长期定位施肥对亚热带丘陵地区红壤旱地质量的影响 Ⅰ.酸度

EFFECT OF LONG-TERM STATIONARY FERTILIZATION ON UPLAND RED SOIL QUALITY IN SUBTROPICAL HILLY REGIONSⅠ.ACIDITY

研究了中国科学院红壤生态实验站长期定位施肥试验5种不同施肥处理对土壤pH、土壤交换性氢、铝的影响,及其与土壤有机质之间的相关性。结果表明,长期不同施肥处理均提高了土壤pH,降低了土壤交换性氢和交换性铝含量,改良了红壤的酸性。施用有机肥(M)、有机肥+菌剂(BM)、有机肥+菌剂+微量元素(BMT)显著优于施用化肥(F)和化肥+微量元素(TF)的处理。添加微量元素和有效菌剂后土壤交换性氢、铝含量略有提高。土壤有机质与土壤pH呈显著正相关,与土壤交换性氢含量的相关性不显著,而与土壤交换性铝含量呈显著负相关。随着土壤有机质含量的增加,土壤交换性氢占土壤交换性酸度比例越大。长期施用有机肥、提高土壤有机质含量是改良红壤酸度和减轻铝毒较好的农艺措施。

A long-term stationary field experiment consisting of 5 fertilization treatments was carried out in the Red Soil Ecological Experiment Station of CAS to study effects of fertilization on pH and exchangeable H＋ and Al3 ＋ in soil and analyze relationships of organic matter （OM） content with soil pH, and contents of exchangeable H ＋ and Al3＋. Results show that fertilization in all treatments increased soil pH and decreased contents of exchangeable H＋ and Al3 ＋. Treatment M （organic manure） , Treatment BM （organic manure ＋ microbial agent） and Treatment BMT （organic manure ＋ microbial agent ＋ microelement fertilizer） were significantly superior to Treatment F （ chemical fertilizer） and Treatment TF （chemical fertilizer ＋ microelement fertilizer） in reducing soil acidity. Addition of microelements and microbial agent increased the contents of exchangeable H＋ and Al3＋ slightly. Soil OM content was significantly correlated positively with soil pH value, and not significantly related with exchangeable H＋ content in soil, but negatively with exchangeable Al3＋ content in soil. With rising soil OM content, the proportion of exchangeable H＋ increased in exchangeable acidity of soil. Long-term application of organic manure to increase soil OM content is a good agronomic practice to reduce acidity and aluminum toxicity in red soil.