Report of supervise and test on soil fertility of mostly infield stamp in Henan province

The variation of the cultivated land fertility in Henan Province was obtained preliminary based on the continuous monitoring results of 45 points and 12 item analysis of 645 samples from 1998 to 2004.Compared with the results of the Second Soil Census almost all nutrients contents including organic material,total nitrogen,alkali-hydrolyzable nitrogen,rapidly available phosphorus and effective microelements in the lands of high and middle fertility had increased in different levels,especially the rapidly available phosphorus,available potassium decreased obviously.The average level of the soil available potassium was 119.96 mg/kg,which decreased 18.94 mg/kg and 1.05 mg/kg one year averagely.But the decreasing trend alleviated in recent years.There were 39.5 kg/hm2 nitrogen(N) and 30.9 kg/hm2 phosphorus(P2O5) more than needed averagely,and 150.0 kg/hm2 potassium(K2O) in deficiency.Though the fertilizer application was high and the rate of fertilizer was 647.96 kg/hm2 in nutrient,the ratio of organic to inorganic was still unreasonable.The ratio of the chemical fertilizer nitrogen(N) phosphorus(P2O5) and potassium(K2O) was 1∶0.42∶0.14.The nitrogen applicated was enough and even higher than that was needed.The phosphorus was proper elementarily and potassium was in deficiency.The yield of wheat which was the main crop increased slightly and that of other autumn harvest crops was stable.