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采用Stanford和Smith提出的长期间隙淋洗通气培养法,对连续7年采用渗灌、滴灌和沟灌灌溉的保护地土壤有机氮的矿化特性进行研究,并结合土壤起始矿质氮含量,探讨了不同灌溉方法条件下保护地土壤供氮能力的差异。结果表明,保护地土壤硝态氮表现出强烈的表聚特点,表聚程度以渗灌>沟灌>滴灌。长期采用不同灌溉方法显著影响保护地土壤氮矿化势及矿化速率。N0值大小的排列顺序为:滴灌>沟灌>渗灌,k值大小的排列顺序与N0恰好相反,为:渗灌>沟灌>滴灌。与渗灌和沟灌处理相比,长期采用滴灌有利于改善保护地土壤有机氮的品质。土壤供氮能力表现为渗灌>沟灌>滴灌。评价保护地土壤供氮能力时,不仅要考虑土壤有机氮累积矿化氮量的大小,同时也要考虑土壤初始矿质氮的含量。从农业节水和提高氮肥利用率及保护生态环境的角度考虑,建议在本试验措施条件下,渗灌和沟灌处理应比滴灌处理适当减少氮肥用量,且无机氮肥也要尽量晚施;在此基础上渗灌处理氮肥还要尽量深施,以减少表层硝态氮的积累,达到既节水又省肥的目的。
Using the long-term gap leaching ventilation culture method proposed by Stanford and Smith, the mineralization characteristics of soil organic nitrogen in the protected areas that were infiltrated with irrigation, drip irrigation and furrow irrigation for 7 consecutive years were studied. Combined with the initial mineral nitrogen content in soil, Differences in Soil Nitrogen Supply Capacity of Protected Areas under Different Irrigation Methods. The results showed that the nitrate nitrogen in the soil of the protected area showed strong characteristics of surface aggregation. The degree of surface aggregation was infiltration> furrow irrigation> drip irrigation. Long-term use of different irrigation methods significantly affected soil nitrogen mineralization and mineralization rate in the protected area. The order of N0 values is: drip irrigation> furrow irrigation> infiltration irrigation. The order of k value is opposite to that of N0: seepage irrigation> furrow irrigation> drip irrigation. Compared with seepage irrigation and furrow irrigation, long-term use of drip irrigation is beneficial to improve the quality of soil organic nitrogen in the protected area. Soil nitrogen availability showed infiltration> furrow irrigation> drip irrigation. When evaluating the capacity of soil nitrogen supply in protected areas, not only the size of soil organic nitrogen accumulated mineralized nitrogen should be considered, but also the content of soil initial mineral nitrogen. From the perspectives of agricultural water conservation and nitrogen fertilizer utilization and ecological environment protection, it is suggested that under the conditions of the test measures, the amount of nitrogen fertilizer should be appropriately reduced and the nitrogen fertilizer should be applied as late as possible in drip irrigation and furrow irrigation; On the basis of seepage irrigation treatment of nitrogen fertilizer but also as far as possible in order to reduce the accumulation of surface nitrate nitrogen to achieve both water-saving and fertilizer purposes.