轮作,连作及不同耕法对氮,磷肥料利用率的影响

１９８７－１９９２六年试验结果表明：轮作、连作氮、磷肥料利用率均以普耕最高，平均氮３２．１％，磷１２．４％，其次是深松为氮２６．１％，磷９．１％；免耕最低为氮１７．３％，磷６．２％，而连作高于轮作。供试作物氮甩利用率轮作：大豆〉玉米〉小麦；连作：小麦〉玉米〉大豆，磷肥利用率轮作、连作均为玉米〉小麦〉大豆。不同年份间氮、磷肥料利用率变化大。相关分析结果表明：大豆氮、磷肥料利用率与７月份降水量相关显著

EFFECT OF CROP ROTATION CONTINUOUS CROPPING AND DIFFERENT CULTIVATION METHODS ON FERTILIZER UTILIZATION RATIO OF NITROGEN AND PHOSPHORUS

The results of experiment from 1987-1992 showed: Thefertilizer utilization ratio of N and P, whether the caop rotation orcontinuous cropping the ordillary cultivation was the highest cue, theaverage value of N was 32.1% and P was 12.4%; the deep ploughing wasthe second one the average value of N was 26.1% and P was 9.1%; andthe third one was exempt from cultivation, the average value of N was17. 3% and P was 6. 2%. In addition, the fertilizer utilization ratio ofcontinuous crpping was higher than that of crop rotation. The fertilizerutilization ratio of N of experimental subjects in cropp rotation was:soybean>maize>wheat; for the continuous cropping, the ratio was:wheat>mali>soybean; both the fertilizer utilization ratio of P ofcrop rotatioll and continuous cropping were: maize> wheat> soybean.During the six years, the change of the fertilizer utilization ratio of Nand P was large. The results of correlation analysis showed that therewas a significant correlationship between the fertilizer utilization ratioof N of soybean and the rain capacity in July, the correlation coefficientsof N and P were 0.8379 and 0.8759 respectively.