长期施肥对半干旱农田土壤氨基酸的影响

Effects of Long-term Application of Fertilizers on Amount of Amino Acid in Soils

采集于肥料长期田间定位试验土样的测定结果表明,施肥对土壤酸解性氨基酸和游离氨基酸含量有极显著影响:施用化肥,特别是在配施秸秆和厩肥后,酸解性氨基酸氮含量大幅度增加,以施高量秸秆和厩肥最为突出。从中性氨基酸（平均216.7μgN/g）,碱性氨基酸（106.9μgN/g）,酸性氨基酸（79.0μgN/g）到含硫氨基酸（1.9μgN/g）,含量依次下降。施肥影响最显著的是中性氨基酸（施肥平均增加82.6μgN/g）,其次为碱性氨基酸（48.2μgN/g）,最后是酸性氨基酸（16.4μgN/g）,对含硫氨基酸影响不大,施肥仅平均增加1.6μgN/g。游离氨基酸不仅在数量上低,而且在种类上也比酸解性氨基酸少。总体上看,施肥也会增加游离氨基酸的含量,并随秸秆用量增加呈增加趋势。

Analyzing results of soils samples collected from a long-term application of fertilizer experiment show that the fertilization had very significant effect on the amount of acidic hydrolyzable amino acids and free amino acids: applying chemical fertilizer, especially after combining straw or compost, the acidic hydrolyzable amino acids increased markedly. In four kinds of acidic hydrolyzable amino acids, from neutral amino acid (216. 7μg N/g), to basic amino acid (106.9μg N/g), to acidic amino acid (79μg N/g) and to sulfur-containing amino acid (1.9μg N/g), decreasing in the above successive order. The order of the effects of fertilization on acidic hydrolyzable amino acids was neutral amino acids (average increase of 82.6μg N/g after fertilization) > basic amino acids (48. 2μg N/g) > acidic amino acids (16. 4μg N/g) > sulfur-containing amino acids (1. 6μg N/g). The results indicate that not only the amount of the free amino acid was lower, but also the kind of the free amino acid was few compared with acidic hydrolyzable amino acid. Fertilization also markedly increased the amounts of free amino acids, and increased with the increase of applying rates of the straw.