铵态氮和水溶性磷酸盐配比对土壤硝化的影响

以钙积干润均腐土为供试土样,采用室内培养法,通过设置不同N/P比.研究了铵态氮不同添加量对硝化作用过程pH和Nmin的影响.结果表明,钙积半干润均腐土铵态氮硝化类型属缓慢型.在一定时间段内,土体中NO2-大量积累并存在,NH4+ 和NO3-形态弱化;氮磷肥配合施用可构成磷酸盐缓冲体系,可暂时性延缓因土壤硝化作用pH值的下降,从而减小了土壤pH的变化幅度.磷酸盐降低了土壤中NH3分压,有利于减少NH3挥发损失.抑制了NH4HCO3加入后土壤pH的增加,有利于硝化作用,可使土壤硝化类型为较快型,NH4+ 和NO3-形态得以强化.土壤硝化周期与氮肥施用量成正比例关系.NP肥配添加可缩短铵态氮的硝化时间,NP配合施肥利于土壤硝化作用.合理的N/P比(2∶2)施肥可缩短硝化时间.

Effect of Match Ratio of Ammonium Nitrogen and Water Solubility Phosphas on Soil Nitrification

Effect of match ratio of ammonium nitrogen and water solubility phosphas on soil nitrification was studied.Fresh Cal-Ustic Isohumasols is used of indoor fostering as the experiment method,according of different of N/P,the difference addition number of ammonium nitrogen process of nitrification pH and N_min were investigated.The results showed the Cal-Ustic Isohumasols of ammonium nitrogen was slow.At stage of soil existence of many accumulation NO₂^-,NH₄⁺ and NO₃^- from weakness; nitrogen and phosphorus mixed fertilizer match ratio consist of bicarbonate and phosphate,temporary delay in soil nitrification was declined pH,phosphate change of decrease soil NH₃,was beneficial to declined NO₃^- of volatilization.When accede to the NH₄HCO₃ was control of soil pH increased,the beneficial to soil nitrification was gradually rapid,so that NH₄⁺ and NO₃^- form can consolidate.Adequate fertilization N/P (2:2) should shorten of nitrification time.