不同施肥模式下西藏农田土壤质量的变化
Soil quality change under different fertilization patterns on the Tibetan Plateau farmland

依据中国科学院拉萨高原生态试验站农田长期施肥试验的监测数据，分析了不同施肥模式（空白、羊粪、羊粪+化肥（羊+化）、化肥）8年后（2008~2015）对高原农田土壤质量部分指标（机械组成、土壤容重、有机质、pH和微生物量碳）的影响。结果显示，与单纯施用化肥的样地相比，施加了有机肥的羊粪和羊+化样地的农田土壤质量表现出了显著的变化：（1）增加了0~20 cm土层中的砂粒含量，降低了粉砂粒和粘粒含量；（2）0~10cm表层土壤容重分别降低10.1%和10.0%；（3）表层土壤中的有机质含量分别增加了72.8%和65.6%，同时土壤的pH保持在一个稳定的状态；（4）显著增加了农田土壤中的微生物量，在青稞的生长期以及收获后，农田土壤微生物量碳均表现为羊粪＞羊粪+化肥＞空白＞化肥。因此表明有机肥可以显著改善高原农田的土壤质量，在西藏地区应加大畜禽粪便等的归田。
Based on monitoring data from an 8-year long-term fertilization experiment on the Tibetan Plateau farmland by Lhasa Plateau Ecological Research Station, Chinese Academy of Sciences, effects of different fertilization treatments on part of indicators of soil quality (soil mechanical composition, soil bulk density, organic matters, pH, microbial biomass C) were studied. Compared with the chemical fertilizer plot, soil quality of farmland applying sheep manure merely and sheep manure and chemical fertilizer simultaneously showed significant difference：(1) The gravel particle content increased but silt and clay particle content decreased in 0~20 cm soil layer;(2) Top soil bulk density decreased by 10.1% and 10.0%, respectively; (3) Soil organic content increased by 72.8% and 65.6%, and the soil pH was stabilized; (4) The soil microbial biomass increased significantly in farmland. Soil microbial biomass carbon average in farmland after fertilization ranked as following: Manure > Manure + Chemical Fertilizer > CK > Chemical Fertilizer during highland barley growth season and post-harvest season.Above results suggested that application of manure can significantly improve the soil quality in plateau farmland, therefore more organic fertilizer should be returned to the farmland in Tibet.