摘要
【目的】在氮、磷、钾肥合理供应下,比较控释尿素和普通尿素中氮素在土壤-植物系统中的转化特点,挖掘控释尿素氮肥利用潜力和减少氮素损失的作用,定量研究控释尿素在稻田的去向和利用率,为高效施用控释肥料提供依据。【方法】通过田间微区试验,设置不施氮肥(CK)、^(15)N标记的粉末状普通尿素(U)和控释尿素(CRU)3个处理,研究不同生育时期水稻对肥料氮的吸收、分配和转运及肥料氮在稻田的去向和利用率。【结果】随生育期的推进,水稻植株茎和鞘的干物质量及^(15)N积累量逐渐增加,开花期达到最大值。开花期,与U处理相比,CRU处理水稻植株茎的干物质量提高13.8%,鞘的干物质量无明显变化,茎和鞘的^(15)N积累量分别提高62.5%和25.5%,随后由于营养器官干物质和^(15)N向籽粒的不断转移而降低。随着叶片的衰老脱落,叶的干物质量及^(15)N积累量从抽穗期开始逐渐下降,成熟期达到最小值。而穗的干物质量及^(15)N积累量从孕穗期开始不断增加,到成熟期达到最大值。成熟期,与U处理相比,CRU处理水稻茎、鞘、穗和地上部的干物质量及^(15)N积累量分别增加17.3%、13.2%、3.5%、3.7%和25.0%、20.0%、15.8%、13.3%,叶的干物质量及^(15)N积累量分别降低14.6%和15.2%。开花期到成熟期,CRU处理的水稻干物质及^(15)N转运量、转运率、对籽粒的贡献率分别为286.78 g·m^(-2)、32.3%、30.8%和2.69 g·m^(-2)、67.2%、83.8%,与U处理相比略有增加,但统计上差异不显著。但灌浆期到成熟期,CRU处理养分供应充足,促进了水稻籽粒的灌浆速率,促进了籽粒中干物质的积累及氮素的同化和营养器官中养分向籽粒的迅速转运。等氮量下,与U处理相比,CRU处理水稻产量和植株吸氮量略有增加,但差异不显著;施用CRU提高水稻植株^(15)N吸收量13.3%,提高水稻^(15)N利用率3.2个百分点,增加水稻植株氮素来自^(15)N肥料的百分比(Ndff)2.9个百分点,增加^(15)N土壤残留率0.9个百分点,提高^(15)N总回收率4.0个百分点,减少^(15)N损失率4.0个百分点。无论施用控释尿素还是普通尿素,土壤氮素均是水稻生长发育所需氮素的主要来源,水稻生育期吸收氮素来自土壤的氮素约占70%以上。肥料氮在土壤中的残留量随土层深度的增加而显著下降,水稻收获后,肥料^(15)N主要残留在0—20 cm土层中,约占总残留量的78%。其次是20—40 cm和40—60 cm土层,这两层土壤中肥料^(15)N残留量相近,约占总残留量的19%左右。而在60 cm土层以下,仍有微量的肥料^(15)N残留,占总残留量的4%以下。【结论】施用控释尿素可以增加水稻各生育期的干物质量和氮素吸收量,增加花后(尤其是灌浆期到成熟期)干物质和氮素的转运,在稳产的情况下,既提高了肥料氮利用率,也减少了肥料氮的损失。
【Objective】The purpose of this paper was to compare the characteristics of nitrogen(N)transformation in soil-plant system between controlled release urea and conventional urea under optimum nitrogen,phosphorus and potassium rates,and to explore the utilization potential of controlled release urea-N and its effect on reducing N loss,and to study quantitatively on the fate and recovery efficiency of controlled release urea in paddy soil,thus providing basis for the efficient application of controlled release fertilizer.【Method】A field microplot experiment was employed with three N fertilizer treatments(no N applied,CK;15N labelled conventional powder urea,U;15N labelled controlled release urea,CRU)to study fertilizer N uptake,distribution and translocation in rice,fertilizer N fate and recovery efficiency in paddy soil.【Result】Dry matter and 15N accumulation of stem and sheath by rice plants increased gradually along with the progress of rice growth,and reached the maximum at anthesis.Compared with U treatment,the dry matter of stem by rice plants in CRU treatment at anthesis increased by 13.8%,that of sheath was not significantly changed,and 15N accumulation of stem and sheath by rice plants in CRU treatment increased by 62.5%and 25.5%,respectively,then decreased due to the continuous transfer of dry matter and 15N of vegetative organs to grain.With the senescence of the leaves falling off,the dry matter and 15N accumulation of leaves decreased gradually from the heading stage,reaching the minimum at maturity.Dry matter and 15N accumulation of panicles increased from the booting stage,reaching the maximum at maturity.At maturity,compared with U treatment,the dry matter and 15N accumulation of stem,sheath,panicles,and aboveground by rice plants in CRU treatment increased by 17.3%,13.2%,3.5%,3.7%and 25.0%,20.0%,15.8%,13.3%,respectively,while those of leaves decreased by 14.6%and 15.2%,respectively.From anthesis to maturity,the dry matter and 15N translocation,translocation efficiency and contribution efficiency to grain in CRU treatment were 286.78 g·m-2,32.3%,30.8%and 2.69 g·m-2,67.2%,83.8%,respectively,slightly increased compared to U treatment,but not statistically significant.However,the nutrient supply from filling to maturity was abundant in CRU treatment,which promoted the grain filling rate of rice,and promoted the dry matter accumulation in grains,the assimilation of nitrogen,and the rapid transfer of nutrients from vegetative organs to grains.Compared with U,grain yield and N uptake of rice plants increased slightly,but there was no statistically significant difference;CRU treatment increased 15N accumulation by 13.3%,improved 15N use efficiency by 3.2 percentage points,increased N derived from 15N fertilizer by 2.9 percentage points,increased soil 15N residual rate by 0.9 percentage points,improved total 15N recovery efficiency by 4.0 percentage points,and reduced 15N loss by 4.0 percentage points.Regardless of application of controlled release urea or conventional urea,soil N was the main source of N for growth and development of rice,and the N from soil was more than 70%during rice growth period.The residual amount of fertilizer nitrogen in soil decreased significantly with the increase of soil depth.After harvest,fertilizer 15N mainly remained in the 0-20 cm soil layer,accounting for 78%of the total residue.The second was 20-40 cm and 40-60 cm soil layer,and the fertilizer 15N residue in the two soil layers was similar,accounting for about 19%of the total residue.Below 60 cm soil layer,there was still a trace amount of fertilizer 15N residue,accounting for less than 4%of the total residue.【Conclusion】Controlled release urea could improve dry matter and N accumulation,and increase the dry matter and N translocation after anthesis(especially from filling to maturity),and reduce the loss of fertilizer nitrogen while maintaining grain yield and improving fertilizer nitrogen use efficiency.
作者
李鹏飞
李小坤
侯文峰
任涛
丛日环
杜昌文
邢烈火
王少华
鲁剑巍
LI PengFei;LI XiaoKun;HOU WenFeng;REN Tao;CONG RiHuan;DU ChangWen;XING LieHuo;WANG ShaoHua;LU JianWei(College of Resources and Environment,Huazhong Agricultural University/Key Laboratory of Arable Land Conservation(Middle and Lower Reaches of Yangtze River),Ministry of Agriculture/Microelement Research Center,Huazhong Agricultural University,Wuhan 430070;The State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008;Wuxue Bureau of Agriculture,Wuxue 435400,Hubei)
出处
《中国农业科学》
CAS
CSCD
北大核心
2018年第20期3961-3971,共11页
Scientia Agricultura Sinica
基金
国家重点研发计划(2017YFD0200108)
国家公益性行业(农业)科研专项(201303103)
中央高校基本科研业务费专项(2662017JC010)
关键词
控释尿素
15N示踪技术
氮素去向
氮肥利用率
稻田
controlled release urea
15N tracer technique
fate of nitrogen
nitrogen use efficiency
paddy field
