滴肥时机对干旱区盐渍化棉田盐氮分布及叶片SPAD值和产量的影响  

The impact of fertilizer application timing on salt and nitrogen distribution,leaf SPAD value,and yield in salinized cotton fields of arid regions

作　　者：蔡帆 许咏梅 谢香文 兰茜 刘曼琪 CAI Fan;XU Yong-mei;XIE Xiang-wen;LAN Xi;LIU Man-qi(College of Resources and Environment,Xinjiang Agricultural University,Urumqi Xinjiang 830000;Institute of Soil Fertilizer and Agricultural Water Saving,Xinjiang Academy of Agricultural Sciences/Key Laboratory of Water-saving Agriculture(Oasis of Northwest China)Ministry of Agriculture and Rural Affairs,Urumqi Xinjiang 830091)

机构地区：[1]新疆农业大学资源与环境学院,新疆乌鲁木齐830000 [2]新疆农业科学院土壤肥料与农业节水研究所/农业农村部西北绿洲节水农业重点实验室,新疆乌鲁木齐830000

出　　处：《中国土壤与肥料》2024年第12期110-118,共9页Soil and Fertilizer Sciences in China

基　　金：国家重点研发计划(2021YFD1900803);自治区重点研发计划(2022B02020-2)。

摘　　要：滴灌条件下如何实现作物根层的氮素富集与盐分驱离,为棉花根系提供适宜的土壤环境,对提高干旱区盐渍化棉花产量具有重要意义。以新疆北部典型盐渍化棉田为对象,采用田间小区试验方法,进行了氮肥不同滴施时机对棉花根系层水、盐、氮分布及棉花长势和产量的影响研究,在统一的水肥管理制度下,即N 290 kg/hm^(2)、P_(2)O_(5)110 kg/hm^(2)、K_(2)O 95 kg/hm^(2)和施肥8次、灌溉定额4500 m^(3)/hm^(2),通过调控氮肥滴入时间,研究氮素与盐分在土壤剖面上的分域。考虑到棉花自苗期至成熟期每次灌水时长不同,一般为6~10 h,设置变量t为棉花各生育时期每次灌水时长,以氮肥投入时间节点为不同处理,分别如下:①T1:先滴水1 h再加入氮肥;②T2:滴水(1+1/3t)h加入氮肥;③T3:滴水(1+2/3t)h加入氮肥。结果表明:氮肥不同滴施时机显著影响了土壤盐分含量和氮素分布。从土壤盐分分布情况看,棉花苗期、蕾期和花铃期,采用先滴水5~5.6 h后再滴入氮肥(T3处理)可显著降低土壤根系层盐分胁迫,推迟氮肥加入的时间也有效提升了根层硝态氮和铵态氮含量,形成了较为明显的“肥盐分域”。后期滴入氮肥(T3处理),显著提高了棉花苗期和花铃期植株叶片SPAD值,为棉花关键期光合提供了适宜条件。棉花单铃重和籽棉产量随着氮肥滴施时机延后显著增加,T3较T1、T2处理的单铃重和籽棉产量分别提高7.18%、4.04%和6.35%、1.52%。综合土壤盐分、氮素分布和棉花产量等指标,建议采用氮肥滴施时机为(1+2/3t)h,即苗期、蕾期和吐絮期先滴水5 h再加入氮肥滴施,花铃期则推荐滴水时长为5.6 h再加入氮肥,与农户习惯施肥相比,滴入氮肥的时间推迟3~3.3 h。How to realize nitrogen enrichment and salt repulsion in the crop rhizosphere under drip irrigation conditions to provide a suitable soil environment for the cotton root system is of great significance to improve the yield of salinized cotton in arid areas.Taking typical salinized cotton fields in northern Xinjiang as the object,the effects of different drip application timing of nitrogen fertilizers on the distribution of water,salt and nitrogen in the cotton rhizosphere as well as the growth and yield of cotton were investigated by using the field plot test method under a uniform water and fertilizer management system,i.e.,N 290 kg/hm^(2),P_(2)O_(5)110 kg/hm^(2),K_(2)O 95 kg/hm^(2)and 8 times of fertilizer application with an irrigation quota of 4500 m^(3)/hm^(2),the partitioning of nitrogen and salinity in the soil profile was studied by regulating the drip time of nitrogen fertilizer.Considering the different duration of each irrigation from seedling to maturity of cotton,generally 6-10 h,the variable t was set as the duration of each irrigation in each fertility period of cotton,and the nitrogen fertilizer input time nodes were used for different treatments as follows:①T1:1 h of dripping before adding nitrogen fertilizer;②T2:(1+1/3t)h of dripping before adding nitrogen fertilizer;③T3:(1+2/3t)h of dripping before adding nitrogen fertilizer.The results showed that different drip application timing of nitrogen fertilizer significantly affected soil salinity content and nitrogen distribution.From the distribution of soil salinity,in the cotton seedling,bud and boll stage,the treatment of first dripping 5-5.6 h and then dripping the nitrogen fertilizer(T3 treatment)significantly reduced the soil rhizosphere salt stress,and the delayed addition of nitrogen fertilizer effectively enhanced the nitrate nitrogen and ammonium nitrogen content in the rhizosphere,which formed a more obvious"fertilizer and salt domain".Nitrogen fertilization at a later stage(T3 treatment)significantly increased the SPAD values of co

关 键 词：氮素滴施时机 干旱区 盐渍化棉田 盐氮分布 SPAD值 产量 

分 类 号：S51[农业科学—作物学]