不同改良剂对连作大黄产量及其土壤肥力的影响

【目的】探究不同改良剂对连作大黄产量及其土壤肥力的影响，为消减大黄的连作障碍及促进大黄产业的健康可持续发展提供理论依据。【方法】选择有机肥、钙镁磷肥和生石灰作为土壤改良剂，以不施用改良剂为对照，对不同处理连作大黄产量及其根际土壤pH、养分含量和生态化学计量特征进行分析，并利用主成分分析法对不同处理连作大黄的土壤肥力进行评价。【结果】施用3种改良剂均可提高连作大黄的产量，其中有机肥和钙镁磷肥处理较对照分别提高75.37%和42.62%，差异达显著水平（P<0.05，下同）。有机肥和生石灰处理显著提高连作大黄的土壤pH，较对照分别提高9.13%和7.34%。有机肥和钙镁磷肥处理显著提高土壤养分含量，其中，土壤有机质、全氮、碱解氮、全磷和速效磷含量分别较对照提高7.45%、8.40%、15.93%、8.27%、31.05%和11.22%、7.56%、15.01%、14.22%、38.46%。与对照相比，生石灰处理的土壤全磷和速效磷含量分别显著提高8.10%和8.83%。3种改良剂处理后连作大黄土壤的C:N、C:P、N:P、C:K、N:K和P:K的变化范围分别为7.77~8.11、14.35~15.62、1.88~2.00、1.26~1.42、0.16~0.18和0.08~0.09。主成分分析表明，不同改良剂处理下，连作大黄土壤肥力综合指数排序依次为钙镁磷肥（1.36） > 有机肥（1.19） > 生石灰（-0.99） > 对照（-1.56）。【结论】3种改良剂对连作大黄增产均有一定的促进作用，也能有效改善连作大黄的根际土壤理化性质，对连作大黄土壤的改良效果依次为钙镁磷肥 > 有机肥 > 生石灰。

Effects of different amendments on the yield of Rheum officinale Baill. and rhizospheric soil fertility under continuous cropping system

【Objective】The aim of this study was to learn the effects of different amendments on the yield of Rheum officinale Baill. and rhizospheric soil fertility. The results would provide a scientific basis for promoting the healthy development of the R. officinale industry.【Method】Organic matter(OM), calcium magnesium phosphate fertilizer(CMP) and quicklime(QL) were as amendments, and control(CK) applied no amendments. R. officinale yield and rhizospheric soil pH, nutrient content and ecological stoichiometric characteristics of different treatments were analyzed, the principal component analysis(PCA) was used to evaluate the rhizospheric soil fertility of R. officinale under continuous cropping.【Result】Application of all three amendments could increase the yield of continuous cropping R. officinale. The OM and CMP treatments significantly increased the yield of R. officinale by 75.37% and 42.62%, respectively, compared with the CK(P<0.05, the same below). The OM and QL treatments significantly increased the soil pH by 9.13% and 7.34% compared with the CK. Moreover, OM and CMP treatments significantly increased the rhizospheric soil nutrient contents, among them, organic matter, total nitrogen, alkali-hydrolyzed nitrogen, total phosphorus and available phosphorus contents increased by 7.45%, 8.40%, 15.93%, 8.27%, 31.05% and 11.22%, 7.56%, 15.01%, 14.22%, 38.46%, respectively, compared with the CK. The total phosphorus and available phosphorus contents under QL treatment were increased by 8.10% and 8.83%, respectively, compared with the CK. The C:N, C:P, N:P, C:K, N:K and P:K ratios of R. officinale rhizosphere soil were 7.77-8.11, 14.35-15.62, 1.88-2.00, 1.26-1.42, 0.16-0.18 and 0.08-0.09 under different amendment treatments. The PCA results showed that the ordination of integrated soil fertility index under different amendment treatments followed the order of CMP(1.36) > OM(1.19) > QL(-0.99) > CK(-1.56).【Conclusion】Three amendments have certain yield promotion effect on the continuous cropping of R. officinale, and can effectively improve its physicochemical properties of the rhizosphere soil. And the promotion effects of the three amendments follow the order of CMP > OM > QL.