽培具有省工、节本、增效等多重功能,但与之伴随的是杂草丛生,防治困难,为此本试验通过在水稻不同种植方式下进行稻鸭共作以探讨稻田杂草的群落特征.由此可知,人工移栽稻鸭共作稻田杂草种类明显低于直播稻鸭共作和机插稻鸭共作,以直播稻鸭共作田杂草的香农指数最高.由于田间环境的不同,各处理稻田的杂草组成也各异,直播稻鸭共作田杂草群落组成为丁香蓼+水苋菜+异型莎草,而稗草、千金子等稻田恶性杂草在直播稻鸭共作田下降为非优势杂草.直播稻鸭共作和机插秧稻鸭共作杂草群落的相似性指数较高,而且两者杂草物种数、杂草物种多样性指数均高于人工移栽稻鸭共作,以及表征杂草群落组成的Wittaker指数以人工移栽稻鸭共作最高.5、绿萍具有固氮富钾、节水、培肥等多重生态功能,通过把稻田养萍与稻鸭共作的有机结合,构成了生态环保型稻鸭萍共作体系.稻鸭萍共作有利于提高土壤肥力,收获后的土壤有机质、碱解氮、速效磷、速效钾分别比对照增加了7.95%、7.05%、6.47%、4.46%;稻鸭萍共作对杂草的控制效果达到98.94%,明显削弱了稻田优势杂草的发生危害,稻田残存杂草为数甚少,Pielou均匀度指数显著提高;稻鸭萍共作对稻田飞虱有显著的控制效应,因此,也明显抑制了主要由灰飞虱传毒危害的水稻条纹叶枯病发病率;稻鸭萍共作虽然对水稻纹枯病也有明显的防治效果,但不能控制住纹枯病的发生.6、通过¹⁵N标记技术分析萍体氮素动态可知,由于鸭子在田间的活动,从而有效地改善了田间的小气候环境,使得水体、土壤、稻株中的¹⁵N回收率均以稻鸭萍共作处理最高,萍体氮素的损失率仅为11.20%,远低于单纯稻田养萍处理的62.45%.以及鸭子、绿萍对稻田生态系统有机肥的补充,显著促进了水稻的旺盛生长,使得稻鸭萍共作处理水稻的产量性状以及各项品质指标都得到了有效改善.7、通过对不同稻作系统能流、养分循环特征分析表明,稻鸭共作系统、稻鸭萍共作系统、常规稻作系统的直接生理能分别占人工辅助能的比例为34.39%、30.83%和32.34%,其中有机能占人工辅助能输入的百分比分别为9.6%、2.8%和0.7%;稻鸭萍共作系统的氮磷钾养分含量都有一定程度的盈余,而常规稻作系统和稻鸭共作系统氮都有亏缺;稻鸭萍共作生态系统和稻鸭共作生态系统的氮磷钾养分循环通量均高于常规稻作系统,表明稻田养分再利用程度均较高,对肥料的依赖程度较低.更多还原

【Abstract】 Rice field of gleyization and swampiness is a largest manual wetland ecological system,it is called "a gene pool of living things" because of its multi-ecological functions, for instance,cleansing sewage and beautifying environment.But its ecological function and productivity declined because that human being excess disturbing it and increasing its utilization and exploitation for economy benefit.Rice-duck integrated farming is an ecology agricultural pattern to adapt to agricultural development status,it is ecological engine system and can control ecological pollution in conventional rice production region.1、Effects of rice-duck integrated farming on rice plant were studied.We examined the stimulation effects of different rice-growing systems on rice plant by the field experiment in Dongtai experimental station of Nanjing Agricultural University,Jiangsu Province. Results showed that rice plant shape apparently changed because of ducks’ activity in rice paddy.Carbohydrate content,C/N ratio and dry matter transfer ratio in stem were higher than control system.Basal internodes length,stem thick,stem mechanical strength and stem lodging resistant index were 2.88%,64.90%,11.78%and 10.95%higher than control system,respectively.Rice-duck integrated farming increased deep layer root ratio and root activity,but decreased black root ratio 16.63%than control system.2、Rice-duck integrated farming availability improved physichemical characters of soil and water,compared to CK treatment,soil surface layer’s bulk density decreased 5.30%, total porosity increased 2.52%and non-capillary porosity increased 19.03%.Organic matter,available N,P,K increased 6.41%、9.74%、5.24%and 5.17%,respectively compared to CK treatment.Total N,P,K of water also increased 9.31%、16.46%and 16.42%.So these results showed that duck dejection can significantly increase water nutrition content,and significantly improve yield characters and quality items.Panicle length of rice-duck integrated farming was 1.41%longer than CK treatment and harvest index hoist 5.48%.Through rice quality items analyzing,brown rice,milled rice,and head rice ratio increased 3.21%、4.82%、3.49%in RD treatment compared to CK treatment,but chalkness decreased 26.17%,amylose content increased 4.03%,gel consistency increased 9.06%,and albumin,glutelin content increased 12.12%and 13.35%respectively.3、This article makes research on the ecological effects of rice-duck integrated farming on developing regularity of flee diseases,insects and weeds.The research finds that rice-duck integrated farming can prevent 96.1%of the weeds from growing,thus reducing the varieties of the weeds,although the Pielou evenness index rises.Rice-duck integrated farming has visible ecological effect on control over brown planthoppers,and the total prevention rate reaches 65.49%.By adopting rice-duck integrated farming,the ducks prey on spiders,which reduces the numbers of spiders,as a result,the ratio between spiders and brown planthoppers is increased.Although ducks have some control effect on Cnaphalocrocis medinalis Guenee and Chilo suppressalis Walker,their control ability over such insects will be weakened with the growth of rice plants.Thanks to the ducks, rice-duck integrated farming can cut down the occurrence rate of rice stripe disease event if this method cannot fully prevent the disease from arising.Besides,rice-duck integrated farming can also effectively control rice blast,and the prevention rate reaches 57.02%.Rice stripe disease transmitted by brown planthopper is one of the most serious viral disease in some rice-growing areas of China in recent years.As an ecological practice of rice growing, rice-duck integrated farming has shown great effects on the controls of rice insects, diseases and weeds.However,there is no direct field evidence of the integrated farming effects on brown planthopper and rice stripe disease.Here we examined the effects of different rice-growing systems on controlling brown planthopper population and rice stripe disease in field experiments in Dongtai experimental station of Nanjing Agricultural University,Jiangsu Province,China.The treatments included Conventional rice production system,Rice-duck integrated system,Rice-duck integrated system with insect proof net during seedling stage and Control system.Results showed that the RD and NRD treatments significantly reduced brown planthopper population,resulting in great decline in the incidence of rice stripe disease during all stages of rice growth.The highest reduction in brown planthopper population was found in the NRD treatment with over 94.01% reduction of rice stripe disease.The RD treatment decreased rice stripe disease incidence by 79.44%,higher than that in CR treatment（78.82%）.The findings suggest that rice-duck integrated farming,especially plant covered with insect proof net cover during the seedling stage,is a safe and high efficiently ecological approach for controlling rice stripe disease in China.4、Light machinery cultivation has many ecological function of decreasing labor and cost,but increasing economical effect.While these dee paddies had many weeds,and difficulties to control them.Weeds varieties in Manpower transplanted rice-duck integrated farming region（TRD） were lower than that in Direct seeding rice-duck integrated farming region（DSRD） and Machine-transplanted rice-duck integrated farming region（MTRD）,but Shannon-wiener index is the highest in DSRD treatment.Weeds community constitution was Ludwigia prostrata+Ammannia baccifera L+Cyperus difformis in DSRD treatment, however,Echinochloa crusgalli and Leptochloa chinensis declined non-dominant weeds. Similarity index of weed communities was higher between in DSRD treatment and MTRD treatment,their weed varieties and Shannon-wiener index all higher than TRD treatment. But Wittaker index was the highest in TRD treatment.5、The article studied main eco-funetions of rice-duck-azolla mutualism compound system.Rice-duck-azolla integrated farming could improve soil fertility and the organic matter,available N、P、K increased 7.95%、7.05%、6.47%、4.46%than the CK treatment, respectively.The controlling effect of rice-duck-azolla integrated farming on weeds reached 98.94%,reduced the infestation of former dominant weed species and weed quantity,but evenness index rose.Rice-duck-azolla integrate farming had apparent controlling effects on planthopper,so decreased happening chances of rice stripe disease. Rice-duck-azolla integrate farming had significantly controlling effect on rice sheath blight, but it couldn’t control the occurrence of rice sheath blight.6、Through ¹⁵N labeling technology analyzed azolla’s N distribution dynamic, rice-duck-azolla integrated farming available improved rice field environment because of ducks’s activity,¹⁵N recovery ratio of water,soil and rice plant in this treatment was all the highest,and azolla N losing ratio was only 11.20%,but rice-azolla treatment’s azolla losing ratio reached 62.45%.So rice-duck-azolla integrated farming availability improved yield characters and quality items with the condition of azolla and duck dejecta supplied nutrition to rice yield.7、The ratio between direct physiological energy and manual supplementary energy were 34.39%、30.83%and 32.34%,in rice-duck-azolla integrated farming,rice-duck integrated farming and conventional rice production region,respectively.The ratio between organic energy and manual supplementary energy were 9.6%,2.8%和0.7%in the three treatments,respectively.The contents of N,P₂O₅,K₂O in rice-duck-azolla integrated farming had profit to some extent,but N content lost in dee-duck integrated farming and conventional rice production region,P₂O₅ and K₂O had profit.Flux of N,P₂O₅,K₂O in rice-duck-azolla integrated farming and rice-duck integrated farming were higher than that in conventional rice production region,this showed that the nutrient cycle degree were higher and low dependence on fertilization in the two treatments.更多还原