土柱模拟水氮条件对马铃薯田氮平衡影响

发布时间：2018-08-13 21:11

【摘要】：武川县地处内蒙古阴山北麓,是内蒙古自治区马铃薯的主产区之一,滴灌是这一地区主要的灌溉模式。近年来,该地区与全国其他粮食种植区相似,农民为了追求高产,灌溉方式粗放,造成当地有限地下水资源的极端浪费。灌溉量的加大,不仅使地下水位急速下降,而且随着氮肥用量的增加,多余的氮素被淋溶到地下,造成了地下水资源的硝酸盐污染,严重响了农牧业生产。本研究通过土柱模拟试验的方法来研究水氮条件对马铃薯田氮平衡的影响,主要对比农民常规灌溉、优化灌溉,和农民习惯施氮、优化施氮,以及不同的氮肥品种对马铃薯田氮平衡的影响,旨在为这一地区农户选择氮肥品种及合理灌溉与施氮提供理论依据。取得的主要结果如下:1.本试验中,尿素添加生物炭处理马铃薯植株平均生物量最大,尿素处理最低。2.土柱模拟试验中,0-30 cm 土壤不同处理下马铃薯收获后土壤中无机氮的平均残留量变化范围为18.1～21.3 mg,无显著差异。3.研究发现,相同施氮量,灌溉量越大,无机氮平均淋失量越多;相同灌溉量,施氮量越多,无机氮平均淋失量越大。农民习惯处理水氮条件下,无机氮平均淋失量最高,平均每个土柱无机氮淋失42 mg,折合每公顷淋失无机氮44 kg;优化水氮处理条件下,平均每个土柱无机氮淋失14 mg,折合每公顷淋失无机氮15 kg,无机氮平均淋失量最低。4.分析土柱不同氮肥处理马铃薯田氮平衡情况,脲酶抑制剂有效抑制了氮淋失,减少了氮素淋失;尿素添加生物炭有效减缓土壤中氮素淋失;树脂包膜尿素、硫加树脂包膜尿素处理氮肥为一次性基施,这两种处理氮淋失较高。5.整体来看,在土柱中不同的灌溉和施氮处理下,尿素添加脲酶抑制剂处理平均表观氮平衡量最小,尿素加生物炭处理平均表观氮平衡量也较小。尿素添加脲酶抑制剂和生物炭处理能提高氮肥利用效率,减少氮素淋失,从而降低氮肥施用的环境风险。
[Abstract]:Wuchuan County is located at the northern foot of Yinshan Mountain in Inner Mongolia and is one of the main producing areas of potato in Inner Mongolia Autonomous region. Drip irrigation is the main irrigation mode in this area. In recent years, this area is similar to other grain growing areas in China. In order to pursue high yield and extensive irrigation methods, farmers have caused extreme waste of local limited groundwater resources. With the increase of irrigation amount, not only the groundwater level drops rapidly, but also with the increase of nitrogen fertilizer, the excess nitrogen is leached to the ground, which results in nitrate pollution of groundwater resources and serious agricultural and animal husbandry production. In this study, the effects of water and nitrogen conditions on nitrogen balance in potato fields were studied by means of soil column simulation test. The effects of water and nitrogen conditions on the nitrogen balance in potato fields were studied, mainly comparing with farmers' conventional irrigation, optimizing irrigation, and farmers' habit of applying nitrogen, optimizing the application of nitrogen. The effects of different nitrogen fertilizer varieties on the nitrogen balance in potato fields were also discussed in order to provide theoretical basis for the farmers to choose nitrogen fertilizer varieties and reasonable irrigation and nitrogen application in this area. The main results are as follows: 1. In this experiment, the average biomass of potato plants was the largest in urea treatment and the lowest in urea treatment. In the soil column simulation experiment, the average residual amount of inorganic nitrogen in potato soil after harvest was 18.1g ~ 21.3 mg under different treatments in 0-30 cm soil, and there was no significant difference. 3. It was found that the greater the amount of irrigation, the greater the average leaching loss of inorganic nitrogen, and the greater the amount of nitrogen applied at the same irrigation rate, the greater the average leaching loss of inorganic nitrogen. The average leaching amount of inorganic nitrogen was the highest under the condition of farmers' habit of treating water and nitrogen, and the average leaching loss of inorganic nitrogen per soil column was 42 mg, which was equivalent to 44 kg per hectare of leaching, and under the optimized conditions of water and nitrogen treatment, the loss of inorganic nitrogen was 44 kg per hectare. The average leaching loss of inorganic nitrogen per soil column was 14 mg, which was equivalent to 15 kg of inorganic nitrogen per hectare, and the average leaching amount of inorganic nitrogen was the lowest. According to the analysis of nitrogen balance in potato field treated with different nitrogen fertilizer in soil column, urease inhibitor effectively inhibited nitrogen leaching loss and reduced nitrogen leaching loss; urea added biological carbon effectively alleviated nitrogen leaching loss in soil; resin coated urea; The nitrogen leaching loss of the two treatments was higher than that of the other two treatments, and the nitrogen fertilizer treated by sulfur resin coated urea was a one-time basal fertilizer, and the nitrogen leaching loss of the two treatments was higher. As a whole, under different irrigation and nitrogen application treatments in soil column, the average apparent nitrogen level measurement of urea plus urease inhibitor treatment was the smallest, and the average apparent nitrogen level measurement of urea plus biochar treatment was also smaller. Urea treatment with urease inhibitor and biochar could improve nitrogen utilization efficiency and reduce nitrogen leaching loss, thus reducing the environmental risk of nitrogen application.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S532

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