25年来种植业结构调整驱动的县域养分平衡状况的变化——以山东惠民县为例

本文以山东省惠民县为例,采用1984年全国第二次土壤普查和2004年土壤调查的实测数据以及历年农户调查结果和统计数据,系统分析了过去25年来惠民县种植业结构调整对该县养分平衡和土壤养分特征的影响。结果表明,惠民县种植业结构由以粮棉为主演变为以棉粮菜为主;该县的养分平衡状况为氮盈余6089～19405t,磷盈余259～7001t,钾亏缺2532～6712t;该县土壤有机质含量、全氮含量、速效磷含量分别增加了57%、22%、303%,速效钾含量则降低了6%。种植业结构的改变影响了农田氮、磷、钾养分的投入,进而影响到整个县域的养分收支平衡和土壤的养分含量,因此如何合理进行作物种植布局并优化不同种植体系的施肥技术将成为今后区域农业生产优质高效的主要方向。

The changes of nutrient balances driven by adjusting crop structure at county level during 25 years——A case study in Huimin County,Shandong Province

The impact of cropping structure on nutrient balance and soil nutrients were investigated in Huimin County in Shandong Province.Data analysis were based on the results of the household survey,the local statistical data,the national soil survey carried out in 1984 and in 2004.In last 25 years cropping systems in Huimin was changed from cereals-cotton to cotton-cereals-vegetables.The calculation of nutrient balance sheet in Huimin County showed that surplus of soil nitrogen and phosphorus were 6089-19405 t and 259-7001 t respectively,whereas deficiency of potassium was 2532-6712 t.Soil organic matter,total nitrogen and OlsenP were increased by 57%,22% and 303%,respectively,while NH4OAC-K was decreased by 6%.It was indicated that changes of the cropping systems had large impact on nutrient inputs in the soil,and further on the nutrient balance and soil nutrient content at regional level.Therefore,the optimization of the cropping systems and the fertilization technique is the key issue for the integrated nutrient management at regional scale in future.