不同肥料对稻田红壤碳、氮、磷循环相关酶活性的影响

Effects of applying different kind fertilizers on enzyme activities related to carbon, nitrogen, and phosphorus cycles in reddish paddy soil

采用中国科学院千烟洲生态站1998年开始的定位试验数据,研究不同肥料(猪粪、秸秆、化肥)对稻田红壤碳、氮、磷养分及相关酶活性[β-1,4-葡萄糖苷酶(βG)、β-1,4-N-乙酰葡糖氨糖苷酶(NAG)、L-亮氨酸氨基肽酶(LAP)、酸性磷酸酶(AP)]的影响.结果表明:施用猪粪(OM)土壤中的βG、NAG和LAP活性显著高于其他处理,比对照(不施任何肥料)分别高1.4、2.6和1.9倍;土壤C/N提高、βG/(NAG+LAP)降低,说明施用猪粪有利于土壤中纤维素的降解和有机碳的积累.施用化肥提高了土壤中βG、NAG和LAP活性,而AP活性比对照低34%;土壤βG/AP和(NAG+LAP)/AP较高,而C/P和N/P较低,说明施用化肥导致稻田红壤无机磷的积累,抑制了土壤中分解磷酸多糖和磷脂的微生物功能.

Based on the long-term fixed position experimental data from Qianyanzhou Ecological Ex- periment Station, Chinese Academy of Sciences in 1998, this paper analyzed the effects of applying different kind fertilizers （straw, ST; pig manure, OM; and chemical fertilizer, NPK） on the nutri- ents （C, N, and P） status and the activities of related enzymes （β-1,4-glucosidase, βG; β-1,4- N-acetylglucosaminidase, NAG; L-leucine aminopeptidase, LAP; and acid phosphatase, AP） in reddish paddy soil. With the application of OM, the activities of soil βG, NAG, and LAP increased significantly, as compared with other treatments, and were 1.4, 2.6, and 1.9 times higher than the control （CK） , respectively. Applying OM also improved the ratio of soil organic carbon to total nitrogen （ C/N）, but decreased the soil βG/（NAG＋LAP） ratio, suggesting that pig manure could benefit the degradation of soil cellulose and the accumulation of soil organic carbon. Applying NPK increased the activities of soil βG, NAG, and LAP, but decreased the AP activity, with a decre- ment of 34% as compared with CK. Under the application of NPK, the soil βG/AP and （NAG＋ LAP）/AP ratios increased, but the ratios of soil organic carbon to total phosphorus （C/P） and of soil total nitrogen to total phosphorus （N/P） decreased, indicating that chemical fertilizers could induce the accumulation of soil inorganic phosphorus, and inhibit the microbial functions of degrad- ing polysaccharides and phosphate phospholipids.