陕西省西部灌区堆土供磷能力与磷肥经济效益的研究

第1期1B/1R易位系的冬小麦单体系统育成……………………………………………………………董安书 朱楚建(1),j麦赤霉瘸药剂防冶技术研究……………………………………一………………·…··商鸿生 王树权井金学(8)细胞,内分裂及细胞内复制诱.导………………·’………………“…………………詹铁生 K.L.Satya—Prokash(15)陕西几种土壤过氧化氢酶的动力学和热力学特征……………………………………·”朱铭莪 白红英代伟(20)丹宁生物活化理论及其应用I.“丹宁生物活化假设”及其科学依据“……………………·…·～…………”史志诚(27)…

THE ABILITY OF LOUTU S01L TO SUPPLY PHOSPHATE AND ECONOMIC RETURNS OF PHOSPHATE FERTILIZER IN THE IRRIGATED AREA OF THE WEST PART OF SHAANXI PROVINCE

Research resu]ts show that there is a logarithmic curve between fastphosphate contents in Loutu soil and phosphate supplies by the soil,andthat with an increase in N application,the ability to supply phosphate towheat can be improved.The calibration coefficient of fast phosphate inLoutu soil is not a conotant,but the equation between calibration coefficientand the determined values of fast phosphate is y=146.5e^-0.02287x on thebasis of which the classification of standard of calibration coefficient andamount of phosphate supplies can be used as the parameters to carry out soilsurvey for fertilizer application.The economic returns of phosphate in wheatfields with loutu soil are different in terms of amount of fast phosphate insoil.Apart from the fact that there is no economic return in the fields richin fast phosphate,the highest economic returns of phosphate application are6kg/mu,4kg/mu and 2kg/mu in the fields extremely deficient,deficient,midium and slight deficient in phosphate respectively.