Research on the current farmland soil nutrient in Ansai | 安塞县农田土壤养分现状分析

Chinese. 分析地处西北内陆黄土高原腹地、具有典型丘陵沟壑特征的陕西省安塞县农田土壤pH值和养分的现状及其相关性，为黄土高原丘陵沟壑区提高土地生产力和培肥土壤提供理论依据。采集安塞县12个乡镇有代表性并能充分反映土壤特性的农田耕层（0~20 cm）土样4 231个，对其pH值及有机质、全氮、碱解氮和速效磷、钾含量进行测定,分析土壤pH值与各养分含量间的相关性。安塞县农田土壤pH值为8.16，偏碱性，变异程度为弱变异。土壤有机质、全氮含量分别为8.73和0.54 g/kg，碱解氮、速效磷、速效钾含量分别为31.11，8.79和100.68 mg/kg，其中只有速效钾的含量达到了中等肥力水平，其他养分含量均处于中等以下肥力水平；各养分含量均为中等变异。土壤pH值与有机质、碱解氮、速效钾含量呈显著或极显著负相关，有机质含量与全氮、碱解氮和速效磷含量呈显著或极显著正相关。安塞县农田土壤养分含量较低，土壤有机质含量和pH值影响着土壤速效养分的含量，今后应积极推广配方施肥技术，推进退耕还林还草工程，以提高土壤肥力水平。

English. Ansai, a typical hilly-gully region, is located in the middle of the Loess Plateau. The research studied the status and correlation of farmland soil pH value and nutrient content, to provide a basis to improve soil productivity and fertility. Soil pH, organic matter, total N, alkali-hydrolyzabled nitrogen, available P, and available K were measured in 4 231 farmland soil samples of 0-20 cm from 12 villages in Ansai. The correlation between soil pH and nutrient content was analyzed. The farmland soil pH value was 8.16, which was alkaline, a weak variation. Organic matter, total N, alkali-hydrolyzabled nitrogen, available P and available K were 8.73 g/kg, 0.54 g/kg,31.11 mg/kg, 8.79 mg/kg and 100.68 mg/kg, only the available K content was at the medium fertility level, other soil nutrient content was at low or lower level, and the variation of each soil nutrient content was middle. The correlation between pH value and organic matter, alkali-hydrolyzabled nitrogen and available K was significantly or extremely negative. The correlation between organic matter and total N, alkali-hydrolyzabled nitrogen and available P was significantly or extremely positive. The fertility of farmland soil was very poor in Ansai. Soil organic matter and pH value affected the content of available nutrient. The implementation of balanced fertilization and the Grain for Green Project could improve soil fertility in the future.