1984年以来广东水稻土pH变化趋势及影响因素

Change Tendency of Paddy Soil pH in Guangdong Province Since 1984 and Influential Factors

利用广东省1984年以来的长期定位监测数据,对全省20多年来的水稻土pH变化趋势进行了分析。结果表明:1984年以来,全省水稻土整体呈现明显的酸化趋势,期间水稻土pH下降了0.33单位,强酸和酸性土壤的分布频率呈明显的上升趋势,分别增加了3.2%和21.9%;珠三角地区的水稻土pH下降了0.54单位,明显高于其他区域。单施化肥使土壤pH降低,而长期坚持化肥结合有机肥施用可以提高土壤抵抗酸化的能力,提高水稻土pH。重化肥而轻有机肥是导致广东省水田土壤pH下降的主要原因,同时日益严重的酸雨也是加速土壤pH下降的重要因素。今后应重视施用有机肥,减缓水稻土的酸化进程。

The change tendency of paddy soil pH was analyzed by using long-term monitoring data of farmland in Guangdong Province, South China. The results showed that the overall variation of paddy soil pH was represented as acidification since 1984,with the average pH value decreased by 0.33 units, and the frequency distribution of strongly acid and acid soil showed a rising trend, increased by 3.2% and 21.9% respectively. The average pH value decreased by 0.54 units in the Pearl River Delta of Guangdong Province, significantly higher than those in the other regions. A single application of chemical fertilizer decreased soil pH value, but mixed application of chemical and organic fertilizers could improve the ability of soil to resist acidification, and improved paddy soil pH value. Heavy application of chemical fertilizers and ignoring the application of organic fertilizer is the main reason for the decline of the pH value of the paddy soil, and increasingly serious acid rain is the important reason for the decline of the soil pH value. We should pay attention to the use of organic fertilizer in the future for the improve- ment of soil acidification.