【摘要】 土壤无机氮素的损失主要是铵氮的挥发损失和硝氮的反硝化和淋失。土壤水分和氮素含量的增加,都将增加氮肥淋失的潜在威胁,如处置不当,获得高产可能需要以环境的污染为代价。节水条件下土壤无机氮素的损失量有所减少,但是氮素利用效率也同时受到了土壤水分状况的限制。探讨了作物产量、氮素损失和农业生产要素(水分、氮素)实际投入量之间的关系,建立了节水条件下土壤氮素损失和环境评价概念型模型,通过在北京水利科学研究所永乐店灌溉试验站3年的试验资料对模型进行了参数求解及校验。更多还原

【Abstract】 Mineral nitrogen losses in dryland involve ammonia volatilization, nitrate leaching and denitrification The objective of this paper is to investigate the relationship between soil mineral losses and soil moisture as well as mineral nitrogen content under watersaving irrigation conditions The field experiments were carried out in a field with winter wheat and corn for three years Based on the observations of field experiments and the analysis of relationship among initial soil mineral nitrogen content, irrigation amount, fertilizer supply, and mineral nitrogen losses, a conceptual model is developed to estimate soil mineral nitrogen losses and evaluate the impact of irrigation water and fertilizer N input on the environment The results show that crop grain yield increased with the increased nitrogen losses Nitrogen use efficiency is also limited by soil water content under watersaving irrigation conditions更多还原