墨脱县农田土壤养分现状与分布特征

本研究利用2017年墨脱县农田测土配方项目土壤调查数据,运用地统计学方法研究了墨脱县耕层土壤有机质(SOM)、碱解氮(AN)、速效磷(AP)和速效钾(AK)养分含量现状及分布特征,以期为墨脱县耕地土壤科学合理施肥提供理论依据。结果表明:当前墨脱全县土壤SOM、AN、AP和AK平均含量为89.18 g/kg、201.25 mg/kg、11.23 mg/kg、313.17 mg/kg;90%的土壤样本有机质含量处于丰富水平;83%的土壤样本碱解氮含量处于丰富、稍丰等级;84%的土壤样本速效磷含量在中等及中等以下肥力水平;46%的土壤样本速效钾含量处于中等及以下水平。从空间分布来看,土壤SOM、AK总体上呈现西高东低,AN含量由北至南呈升高趋势,土壤AP整体上没有明显的空间变化规律。墨脱县耕地土壤养分整体表现为有机质含量丰富,氮素养分较丰富,磷素养分缺乏现象普遍,钾素养分部分区域缺乏。为提升墨脱县耕地土壤肥力水平,各乡镇应该因地制宜进行土壤培肥。

Current Situation and Distribution Characteristics of Soil Nutrients in Cultivated Land of Motuo County

Soil nutrient contents, including soil organic matter (SOM), alkaline nitrogen (AN), available phosphorus (AP) and available potassium (AK) and their distribution characteristics, were studied by using the relevant survey data of farmland soil testing and formulated fertilization in 2017 in Motuo County with geostatistical methods. The results show that the average content of SOM, AN, AP and AK is 89.18 g/kg, 201.25 mg/kg, 11.23 mg/kg and 313.17 mg/kg, respectively; 90% soil samples are rich in SOM, the soil proportion of AN content at abundant and slightly abundant level is 83%, AP content at middle to lower level soil is 84%, and AK content at medium and below medium level is 46%. From the perspective of spatial distribution, the contents of SOM and AK are high in the west and low in the east, the AN content increases gradually from north to south, while AP has no remarkable change. Overall, the cultivated soil in Motuo County of Tibet is rich in organic matter and alkaline N, but the soil phosphorus and potassium content are generally low. Therefore, each township of the county must improve soil fertility by adjusting measures to local conditions.