Variation characteristics of maize yield and fertilizer utilization rate on an upland yellow soil under long term fertilization

An analysis was made on the 16-year experimental data from the long term fertilization experiment of maize on a yellow soil in Guizhou of Southwest China.Four treatments,i.e.,no fertilization(CK),chemical fertilization(165 kg N · hm-2,82.5 kg P 2 O 5 ·hm-2,and 82.5 kg K 2 O·hm-2,NPK),organic manure(30555 kg·hm-2,M),and combined application of chemical fertilizers and organic manure(NPKM),were selected to analyze the variation trends of maize yield and fertilizer use efficiency on yellow soil under effects of different long term fertilization modes,aimed to provide references for evaluating and establishing long term fertilization mode and promote the sustainable development of crop production.Overall,the maize yield under long term fertilization had an increasing trend,with a large annual variation.Treatment NPKM had the best yield-increasing effect,with the maize yield increased by 4075.71 kg·hm-2and the increment being up to 139.2%.Long term fertilization increased the fertilizer utilization efficiency of maize.In treatment M,the nitrogen and phosphorus utilization rates were increased significantly by 35.4% and 18.8%,respectively.Treatment NPK had obvious effect in improving potassium utilization rate,with an increment of 20% and being far higher than that in treatments M(8.7%) and NPKM(9.2%).The results showed that long term fertilization,especially the combined application of chemical fertilizers and organic manure,was of great importance in increasing crop yield and fertilizer use efficiency.