基于主成分和聚类分析的黑土肥力质量评价

摘要

[目的]以吉林省农业科学院(公主岭)国家黑土长期定位试验基地为研究平台,定量评价不同施肥措施对土壤肥力质量的影响,为建立东北黑土区合理施肥模式和土壤肥力质量定量评价体系提供科学依据.[方法]通过主成分和聚类分析,综合评价了长期不同培肥措施的土壤肥力质量差异.以欧氏距离作为衡量不同处理肥力差异的大小,采用最短距离法对各定位施肥处理进行系统聚类.[结果]长期不同施肥处理的玉米产量与土壤酶活性、土壤全量养分、速效养分、有机质、微生物碳和微生物量氮都表现出显著或极显著正相关,与土壤pH值表现出负相关趋势.玉米产量与土壤硝态氮、铵态氮没有明显的相关性.土壤生物肥力与化学肥力呈极显著的正相关关系.土壤肥力质量排序为1.5 (NPK+M1)＞NPK+M2＞NPK+M1＞NPK+M1 (R)＞NPK+S＞NPK＞ CK,其中R表示轮作.不同培肥措施的土壤肥力质量可聚为4类,1.5 (NPK+ M1)和CK单独聚为一类,分别为土壤肥力质量最好(一等)和最差(四等);NPK+ M2、NPK+ M1、NPK+ M1 (R)三个处理聚为一类,土壤肥力质量为二等;NPK+S和NPK聚为一类,土壤肥力质量为三等.[结论]长期有机肥与化肥配施土壤肥力质量明显优于秸秆还田和单施化肥处理,秸秆还田的土壤肥力质量优于化肥单施.因此,应提倡长期有机无机肥配施以提高土壤肥力质量,实现农田的可持续利用.%[Objectives] Based on long-term experiment on black soil fertility and fertilizer efficiency (Gongzhuling),a field experiment was conducted to assess the effects of different fertilization measures on the qualities of soil fertility,so as to provide scientific references for establishing the optimal fertilization pattern in the northeast black soil region of China.[Methods] By means of principal component and cluster analysis,differences of soil fertility quality were assessed under long-term fertilization comprehensively,soil fertility difference on different fertilization was developed using Euclidean distance method and single linkage cluster.[Results] Maize yields were positively and significantly correlated with soil enzyme activity,the contents of total N,P and K,available N,P and K,soil organic matter,soil microbial carbon and nitrogen (P ＜ 0.05,P ＜0.01),negatively correlated with soil pH,not significantly correlated with soil nitrate N and ammonium N.The soil fertility qualities were in order of 1.5 (NPK + M1) ＞ NPK + M2 ＞ NPK + M1 ＞ NPK + M1(R) ＞ NPK + S ＞ NPK ＞ CK,whereas R was rotation of corn with soybean.The soil fertility quality was clustered into four classes,the fertility quality in 1.5 (NPK + M1) and CK were respectively clustered into the best (first-class) and the worst (fourth-class) one,and those in treatments ofNPK + M2,NPK + M1,NPK + M1 (R) were clustered into the second-class,those in NPK + S and NPK treatments were clustered into the third-class.[Conclusions] The soil fertility qualities are in descended order of chemical fertilizers combined with manures,NPK fertilizer combined with straw returning,single NPK fertilizers and CK.Therefore,mixed application of chemical fertilizers with organic fertilizers should be promoted for the improvement of soil fertility quality and the everlasting use of farmland.