摘要
【目的】利用川东南冬水田区连续多年稻鱼共作系统,研究施氮(N)量对免耕栽培杂交稻产量形成和土壤养分的影响,为制定稻鱼共作系统下免耕栽培杂交稻长期、合理的氮肥管理策略提供理论依据。【方法】于2018—2022年在川东南冬水田区开展了5年大田定位试验,供试杂交稻品种为蓉优1015和内6优103,耕作方式为免耕。设置N 0、45、90、135 kg/hm^(2)4个施氮水平,分别记作N_(0)、N_(45)、N_(90)、N_(135)。在水稻收获期,调查杂交稻产量及产量构成因素,分析0—20 cm土层土壤全量和速效氮、磷、钾含量,以及有机质含量和pH,通过回归分析,研究施氮量与水稻产量和土壤养分因子含量变化之间的关系。【结果】稻鱼共作系统下,年份、施氮量对杂交稻产量及产量构成的影响达极显著水平。5年间,杂交稻产量与施氮量均呈极显著正相关(r=0.9070^(**)~0.9720^(**)),与低氮量处理N_(45)相比,N_(90)和N_(135)处理杂交稻产量分别增加了6.37%~26.53%、9.11%~25.11%,单位面积有效穗数和每穗粒数也显著增加。而N_(90)处理杂交稻产量与N_(135)处理相当或更高。逐步回归分析结果表明,杂交稻产量构成(单位面积有效穗数、每穗粒数、结实率和千粒重)与产量的偏相关系数达显著或极显著水平(t=2.20*~9.17^(**))。通径分析结果表明,杂交稻单位面积有效穗数和每穗粒数对产量的直接贡献(分别为0.8754和0.4987)和总贡献(分别为0.6364和0.3598)较大,表明单位面积有效穗数和每穗粒数是影响产量的主要因素。在N_(0)、N_(45)处理下,土壤全氮、碱解氮含量随稻鱼共作年限的增加而下降,而在N_(90)、N_(135)处理下随稻鱼共作年限的增加而增加。土壤全氮、碱解氮含量随施氮量增加而提高,而全磷、全钾、速效磷、速效钾含量则随施氮量增加而下降。杂交稻产量与土壤养分含量呈极显著正相关,可见提高磷素、钾素供给能力是稻鱼共作系统杂交稻高产的重要基础。【结论】川东南冬水田区稻鱼共作系统下,年施氮90 kg/hm^(2)可以提高杂交水稻的单位面积有效穗数和每穗粒数,进而维持甚至提高水稻产量。连续施用中、高量氮肥还可以提升土壤有机质、全氮、全磷、全钾、碱解氮、速效磷和速效钾含量,且随稻鱼共作年限延长呈增加趋势;土壤pH值则随稻鱼共作年限延长呈下降趋势。
【Objectives】We investigated the rice yield and soil nutrient and pH variations caused by nitrogen application rates under no-tillage cultivation practice in a fish-rice integrated farming system,so as to provide a theoretical basis for long-term and reasonable fertilizer management under the system.【Methods】A localized field experiment was carried out for five years in a winter logging-water field in Southeast of Sichuan Province from 2018 to 2022.No-tillage cultivation practice was used,and two hybrid rice cultivars Rongyou 1015 and Nei 6you 103 were used as test materials.Four N fertilizer treatments were 0,45,90 and 135 kg/hm^(2)(denoted as N_(0),N_(45),N_(90),and N_(135)),representing low,meddle and high N rate,except the N_(0).At rice harvesting stage of each year,the grain yield,yield components,and nitrogen content in different part of hybrid rice were analyzed.The soil total and available N,P and K content,and the pH in 0−20 cm layer were determined.【Results】Experimental years and N rates significantly affected grain yield and yield components of hybrid rice in the rice-fish integrated farming system.During the five years,the grain yield was positively correlated with N rate(Fyear=7.95^(**)−63.44^(**),FN rate=3.95*−282.99^(**)).Compared with N_(45),N_(90) and N_(135) treatment increased grain yield by 6.37%−26.53%and 9.11%−25.11%,respectively,due to the higher panicle number per unit area and spikelet per panicle.And N_(90) was also recorded similar or even higher grain yield,compared with N_(135).Stepwise regression analysis showed that the yield components were positively correlated with grain yield,and the path analysis showed that panicle number and spikelets per panicle had the highest direct contribution(0.8754 and 0.4987,respectively)and total contribution(0.6364 and 0.3598,respectively)to grain yield.In the fish-rice integrated farming,soil pH significantly decreased with the elongation of experimental years(r=−0.9823^(**)−0.9385^(**)),while soil organic matter,total and available P and K kept increased(r=0.7128^(**)−0.9932^(**)).The soil total and alkali hydrolyzed N(AN)significantly decreased with the increase of experimental years under N_(0) and N_(45),but significantly increased under N_(90) and N_(135).There was a linear relationship(P<0.01)between grain yield and soil nutrient content under rice-fish integrated farming system,and improving the supplying capacity of soil phosphorus and potassium was an important approach to obtain high rice grain yield.【Conclusions】The optimal N application rate for hybrid rice is 90 kg/hm^(2) under rice-fish co-culture system,due to the higher panicle number per unit area and spikelet number per panicle of hybrid rice.Continuous application of medium and high nitrogen rate could increase soil organic matter,total and available nitrogen,phosphorus,and potassium,and the organic matter and nutrient contents tend to become higher with the extension of rice-fish co-culture years,while the soil pH is on the opposite.So nitrogen application rate should be controlled to relatively low level in the rice-fish co-culture system of southeast of Sichuan Province.
作者
徐富贤
周兴兵
张林
郭晓艺
刘茂
朱永川
熊洪
郭长春
蒋鹏
XU Fu-xian;ZHOU Xing-bing;ZHANG Lin;GUO Xiao-yi;LIU Mao;ZHU Yong-chuan;XIONG Hong;GUO Chang-chun;JIANG Peng(Rice and Sorghum Research Institute,Sichuan Academy of Agricultural Sciences/Key Laboratory of Southwest Rice Biology and Genetic Breeding,Ministry of Agriculture and Rural Affairs,Deyang,Sichuan 618000,China;Crop Ecophysiology and Cultivation Key Laboratory of Sichuan Province,Deyang,Sichuan 618000,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2024年第5期909-921,共13页
Journal of Plant Nutrition and Fertilizers
基金
国家现代农业产业技术体系建设专项(CARS-01)
四川省科技计划项目(2022ZDZX0016)
四川省财政自主创新专项(2022ZZCX072)
四川省“天府万人计划”项目。
关键词
冬水田
稻鱼共作
氮肥管理
水稻产量
土壤养分
all-time logging-water paddy fields
rice-fish co-culture system
nitrogen management practice
rice grain yield
soil nutrients
作者简介
徐富贤,E-mail:xu6501@163.com;通信作者:蒋鹏,E-mail:jiangyipeng137@163.com。
