[Objetive] To make clear the regional agricultural development level.[Method] To accelerate the process of modern agricultural development of Bohai Rim,the assessment index system of modern agriculture was established preliminarily and the data of provinces and cities in Bohai Rim was evaluated and analyzed,regarding the comprehensive development level of modern agriculture as general target and the input level of modern agriculture,the output level of modern agriculture,the social development level of countryside and the sustainable development level of agriculture as grading index.[Result] The results showed that Bohai Rim just entered the developmental stage of modern agriculture,with the integrated index of 0.585.Viewed from regional perspective,Beijing topped the others with the index of 0.798,which was followed by 0.694 of Tianjin,0.644 of Shandong,0.606 of Liaoning and Hebei province had the lowest value of 0.595.[Conclusion] Among all cities in this region,none of them reached at the developed level of modern agriculture.There were ten cities,which were mainly located in Shandong Province,were at the primary stage while the most of others were at the preliminary or initial stage.
通过3年定位试验,采用静态箱/气相色谱法对壤质草甸土区玉米生产进行了全生长季N2O排放通量的观测,分析了不同施氮方式对N2O排放总量、排放系数和玉米产量的影响。结果表明:减少氮肥用量20%的缓控释肥处理与秸秆还田配化肥处理产量居高,而且二者间差异不显著;秸秆还田促进了农田土壤N2O排放,使得秸秆还田配化肥处理的年均N2O季节排放总量最高,达到1.50 kg N·hm-2;年均N2O季节排放总量与施肥量之间相关系数达到了0.97;随着试验年限的增加,N2O-N季节排放系数受施肥量的影响逐年增加,相关系数从2009年的-0.015增加到2011年的0.624。因此不同施氮方式对N2O季节排放的影响需要通过多年定位来准确把握,同时在研究农田N2O-N季节排放时要适当考虑植株生长过程中N2O的排放。兼顾产量和减排2个因素,建议推广缓控释肥的减量施用。
