元阳梯田核心区稻田土壤养分含量与微生物数量的时空变异特征

Temporal and Spatial Variation Characteristics of Soil Nutrient Content and Microorganism Quantities of Rice Paddy in Core Zone of Yuanyang Terrace

【目的】探索元阳梯田核心区稻田土壤养分含量和微生物数量的时空变异特征。【方法】在不同月份采集元阳梯田核心区箐口村不同海拔(1 450、1 500、1 600、1 700和1 800 m)稻田的土壤,分析土壤养分(全氮、全磷、全钾、碱解氮、速效磷、速效钾)的含量与微生物(细菌、放线菌、自生固氮菌、纤维分解菌和真菌)的数量。【结果】低海拔梯田土壤全氮、全钾含量高于高海拔梯田土壤全氮、全钾含量,高海拔(1 700、1 800 m)的梯田土壤碱解氮、速效磷含量要高于相对低海拔(1 450、1 500 m)的稻田,土壤碱解氮、速效钾含量在休闲期高于水稻生长期。土壤微生物数量总体上在低海拔(1 450、1 500 m)稻田较高,土壤自生固氮菌和放线菌在3月、细菌和真菌在5月、纤维分解菌在9月的数量相对较多。【结论】元阳梯田核心区稻田土壤速效养分含量与微生物数量受季节的明显影响,并表现出明显的垂直分布特征。

[Purpose] To investigate the temporal and spatial variation characteristics of nutrient contents and microorganism quantities of rice paddy in core zone of Yuanyang Terrace.[Method] Soils were sampled from rice paddy of Qingkou Village in Yuanyang Terrace at different altitudes (1 450, 1 500, 1 600, 1 700 and 1 800 m) in different months. The nutrient contents (total nitrogen, phosphorus, potassium, and available nitrogen, phosphorus and potassium) and the microorganism quantities (bacteria, actinomycetes, azotobacter, cellulose decomposing bacteria and fungi) in soils were analyzed.[Results]The contents of total nitrogen and potassium in soils at a low altitude were higher than that at a high altitude. The contents of available nitrogen and phosphorus at the high altitudes (1 700 and 1 800 m) were greater than those at relatively low altitudes (1 450 and 1 500 m). The contents of available nitrogen and phosphorus in soils at the fallow period were higher than that at the rice growth period. On the whole, the microorganisms’ quantities were higher in the rice paddy at a low altitude (1 450, 1 500 m). The quantities of azotobacter and actinomycetes in March, bacteria and fungi in May, and cellulose decomposing bacteria in September were relatively high.[Conclusion]The contents of available nutrients and the microorganism quantities in rice paddy in the core zone of Yuanyang Terrace were significantly influenced by season, and showed obvious vertical distribution characteristics.