植被过滤带对黑土缓坡耕地氮、磷养分阻控研究

发布时间：2018-11-04 20:30

【摘要】：水土流失与农田面源污染是目前黑土区面临的两大生态环境问题,水土流失导致耕层变薄,地力下降;面源污染导致水体富营养化,水质恶化。在坡耕地的农业生产中,两者存在着必然的联系。主要表现为随着坡耕地水土流失强度的增大,农田中N、P养分的流失显著增加。为防治黑土区坡耕地水土流失及阻控土壤N、P营养的流失,从源头抑制农田面源污染的发生。本研究在黑土缓坡(5°)耕地上设置了等高植被过滤带试验,过滤带植被选择耐密性作物——谷子和大豆,种植密度分别设置为1.8m、3.0m和4.2m三种宽度。通过对两种过滤带对坡耕地泥沙及N、P养分的阻控效果的测定与分析,得出以下结论。1、谷子过滤带,在1.8 m、3.0 m、4.2 m三种宽度下,对泥沙的拦蓄率分别为44.83%、55.17%、72.41%。当过滤带植被为大豆时,对应的泥沙拦蓄率分别为62.07%、65.52%、68.97%。试验证明,大豆对泥沙的拦蓄作用平均高于谷子。随宽度的增加谷子对泥沙的拦蓄效果明显增高,宽度的变化对大豆拦蓄效果影响较小。2、谷子过滤带,在1.8 m、3.0 m、4.2 m三种宽度下对速效氮的拦蓄量分别为0.521kg/hm2、1.015 kg/hm2、1.1 kg/hm2,对全氮的拦蓄量分别为15.86 kg/hm2、16.705 kg/hm2、22.058 kg/hm2。当过滤带植被为大豆时,在1.8 m、3.0 m、4.2 m三种宽度下对速效氮的拦蓄量分别为0.485 kg/hm2、1.023 kg/hm2、0.95 kg/hm2,对全氮的拦蓄量分别为14.487 kg/hm2、18.967 kg/hm2、19.011 kg/hm2。试验证明,谷子对速效氮及全氮的拦蓄效果平均高于大豆,而且随着带宽增加,谷子对速效氮及全氮的拦蓄逐渐增加,而大豆对速效氮及全氮的拦蓄增幅不显著。3、谷子过滤带,在1.8 m、3.0 m、4.2 m三种宽度下,对速效磷的拦蓄量分别为0.149kg/hm2、0.231 kg/hm2、0.218 kg/hm2,对全磷的拦蓄量分别为2.503 kg/hm2、3.222 kg/hm2、3.805 kg/hm2。当过滤带植被为大豆时,在1.8 m、3.0 m、4.2 m三种宽度下对速效磷的拦蓄量分别为0.233 kg/hm2、0.247 kg/hm2、0.233 kg/hm2,对全磷的拦蓄量分别为3.742 kg/hm2、4.031 kg/hm2、3.309 kg/hm2。试验研究证明,大豆对速效磷以及全磷的拦蓄效果要平均高于谷子,过滤带宽度变化对谷子影响较大。经研究证实植被过滤带对泥沙、氮、磷阻控效果非常显著,能够有效的控制农田的土壤侵蚀与下游水体的污染,而且具有非常重要的科学和实践意义。
[Abstract]:Soil erosion and farmland non-point source pollution are two major ecological environmental problems in black soil area at present. Soil erosion results in thinning of tilling layer and decrease of soil strength, and non-point source pollution leads to eutrophication of water body and deterioration of water quality. In the agricultural production of sloping farmland, there is an inevitable relationship between the two. With the increase of soil and water loss intensity of sloping farmland, the nutrient loss of N ~ (2 +) P in farmland increased significantly. In order to control soil and water loss of sloping farmland in black soil area and to control the nutrient loss of soil, the occurrence of non-point source pollution in farmland was restrained from the source. In this study, an experiment of equi-high vegetation filtration zone was carried out on the cultivated land with a mild slope of black soil (5 掳). The vegetation in the filter zone selected millet and soybean, the planting density of which was 1.8 m 3.0m and 4.2m width, respectively. Based on the determination and analysis of the control effect of two kinds of filtration zones on sediment and Nu P nutrients in sloping farmland, the following conclusions are drawn: 1. Under the width of 1.8 m ~ 3.0 m ~ (2) ~ (2) m, the following conclusions can be drawn. The interdiction rate of sediment is 44.83 and 72.41, respectively. When the vegetation in the filter zone is soybean, the corresponding sediment retention rate is 62.07 and 65.52 respectively. The results show that the silt blocking effect of soybean is higher than that of millet on average. With the increase of the width, the silt retention effect of millet increased obviously, and the change of width had little effect on the storage effect of soybean. The amount of available nitrogen was 0.521 kg / hm ~ (2 +) 1.015 kg/hm2,1.1 kg/hm2, and 15.86 kg/hm2,16.705 kg/hm2,22.058 kg/hm2. 路min ~ (-1) 路m ~ (-1) 路m ~ (-1). When the vegetation in the filter zone is soybean, the storage capacity of available nitrogen is 0.485 kg/hm2,1.023 kg/hm2,0.95 kg/hm2, under the three widths of 1.8m ~ 3.0mL ~ (2) m ~ (2 +) ~ 4 ~ (2) m. The storage capacity of total nitrogen was 14.487 kg/hm2,18.967 kg/hm2,19.011 kg/hm2., respectively. The results showed that the blocking effect of available nitrogen and total nitrogen in millet was on average higher than that in soybean, and with the increase of bandwidth, the blocking effect of available nitrogen and total nitrogen in millet gradually increased, but the increase of available nitrogen and total nitrogen in soybean was not significant. 3. The storage capacity of available phosphorus was 0.149 kg / hm ~ 2 ~ 0.231 kg/hm2,0.218 kg/hm2, under three widths of 1.8m ~ 3.0m ~ (-1) m ~ (-2) ~ (2) m ~ (-1) ~ (-1) m ~ (-1), respectively. The storage capacity of total phosphorus was 2.503 kg/hm2,3.222 kg/hm2,3.805 kg/hm2., respectively. When the vegetation in the filter zone is soybean, the storage capacity of available phosphorus is 0.233 kg/hm2,0.247 kg/hm2,0.233 kg/hm2, under the three widths of 1.8m ~ 3.0mL ~ 4.2m. The storage capacity of total phosphorus was 3.742 kg/hm2,4.031 kg/hm2,3.309 kg/hm2., respectively. The experimental results showed that the effect of soybean on available phosphorus and total phosphorus was higher than that of millet on average, and the change of the width of filter band had a great influence on millet. It is proved by the research that the effect of vegetation filtration zone on controlling sediment nitrogen and phosphorus is very significant and can effectively control soil erosion and water pollution in the lower reaches of farmland. It is also of great scientific and practical significance.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X52;X173

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