模拟酸雨条件下草茬还田对水稻土壤养分的影响

发布时间：2018-03-02 01:17

本文关键词： 模拟酸雨水稻土草茬还田土壤养分　出处：《湖南农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：我国南方地区已被列入世界三大酸雨重灾区之一,土壤酸化严重,而但呈现进一步加剧扩大的趋势。酸雨能降低土壤pH值,导致土壤肥力下降,影响土壤养分转化,最终使生产力下降,严重阻碍农田的可持续发展。秸秆还田能改善土壤肥力,补充土壤有机质等多种养分,缓解酸雨造成的土壤养分淋失,具有培肥地力、提高作物产量的功效,已得到大量研究证实。但目前不同草种的草茬还田后对在酸雨淋溶条件下土壤不同养分形态的缓解效果的研究还鲜见报道。因此,本研究选取水稻土作为供试土壤,添加六种适宜于冬季种植的冷季型草茬,分别为黑麦草、看麦娘、燕麦草、紫云英、白三叶和油菜,采用模拟酸雨对草茬还田后进行淋溶试验,旨在探明模拟酸雨条件下草茬还田后水稻土壤中碳、氮、磷元素及土壤酶活性的变化规律。主要研究结果如下：1、草茬还田能缓解模拟酸雨对水稻土中碳元素的淋失。缓解有机质淋失效果最好是看麦娘草茬,其次是紫云英、三叶草、油菜和燕麦草茬,黑麦草草茬最差。缓解活性有机碳淋失效果以三叶草草茬效果最优,其次是油菜、燕麦、黑麦草和紫云英草茬,看麦娘草茬最差。2、草茬还田能缓解模拟酸雨对水稻土中氮元素的淋失。缓解全氮淋失效果最好是看麦娘草茬,其次是紫云英、三叶草、油菜和燕麦草茬,黑麦草草茬最差。缓解速效氮淋失效果最好的是看麦娘草茬,其次是燕麦、黑麦草、油菜和紫云英草茬,三叶草草茬最差。3、草茬还田能缓解模拟酸雨对水稻土中磷元素的淋失。缓解全磷淋失缓解效果最好的是油菜草茬,其次是三叶草、紫云英、看麦娘和黑麦草草茬,燕麦草茬最差。缓解水稻土中速效磷淋失效果最好的是油菜草茬,其次是三叶草草茬、紫云英草茬、看麦娘草茬和黑麦草草茬,燕麦草茬最差。4、草茬还田能缓解模拟酸雨对水稻土中酶活性的破坏。缓解对蛋白酶活性的破坏效果最好的是油菜草茬,其次是黑麦草、紫云英、三叶草和看麦娘草茬,燕麦草茬最差。缓解对酸性磷酸酶活性的破坏以三叶草草茬最优,其次是紫云英、黑麦草、看麦娘和油菜草茬,燕麦草茬最差。缓解对过氧化氢酶活性的破坏以三叶草草茬最优,其次是油菜、燕麦、看麦娘和黑麦草草茬,紫云英草茬最差。缓解对脲酶活性的破坏以油菜草茬最优,其次是三叶草、黑麦草、紫云英和看麦娘草茬,燕麦草茬最差。
[Abstract]:The southern region of China has been listed as one of the three major acid rain disaster areas in the world. The acidification of soil is serious, but it shows a trend of further aggravation and expansion. Acid rain can reduce the soil pH value, lead to the decline of soil fertility, and affect the soil nutrient transformation. It can improve soil fertility, supplement soil organic matter and other nutrients, alleviate the leaching of soil nutrients caused by acid rain, and have fertility. The effect of increasing crop yield has been confirmed by a large number of studies. However, there are few reports on the mitigation effects of different nutrient forms of soil under acid rain leaching after the straw stubble is returned to the field. In this study, paddy soil was selected as the tested soil, and six kinds of cold-season stubble suitable for winter planting were added, which were ryegrass, Ophiopogon, oatgrass, purple cloud, white clover and rape, respectively. Simulated acid rain was used to study the carbon and nitrogen in rice soil after returning stubble to field under simulated acid rain. The main results are as follows: 1. Returning straw stubble to field can alleviate the leaching loss of carbon element in paddy soil by simulated acid rain. In rape and oat stubble, ryegrass stubble was the worst, and clover stubble was the best, followed by rape, oat, ryegrass and yew stubble. The wheat stubble is the worst. 2. Returning the stubble to the field can alleviate the leaching loss of nitrogen element in paddy soil by simulated acid rain. The best way to mitigate the total nitrogen leaching is to see the wheat bristles, followed by purple cloud, clover, rapeseed and oat stubble. The stubble of ryegrass was the worst. The best way to mitigate the rapid nitrogen leaching was to see the stubble, followed by oats, ryegrass, rapeseed and yew stubble. The clover stubble was the worst. 3. The return of clover stubble to field could alleviate the leaching loss of phosphorus in paddy soil by simulated acid rain. The best mitigation effect of total phosphorus leaching was rape stubble, followed by clover, purple cloud, wheat mildew and ryegrass stubble. Oat stubble was the worst. The best available phosphorus in paddy soil was rape stubble, followed by clover stubble, Laver stubble, wheat bristles stubble and ryegrass stubble. Oat stubble was the worst. 4. Returning stubble could alleviate the damage of enzyme activity in paddy soil caused by simulated acid rain. The most effective way to alleviate the damage of protease activity was rape stubble, followed by ryegrass, purple cloud, clover and prickly stubble. The stubble of oats was the worst. In order to alleviate the damage to the activity of acid phosphatase, clover stubble was the best, followed by Laver, ryegrass, wheat mildew and rape stubble, Oat stubble was the worst. Clover stubble was the best to alleviate the damage to catalase activity, followed by rape, oat, wheat millet and ryegrass stubble, yew turnip stubble was the worst, and rapeseed stubble was the best to mitigate the damage to urease activity. Followed by clover, ryegrass, yew and wheat bristles, oats the worst stubble.
【学位授予单位】：湖南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S158;X517

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