猪粪氮素有效性与替代化肥氮当量研究

Nitrogen availability of pig manure and its fertilizer equivalence

采用温室盆栽试验,初步研究了猪粪氮素的有效性和替代氮肥的替代当量,并结合田间试验对等有效氮条件下有机无机配施与单施化肥的效果进行了比较。盆栽试验表明,随着猪粪用量的增加,氮素回收率逐渐降低,回收率为22.5%～38.3%,平均30.6%。当猪粪用量为N 120 mg/kg时,其氮素相对于化肥的相对有效性为27%。不同用量下猪粪的替代氮肥当量也具有一定差异,相对替代当量为24.0%～40.8%,平均32.9%。田间试验表明,利用猪粪中的有效氮替代30%的化肥氮对春玉米干物质和籽粒产量以及氮素吸收量没有影响,与100%化肥氮处理相当。

A pot experiment was conducted to investigate the availability of N from pig manure and its fertilizer equivalence（FE）.Field studies were also arranged to test the results from pot experiment.Effect of combination of pig manure with urea on dry matter,grain yield and N uptake in maize was compared with single fertilizer N application under equal available N.Results indicated that the recovery efficiency of N from pig manure was 22.5%~38.3% with an average of 30.6%,and decreased with the increased rate of pig manure application.The relative availability of N from manure calculated by the ratio of N recovery from pig manure to N recovery from chemical N was 27% when manure was applied at N 120 mg/kg.The FE was some different at various rate of pig manure N,the relative fertilizer equivalence（RFE）of pig manure was 24.0%~40.8% with a mean of 32.9%.Testing studies indicated that pig manure N substitution for 30% of recommended N according to fertilizer equivalence produced similar total dry matter,grain yield and N uptake by maize compared with 100% recommended chemical fertilizer N.