施肥进步在粮食增产中的贡献及其地理分异

采用中长期田间试验对８种模拟施肥模型在温带的海伦试验站、暖温带的沈阳试验站和亚热带的桃源试验站进行了６～１０年试验,以比较、评价施肥在粮食生产中的贡献．结果发现,施肥在作物产量形成中的贡献随施肥制度和气候的热量因素所影响;在最佳施肥条件下,施肥在产量中的贡献率分别为海伦（温带）３０％、沈阳（暖温带）３８％、桃源（亚热带）４４％．按这一实验结果可以一般地估计：当其他技术条件不变时,施肥在产量形成中的贡献率最高可达３０～４５％,随所在地区气候的热量条件而不同．     

农业生态系统养分循环再利用作物产量增益的地理分异

通过４个地点中长期田间试验联网比较获得以下结果,农业生态系统养分循环再利用的作物产量增益受气候的热量因素、化肥施用和养分循环再利用持续时间的长短等因素影响．在不施化肥情况下,保持０．８循环率养分循环再利用的平均粮食增产量自北向南分别是：温带黑龙江海伦２５３ｋｇ·ｈｍ－２（１０年平均）、暖温带辽宁沈阳１１２２ｋｇ·ｈｍ－２（６年）和喀左１３３２ｋｇ·ｈｍ－２（８年）、亚热带湖南桃源２８８４ｋｇ·ｈｍ－２（７年）;在施用ＮＰ化肥基础上保持养分循环再利用则分别为海伦２２５、沈阳６９４、喀左７８６、桃源１３２１ｋｇ·ｈｍ－２．循环回田的农家肥养分对作物增产有着明显的残效叠加作用,在施用ＮＰＫ化肥基础上保持养分循环再利用的作物增产率在试验期间的前３年平均为５％,后３年平均可上升至１４％．     

黄绵土坡耕地大豆的水肥产量效应

研究了不同施肥量(N、P配施)下黄绵土坡耕地大豆的水肥产量效应．结果表明,水分利用效率(WUE)与作物产量(Y)正相关,y＝0．0017l 0.0035WUE．单施磷时,作物产量和WUE随磷的增加而增大;单施氮时,作物产量和WUE随氯的增加先增大后降低,表明施用氮应该配合施用一定量的磷．施肥能显著提高作物产量和WUE,与不施肥相比,施肥时作物产量和WUE分别提高了86．76％一470．16％和69．64％一438．47．与单施氦、磷相比,氮、磷合理配施能提高作物产量和水分利用效率,适宜的N、P(P205)配施比例为1．3：1．     

间作对玉米品质、产量及土壤微生物数量和酶活性的影响

为了进一步深入了解禾本科作物和豆科作物间作的优势机理,研究了在不同施肥条件下玉米单作、玉米‖花生间作和玉米‖大豆间作对玉米籽粒品质、单株经济产量和生物产量﹑产量及土壤中细菌、真菌、放线菌和固氮菌数量及酶活性的影响。结果表明,在不施肥条件下玉米间作可以显著提高玉米籽粒蛋白质、油分和赖氨酸含量,但对淀粉含量影响不显著;在施肥条件下玉米间作可以显著提高淀粉和赖氨酸含量,但对油分和蛋白质含量的增加却影响不显著;间作在提高玉米籽粒淀粉、蛋白质和赖氨酸含量方面的效果没有该施氮水平(50kg/km²)显著。间作可以增加玉米产量及其单株经济产量和生物产量,其中在不施肥和施肥条件下产量分别比单作增加了3.7％、9.7％、19.0％和18.6％,但间作在增加产量方面的效果没有该施氮水平显著。间作在不同施肥条件下可明显增加土壤中细菌、真菌、放线菌和固氮菌的数量,且效果达到显著水平。土壤中的酶活性也显著受到间作的影响,在不施肥条件下玉米间作和单作土壤中的转化酶活性差异达到显著水平,在施肥条件下间作和单作土壤中转化酶和磷酸酶活性差异达到显著水平。4种微生物数量和4种酶活性之间呈显著或极显著正相关,玉米籽粒品质、产量及单株生物产量除与转化酶及磷酸酶活性部分相关不显著外,与土壤中的其它酶活性及微生物数量皆显著或极显著正相关。     

鄱阳湖流域长期施肥下双季稻田的土壤基础地力

为探讨鄱阳湖流域不同施肥措施的土壤基础地力变化规律,基于长期施肥定位试验(始于1981年),采集定位30年时的不施肥(CK)、施用氮磷钾肥(NPK)和氮磷钾肥与有机肥配施(NPKM)土壤,于2012—2014年进行连续3年的施肥和不施肥试验,分析水稻产量和土壤基础地力贡献率的差异及关键影响因子.结果表明:不论施肥与否,3年的水稻产量均表现出NPKM处理显著高于NPK和CK处理,尤其是在不施肥条件下,NPKM处理的年产量分别比CK和NPK处理增加37.7%～143.9%和20.8%～66.7%.3年间,CK、NPK和NPKM处理的土壤基础地力贡献率分别为41.8%～53.1%、45.2%～62.6%和59.1%～88.1%,且NPKM处理的土壤基础地力贡献率均显著高于NPK和CK处理.进一步分析发现,土壤有机质和有机碳平衡量与土壤基础地力贡献率呈显著正相关.总之,在鄱阳湖流域的双季稻田,长期有机无机肥配施有利于该地区土壤基础地力的提升,且土壤有机质和有机碳平衡是土壤基础地力变化的关键因子.     

水稻叶片性状和根系活力的QTL定位

应用由247个株系组成的珍汕97B/密阳46重组自交系(RIL)群体及其分子标记连锁图谱,检测控制剑叶、倒二叶、倒三叶的5个形态性状和控制根系伤流量性状的数量性状座位(QTL)。在9个标记区间检测到控制叶片形态性状的24个QTL,LOD值为2．9～11．8,单个QTL的表型变异贡献率为4．0％～32．5％;分别检测到56对和4对控制叶片形态和根系活力的上位性互作,绝大多数互作发生在2个不表现加性效应的座位之间。与该群体产量性状QTL的研究结果相比较,发现控制叶片性状和根系活力的QTL与产量性状QTL往往处于相似的染色体区间。     

稻田氮肥的氨挥发损失与稻季大气氮的湿沉降

通过田间小区与大田试验,对稻季期间氮肥的氨挥发损失和大气氮湿沉降状况进行了收集和监测。结果表明,每次施肥后的1～3日内氨挥发损失达到最大值,氨挥发损失受当地气候条件(如光照、温度、湿度、风速、降雨量)、施肥时期以及田面水的NH4^+-N浓度等因素的影响,大气氮湿沉降与施肥量和降雨量有关,稻季内由湿沉降带入土壤或地表水中的氮为7．51kg·hm^-2。其中,NH4^+-N的比例为39．8％～73.2％,平均为55．5％;稻季中总氨挥发量与湿沉降的NH4^+-N平均浓度和总沉降量的相关系数分别达到0．988和0．996,呈显著相关性。     

灌水量和滴灌施肥方式对温室黄瓜产量和品质的影响

以黄瓜为试验材料,研究灌水量和滴灌施肥方式对日光温室黄瓜生长、产量和品质的影响.设两个水分水平(100％ET0,W1;75％ET0,W2)和4种滴灌施肥方式处理,不同滴灌施肥方式处理按推荐施肥量(N∶P2 O5∶K2 O分别为360∶180∶540 kg·hm-2)的100％、66.6％、33.3％、0％(Z100、Z66、Z33、Z0)分8次滴灌施肥,剩余肥料一次性基施;另设不施肥处理为对照(CK).结果表明:滴灌施肥比例和水分与黄瓜的株高、叶面积、干物质量、产量和品质均呈正相关关系.W1 Z100处理的产量最高(67760 kg·hm-2);W2处理的平均水分利用效率比W1处理高9.4％,其中W2Z100处理的水分利用效率最高(47.71 kg·m-3),其产量比最高产量低3.4％却节水25％.与Z0相比,Z100的黄瓜产量和干物质量分别增加15.3％和16.8％;同时,黄瓜果实中维生素C、可溶性蛋白和可溶性糖含量增加;水分利用效率增加19.1％.W2Z100处理为温室黄瓜高产、优质、节水的最佳处理.     

水肥空间组合对冬小麦光合特性及产量的影响

以肥熟土垫旱耕人为土为供试土壤,用分层土柱试验法研究了不同土层水分、氮、磷空间组合对冬小麦不同生育时期光合特性及籽粒产量的影响.结果表明:与0～90cm土层整体湿润相比,上干下湿(0～30cm土层干旱胁迫,30～90cm土层湿润)水分处理显著降低了小麦叶片叶绿素相对含量(SPAD)、净光合速率(Pn)和籽粒产量.2种水分条件下,氮磷配施处理对叶片SPAD、Pn和小麦籽粒产量的影响最为显著,其次是施磷处理,而施氮处理影响不显著.不同土层施氮在2种水分条件下各指标的变化趋势相同,均表现为0～90cm土层施氮小麦叶片SPAD、Pn及籽粒产量显著高于0～30、30～60和60～90cm土层施氮.不同土层施磷在2种水分条件下各指标的变化趋势也相同,表现为0～90cm土层施磷小麦叶片SPAD、Pn和籽粒产量与0～30cm土层施磷间差异不显著.不同土层氮磷配施在2种水分处理下表现不同:整体湿润条件下0～90cm土层施肥处理的小麦叶片SPAD、Pn及籽粒产量最高,与0～30cm土层差异不显著,但二者均显著高于30～60和60～90cm土层处理;上干下湿条件下各土层施肥处理间小麦叶片SPAD差异不显著,0～90cm土层施肥处理小麦叶片Pn和籽粒产量显著高于30～60cm土层施肥处理,30～60cm土层施肥处理显著高于60～90cm土层施肥处理和不施肥处理.表明在2种土壤水分条件下,氮磷配施时仍应施入0～30cm土层.     

长期施肥对作物产量的贡献

以中国科学院沈阳生态试验站16年定位试验为平台,研究了8种施肥制度的增产效应与稳产性能。结果表明:不同施肥处理对作物产量有明显影响,作物平均产量NPK>NP>NK>N>PK>P>K>CK,不施N肥时(即P、K、PK等处理)作物产量低;肥料对作物产量的年际贡献率在N、NP、NK、NPK处理中总体呈上升趋势,而在P、K、PK处理中则表现出下降的趋势;从化肥N、P、K的增产效果上看,总趋势是N>P>K;作物年际间产量的变异系数随化肥的均衡施用呈下降的趋势;玉米在NPK处理时的稳产性能最好,大豆在PK处理的稳产性最好。     

连续施肥对农田黑土微生物功能多样性的影响

应用Biolog Eco微平板培养法研究了中国科学院海伦农业生态试验站20余年连续不同施肥处理(对照、氮磷钾、氮磷钾+秸秆、氮磷钾+猪粪1、氮磷钾+猪粪2和氮磷钾+猪粪3)下土壤微生物代谢功能多样性的变化。结果表明:长期施肥条件下,单施化肥和有机肥与化肥配施对土壤细菌、真菌数量影响不明显,但高量有机肥与化肥配施可以显著增加放线菌数量。Biolog结果表明,施用有机肥的平均颜色变化率高于单施化肥和对照。Shannon指数、Simpson指数和McIntosh指数均是有机肥和化肥配施高于化肥单施与对照。主成分分析结果表明,对照、NPK与其他几种处理有较明显的距离,说明有机肥的连年施用导致了土壤微生物代谢功能多样性的变化。     

Contribution of crop model structure,parameters and climate projections to uncertainty in climate change impact assessments

Climate change impact assessments are plagued with uncertainties from many sources, such as climate projections or the inadequacies in structure and parameters of the impact model. Previous studies tried to account for the uncertainty from one or two of these. Here, we developed a triple‐ensemble probabilistic assessment using seven crop models, multiple sets of model parameters and eight contrasting climate projections together to comprehensively account for uncertainties from these three important sources. We demonstrated the approach in assessing climate change impact on barley growth and yield at Jokioinen, Finland in the Boreal climatic zone and Lleida, Spain in the Mediterranean climatic zone, for the 2050s. We further quantified and compared the contribution of crop model structure, crop model parameters and climate projections to the total variance of ensemble output using Analysis of Variance (ANOVA). Based on the triple‐ensemble probabilistic assessment, the median of simulated yield change was ?4% and +16%, and the probability of decreasing yield was 63% and 31% in the 2050s, at Jokioinen and Lleida, respectively, relative to 1981–2010. The contribution of crop model structure to the total variance of ensemble output was larger than that from downscaled climate projections and model parameters. The relative contribution of crop model parameters and downscaled climate projections to the total variance of ensemble output varied greatly among the seven crop models and between the two sites. The contribution of downscaled climate projections was on average larger than that of crop model parameters. This information on the uncertainty from different sources can be quite useful for model users to decide where to put the most effort when preparing or choosing models or parameters for impact analyses. We concluded that the triple‐ensemble probabilistic approach that accounts for the uncertainties from multiple important sources provide more comprehensive information for quantifying uncertainties in climate change impact assessments as compared to the conventional approaches that are deterministic or only account for the uncertainties from one or two of the uncertainty sources.     

Fertilization regulates the response of wheat yield to interannual temperature variation in North China

Aims Understanding the effect of long-term fertilization on the sensitivity of grain yield to temperature changes is critical for accurately assessing the impact of global warming on crop production. In this study, we aim to assess the impacts of temperature changes on grain yields of winter wheat (Triticum aestivum L.) under different fertilization treatments in a long-term manipulative experiment in North China.Methods We measured grain yields of winter wheat under four fertilization treatments at the Yucheng Comprehensive Experimental Station each year from 1993 to 2012. We also measured air temperature at 0200, 0800, 1400 and 2000h each day since 1 January 1980. We then used the first-difference method and simple linear regression models to examine the relationship of crop yield changes to mean air temperature, mean daytime and nighttime air temperature in crop growing seasons.Important findings We found that increases in mean daily temperature, mean daytime temperature and mean nighttime temperature each had a positive impact on the grain yield of winter wheat. Grain yield increased by 16.7–85.6% for winter wheat in response to a 1°C increase in growing season mean daily temperature. Winter wheat yield was more sensitive to variations of nighttime temperature than to that of daytime temperature. The observed temperature impacts also varied across different fertilization treatments. Balanced fertilization significantly enhanced grain yields for winter wheat under a warming climate. Wheat plots treated with nitrogen and phosphorous balanced fertilization (NPK- and NP-treated plots) were more responsive to temperature changes than those without. This report provides direct evidence of how temperature change impacts grain yields under different fertilization treatments, which is useful for crop management in a changing global climate.     

不同施肥制度下茬口对作物产量增益、土壤养分状况及施肥贡献率的影响

根据1991—2002年共12年的田间试验,研究了不同施肥制度下,茬口对作物产量增益、土壤养分状况及对施肥贡献率的影响。结果表明:与重茬相比,豆茬较有利于作物的高产和稳产;施用氮肥使其产量增益减小,并且施用氮肥愈多,产量增益愈小;增施有机肥情况下,产量增益的减小更为明显。在土壤养分方面,豆茬不仅能提高土壤的供氮能力,还能改善土壤的供磷、供钾量,有助于土壤养分状况的改善;施肥制度进步能够提高作物产量;施肥贡献率随着施肥制度的进步逐渐增大,但其增幅趋缓;随着施肥制度的进步,施肥贡献率在豆茬和重茬上所表现的差异逐渐缩小,最后趋同。     

内蒙古伊金霍洛旗农业生产力的评估与预测

运用伊金霍洛旗40年的气象与农业统计资料,分析了气候与化肥使用量对于粮食产量的综合影响．选取综合模型为基础,将化肥对粮食气候生产潜力的影响考虑为调节因子,建立了基于气候和化肥使用量的粮食产量评估模型．同时,基于伊金霍洛旗地区人口、气候以及化肥的未来变化情景,预测了未来30年的粮食需求增长量,指出在满足当地人民对粮食作物基本需求的基础上,从目前到2010年期间退耕面积达622～5948hm^2,相当于原有耕地的3％～31％;从2010年到2020年期间退耕面积最大,达3263～8164hm^2,相当于原有耕地的17％42％;随后10年由于土地单位面积的增产是有限度的,而人口继续增长,将导致耕地面积有所回升,但变动幅度不会太大,基本维持在2020年的水平。     

不同施肥模式对下辽河平原水稻生态系统生产力及养分收支的影响

采用田间肥料试验,研究了不同施肥模式对稻田生态系统的生产力和养分收支的影响。结果表明:随养分配施均衡程度的增加,系统的生产力逐渐提高,其中氮磷钾处理的生产力最高;氮肥对水稻生产力的贡献最大(对生物量的贡献约20%,对籽实产量的贡献约34%),磷肥和钾肥的贡献相当;在水稻各部位对氮、磷、钾养分的吸收中,氮的吸收主要集中在籽实和秸秆中,磷的吸收则主要集中在籽实中,钾的吸收主要集中在秸秆中;在各施肥处理中,土壤全量养分和有机质的变化不大,而速效养分的变化较大,特别是速效磷库和速效氮库;单施化肥处理的土壤,其速效养分含量不高,而施有机肥处理土壤的速效养分含量较高,表明有机肥较有利于土壤养分的积累。     

施肥对潮棕壤钾收支及钾在作物体内分配的影响

通过15年的定位试验,研究了不同施肥制度下土壤K的收支及K在作物体内的分配.结果表明,施K肥处理的大豆籽实和秸秆中K浓度高于不施K肥处理;而施K肥处理的玉米籽实K浓度在各个处理间几乎没有变化.在不施K肥条件下,单一施用N肥或NP配施均可造成K的严重亏缺.保持农业系统养分循环再利用可以缓解K收支赤字,而配合适量K肥的施用可以实现作物高产,平衡土壤中K收支.     

Quantification of physical and biological uncertainty in the simulation of the yield of a tropical crop using present-day and doubled CO2 climates

The impacts of climate change on crop productivity are often assessed using simulations from a numerical climate model as an input to a crop simulation model. The precision of these predictions reflects the uncertainty in both models. We examined how uncertainty in a climate (HadAM3) and crop General Large-Area Model (GLAM) for annual crops model affects the mean and standard deviation of crop yield simulations in present and doubled carbon dioxide (CO2) climates by perturbation of parameters in each model. The climate sensitivity parameter (gamma, the equilibrium response of global mean surface temperature to doubled CO2) was used to define the control climate. Observed 1966-1989 mean yields of groundnut (Arachis hypogaea L.) in India were simulated well by the crop model using the control climate and climates with values of gamma near the control value. The simulations were used to measure the contribution to uncertainty of key crop and climate model parameters. The standard deviation of yield was more affected by perturbation of climate parameters than crop model parameters in both the present-day and doubled CO2 climates. Climate uncertainty was higher in the doubled CO2 climate than in the present-day climate. Crop transpiration efficiency was key to crop model uncertainty in both present-day and doubled CO2 climates. The response of crop development to mean temperature contributed little uncertainty in the present-day simulations but was among the largest contributors under doubled CO2. The ensemble methods used here to quantify physical and biological uncertainty offer a method to improve model estimates of the impacts of climate change.     

Tradeoffs between Maize Silage Yield and Nitrate Leaching in a Mediterranean Nitrate-Vulnerable Zone under Current and Projected Climate Scenarios

Future climatic changes may have profound impacts on cropping systems and affect the agronomic and environmental sustainability of current N management practices. The objectives of this work were to i) evaluate the ability of the SALUS crop model to reproduce experimental crop yield and soil nitrate dynamics results under different N fertilizer treatments in a farmer’s field, ii) use the SALUS model to estimate the impacts of different N fertilizer treatments on NO₃^- leaching under future climate scenarios generated by twenty nine different global circulation models, and iii) identify the management system that best minimizes NO₃^- leaching and maximizes yield under projected future climate conditions. A field experiment (maize-triticale rotation) was conducted in a nitrate vulnerable zone on the west coast of Sardinia, Italy to evaluate N management strategies that include urea fertilization (NMIN), conventional fertilization with dairy slurry and urea (CONV), and no fertilization (N0). An ensemble of 29 global circulation models (GCM) was used to simulate different climate scenarios for two Representative Circulation Pathways (RCP6.0 and RCP8.5) and evaluate potential nitrate leaching and biomass production in this region over the next 50 years. Data collected from two growing seasons showed that the SALUS model adequately simulated both nitrate leaching and crop yield, with a relative error that ranged between 0.4% and 13%. Nitrate losses under RCP8.5 were lower than under RCP6.0 only for NMIN. Accordingly, levels of plant N uptake, N use efficiency and biomass production were higher under RCP8.5 than RCP6.0. Simulations under both RCP scenarios indicated that the NMIN treatment demonstrated both the highest biomass production and NO₃^- losses. The newly proposed best management practice (BMP), developed from crop N uptake data, was identified as the optimal N fertilizer management practice since it minimized NO₃^- leaching and maximized biomass production over the long term.