湖南省花垣县农田土壤钾素现状、存在问题及对策

基于花垣县2007年农田土壤钾素调查数据与1980年湖南省第二次土壤普查数据,分析花垣县农田土壤钾素现状,探讨其存在问题,从而提出因地制宜的农田土壤钾素肥力管理措施。结果表明,花垣县农田土壤全钾平均含量为12.93 g/kg,与湖南省第二次土壤普查相比下降了22.44%;土壤速效钾含量总体水平偏高,平均达到124.66g/kg,与湖南省第二次土壤普查相比增加了54.76%,呈明显增加趋势;缓效钾含量总体偏低,低于100 mg/kg的农田占全县农田面积的87.46%。目前花垣县农田土壤存在钾素储备偏低,长期供钾潜力不足的问题。针对花垣县农田土壤钾素现状及存在的问题,应当改善耕作方式,防止农田钾素流失;实行秸秆还田,有效防止农田钾素失衡;推广测土配方施肥,实现钾素投入平衡等有效措施,提高土壤钾素肥力。

Potassium status, existing problems and countermeasures of cropland in Huayuan, Hunan Provincematerials and its impacting factors

This study examined historical changes of cropland potassium (K) content in Huanyuan, Hunan, using soil samples collected for Huayuan County in 2009 and the data of second soil survey of Hunan Province in 1980. The results showed that total K content was 12.93 g/kg, 22.44% lower than that of Hunan Province in 1980. In contrast, the available K was 124.66 g/kg, 54.76% higher than that of Hunan Province in 1980. Slowly available K was relatively low; whose values for 87.46% of cropland are smaller than 100 mg/kg. As a result, the main problem of cropland in Huayuan County was low potassium stock level and the probability of cropland to supply enough potassium for vegetation growth in the long run is low. Consequently, it is suggested that effective measures should be taken to increase soil potassium content. These measures include improving tillage methods to lower the loss of potassium from cropland, returning crop straw to cropland to effectively maintaining cropland potassium balance, and applying fertilizers to cropland according to results of soil tests.