长期不同施肥下黄壤综合肥力演变及作物产量响应

【目的】 评价长期不同施肥下黄壤综合肥力的演变特征及其与作物产量的响应关系，寻求黄壤综合肥力提升和作物高产、稳产和可持续生产的科学施肥模式，为黄壤耕地保育和地力提升提供依据。 【方法】 依托农业部贵州耕地保育与农业环境科学观测实验站的黄壤肥力与肥料效益长期定位试验，采集10个不同施肥处理2011～2016年的作物产量和耕层土壤样品，包括:不施肥 (CK)、施氮肥 (N)、施氮磷肥 (NP)、施氮钾肥 (NK)、施磷钾肥 (PK)、氮磷钾肥 (NPK)、3/4化肥 + 1/4有机肥 (3/4NP + 1/4M)、1/2化肥 + 1/2有机肥 (1/2NP + 1/2M)、有机肥 (M)、氮磷钾肥 + 有机肥 (NPK + M)，运用改进的内梅罗指数法对土壤综合肥力进行评价。采用相关分析和通径分析评估土壤性质指标与土壤综合肥力的关联性。采用稳定性指数和可持续性指数评估不同施肥管理下土壤综合肥力对作物高产、稳产和可持续生产的影响。 【结果】 通过20年的不同施肥管理，黄壤综合肥力发生了显著 (P < 0.01) 的变化，土壤综合肥力指数以NK处理最低，NPK + M处理最高；长期不施肥 (CK) 或者偏施化肥各处理 (N、NP、NK、PK) 土壤综合肥力指数显著低于施用有机肥的各处理 (3/4NP + 1/4M、1/2NP + 1/2M、M、NPK + M)。相关分析和通径分析表明，土壤综合肥力指数与土壤性质指标均呈显著正相关关系，pH值、碱解氮、全磷和全钾含量极显著地直接影响土壤综合肥力指数的高低。土壤综合肥力指数与作物产量呈极显著的直接正相关，相关系数达0.704 **，通径系数达0.716*。分析不同施肥处理维持作物高产、稳产和可持续性表明，长期施用有机肥各处理具有高综合肥力和作物高产，不施肥或偏施化肥各处理具有低综合肥力和作物低产；NPK和NPK + M处理作物在获得高产的同时，能够维持产量的高稳定性和高可持续性；CK和PK处理作物低产，并且产量稳定性和可持续性低。 【结论】 土壤综合肥力指数能够客观反映黄壤生产力的高低，长期施用有机肥促进了黄壤综合肥力提升并维持作物高产。合理平衡施用化肥或与有机肥配合施用可以维持较高的产量和产量的稳定性和可持续性。

Evolution of yellow soil fertility under long-term fertilization and response of corp yield

【Objectives】 The changes of yellow soil fertility under long-term fertilization were studied and the fertilization patterns were compared, aiming to provide support for choosing scientific nutrient managements for a steady and sustainable agricultural production. 【Methods】 The study was based on the long-term fertilization experiment, which has been carried out for more than 20 years by the Scientific Observing and Experimental Station of Arable Land Conservation and Agricultural Environment (Guizhou), Ministry of Agriculture. The ten fertilization treatments include CK, N, NP, NK, PK, NPK, 3/4NP + 1/4M, 1/2 NP + 1/2M, M and MNPK. The crop yields and topsoil properties were measured, and the change trends of soil fertility was assessed using the improved Nemoro index (IFI), and the stability index and sustainability index were used to evaluate the effects of soil fertility and crop yield. 【Results】 Different fertilization treatments led to different trends of soil fertility after 20 years. The lowest IFI was in the treatment NK and the highest in the treatment NPK + M. The IFIs in CK and partially fertilized treatments N, NP, NK and PK were all lower than those in treatments 3/4NP + 1/4M, 1/2NP + 1/2M, M, NPK + M. The IFI index was positively correlated with soil properties, soil pH and the contents of available N, total P and total K significantly affected the IFI index. The IFI was positively correlated with crop yield, with a correlation coefficient of 0.704** and a path coefficient of 0.716*. High yield and high IFI were found in manure application treatments (3/4NP + 1/4M, 1/2NP + 1/2M, M, NPK + M), while low yield and low IFI were found in CK and partially fertilized treatments (N, NP, NK and PK). NPK and NPK + M treatments maintained high yield and high stability and sustainability, while CK and PK treatments led to low yield and low stability and sustainability. 【Conclusions】 Soil fertility could be measured well by the Nemoro index, and long-term manure application increased both soil fertility and crops yields in yellow soils. Long-term balanced fertilization and manure application can maintain the high yield with high stability and sustainability.