恩施州植烟区土壤养分现状及演变趋势

摘要

分析了采集于2011年11月~2012年4月的2982份恩施州植烟区土壤样品，并与近30年来的相关数据进行了比较。结果表明：恩施州烟区酸性土壤( pH值<5．5)面积达到了37．7%，土壤有机质、全氮、碱解氮、有效磷和速效钾含量分别为(24．1±7．9) g/kg、(1．90±0．53) g/kg、(151．4±42．5) mg/kg、(41．5±21．9) mg/kg和(239．3±140．6) mg/kg。2001至2011年，酸性土壤区域增加了约29．3%；土壤有机质含量稍降低。土壤全氮和碱解氮含量在1981~2001年期间上升较快，在2001~2011年间较稳定；土壤有效磷含量自1981年来一直呈增加的趋势，其中在2001~2011年间提高的幅度较大；土壤速效钾含量在1981~2001年间变化较小，呈现稍下降趋势，而在2001~2011间增加幅度较大。恩施州烟区土壤养分演变趋势与全国多数耕地的变化趋势有所不同，分析表明这与烟草施肥密切相关。%2 982 soils sampled in tobacco fields of Enshi region from November 2011 to April 2012 were tested by routine method, the results were analyzed and compared with the related data in recent 30 years. Results showed that, the percent-age of acid soils ( pH<5. 5 ) in tobacco fields in Enshi region accounted for 37. 7%. The content of soil organic matter (OM), total nitrogen (N), alkalystic N, available phosphorus (P) and available potassium (K) was (24. 1 ± 7. 9) g/kg, (1. 90 ± 0. 53) g/kg, (151. 4 ± 42. 5) mg/kg, (41. 5 ± 21. 9) mg/kg and (239. 3 ± 140. 6) mg/kg, respec-tively. Compared with the data in 2001, acid soils (pH<5. 5) in tobacco fields increased by about 29. 3%, soil OM con-tent tended to decrease. The content of soil total N and alkalystic N increased rather quickly form 1981 to 2001, while was relatively stable from 2001 to 2011. Soil available P content had tended to increase since 1981, and increased rather rapidly during 2001~2011. Soil available K content was rather stable from 1981 to 2001, whereas increased a little bit rapidly dur-ing 2001~2011. The above results implied that, the changing tendency of soil nutrients in tobacco fields in Enshi region was to some extent different from that of most arable land in China, which was closely related to the fertilization status on to-bacco.