控释肥在宁夏灌淤土中的氮素释放特征研究  

Study on N releasing characteristics of controlled-release fertilizer in irrigation silting soils of Ningxia

作　　者：洪瑜[1] 赵营[1] 王芳[1] 刘汝亮[1] 李友宏[1] 赵天成[1] 陈晨[1] HONG Yu;ZHAO Ying;WANG Fang;LIU Ru-liang;LI You-hong;ZHAO Tian-cheng;CHEN Chen(Institute of Agricultural Resources and Environment,Ningxia Academy of Agriculture and Forestry Sciences,Yinchuan Ningxia 750002)

机构地区：[1]宁夏农林科学院农业资源与环境研究所,宁夏银川750002

出　　处：《中国土壤与肥料》2018年第5期64-69,114,共7页Soil and Fertilizer Sciences in China

基　　金：国家重点研发计划(2017YFD0200107);国家自然科学基金项目(31660597);宁夏农林科学院科技创新先导资金(NKYJ-16-0904NKYJ-15-05);水体污染控制与治理重大专项(2014ZX07201-009);宁夏环保科技项目

摘　　要：为了寻求改善宁夏灌淤土水稻氮素利用的有效措施,通过静水浸泡与盆栽试验,以自研聚氨酯包膜控释肥为研究对象,研究了3种控释肥的氮素释放特征,在氮磷钾等养分供应下研究了5个施肥处理对水稻产量与氮素吸收利用的影响。结果表明:自研控释肥CRF1、CRF2在静水(25℃)中的氮素累积释放比例的动态变化趋势基本一致,都呈"抛物线"形状,其24 h初期释放率分别为3.54%、2.28%(≤15%),28 d的氮素累积释放率分别为33.17%、30.58%(≤80%),符合缓释肥料的国家标准要求。与等量NPK处理相比,CRF2处理主要通过提高水稻穗粒数与千粒重获得最高子粒产量,达到31.21 g/盆,增加了10.44%;其地上部总吸氮量达到150.89 kg/hm^2,提高了10.46%;其氮肥利用率达到36.64%,提高了5.49个百分点。不同施肥处理下土壤铵态氮、硝态氮与无机氮含量峰值均出现在水稻插秧后的15 d前后,随后不同程度的下降,控释肥处理下降较慢,在土壤中氮素释放时间达到75 d以上。其中CRF2处理由于添加了硝化抑制剂双氰胺,能够在水稻移栽45 d前保持最高的硝态氮(第45 d:99.41 mg/kg)和无机氮含量(第45 d:104.46 mg/kg),在60 d前保持最高的铵态氮含量(第60 d:4.03 mg/kg),满足了水稻生育关键期对氮素的需求,从而保证稻谷产量。In order to explore the effective measures that improve nitrogen utilization in irrigation silting soils of Ningxia,a water immersion test and pot experiment was conducted to study on N releasing characteristics of three kinds of controlled-release fertilizer,respectively;and the effects of five fertilizer treatments on rice yield and nitrogen use efficiency under the same N,P,K nutrients input were investigated.The coated controlled-release fertilizer by polyurethane was the tested material.The results indicated that there were very similar tendencies of accumulative N releasing ratio for the two kinds of controlled-release fertilizer(CRF1,CRF2)in water(25℃).The initial releasing rate in 24 h of CRF1 and CRF2 treatment were 3.54%and 2.28%(≤15%),and accumulative N releasing ratios in 28 d were 33.17%and 30.58%(≤80%),which were accorded with national standards of slow release fertilizers.Compared to the NPK treatment,the rice grain yield of the CRF2 treatment was 31.21 g/pot which was increased by 10.44%,the aboveground N uptake was 150.89 kg/hm 2 which was increased by 10.46%,the nitrogen use efficiency was 36.64%which was increased of 5.49 percentage points.The peaks of soil NH+4-N,NO-3-N and mineral N content in different fertilizer treatments were happened at about 15 d of rice growth,and then declined to some extent respectively.The controlled-release fertilizer treatments were decreased slowly,and the corresponding N releasing periods were greater than 75 d.Due to adding nitrification inhibitor dicyandiamide,the CRF2 treatment could maintain the highest soil NO3^--N(the 45th day:99.41 mg/kg)and mineral N content(the 45th day:104.46 mg/kg)in 45 days after transplanting of rice,and the highest soil NH4^+-N content(the 60th day:4.03 mg/kg)in 60 days,which satisfied the demand of nitrogen for the critical period of rice growth and ensured the grain yield.

关 键 词：控释肥 灌淤土 氮素释放 水稻 氮肥利用率 

分 类 号：S143.1[农业科学—肥料学]