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研究了大田条件下有代表性的适于耕种的黄土和冲积土上被粘土矿物所固定的(非交换性)NH_4~+的释放。在冬大麦(黄土)或春燕麦(冲积土)生长期间,分别于五个时期对三个深度的土壤非交换性 NH_4~+含量进行了测定。生长期间,非交换性 NH_4~+的含量变化是显著的,特别是在作物生长早期,上层土壤(0—60cm)的非交换性 NH_4~+已耗尽;在晚期,60—90cm 土层非交换性 NH_4~+含量降低。在生长旺期,冲积土中非交换性 NH_4~+的含量接近其原始水平。在黄土中,非交换性 NH_4~+净损失约40ppm,相当于在90cm 土层施氮500公斤 N/公顷。将非交换性~(15)NH_4~+标记的土壤样品施于糖用甜菜大田所需采样的深度,在5—10月间,75cm 土层中释放的非交换性 NH_4~+,在黄土中大约相当于350公斤 N/公顷;在冲积土中大约相当于150公斤 N/公顷。由此可知,在这些可代表中欧耕地的土壤类型中,所谓的固定 NH_4~+亦包括在一般的土壤氮的循环之中。
The release of non-exchangeable NH_4 ~ + fixed by clay minerals on representative cultivated loess and alluvial soil under field conditions was studied. During the growth of winter barley (loess) or spring oats (alluvial soil), the soil non-exchangeable NH_4 ~ + contents in three depths were measured in five periods respectively. During the growth period, the content of non-exchangeable NH_4 ~ + was significant, especially at the early stage of crop growth, the non-exchangeable NH_4 ~ + in upper soil (0-60cm) had been exhausted. In late stage, Exchangeable NH_4 ~ + content decreased. In the growing season, alluvial soil non-exchangeable NH_4 ~ + content close to its original level. In loess, the net loss of non-exchangeable NH_4 ~ + is about 40ppm, which is equivalent to nitrogen application of 500kg N / ha in 90cm soil layer. Non-exchangeable ~ (15) NH_4 ~ + labeled soil samples were applied to sugar beet field sampling required depth, from May to October, 75cm soil layer release of non-exchangeable NH_4 ~ +, in loess Approximately equivalent to 350 kg N / ha; in alluvial soil approximately 150 kg N / ha. It can be seen from this that in these soil types that represent the cultivated land of Central Europe, the so-called fixed NH 4 + is also included in the circulation of common soil nitrogen.