秸秆覆盖对梨园土壤养分的影响

测定了 3种梨园———不灌覆盖园、不灌无覆盖园和灌溉园不同土层中有机质、全氮、全磷、全钾和速效氮、速效磷、速效钾的含量。结果表明 ,秸秆覆盖后 ,梨园表土层 (0～ 2 0cm)中的有机质和全氮、全磷、全钾含量均有所提高 ,而下层 (2 0～ 4 0cm)土壤中的含量却有所降低。不同土层中的速效磷和速效钾含量均明显增高 ,尤其是速效磷 ,表土层中的含量增加了 3倍以上 ,平均增加约 1倍半。表土层中的速效氮有所降低 ,但下层土壤中的含量却有较明显的提高

Effects of Stalk Mulching to the Soil Nutrients in Pear Orchard

The contents of organic matter,total nitrogen phosphorous and potassium,and effective nitrogen,phosphorous and potassium at different layers of soil in mulched irrigated.immulched unirrigated and irrigated pear orchards were determined.The results showed that the contents of the organic matter and total nitrogen,phosphorous and potassium increased in the topsoil (0～20cm) while in the lower layer of soil droped.The contents of effective potassium,especially effective phosphorous at different layers of soil mulched with stalks obviously increased.The amount of the latter in the topsoil increased by threefold or more.The mulching increased the content of effective nitrogen in the lower layer of soil but not in the topsoil.