滴灌施肥条件下土壤铵氮分布规律的研究

研究了大田土壤点源滴灌施肥条件下滴头流量(q)和灌水施肥量(Q)对土壤NH4 -N扩散分布的影响,分析水平和垂直两方向上NH4 -N含量的变化规律。结果表明:随滴头流量和灌水量的增大,水平垂直两方向的最大湿润距离增大,且随滴头流量增大,表层积水区半径增大。滴头流量在一定尺度增大会改变NH4 -N在土壤湿润体内的运移扩散方式,进而影响扩散边缘处的NH4 -N浓度和最大扩散距离。灌水施肥量增大使NH4 -N随水运移扩散的距离增大,使扩散区域内NH4 -N浓度提高。

Distribution pattern of NH+4-N in soil under dripping irrigation and fertilization

The experiment was conducted to investigate the influence of dripping end flow and irrigation volume on the distribution pattern of NH_4~ -N in soil,and to analyze the change rules of NH_4~ -N concentration in horizontal and vertical directions.The results showed that the biggest wetting distances in both horizontal and vertical directions were expanded along with the increase of dripping end flow and irrigation volume,and the surface seeper radius was also expanded along with the increase of dripping end flow.An increase of dripping end flow in certain scale could change the distribution pattern of NH_4~ -N in wet soil,and influence the NH_4~ -N concentration in the spread boundary and the biggest spread distance.As the volume of irrigation and fertilization was increased,the spread distance of NH_4~ -N was enlarged and the NH_4~ -N concentration in the spread zone was enhanced.