论文部分内容阅读
通过田间小区试验和~(15)N标记的微区试验,研究了(土娄)土中非代换铵含量、它在小麦生长期的动态变化以及其对小麦的有效性。试验结果表明,(土娄)土具有可观的非代换铵贮量。供试土壤耕层含非代换铵236ppm N,占该层土壤全氮的22.9%。0—75cm土体中平均含252ppm N,占全氮的四分之一多。(土娄)土“新固定”的和“固有的”非代换铵对小麦生长都有重要意义。前者以其高有效性占优势,后者则以其较大的供应量为特点。在小麦生育期内,0—75cm土体中的非代换铵最大净释放率,“新固定”的为38.0—70.5%,“固有的”为10.4—22.2%。以最大净释放量计,“固有的”(12—72ppm N)大于新固定的(7.4—10.9 ppm N)。非代换铵的最大净释放率随土层加深而减小。试验还表明,(土娄)土粘土矿物固定铵作用相当于一个蓄氮库。施用氮肥有增加土壤非代换铵的趋势。
Field test and field experiment with ~ (15) N were used to study the non-substituted ammonium content in (Lou) soil, its dynamic change during wheat growth and its availability to wheat. Test results show that (LOU) soil has a considerable non-substituted ammonium storage. The test soil plow contains non-substituted ammonium 236ppm N, accounting for 22.9% of the total soil nitrogen. 0-75cm soil contains 252ppm average N, accounting for more than a quarter of total nitrogen. (Soil) soil “new fixed” and “inherent” non-substituted ammonium are important for wheat growth. The former is dominated by its high effectiveness while the latter is characterized by its larger supply. During wheat growth, the maximum net release rate of non-substituted ammonium in 0-75 cm soil was 38.0-70.5% for “freshly fixed” and 10.4-22.2% for “native”. In terms of maximum net release, “native” (12-72 ppm N) is greater than freshly fixed (7.4-10.9 ppm N). The maximum net release rate of non-substituted ammonium decreases with the deepening of the soil layer. The tests also showed that the fixed ammonium action of (loam) clay is equivalent to a nitrogen storage reservoir. Nitrogen fertilizers have the potential to increase soil non-substituted ammonium.