【作者】 林超文；

【导师】 张新全；

【作者基本信息】 四川农业大学 ， 草业科学， 2010， 博士

【摘要】 本研究采用长期定位(8年)的方法,以紫花苜蓿(Medicago sativa)、香根草(Vetiveria zizaniodes)、紫穗槐(Amsopha fruticosa)、多变小冠花(Coronilla varia)、蓑草(Eulaliopsis binata)等植物为研究材料,对不同植物篱模式下的水土流失量、土壤养分在系统内的空间再分配规律、植物篱种植系统的各组分间相互作用及能量利用关系、农田节肢动物多样性变化规律、微生物多样性变化规律等方面内容开展深入研究,为植物篱农作模式优化、新模式创制提供理论依据。主要研究结果如下：1.植物篱可以显著减少泥沙流失量和径流量,控制水土流失效果好、见效快；植物篱提升了整个系统能量产投比率,是提高四川丘陵区农业能效的有效措施。豆科饲草植物篱能为地面蜘蛛提供良好的避难场所,地面蜘蛛的活动密度在冬小麦生长季节均显著高于对照,丰富了农田蜘蛛多样性；植物篱显著增加了土壤细菌、放线菌、真菌数量、土壤微生物量碳、氮,提高了土壤氨化作用强度,降低了土壤硝化和亚硝化强度,同时,也丰富了农田微生物遗传多样性。因此,饲草植物篱显著改善了紫色丘陵农区旱坡耕地的农田生态,是适于该区域的可持续高效农作模式。2.采用标准土壤侵蚀监测小区和SW40型日记式水位计监测不同植物篱模式下的水土流失量,植物篱可以显著减少泥沙流失量和径流量,8年共减少泥沙165.4-242.8t/hm2,在栽种植物篱的第二年,径流减少63.0%-70.8%,泥沙减少79.1%-85.7%,可见控制水土流失效果好、见效快。种植植物篱后土壤坡度减缓明显,两个地块的小区坡度分别从原来的20°、13°减小为16028’和17011’、10°28’和11°5’。植物篱上部有明显的泥沙堆积,香根草、紫花苜蓿、蓑草植物篱前土壤带平均粘粒含量为29.6%、28.9%、33.1%,分别比带间中部和篱下土壤高6.6%和6.5%、5.9%和9.3%、7.0%和15.0%(相对差异),土壤粘粒在篱前富积,篱下加剧侵蚀,粘粒的富积与侵蚀沿等高线成水平带状分布。土壤有机质、N、P等主要营养元素出现与土壤颗粒相同的分布规律,对K来说,其分布不受植物篱的影响。从土壤养分的绝对数量来看,P呈高度富积,香根草、紫穗槐、紫花苜蓿、蓑草植物篱区坡面平均全磷含量分别达0.105%、0.098%、0.096%、0.090%,分别比初始土壤全磷含量提高了54.1%、44.1%、35.2%、26.8%；而有机质和K则是高度耗竭,所有处理的土壤有机质含量较试验初始时都有降低,其中1号地对照、香根草、紫穗槐植物篱区平均降低了34.3%、25.8%、21.8%,2号地对照、紫花苜蓿、蓑草植物篱区平均降低了25%、21.9%、30.2%,钾也表现出类似情况。3.通过连续2年的定位试验,对坡度为8-20°的坡耕地“作物—植物篱”系统能流特征如能结构、能效率进行了研究。结果表明：①“作物—植物篱”系统产出能和输入能的数量和结构的变化主要受到植物篱子系统类型的影响,与大面积坡耕地传统农作物生产系统如“小麦/花生(或玉米)/甘薯”比较：由于果树、草本等植物篱的冠层及根系在形态和空间分布上与作物的异质性,形成了对光、热、水、土、肥等资源的连续、多层次的利用,因此能有效提高系统的光能利用率、人工输入能效率和耕地单位面积总产出能。香根草、紫穗槐、梨间作黄花模式的光能利用率分别提高24.62%、14.78%、15.60%；“作物—草本植物篱”的人工输入能效率提高幅度达67.88%-102.32%；坡度越大,耕地单位面积总产出能相对增幅亦越大,1号地增幅为9.8%-24.6%,2号地和3号地增幅为1.2%-15.61%。与对照相比,所有具有植物篱的种植模式都能极显著减少无机能输入能,减幅达30.0%-41.0%,这有利于降低化肥农药使用量,减少对环境的污染和破坏。②“作物—果树类植物篱”系统输入能总量和有机能输入量大幅度增加,“作物—枣”、“作物—梨/黄花”、“作物—枇杷/黄花”系统输入能和有机能分别增加21.6%和69.8%、43.7%和146.1%、43.5%和146.2%,因此有利于优化输入能结构,促进坡地生态系统良性循环和集约高效农业发展。③选择香根草、紫穗槐、小冠花、紫花苜蓿作为植物篱构成的“作物—草本植物篱”系统,人工辅助能的输入量大幅度下降,由于所需投入能少,有机能耗和无机能耗均低,人工输入能效率很高而生物产量也较高,并且它们提高了与其间作的其他作物的能量产投比,其增幅分别为40.93%、8.21%、39.38%、42.91%,因此提升了整个系统能量产投比率,分别达到64.15%、45.03%、41.50%、40.79%；由于保水固土的生态功能显著,使它能在四川广大山地、丘陵区退耕还林还草工程中发挥重要作用。4.2005-2007年两个冬小麦和夏玉米生长季节,在1号试验地(坡度20°)和2号试验地(坡度13°)利用陷阱法对香根草(1号地)、紫穗槐(1号地)、蓑草(2号地)和苜蓿(2号地)4种植物篱类型对农田地面蜘蛛的活动密度(种群密度和活动性的参数)的影响进行了调查。结果表明：植物篱处理植物篱带地面蜘蛛的活动密度在冬小麦生长季节均显著高于对照裸地,植物篱处理植物篱带地面蜘蛛的活动密度在夏玉米生长季节也高于对照裸地,但是只有蓑草和苜蓿植物篱带地面蜘蛛的活动密度显著高于对照裸地。植物篱处理和对照处理之间农田地面蜘蛛的活动密度在冬小麦和夏玉米生长季节均没有显著差异。5.通过对不同处理土壤微生物数量、微生物量碳、氮,土壤氨化强度、土壤硝化强度和土壤亚硝化强度进行测定,并采用BOXAIR-PCR和16S rDNA PCR-RFLP研究分离自不同植物篱处理土壤氨化细菌和根瘤菌的遗传多样性,进而对代表菌株测序分析,揭示出不同植物篱对氨化细菌和根瘤菌种群特性的影响。结果表明：种植香根草和紫穗槐植物篱处理土壤细菌、放线菌、真菌数量分别比对照土壤增加了63.43%和36.63%、47.87%和71.89%、74.60%和43.65%；土壤微生物量碳、氮分别增加了90.02%和83.32%,24.97%和45.04%；土壤氨化作用强度分别增加了73.28%和75.65%；而土壤硝化和亚硝化强度则分别降低了26.97%和52.96%、6.46%和22.19%；细菌、根瘤菌的16S rDNA PCR-RFLP分析显示,分离自香根草、植物篱处理的细菌、根瘤菌遗传类型都较对照多,对代表菌株进行的16S rDNA全序列测定结果表现出丰富的遗传多样性。更多还原

【Abstract】 Though choosing Medicago sativa, Vetiveria zizanioldes, Amorpha fruticosa, Coronilla varia and Eulaliopsis binata as the central materials, soil erosion quantity of different forage dedgerow pattens, the space redistribution law of soil nutrient in the system, the interaction and energy utilization relationship of various components in dedgerow cropping system, diversity change rules of farmland arthropod and microorganism were deeply studied by the method of long-term(eight-year) located, it provided theoretical basis for optimizing and innovating dedgerow agricultural pattern. The results were as follows:1.The amounts of runoff and sediment were decreased significantly after planting hedgerows, the effect of controlling soil erosion was good and quick. The energy out-input ratio of whole system was improved by hedgerow, it was a effective measure of improving agricultural energy efficiency in Sichuan hilly area. Leguminosae forage hedgerows provided favorable evacuee shelter for ground-dwelling spiders, whose activity density was significantly improved than in the bare soil strips during the winter wheat season, and the diversity was also enriched. The amounts of soil bacteria, actinomycetes, fungi of the VH and AH treatments, microbial biomass carbon and ammonification activity were increased by hedgerows. So the farmland ecology of purple soil was significantly improved by hedgerows, forage hedgerow system was one of surstainable farming methods in the purple soil area of Sichuan province.2. Using the standard soil erosion monitoring plot and the SW 40 diary water level recorder to monitor the effect of different hedgerows against the control treatment on soil erosion and fertility. Results showed that, the amounts of runoff and sediment were decreased significantly after planting hedgerows,165.4-242.8 t/hm2 sediments were totally reduced in 8 years, the amounts of runoff and sediment were reduced by 63.0%-70.8% and 79.1%-85.7% in the following year of planting hedgerows, the effect of controlling soil erosion was good and quick. The soil grade significantly eliminated after planting hedgerows, the slope gradient of two plots respectively decreased from 20°,13°to 16°28’ and 17°11’,10°28’and 11°5’. There was obvious sediment deposition in the upper part of hedgerows, the average clay contents of Vetiveria zizaniode, Medicago sativa, Eulaliopsis binata’s soil zone above the hedgerows were 29.6%,28.9%,33.1%,6.6% and 6.5%,5.9% and 9.3%,7.0% and 15.0% respectively more than middle zone and zone below the hedgerows(Relative difference), clay particles tended to accumulate above the hedgerows and to be eroded downward below the hedgerows along contour lines across the field. Distribution of soil organic matter and all plant nutrients except K showed the same pattern as the clay particles. Potassium (K), however, was evenly distributed in the field without any noticeable influence from the hedgerows. Since the fixed experiment started, soil P has kept accumulating, the average total P contents of Vetiveria zizaniodes, Amsopha fruticosa, Medicago sativa and Eulaliopsis binata hedgerows were respectively up to 0.105%, 0.098%,0.096%,0.090%, increased by 54.1%,44.1%,35.2%,26.8% more than that of total P content of initial soil. While soil organic matter and K were in depletion, the organic matter content of all treatments decreased compared to the beginning of experiment, the organic matter content of control treatment and Vetiveria zizaniodes, Amsopha fruticosa hedgerows were decreased by 34.3%,25.8%,21.8% in field no.1, the organic matter content of control treatment and Medicago sativa, Eulaliopsis binata hedgerows were decreased by 25%,21.9%,30.2% in field no.2, K content had the similar statement.3. The energy flow characteristics of "crop-hedgerow" system, such as the structure and efficiency on slopping land(8-20°) had been studied for 2 years. There were 3 main conclusions.①The quantity and structure change of output and input energy of "crop-hedgerow" system was mainly affected by the type of hedgerow subsystem, in comparison with the traditional crop production system on large area sloping land, for instance, wheat/peanut(or corn)/sweet potato system:there was difference between hedgerows (including fruit tree, herb etc.) and crop in shape and space distribution of crown and root so that the natural resources of light, heat, water and soil were continuously utilized in time and space, which enhanced light energy utilization efficiency, input labour energy utilization efficiency and total output energy per unit area. The light energy utilization of Vetiveria zizaniodes, Amsopha fruticosa and intercropping pear and yellow flower pattens were increased by 24.62%,14.78% and 15.60% respectively, the increased range of "crop-herb" hedgerow system’s input labor energy utilization efficiency was up to 67.88%-102.32%, the steeper the sloping land, the higher the relative amplitude, the increase amplitude of field no.1 was 9.8%-25.62%, and which of no.2 and no.3 was 1.2%-15.61%. Compared to control treatment, all the input inorganic energy was reduced significantly through planting hedgerows, the reduction amplitude was up to 30.0%-41.0%, the quantity of chemical fertilizer and pesticide can be reduced, resulting environment protection.②The total input energy (including organic energy) of "crop-fruit" hedgerow system was increased, which of "crop-jujube", "crop-pear/yellow flower", "crop-loquat/yellow flower"system were increased by 21.6% and 69.8%,43.7% and 46.1%, 43.5% and 146.2% respectively. It was useful for improving input energy structure and ecosystem, and enhancing intensive agriculture development.③Choosing Vetiveria zizaniodes, Amsopha fruticosa, Coronilla varia and Medicago sativa as the hedgerow of "crop-herb" hedgerow system, the input artifical supplementary energy was greatly decreased, the fewer demand of input energy and the low level of organic and inorganic energy resulted in increasing the input labour energy utilization efficiency and biomass, energy out-input ratio of inter-planted crops, the increase amplitude of four hedgerows’ energy out-input ratio were 40.93%,8.21%,39.38%,42.91% respectively, hence the energy out-input ratio of whole system was improved to 64.15%,45.03%,41.50%,40.79%. It conserves water and soil, play an important role in agricultural reform in vast mountainous and hilly area in Sichuan.4. We investigated the effects of four hedgerow plant species, which served as undisturbed and permanent semi-natural habitats, on ground-dwelling spider activity density (a parameter of population density and relative activity) by using pitfall trapping methord. Samples were collected over two winter wheat and two summer maize growing seasons during 2005-2007 in trial field 1 (slope gradient of 20%) and field 2 (slope gradient of 13%). The hedgerow species evaluated were Amorpha fruticosa (field 1), Vetiveria zizanioides (field 1), Eulaliopsis binata (field 2) and Medicago sativa (field 2). The results showed that:activity density of ground-dwelling spiders was significantly higher in the hedgerow strips than in the bare soil strips during the winter wheat season. Activity density of ground-dwelling spiders was also higher in the hedgerow strips than in the bare soil strips during the summer maize season, however, only the Eulaliopsis and Medicago strips had significantly higher activity densities of ground-dwelling spiders than the bare soil strips. Activity density of ground-dwelling spiders in the crop fields did not differ significantly between hedgerow and control plots during the winter wheat or summer maize seasons.5. Though determining soil microbial quantity, microbial biomass carbon and nitrogen, soil ammonifying capacity, soil nitrifying capacity and soil Nitrosation capacity of different treatments, studying genetic diversity separated from different plant hedgerow treatments of soil ammonifying bacteria and rhizobia by using BOXAIR-PCR and 16S rDNA PCR-RFLP methods, then squencing analysis representative strain, the effect of different plant hedgerow on population characteristics of ammonifying bacteria and rhizobia was revealed.The results showed that, compared with CK, the amounts of soil bacteria, actinomycetes and fungi of the VH and AH treatments were increased by 63.43% and 36.63%,47.87% and 71.89%,74.60% and 43.65%; MBC was increased by 90.02% and 24.97%; MBN was increased by 83.32% and 45.04%; ammonification activity was increased by 73.28% and 75.65%; however, nitrosification and nitrification activity was decreased by 26.97% and 52.96%,6.46% and 22.19%, respectively. The 16S rDNA PCR-RFLP analysis results of bacteria and rhizobia showed that, genetic types separated from Vetiveria zizaniodes and Amsopha fruticosa treatments of soil ammonifying bacteria and rhizobia were more than CK. The squencing results of representative strain showed abundant genetic diversity.更多还原