基于长期氮肥示踪试验评估氮肥利用率算法的合理性  

Evaluation of the rationality of nitrogen use efficiency approaches based on long-term fate of nitrogen fertilizer tracing experiments

作　　者：巨晓棠 田雪 冀宏杰[2] 田昌玉[2] JU Xiao-tang;TIAN Xue;JI Hong-jie;TIAN Chang-yu(School of Tropical Agriculture and Forestry,Hainan University,Haikou,Hainan 570228,China;Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing,100081,China)

机构地区：[1]海南大学热带农林学院,海南海口570228 [2]中国农业科学院农业资源与农业区划研究所,北京100081

出　　处：《植物营养与肥料学报》2024年第7期1284-1294,共11页Journal of Plant Nutrition and Fertilizers

基　　金：海南省重大科技计划项目(ZDKJ2021008);海南大学科研启动基金项目[KYQD(ZR)-20098]。

摘　　要：氮肥利用率是衡量氮肥被作物利用的一个指标,常规采用的计算方法为差减法和15N示踪法,主要是通过作物吸收的氮量来计算氮肥利用率。由于这两种方法没有考虑氮肥在土壤中的残留和后效,显著低估了施用氮肥的实际效应。为此,国内外研究者一直在探索更实际的氮肥利用率计算法。不同的改进方法以不同的表现形式包含了氮肥的遗留效应,弥补了差减法和15N示踪法在短期试验中对实际氮肥利用率的严重低估,基本接近于实际氮肥利用率,但远高于常规差减法或15N示踪法估算值。在本文中定义的实际氮肥利用率(ANUE)为:在土壤残留示踪氮被完全消耗的条件下,作物地上部吸收肥料氮占施氮量的百分比。法国28年旱地作物的氮肥叠加利用率为61.3%~65.3%,中国太湖地区17年的水旱轮作体系示踪氮肥试验中氮肥叠加利用率为38.6%~43.0%。本研究采用Origin 2021的图形数字化工具,获取这两个长期定位试验数据,包括每季作物吸收15N、土壤残留15N数据,分别以耗竭耕层(0—20 cm)、1 m、2 m土体中的氮素残留量来计算氮肥利用率。以此为参照标准,评估土壤氮素平衡法和氮肥有效率法计算结果的合理性。基于2 m土体残留肥料氮的土壤氮素平衡法和氮肥有效率法,会高估旱地作物的氮肥利用率;而以耕层土壤残留肥料氮作为估计参数时,则与旱地实际氮肥利用率基本一致(61%~74%);而氮肥有效率(41%~52%)可以很好地估算我国太湖地区水旱轮作体系的实际氮肥利用率。因此,跨地块或作物系统的氮肥利用率比较,应选择适当的计算方法,以避免由不同方法导致的不可比性而产生误解。氮肥有效率法(将作物吸收和土壤残留氮均视为有效部分)可以通过短期试验获得接近实际的氮肥利用率,具有广泛的应用价值。Nitrogen use efficiency(NUE)is a key indicator for evaluating the crop uptake of nitrogen(N)fertilizer applied to cropland.The principal approaches for quantifying NUE include N difference and 15N tracer.However,these approaches significantly underestimated the actual efficiency of N fertilizer,as these approaches failed to consider the residual and legacy effects of N fertilizer in soil.Therefore,researchers all over the world have been investigating the more actual NUE.The NUE calculated by improvement methods is analogous to the actual NUE,but higher than the N difference or the 15N tracer approaches.This can be attributed to the differing forms in which various improvement methods incorporate the legacy effects of N fertilizer,thereby compensating for the underestimation of NUE using the N difference or the 15N tracer approaches in short-term experiments.In this review,the actual NUE is defined as the percentage of N fertilizer uptake by the crop aboveground to the amount of N fertilizer inputs,while completely consuming the residual N fertilizer in soil.The accumulative N recovery efficiency is 61.3%−65.3%of a 28-year upland cropping system in France,and 38.6%−43.0%of a 17-year paddy-upland rotation system in the Taihu Lake region of China.We obtained the data from the two long-term field experiments using the Digitizer tool of Origin 2021,including the crop 15N uptake and the residual 15N in soil.The NUE was calculated based on the N residual in the topsoil(0−20 cm),1 m,and 2 m soil,respectively.We analyzed and evaluated the rationality of the computed results of the soil N balance and N fertilizer efficiency approaches by comparing them to the actual NUE.The soil N balance and N fertilizer efficiency approaches significantly overestimated NUE when calculated by two meters of residual N in the soil.The surface(0−20 cm)soil residual N was found as a calculation parameter for estimating the actual NUE in these two approaches(61%−74%).However,the N fertilizer efficiency(41%−52%)was the only approac

关 键 词：氮肥利用率 差减法 15N示踪法 土壤氮素平衡法 氮肥有效率 

分 类 号：S143.1[农业科学—肥料学]