甘蔗种植方式对蔗地土壤侵蚀及氮素流失特征的影响  

Effects of Planting Methods on Soil Erosion and Nitrogen Loss in a Sugarcane Field

作　　者：黄艳荟 宁嘉丽 李桂芳 杨任翔 王坚桦 陈钊柱 Huang Yanhui;Ning Jiali;Li Guifang;Yang Renxiang;Wang Jianhua;Chen Zhaozhu(Guangxi Key Laboratory of Agro-environment and Agro-product Safety,Agricultural College of Guangxi University,Nanning,Guangxi 530004,China)

机构地区：[1]广西大学农学院广西农业环境与农产品安全重点实验室,广西南宁530004

出　　处：《水土保持通报》2022年第6期121-128,136,共9页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目“植蔗坡耕地土壤侵蚀及养分流失特征和机制”(41967010);广西自然科学基金项目(2018GXNSFBA138024)。

摘　　要：[目的]探讨自然降雨条件下甘蔗种植方式(宿根和新植)对坡地的土壤侵蚀及氮素流失特征的影响,为区域水土流失防治和甘蔗合理种植提供理论依据。[方法]基于径流小区原位观测试验,以10°赤红壤植蔗坡地为研究对象,设置甘蔗宿根和新植两种种植方式,测定自然降雨条件下坡面径流、侵蚀量及硝态氮和铵态氮流失量,获得自然降雨条件下宿根蔗和新植蔗坡地土壤侵蚀特征和氮素流失的特征。[结果]①2021年5—10月宿根蔗和新植蔗地分别发生侵蚀性降雨40场和43场,累计侵蚀性降雨981.8 mm和1013.0 mm。蔗地径流、侵蚀量及氮素流失量均集中在6月,径流和侵蚀泥沙中硝态氮和铵态氮主要随地表径流流失,占径流侵蚀氮素流失总量的96.0%以上;径流中的氮流失以硝态氮为主(>70.0%),而侵蚀泥沙中则以铵态氮流失为主(>80.0%)。宿根蔗坡面径流、侵蚀量较新植蔗减少了31.8%和83.5%,径流中硝态氮和铵态氮流失量减少了56.7%和51.9%,侵蚀泥沙中则减少了85.4%和60.2%。②次降雨条件下,蔗地坡面径流、侵蚀和氮素流失随降雨量波动变化,宿根蔗和新植蔗地的径流、侵蚀量及氮素流失量主要发生在2021年6月3—24日降雨中,且整体上均表现为宿根蔗小于新植蔗。随着甘蔗的生长,蔗地坡面径流、侵蚀及其携带氮素流失量均逐渐减小。③最大30 min降雨强度(I_(30))和降雨量是影响蔗地径流中和侵蚀泥沙中氮素流失的主要因子;最大60 min降雨强度(I_(60))和I_(30)分别是影响宿根蔗和新植蔗坡面径流侵蚀的最主要降雨因子。[结论]蔗地坡面土壤径流、侵蚀泥沙中的硝态氮和铵态氮流失以地表径流中的硝态氮流失为主;与新植蔗相比,宿根蔗在甘蔗苗期和分蘖期可以有效降低坡面径流侵蚀及氮素流失,伸长后期二者差异逐渐变小。[Objective]The effects of sugarcane planting methods〔ratoon sugarcane(RS)and newly planting sugarcane(NS)〕on soil erosion and nitrogen loss characteristics of slope land under natural rainfall were determined in order to provide a theoretical basis for regional water and soil loss prevention,and for determining reasonable planting practices for sugarcane.[Methods]In-situ observations were made of natural rainfall processes,runoff,sediment yield,and nitrate nitrogen and ammonium nitrogen losses under individual rainfall events for different sugarcane planting patterns〔ratoon sugarcane(RS)and newly planting sugarcane(NS)〕on lateritic soil from May to October in 2021.[Results]①The numbers of individual erosive rainfall events in the NS and RS treatments were 40 and 43,respectively,and the erosive rainfall amounts were 981.8 mm and 1013.0 mm,respectively,from May to October in 2021.Runoff,sediment,and nitrogen losses of sugarcane land mainly occurred in June.Nitrogen losses were mainly lost through surface runoff,accounting for more than 96.0%of the total nitrogen loss in runoff and sediment.Nitrate nitrogen loss accounted for more than 70%of total dissolved nitrogen in runoff,while ammonium nitrogen was the main nitrogen loss type in sediment(>80%).Compared with the NS treatment,the total runoff and soil erosion of the RS treatment decreased by 31.8%and 83.5%,respectively,the loss of nitrate nitrogen and ammonium nitrogen in runoff decreased by 56.7%and 51.9%,and the sediment loss decreased by 85.4%and 60.2%.②Runoff,sediment yield,and nitrogen losses of sugarcane land under the different treatments fluctuated with individual rainfall events among sugarcane growing treatments,and losses mainly arose from the rainfall occurring from June 3 to 24,2021.The losses of nitrate and ammonium nitrogen in runoff and erosion sediment for the RS treatment were generally lower than for the NS treatment.Additionally,runoff,sediment,and the nitrogen losses in runoff erosion gradually decreased with the growth of sugarca

关 键 词：宿根蔗 新植蔗 降雨 土壤侵蚀 氮流失 

分 类 号：S157.1[农业科学—土壤学]