菜地土壤有机肥转化试验

Experiment on transformation of organic manure in vegetable soil

采用通气培养法 ,定期测定土壤Nmin的变化 ,计算土壤氮素矿化量。结果表明 :0～ 30cm表层土壤的有机氮矿化速率明显高于 30～ 60cm的深层土壤。本试验条件下 ,有机肥先产生氮的净固定作用 ,后开始缓慢释放 ,其氮素平均矿化速率为 0 30mg/kg·d ,低于 0～ 30cm土壤。商品有机肥与尿素配施处理同尿素处理相比 ,对土壤Nmin无明显影响 ,而菜花和苋菜残体与尿素配施明显提高了土壤Nmin。

A ventilation incubation experiment was carried out to determine the mineralization rate of organic nitrogen of organic manure applied in the vegetable soil at regular intervals.The mineralized nitrogen was quantified at the same time.The results indicated that nitrogen was mineralized from manure at an average rate of 0 30 mg/kg·d.The mineralization rate of organic nitrogen in surface layer of soil was higher than that in the bottom.Organic manure showed net fixation of organic nitrogen at earlier stage of the experiment,and then released slowly later.Treatment of combination of organic manure with urea had no significant effect on N min of soil compared with treatment of urea,while treatment of combination of vegetable remains with urea produced positive effect on N min .