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辽宁省耕地棕壤自第二次土壤普查以来酸化趋势明显,pH整体平均值从第二次普查时期的6.42降至5.73。对辽宁省4个典型地区(昌图、沈阳、瓦房店、清原)的耕地棕壤耕层(0-20cm)缓冲性能、酸化速率及其影响因素进行研究,结果表明:各地区酸碱缓冲容量变幅为29.66～39.87mmol/kg.pH unit,其中辽宁北部和中部地区酸碱缓冲容量明显高于辽南和辽东地区。酸化速率以辽南地区下降速率最快,其值为2.69H+kmol/(hm2.a),而速率最慢的地区为辽东,其酸化速率为1.44H+kmol/(hm2.a)。土壤初始pH、阳离子交换量、颗粒组成及有机质含量均是影响酸碱缓冲容量变化的主要因素。北部和中部质地以粉(砂)壤土为主,阳离子交换量、盐基饱和度及粘粒含量均高于南部和东部地区,因此缓冲性能也较强。施肥及其他人为因素对辽宁耕地棕壤酸碱缓冲容量及酸化速率的影响有待进一步研究。
The arable land brown soil in Liaoning province has obvious acidification tendency since the second soil census. The average value of pH overall decreased from 6.42 in the second census period to 5.73. The buffering performance, acidification rate and influencing factors of cultivated brown soil topsoil (0-20cm) in 4 typical areas (Changtu, Shenyang, Wafangdian and Qingyuan) of Liaoning Province were studied. The results showed that: The capacity range was 29.66-39.87 mmol / kg.pH unit, of which the acid-base buffer capacity in northern and central Liaoning was significantly higher than that in southern Liaoning and eastern Liaoning. The rate of acidification was the fastest in southern Liaoning, with a value of 2.69H + kmol / (hm2.a) and the slowest rate was Liaodong, with an acidification rate of 1.44H + kmol / (hm2.a). Soil initial pH, cation exchange capacity, particle composition and organic matter content are the main factors affecting the change of acid-base buffer capacity. The texture of the northern and central parts is dominated by powdery (sandy) loam, with higher cation exchange capacity, base saturation and clay content than in the southern and eastern parts of the country, resulting in better cushioning properties. Fertilization and other human factors on the arable land in Liaoning acid-base buffer capacity and acidification rate of the impact of further study.