Some alternative functional forms for estimating economically optimal nitrogen fertilizer rates

Abstract

Estimation of economically optimal nitrogen (N) fertilizer rates involves fitting some production functions to crop yield data obtained at different N fertilizer rates. Most common production functions that have been used in previous N fertilizer response studies are quadratic and square root. In this paper, we employ two alternative production functions, namely Cobb‐Douglas and transcendental, for estimating economically optimal N fertilizer rates. Although these production functions are quite popular in production economics literature, they have not been used in N fertilizer response studies. The two functions were used to estimate economically efficient N fertilizer rates for corn (Zea mays L.). Estimation involves corn yield data obtained from six site‐years in New Jersey during the period 1992–1995. Each site‐year had 10 rates of fertilizer N applied as sidedress. The results obtained by the two functions were compared with those obtained for quadratic and square root models. Economically optimal mean rate for each model was computed assuming that average profits are maximized over observed site‐years. Mean economically optimal N rates for the four models at a common fertilizer‐to‐corn price ratio ranged from 184 kg N ha^‐1 for the transcendental to 344 kg N ha^‐1 for the Cobb‐Douglas functions. Statistical analyses indicate that the transcendental model is a better predictor of economically optimal N fertilizer rates than the other three models.     

Corn and soybean grain yield responses to soil amendments and cover crop in upland soils

A field study was conducted on upland soils for six years to determine interactive effects of winter wheat (Triticum aestivum L.) cover crop, organic and inorganic soil amendments on grain yields and nutrient utilizations in a no-till corn (Zea mays)-soybean (Glycine max) rotation. Experimental design was a split-plot arrangement with four replicates. Cover crops were the main plots and fertilization treatments used as sub-plot. Fertilization treatments included an unfertilized control, poultry litter, poultry litter (PL) plus flue gas desulfurization (FGD) gypsum and inorganic N fertilizer applied every other year to corn. Corn grain yield and grain N and P uptake were greater with PL than inorganic fertilizer in 2014 and 2016. Addition of FGD gypsum to PL significantly increased corn grain yield by 15% in 2016. Cover crop increased corn and soybean grain yields in a year with less seasonal rainfall possibly by conserving soil moisture.     

无人机搭载数码相机航拍进行小麦、玉米氮素营养诊断研究

精准施肥是减少农业面源污染的重要技术之一,而土壤养分测试与作物营养诊断是其实施的技术保障,特别是在农业规模化经营方式下,急需发展快速、经济、无损的作物氮素营养诊断技术。本文在应用数字图像进行冬小麦、夏玉米氮素营养诊断研究的基础上,将数码相机搭载到无人机上,利用无人机航拍技术采集作物冠层数字图像,研究不同航拍高度下冠层图像相关色彩参数反演冬小麦和夏玉米氮素营养状态的差异,以确定适宜的航拍高度与敏感的色彩参数,建立利用无人机航拍数字图像诊断冬小麦和夏玉米氮素营养状态模型。研究结果表明:在冬小麦拔节期适宜的航拍高度是16 m,敏感的色彩参数是可见光大气阻抗植被指数(VARI),诊断模型为:冬小麦茎基部硝酸盐浓度=2.103 4e18.874VARI;夏玉米大喇叭口期适宜的航拍高度是50 m,敏感色彩参数是蓝光标准化值[B/(R+G+B)],诊断模型为:夏玉米第1完全展开叶叶脉硝酸盐浓度=1.526?1032?[B/(R+G+B)]50.445。依据建立的航拍方法与诊断模型,分别对冬小麦、夏玉米进行了氮素状态监测的验证,结果表明诊断结果与冬小麦、夏玉米实测数据的决定系数分别为0.80和0.85,且均在P0.01水平显著相关。最后将研究结果进行应用,生成了冬小麦、夏玉米氮肥追肥作业图。利用无人机搭载数码相机对冬小麦、夏玉米进行氮素营养诊断简单、可行,但仍有一些技术细节需要完善,以提高该技术的实用性。     

施肥对小麦/玉米带田养分吸收及土壤硝态氮累积的影响

小麦与玉米间作是西北干旱灌区常见的高产栽培模式,为了给小麦/玉米带田高效施肥提供科学依据,通过在干旱灌区进行的小麦/玉米带田田间试验,研究了不同施肥模式对小麦/玉米带田产量、养分吸收及土壤硝态氮累积的影响。结果表明,以有机肥与化肥配施、养分均衡供给与合理运筹为核心的优化施肥模式(施有机肥22.5 t/hm2、N 300 kg/hm2、P2O5 120 kg/hm2、K2O 120 kg/hm2,有机肥、全部磷钾肥及20%的氮肥做底肥,80%的氮肥在小麦三叶期追施10%、小麦挑旗期追施20%、玉米喇叭口期追施30%、玉米灌浆中期追施20%)促进了间作体系作物植株对氮、磷、钾等养分的吸收,相对于增量施肥模式,优化施肥模式的氮肥偏生产力和氮肥农学效率分别提高了38.8%和36.9%,氮肥利用效率增加了14百分点,0～120 cm土层土壤硝态氮累积量减少43.9%～58.0%,小麦产量达5 358 kg/hm2,玉米产量达12 453 kg/hm2。     

石灰性紫色土种植小麦适宜施肥量的研究

  目的  目前我国小麦施肥效应研究主要集中在中部及北方地区,南方石灰性紫色土上小麦施肥效应及适宜施肥量尚不清楚。  方法  2018年10月至2020年5月在四川盐亭县青峰村石灰性紫色土农田,设农户习惯施肥（FP）、地方科技部门推荐施肥（ST）、养分专家系统优化施肥（NE）、优化施肥配施锌肥（NE + Zn）和优化施肥增减氮肥等12个处理,进行小麦施肥小区试验。  结果  石灰性紫色土上不同施肥处理对小麦的生物量和产量影响显著,而对千粒重无明显影响;NE + Zn处理产量最高,即优化施肥配施锌肥小麦增产效果显著,与FP处理相比平均增产约20%;不施氮肥和氮肥用量增减对小麦影响不明显,但不施磷肥则影响显著:相对于NE + Zn处理减产约30%。  结论  石灰性紫色土种植小麦的推荐施氮量为N 93 kg hm?2,同时配施磷肥和锌肥小麦有显著增产效果。     

优化施肥条件下华北冬小麦/夏玉米轮作体系的土壤氨挥发

采用密闭室间歇通气法研究优化施肥条件下华北冬小麦/夏玉米体系的土壤氨挥发损失。结果表明,肥料氮素氨挥发损失主要发生在施肥后的14 d 内, 冬小麦和夏玉米两个生长季氨挥发损失总量及其损失率均表现出随施氮量的降低而降低,玉米季氨挥发损失高于小麦季。习惯施肥小麦季和玉米季氨挥发总量是氮肥减量后移的2.28和2.03倍,而氮肥减量后移处理的小麦和玉米产量显著高于习惯施肥。氮肥后移可节省氮肥30%,是降低氨挥发损失的理想施肥方式。     

Application of the Bray–Mitscherlich Equation Approach for Economically and Environmentally Sound Fertilization of Field Crops in Hungary

Abstract

A database was compiled from the results of Hungarian long‐term N, P, and K fertilization field trials published between 1960 and 2000. Database correlations were described between the soil organic matter (SOM) content of PK (N control) plots and the responses of winter wheat and corn to N application; between the soil P test (ammonium lactate, AL) values of NK (P control) plots and the responses of wheat and corn to P application; and between the soil K test (ammonium lactate, AL) values of NP (K control) plots and the responses of wheat and corn to K application, using the Bray–Mitscherlich equation approach. The nutrient responses were expressed as both relative yields and surpluses. The database also made it possible to investigate how the responses of winter wheat and corn to N, P, and K fertilization were affected by the available nutrient contents, soil texture, pH, and carbonate status, soil type, and nutrient supply category of the control plots. Based on the correlations established in the database, new, more accurate soil N, P, and K supply categories were elaborated, providing opportunities for cost saving and environmentally sound fertilizaton of Hungarian crops.     

利用正交趋势分析进行大面积经济施肥建模

以田间肥料效应试验为基础,利用正交趋势分析建立了大面积经济施肥的数学模型,分析了建模的理论与方法,讨论了模型的特点。该模型反映了作物产量、需肥量和土壤供肥量三者之间的关系。通过测试土壤供肥量来确定肥料效应方程,从而计算经济合理施肥量。水稻大面积施肥试验证明了该施肥模型有较高的准确性和敏感性。     

砂姜黑土强筋小麦施肥技术研究

通过田间试验研究了施用不同肥料和不同施肥方法等对强筋小麦养分吸收和产量品质的影响。结果表明:在氮肥用量相同时,氮肥后移小麦产量和品质均好于全部基施(习惯施肥)处理;高氮和硫酸铵处理能提高强筋小麦的品质。磷酸二铵提高小麦产量效果好于过磷酸钙,而对子粒品质影响则过磷酸钙好于磷酸二铵;高量磷肥虽然不能进一步提高小麦产量,但能改善小麦的品质。增施有机肥和钾肥可促进小麦对N、P、K养分的吸收,显著提高小麦产量和品质,是砂姜黑土区优质高产强筋小麦重要施肥技术。锌肥能提高小麦产量和品质,含硫肥料有改善小麦品质的作用。试验表明,在砂姜黑土上,施用有机肥,稳定磷肥用量,加大氮、钾肥用量,配施锌肥和硫肥,分期施用氮肥(追肥量占总氮量比例在40%以上)有利于强筋小麦的优质高产。     

Effects of Nitrogen and Phosphorus Fertilizers and Intercropping on Uptake of Nitrogen and Phosphorus by Wheat,Maize, and Faba Bean

Abstract

One‐third of all the cultivated land area is used for multiple cropping and half of the total grain yield is produced with multiple cropping in China. There have been numerous studies on nutrient acquisition by crops in legume/non‐legume intercropping systems, but few on nutrient uptake in cereal/cereal intercropping. This paper describes a field experiment in which integrated wheat/maize and maize/faba bean systems were compared with sole wheat and sole faba bean cropping to assess the effects of intercropping on nutrient uptake by wheat, maize, and faba bean under various application rates of nitrogen (N) and phosphorous (P) fertilizers. Results show that both N and P fertilizers and intercropping enhanced N uptake by wheat, while only P fertilizer and intercropping increased P acquisition by wheat. The advantage of N uptake by border rows of wheat intercropped with maize declined with increasing N fertilizer application rate, but that of P acquisition was not affected by P fertilizer. The amounts of both N and P taken up by maize intercropped with faba bean were much higher than those by maize intercropped with wheat throughout the period of intercropping. Both fertilization and intercropping did not influence the N and P uptake by faba bean.     

长期不同施肥对(土娄)土肥力及作物产量的影响

在陕西关中典型土壤——塿土进行了连续25年的定位施肥试验。通过对25年来不同施肥小区土壤肥力差异的分析研究表明,多年连续施肥,可以明显提高土壤中有机质、全氮、全磷、碱解氮、速效磷含量以及作物产量,即单施化肥或有机—无机肥料配合施用,都可以增强土壤养分容量及其供应强度,有利于培肥土壤,提高作物产量,其中又以有机—无机肥料配合施用的效果更好。     

长期不同施肥对缕土肥力及作物产量的影响

在陕西关中典型土壤——蝼土进行了连续25年的定位施肥试验。通过对25年来不同施肥小区土壤肥力差异的分析研究表明，多年连续施肥，可以明显提高土壤中有机质、全氮、全磷、碱解氮、速效磷含量以及作物产量，即单施化肥或有机-无机肥料配合施用，都可以增强土壤养分容量及其供应强度，有利于培肥土壤，提高作物产量，其中又以有机-无机肥料配合施用的效果更好。     

长江流域冬小麦氮磷钾肥增产效应及其影响因素

  【目的】  分析长江流域施用氮、磷、钾肥对小麦产量的增产效应及主要影响因素的贡献率,旨在明确不同条件下施用氮、磷、钾肥对小麦产量的影响,为优化长江流域的小麦养分管理提供科技支撑。  【方法】  数据来源于国际植物营养研究所在我国长江流域开展的小麦田间试验,以及在中国知网通过检索到的有关施肥增产效应的文献,检索关键词为“冬小麦”、“冬小麦 + 产量”、“冬小麦产量 + 肥料利用率”,符合Meta分析标准的氮、磷和钾数据分别有724、624和658组。以不施某种养分处理为对照,以反应比作为该养分的增产效应值,采用Meta分析方法,定量分析施用氮、磷、钾肥对小麦产量变化的贡献,并分别分析施肥水平、基础地力水平、种植区域、土壤有机质、pH及土壤养分对产量效应的影响。  【结果】  与不施氮、磷或钾肥处理相比,长江流域冬小麦施用氮、磷和钾肥分别可显著增加小麦产量66.0%、17.9%和10.0%,以氮肥增产效应最高。基础地力对氮、磷、钾肥的增产效应均具有显著影响,氮、磷、钾肥均在低肥力土壤 (产量< 2.0 t/hm2) 上的增产率最高,分别为134.2%、30.0%和12.1%,氮、磷肥的增产效应与基础地力呈负相关关系。长江流域不同种植区域冬小麦氮、磷、钾肥的增产效应差异显著,以重庆市的氮效应最高,为136.1% [ln(R) = 0.859],以浙江省的磷效应最高,为39.1% [ln(R) = 0.330],贵州省的钾效应最高,为19.1% [ln(R) = 0.175]。氮、磷、钾肥均在酸性土壤的增产效果最好,增产效应随着土壤pH升高呈降低趋势,增产率分别为95.2%、29.4%和14.0%。土壤有机质含量对磷效应影响显著,对氮和钾效应影响不显著。当土壤全磷 > 1.0 g/kg、全钾 > 20.0 g/kg、碱解氮 < 80.0 mg/kg、速效磷 > 25.0 mg/kg及速效钾 < 90.0 mg/kg时,施氮增产效应最显著;在土壤全磷 < 0.7 g/kg和土壤速效磷 < 15.0 mg/kg时,施磷增产效应最显著;在土壤速效钾 < 90.0 mg/kg时,施钾增产效应最显著。  【结论】  长江流域冬小麦施用氮、磷、钾肥的增产率分别为66.0%、17.9%和10.0%,氮肥仍是影响长江流域冬小麦增产的最重要养分因子。基础地力决定着施肥效应,产量 < 2.0 t/hm2的土壤施肥的增产潜力最高。土壤肥力因素中,pH、有机质和矿质养分含量应作为肥料投入的依据。     

不同产量水平旱地冬小麦品种的氮磷利用差异分析

以9个旱地冬小麦品种为材料,通过田间试验研究不同产量水平旱地冬小麦品种氮、磷效率的差异。结果表明,不同冬小麦品种的籽粒和地上部吸氮量、吸磷量、氮磷收获指数、氮磷效率均存在明显差异。随养分投入水平的提高,不同产量水平品种的籽粒和地上部吸氮量、吸磷量均提高,高产品种随养分投入增加而提高的敏感程度高于中产和低产品种。氮磷收获指数随养分投入水平的提高没有明显的变化规律。低养分投入水平下,高产品种的氮肥回收率和偏生产力分别较低产品种高222%和49%;磷肥回收率和偏生产力分别较低产品种高766% 和49%,高投入降低了各产量水平品种的偏生产力。     

Comparison of statistical models for predicting cost effective nitrogen rate at rice–wheat cropping systems

Due to increased economic and environmental concerns, developing statistical models of crop yield has become one of the most important steps in determination of the cost effective rates (CERs) of nitrogen (N) fertilization. Although quadratic models are commonly used to describe wheat and paddy rice yield response to fertilizer rates in the Taihu Lake region of China, few studies have investigated why this model is selected over others. This study evaluated quadratic, exponential and square root models describing the wheat (Triticum aestivum L.) and rice (Oryza sativa L.) yield response to N fertilizer when determining the CERs, while also considering the environmental costs of N losses. All models fit the data almost equally well when evaluated using the variability and standard error statistics. However, there were marked discrepancies among models when calculating the CER of fertilization and the economic returns form Z-test. The quadratic model had a greater CER value (194?kg N ha^–1 for rice and 185?kg N ha^–1 for wheat) averaged over all sites than the exponential and square root models. The residuals obtained from the quadratic models were closer to a normal distribution than those of the other two models, indicating a less systematic bias. The mean economic uncertainties resulting from the quadratic model were more dependable than the other two models evaluated. These results show that the quadratic model best describes the rice and wheat yield responses and tends to indicate the optimal rates of fertilization while considering the environmental and economic effects of over fertilization for rice and wheat in the Taihu Lake region.     

基于GIS的河南省不同区域小麦氮磷钾推荐量与施肥配方

[目的]河南省是我国小麦种植大省,明确河南省不同区域小麦氮、磷、钾肥推荐用量,建立施肥配方图,对于当地小麦配方肥生产与合理施肥具有重要意义.[方法]河南省按照地理条件划分为平原适宜区、稻麦轮作区、南部盆地区、中部丘陵区、西部山地区5个区域.本研究共收集了2829组小麦田间试验和83.71万组土壤养分数据(1247组"3...     

水稻专用BB肥研究

根据化肥长期定位试验和全省化肥试验网的结果,广东省多数稻田施用氮磷钾营养元素的水稻增产效应为: Ｎ＞ Ｋ＞ Ｐ。大部分水稻土有效磷含量丰富或极丰富,施磷一般对当季水稻增产效果差甚至不显效。然而,连续数季植稻不施磷则导致氮钾施肥的增产效果下降而出现减产。综合养分不同丰缺类型水稻土的肥料效应和土壤养分平衡状况,通过肥料效应的回归分析,建立施肥量与产量之间的函数关系,确定广东省水稻专用BB肥营养配方及其产品的施用技术。经田间重复示范验证,本专用 Ｂ Ｂ 肥较之各地常规施肥和等实物量进口复合肥(15－15－15) 有明显的增产效果,并可节约肥料资源,降低施肥成本。     

Estimation of Optimum Nitrogen Fertilizer Rates in Winter Wheat in Humid Mediterranean Conditions,I: Selection of Yield and Protein Response Models

Nitrogen (N) fertilization management directly affects yield and grain protein content of soft red winter wheat, so there is a need to estimate the optimum N fertilizer dose needed to obtain the greatest yield and the desired protein content under a humid Mediterranean climate. The objective of this work was to select the best response models of wheat yield and protein content to applied N fertilizer. To fulfil this objective, 13 experiments were conducted in the years 2001, 2002, 2003, and 2004 in northern Spain where 0, 100, 140, 180, and 220 kg N ha^–1 were applied. The quadratic plateau model best described yield response to N fertilizer, with 182 kg N ha^–1 producing the maximum yield. The quadratic model was chosen for modeling protein response to N fertilization, and 176 kg N ha^–1 was the rate required for achieving protein contents greater than 125 g kg^–1.     

长期不同施肥对黄潮土区冬小麦产量及土壤养分的影响

【目的】分析长期施肥方式下小麦产量的变化规律,以探明黄潮土区小麦产量稳定性对不同施肥方式的响应机制,为黄潮土区合理施肥的管理及其土壤生态系统的改善提供依据。【方法】以 35 年长期定位试验为研究平台,设 5 种施肥方式:不施肥 (CK)、单施氮肥 (N)、氮磷钾配施 (NPK)、单施有机肥 (M)、有机无机配施 (MNPK),测定小麦的平均产量及土壤养分状况。【结果】小麦产量和肥料贡献率以有机无机配施 (MNPK) 最高,平均产量为 6393 kg/hm2;其次为 NPK 处理,与当年不施肥处理相比,产量提高了 374.2%;单施有机肥增产幅度位居第三;单施氮肥处理增产效果最低。单施氮肥处理小麦产量变异系数 (CV) 偏高 (26.72%～38.72%)、可持续性产量指数 (SYI) 偏低 (0.32～0.51),产量稳定性最低,MNPK 处理的CV 最低 (4.86%～7.76%)、SYI 最高 (0.79～0.89),产量稳定性最高,而单施有机肥处理 (CV = 5.44%～15.87%,SYI = 0.60～0.87) 的产量稳定性和生产可持续性不及 NPK 处理 (CV = 5.72%～9.67%,SYI = 0.75～0.83)。施用有机肥显著提高土壤有机质、全氮、有效磷和速效钾含量,其中 MNPK 处理 35 年土壤有机质、全氮、有效磷、速效钾平均含量分别较 CK 处理提高 1.20、1.18、16.13、0.95 倍,增加幅度最为显著。通过相关分析可得,小麦产量与土壤有机质、全氮、有效磷和速效钾含量呈极显著正相关关系 (P < 0.01)。【结论】施肥处理均可有效提高黄潮土区小麦产量,以有机无机配施增产效果最佳,最有利于促进小麦产量稳定性、提高产量可持续性指数,提升土壤有机质、全氮、有效磷、速效钾含量。因此,有机无机配施的施肥方式最为合理,有利于保持黄潮土养分均衡,促进农田生产力稳定。     

Relationships between relative crop yields,soil test phosphorus levels,and fertilizer requirements for phosphorus

Abstract

More uniformity in methods of deriving fertilizer P recommendations from crop response data should improve accuracy and precision of fertilization rates. Experimental data that relate crop yields to soil test levels and describe the effect of fertilizer P on soil test levels provide the basis for determining fertilization rates for specific crop‐soil situations. A modification of the Mitscherlich equation was used in derivation of a new equation for calculating fertilizer P requirements as a function soil test levels of P. The equation was applied to response data for 4 crops.

Response curves and fertilizer requirements as calculated for corn, soybeans, alfalfa, and clover‐grass indicated that soybeans yielded relatively more than the other three crops at low soil test levels of P. Corn and alfalfa required higher soil test levels to reach 95% maximum yield and required higher rates of fertilizer P when initial test levels were low.