中文摘要：

我国红壤旱地普遍具有“酸、瘦、黏、板”的特点，N素作为一种重要的生命物质和作物营养的必需元素，对作物产量和人民生活质量的提高具有重要的意义。然而N素过量又会造成环境污染和生态破坏，同时危及人类的健康。本文通过对红壤地区N素平衡的特征分析和探讨表明，我国红壤旱地1991-2005年N素年收入为N143．7～614．9kg／hm^2，年支出N素为N40～688kg／hm^2，年际N素盈余为N-70．0～237．6kg／hm^2，最高盈余达N1061．7kg／hm^2。其中，N素年收入以肥料N为主，平均占总收入的82．4％：年支出以作物带走最多，平均占总输出的65．8％。

英文摘要：

Red soil in China is generally characterized with acidness, thinness, stickiness and compactness. Being an important substance in life and an essential nutrient for plants, nitrogen plays a crucial role in improving crop yield and living quality of the people. However, when in excess, nitrogen would cause environmental pollution and ecologic destruction, and in turn undermine human health. Exploration and analysis of characteristics of N balance in red soil regions showed that N input varied in the range of N 143.7 - 614,9 kg/（hm^2· a）, while N output in the range of N 40 - 688 kg/（hm^2· a）. Balancing the former against the latter revealed a surplus in the range of-70.0 - 237.6 kg/（hm^2· a） in the period from 1991 to 2005. What＇s more, the N surplus may reached as high as N 1061.7 kg/（hm^2· a）, The total annual N input was composed mainly of N fertilizer, which accounted for 82.4%, whereas the total annual N output occurred mainly through crop absorption and removal, which accounted for 65.8% of the total.