基于产量反应和农学效率的小麦智能化推荐施肥方法研究

The study of intelligent fertilizer recommendation method for wheat based on yield response and agronomic efficiency

【目的】为更准确地优化小麦肥料用量,提高肥料利用效率,我们基于产量反应和农学效率,分别建立了适用于长江流域和北方地区的小麦养分专家系统(NE),并采用大量田间试验验证了其可行性。【方法】收集汇总来自于国际植物营养研究所中国项目部、团队研究以及公开发表的多年多点小麦田间试验结果,建立产量和养分吸收数据库,采用QUEFTS模型分析不同种植区域小麦养分吸收特征,分析小麦产量反应、农学效率和相对产量参数及其内在联系,构建施肥模型,开发小麦养分专家系统。于2011—2020年,在小麦主产区11省份开展了467个田间试验对系统进行校正和改进。每个试验包括6个处理:小麦养分专家系统推荐施肥(NE)、农民习惯施肥(FP)、土壤测试施肥(ST)以及基于NE的不施氮、不施磷和不施钾处理。调查了小麦产量、经济效益、养分回收率和肥料农学效率。【结果】1)将数据分为北方地区和长江流域两部分,经QUEFTS模型模拟小麦养分吸收结果显示,每生产1 t小麦籽粒地上部所需氮、磷和钾养分北方地区为25.6、4.6和20.1 kg,长江流域为20.6、3.9和16.1 kg;小麦对氮、磷和钾肥的平均产量反应北方地区为1.69、0.85和0.69 t/hm^(2),长江流域为2.60、0.99和0.72 t/hm^(2);小麦氮、磷和钾肥的平均农学效率北方地区为8.7、8.9和7.0 kg/kg,长江流域为12.6、12.2和8.4 kg/kg;小麦氮、磷和钾养分的平均相对产量北方地区为0.76、0.88和0.90,长江流域为0.59、0.83和0.87。2)田间试验结果显示,与FP处理相比,我国北方地区和长江流域NE处理氮和磷肥用量平均分别减少了37.4%和26.1%,钾肥用量增加了39.2%;与ST处理相比,氮、磷肥用量分别减少了18.2%、14.1%,而钾肥用量相当。NE处理的产量和经济效益较FP处理分别增加了0.22 t/hm^(2)和998元/hm^(2),与ST处理产量相同,但经济效益增加了260元/hm^(2)。NE处理氮肥回收率较FP和ST处理分别增加了12.9和4.6个百分点,农学效率分别增加了4.0和1.5 kg/kg;磷肥回收率分别增加了5.7和1.1个百分点,农学效率分别增加了2.9和0.6 kg/kg;钾肥回收率较FP处理提高了2.0个百分点,与ST处理相当。【结论】我国北方生产1 t小麦所需的氮、钾养分量高于长江流域,两个区域磷养分需求量差异较小。长江流域小麦产量对氮肥的反应以及氮肥农学效率均高于北方,两个区域磷肥和钾肥的产量反应和农学效率差异较小。经多年多点田间试验证实,分区域建立的小麦养分专家系统进行施肥推荐,可保证小麦产量,增加农民经济效益,提高肥料利用率,是解决我国小麦种植区小农户推荐施肥难题的科学方法。

【Objectives】Aiming to optimize fertilizer application rate and improve fertilizer use efficiency with a simple and easy-to-operate recommendation system,we constructed Nutrient Expert(NE)system suitable for the north of China and the Yangtze Valley,respectively,and verified their feasibility by large amount of field experiments.【Methods】The wheat yield and nutrient uptake database was setup using multi-year and-site wheat field experiments from International Plant Nutrient Institute(IPNI)China Program,our research group and the published literatures.QUEFTS model was used to calculate the nutrient uptake,yield response,agronomic efficiency and relative yield in the north of China and the Yangtze Valley,respectively,to establish the interrelationships among them,and construct a fertilizer application model and develop NE system for wheat.Totally 467 field experiments were conducted in eleven provinces in the main wheat producing areas of China from 2011 to 2020 to calibrate and improve the system.Each experiment included six treatments:fertilizer recommendation based on Nutrient Expert system(NE),farmers’practices(FP),conventional recommendation based on soil testing(ST),and N omission,P omission and K omission based on the NE treatment.Wheat yield,economic benefit,nutrient use efficiency and fertilizer agronomic efficiency were investigated.【Results】1)The calculation results by QUEFTS model showed that the aboveground N,P and K requirements to produce 1 ton of wheat grain were 25.6,4.6 and 20.1 kg in the north region,and 20.6,3.9 and 16.1 kg in Yangtze Valley,respectively;the average yield responses to N,P and K fertilizer were 1.69,0.85 and 0.69 t/hm^(2) in the north region,and 2.60,0.99 and 0.72 t/hm^(2) in the Yangtze Valley;the average agronomic efficiency of N,P and K fertilizer were 8.7,8.9 and 7.0 kg/kg in the north region,and 12.6,12.2 and 8.4 kg/kg in the Yangtze Valley.The average relative yield of N,P and K fertilizer were 0.76,0.88 and 0.90 kg/kg in the north region,and 0.59,0.83 and 0.87 kg/kg in the Yangtze Valley.2)The results of field validation showed that NE treatment applied 37.4%and 26.1%less N and P fertilizer and 39.2%more K fertilizer than FP treatment,and 18.2%and 14.1%less N and P fertilizer than ST treatment and the same amount of K fertilizer with ST.Compared with FP,NE treatment increased yield and net profit by 0.22 t/hm^(2) and 998 yuan/hm^(2);compared with ST,NE treatment produced the same yield but extra 260 yuan/hm^(2) of net profit.Compared with FP and ST treatments,NE increased N recovery efficiency by 12.9 and 4.6 percentage points,and the agronomic efficiency of N fertilizer by 4.0 and 1.5 kg/kg;increased P recovery efficiency by 5.7 and 1.1 percentage points,and the agronomic efficiency of P fertilizer increased by 2.9 and 0.6 kg/kg;increased K recovery efficiency by 2.0 percentage points than FP treatment and exhibited similar K recovery efficiency to the ST treatment.【Conclusions】The north of China requires more N and K,and similar P for one ton of wheat production,compared to the Yangtze Valley.The yield response to N and the agronomic efficiency of N fertilizers in the Yangtze valley are higher than in the north region,and both regions have similar yield response to P and K and the agronomic efficiencies of P and K fertilizers.The multi-year and-site field experiments verified the easy-to-operate and simplification of the constructed Nutrient Expert for Wheat system specified for the north region and the Yangtze Valley.