紫云英翻压后稻田土壤可溶性有机氮迁移特性与损失风险  

Migration and Risk of Loss of Soluble Organic Nitrogen in Paddy Soil After Incorporation of Chinese Milk Vetch

作　　者：杨静[1] 郭文圻 杨文浩[1,2] 周碧青 张黎明[1,2] 邢世和 YANG Jing;GUO Wenqi;YANG Wenhao;ZHOU Biqing;ZHANG Liming;XING Shihe(College of Resources and Environment,Fujian Agriculture and Forestry University,Fuzhou 350002,China;Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation,Fuzhou 350002,China)

机构地区：[1]福建农林大学资源与环境学院,福州350002 [2]土壤生态系统健康与调控福建省高校重点实验室,福州350002

出　　处：《土壤学报》2022年第3期786-796,共11页Acta Pedologica Sinica

基　　金：国家自然科学基金项目(41671490);福建农林大学科技创新项目(KF2105074)资助。

摘　　要：可溶性有机氮在氮素转化和生态环境安全方面具有重要的作用。在等氮磷钾条件下以单施化肥(CK)为对照,研究不同数量紫云英(CMV1,15000 kg·hm^(-2);CMV2,30000 kg·hm^(-2)和CMV3,45000 kg·hm^(-2))翻压后灰泥田土壤可溶性有机氮(SON)和溶解性有机氮(DON)的动态变化、迁移特征及损失量。结果表明,不同施肥处理20~40 cm和40~60 cm土层SON含量分别较0~20 cm土层降低了58.50%和78.47%;施用紫云英利于SON在灰泥田土壤剖面中累积,水稻生育期0~60 cm土层CMV1、CMV2和CMV3处理SON密度分别较CK处理提高5.57%、10.11%和21.39%;不同施肥处理DON总损失量介于18.33~58.55 kg·hm^(-2),占可溶性总氮的46.52%~50.16%,其中3.77~37.85 kg·hm^(-2)(以N计,下同)随淹水层径流损失,14.5~18.02 kg·hm^(-2)随渗滤液迁移损失,且DON在土层间的迁移具有一定的延迟性;每季水稻CMV1、CMV2和CMV3较CK可分别减少16.90、31.09和37.52 kg·hm^(-2)的DON损失。上述结果表明DON是稻田土壤氮素损失的重要形态,施用紫云英后灰泥田DON的损失量低于施用等氮量尿素,可减少水田氮素面源污染。【Objective】Soluble organic nitrogen(SON)is one of the most active components of the soil nitrogen pool in farmland and plays an important role in nitrogen transformation and ecological environment security.As SON is highly mobile,it is prone to get lost with runoff or leaching,and thus,and hence affect water quality.【Method】To provide a theoretical basis for rational fertilization in paddy fields,prevention and control of non-point source nitrogen pollution from paddy fields and improvement of the theory of nitrogen cycling,a field experiment,designed to have the following treatments,all equivalent in nutrient content,i.e.CK(application of chemical fertilizer only),CMV1(application of chemical fertilizer plus incorporation of milk vetch at 15000 kg·hm^(-2));CMV2(application of chemical fertilizer plus incorporation of milk vetch at 30000 kg·hm^(-2));and CMV3(application of chemical fertilizer plus incorporation of milk vetch at 45000 kg·hm^(-2)),was carried out to explore dynamics,migration and loss of SON and dissolved organic nitrogen(DON)in grey-mud field soils.Soil samples from the treatments were analyzed for SON,respectively,using the hot water extraction method.SON concentrations were calculated by deducting TSN from the sum of SIN in the extracts.【Result】During the growing period of rice,SON content in the 0-60 cm soil layer varied in the range from 2.09 to 22.32 mg·kg^(-1),showing a trend of“increasing-decreasing-increasing-decreasing to stable”.In the treatments the SON concentration was 140.95% and 364.44%,higher in the 0-20 cm soil layer,respectively,than in the 20-40 cm soil layer and the 40-60 cm soil layer,and 92.75% higher in the 20-40 cm soil layer than in the 40-60 cm soil layer.It is quite obvious that incorporation of Chinese milk vetch during the growth period of rice is beneficial to accumulation of SON in the soil(0-60 cm).In SON concentration in the 0-60 cm soil layer during the rice growth period,Treatment CMV1,CMV2 and CMV3 was 5.57%,10.11% and 21.39%,respectively,hig

关 键 词：紫云英 灰泥田 可溶性有机氮 溶解性有机氮 迁移 损失量 

分 类 号：S154[农业科学—土壤学]