长期定位施肥对灰漠土磷肥肥效与形态的影响

通过11年定位试验,研究了灰漠土中土壤与肥料的供肥能力、磷肥肥效的变化,以及不同施肥措施对灰漠土磷素含量、形态转化及有效性的影响.初步结果表明:(1)灰漠土的自然供磷能力为102.3;,呈逐年下降趋势,肥料的供肥能力呈逐年上升趋势,土壤与肥料的供肥能力每年下降和上升3.59;,年度与供肥能力间的关系达显著相关.(2)磷肥平均利用率为25;.随着土壤速效磷含量的提高,磷肥利用率则降低,高量有机肥不能提高磷肥利用率;连续施肥土壤磷素盈余量达到施肥量的60;,不施磷肥土壤磷素亏缺,平均每年亏缺18kg/hm2.(3)长期定位施肥对土壤速效磷变化尤为明显.PK处理土壤速效磷上升了32;,年递增相关性达显著相关;其它单施化肥处理的土壤速效磷均有所下降,尤其是NPK处理下降指数达32;;增施有机肥处理呈上升趋势,年递增相关性达显著水平;连续耕作后,CK处理土壤速效磷的含量达到了一种动态平衡.(4)灰漠土无机磷以钙磷为主,其中Ca10-P和Ca8-P约占无机磷总量的81.5;,是灰漠土的潜在磷库;而有效性最高的Ca2-P仅占2.3;,是灰漠土中有效磷的主要来源;O-P的有效性最差,很难为作物吸收利用;连续耕作使单施氮肥或氮钾肥处理的Ca2-P、Fe-P有下降趋势.

The Effect of Long-term Fertilization on Phosphor Efficiency and Modality in Grey Desert Soil

Through eleven years position experiments, we preliminarily found out the phosphor supply capacity of the soil and the fertilizer, and the variety of phosphor efficiency, and the effect of phosphor content, modality transformations and validity under different fertilizer supply measures in gray desert soil .Its results showed: (1) In gray desert soil, natural phosphor supply capacity was 102.3%, and the descending tendency every year. The supply capacity of fertilizer had the increasing tendency. Both of the descending and increasing phosphor supply capacity in the soil and fertilizer was 3.59% each year, and the relation between the year and the phosphor supply capacity was significantly relevant. (2) The average utilization ratio of phosphor fertilizer was 25%. With the increasing of available phosphor content in the soil, the utilization ratio of phosphor fertilizer descended, and the high quantity organic fertilizer could not increase it; If we fertilized continually, the quantity of phosphor surplus in the soil reached the 60% of fertilizing quantity; If we did not fertilize phosphor, the average defective value of phosphor in the soil was 18kg/hm 2 every year. (3) The available phosphor variety in the soil was especially evident under the fixed position long-term fertilization. The available fertilizing phosphor and potassium treatment, and the annual increasing resilience was marked; The available phosphor in the soil decreasing for the other single fertilization treatment, the decreasing range was 32%; Its tendency was increasing for the fertilizing organic, and the annual increasing resilience was marked. (4) The inorganic phosphor of the grey desert soil was mainly calcium phosphor. The Ca10-P and Ca8-P accounted for 81.5%, and they were the potential phosphor depository of the grey desert soil; The most efficient Ca2-P was only 2.3%, and it was the main resource of the available phosphor of the grey desert soil; The O-P availiable was the worst, and it was difficult to be absorbed and utilized by the crop;Under the continuous cultivation ,the Ca2 -Pand Fe -Pof the singly fertilizi ngnitrogen and the fertilizi ngnitrogen and potassium treatment had the decreasing tendency.