秸秆还田下直播稻-油轮作的钾肥效应及适宜用量  

Effects and optimum recommendation of K fertilizer for direct seeding rice-rapeseed under straw incorporation

作　　者：李继福[1] 张旭[1] 冉娇 潘晨 王雨晴 李燕丽 邹家龙 陈华东 LI Jifu;ZHANG Xu;RAN Jiao;PAN Chen;WANG Yuqing;LI Yanli;ZOU Jialong;CHEN Huadong(Engineering Research Center of Ecology and Agricultural Use of Wetland,Ministry of Education/College of Agriculture,Yangtze University,Jingzhou 434025,China;Agro-Tech Extension and Service Center of Jingzhou District,Jingzhou City,Jingzhou 434025,China;Agro-Tech Extension and Service Center of Chuandian Town,Jingzhou District,Jingzhou City,Jingzhou 434025,China)

机构地区：[1]湿地生态与农业利用教育部工程研究中心/长江大学农学院,荆州434025 [2]荆州市荆州区农技推广中心,荆州434025 [3]荆州市荆州区川店镇农技推广中心,荆州434025

出　　处：《华中农业大学学报》2019年第6期77-85,共9页Journal of Huazhong Agricultural University

基　　金：国家重点研发计划项目（2018YFD0200900）;湖北省教育厅中青年人才项目（Q20181303）;长江大学第十一批大学生创新创业训练计划项目（2018290)

摘　　要：2017-2018年在湖北省江汉平原开展钾肥一次性施用肥效田间试验,研究秸秆全量还田下钾肥用量对江汉平原直播水稻-油菜轮作产量及其构成因子、农田钾素表观平衡和钾肥(钾素)吸收利用率及农学利用率的影响,并结合肥效模型明确直播稻-油轮作的钾肥适宜用量。结果表明:钾肥施用能够显著提高直播水稻和油菜的产量、地上部干物质量及钾素吸收,并通过增加直播水稻的密度、单位面积有效穗数、每穗粒数,结实率和直播油菜的密度、一级分枝数,角果总数来实现增产。秸秆不还田、周年钾肥投入量(K 2 O)360 kg/hm 2条件下,轮作系统的钾素表观平衡仍为负值,亏缺量达85.4 kg/hm 2;而秸秆全量还田下,年投入90 kg/hm 2钾肥即可实现农田钾素表观盈余。直播水稻和油菜的钾肥农学利用率平均分别为10.6 kg/kg和2.9 kg/kg,而钾肥吸收利用率则为42.6%和54.1%,表明直播水稻施用钾肥增产效果明显高于油菜,同时也反映出直播油菜更依赖于外源钾肥投入。水稻季钾素农学利用率、吸收利用率与其钾肥农学利用率、吸收利用率结果一致,而油菜季的钾素农学利用率和吸收利用率则分别为2.1 kg/kg和38.5%,均显著低于油菜季钾肥农学利用率和吸收利用率。根据线性加平台方程拟合并结合农田钾素平衡得出秸秆还田下直播水稻和油菜的钾肥适宜用量分别为62.31 kg/hm 2和70.18 kg/hm 2,对应的经济产量为10 066 kg/hm 2和2 182 kg/hm 2,比当地推荐钾肥用量分别减少44.4%和28.2%,且旱地直播油菜需要更多钾肥投入来支撑群体生长。因此,鉴于直播方式下作物生长对养分需求存在差异,应根据农业轻简化生产要求重视直播稻-油轮作的钾素养分管理,以提高作物产量、养分利用率和经济效益。A on-farm experiment of potassium(K)fertilizer one-off application was conducted in Jingzhou City,Hubei Province from 2017 to 2018.The aim was to assess the K rate on yield,K apparent balance,K efficiency of rice-rapeseed rotation in Jianghan Plain,and combined with the fertilizer efficiency model to clarify the appropriate amount of K fertilizer.The results showed that the application of K fertilizer could significantly increase the yield of rice and rapeseed,the dry matter amount and K uptake of the aboveground,where the increasement came from the density,number of kernels,seed setting rate of rice and density,number of 1st branches and pods of rapeseed.When the K fertilizer input(K 2 O)reached 360 kg/hm 2 per year,the K apparent balance in the rotation was still negative,and the deficit was 85.4 kg/hm 2 without straw returning.On the contrary,the annual K balance of farmland could be achieved positively by inputting 90 kg/hm 2 K fertilizer with straw incorporation.Compared with no K fertilizer application,the agronomic K fertilizer efficiency(KfAE)of rice and rapeseed applied with K fertilizer were 10.6 kg/kg and 2.9 kg/kg,where the K fertilizer recovery efficiency(KfRE)of those were 45.5%and 54.1%,respectively,indicating that the yield production of K fertilizer applied to direct seeding rice was significantly higher than that of rapeseed,and it also reflected from the side that rapeseed was more dependent on external K fertilizer than rice.Considering the input of straw K,the K efficiency(KAE and KRE)in rice season was consistent with that of KfAE and KfRE,while the KAE and KRE in rape season were 2.1 kg/kg and 38.5%,which were significantly lower than that of KfAE and KfRE.The comprehensive linear plus platform model and the K apparent balance of farmland showed that the suitable K fertilizer rate for direct seeding rice and rapeseed were 62.31 kg/hm 2,70.18 kg/hm 2 and yield for 10 066 kg/hm 2,2 182 kg/hm 2 under straw returning,respectively,which was lower than the recommended K fertilizer amount of 90 kg

关 键 词：直播 水稻-油菜轮作 秸秆还田 钾肥用量 轻简化生产 钾素表观平衡 

分 类 号：S565.506[农业科学—作物学]