WINTER CHANGES IN SOIL NITRATE AND EXCHANGEABLE AMMONIUM
[摘要] Cylindersofaloamsoilwereplacedinthefieldinlatefallandsampledinmidwinterandearlyspring.Insoilwettedtonearfieldcapacity,nitrateandmoisturemovedupwardsinwinteranddownwardsagaininearlyspring.Theamountofmovementwasnegligibleinasoilwettonearthewiltingpercentage.Toinhibitnitrification,N-servewasappliedin10 cmofwatertofieldplots(120 × 120 cm)inlatefall.OtherplotsreceivedwaterbutnoN-serve.Regularmonitoringofsoilnitrate,exchangeableammonium,andsoilmoistureandtemperatureinthetop90 cmoftheseplotsshowedevidenceofupwardmoistureandnitratemovementasthesoilfroze.Largeandsuddenunexplainabledecreasesinexchangeableammoniumoccurredfollowingsteadyfallbuild-up.
[发布日期] [发布机构]
[效力级别] [学科分类] 农业科学（综合）
[关键词] [时效性]
