Yield and water use responses of winter wheat to irrigation and nitrogen application in the North China Plain

With increasing water shortage resources and extravagant nitrogen application, there is an urgent need to optimize irrigation regimes and nitrogen management for winter wheat(Triticum aestivum L.) in the North China Plain(NCP). A 4-year field experiment was conducted to evaluate the effect of three irrigation levels(W1, irrigation once at jointing stage; W2, irrigation once at jointing and once at heading stage; W3, irrigation once at jointing, once at heading, and once at filling stage; 60 mm each irrigation) and four N fertilizer rates(N0, 0; N1, 100 kg N ha~(-1); N2, 200 kg N ha~(-1); N3, 300 kg N ha~(-1)) on wheat yield, water use efficiency, fertilizer agronomic efficiency, and economic benefits. The results showed that wheat yield under W2 condition was similar to that under W3, and greater than that under W1 at the same nitrogen level. Yield with the N1 treatment was higher than that with the N0 treatment, but not significantly different from that obtained with the N2 and N3 treatments. The W2 N1 treatment resulted in the highest water use and fertilizer agronomic efficiencies. Compared with local traditional practice(W3 N3), the net income and output-input ratio of W2 N1 were greater by 12.3 and 19.5%, respectively. These findings suggest that two irrigation events of 60 mm each coupled with application of 100 kg N ha~(–1) is sufficient to provide a high wheat yield during drought growing seasons in the NCP.     

黄土高原半干旱地区春小麦施氮效应研究

于2003年在甘肃定西对旱地春小麦施氮效应与效益进行了初步研究。研究结果表明,在高降水变率的干旱年份,春小麦产量水平较低,施氮肥能增加产量以及穗粒数和千粒重,而且水分效率明显提高,各肥料处理之间产量和水分效率的变异系数达到10.1%和9.8%。其中以N105处理的产量及水分效率最高,分别为1.41t/hm2和5.17kg/mm。从经济施肥角度考虑,定西地区获得最佳经济产量氮的施用量为52.5kg/hm2。由于生育关键期的水分亏缺,各肥料处理之间的干物质无显著差异。     

优化氮肥配置提高冬小麦-夏玉米贮墒旱作栽培水氮利用效率

为探明与冬小麦-夏玉米周年贮墒旱作节水栽培模式相配套的氮肥高效施用技术,基于贮墒旱作栽培(冬小麦和夏玉米灌底墒水或出苗水,生育期内不灌水),在全年施氮量360 kg/hm2下开展了前后茬作物施氮量配比不同的大田试验.试验设置4种施氮处理,分别为冬小麦120 kg/hm2+夏玉米240 kg/hm2(W0N1);冬小麦1...     

Growth and nitrogen productivity of drip-irrigated winter wheat under different nitrogen fertigation strategies in the North China Plain

Excessive application of nitrogen (N) fertilizer is the main cause of N loss and poor use efficiency in winter wheat (Triticum aestivum L.) production in the North China Plain (NCP).  Drip fertigation is considered to be an effective method for improving N use efficiency and reducing losses, while the performance of drip fertigation in winter wheat is limited by poor N scheduling.  A two-year field experiment was conducted to evaluate the growth, development and yield of drip-fertigated winter wheat under different split urea (46% N, 240 kg ha^–1) applications.  The six treatments consisted of five fertigation N application scheduling programs and one slow-release fertilizer (SRF) application.  The five N scheduling treatments were N0–100 (0% at sowing and 100% at jointing/booting), N25–75 (25% at sowing and 75% at jointing and booting), N50–50 (50% at sowing and 50% at jointing/booting), N75–25 (75% at sowing and 25 at jointing/booting), and N100–0 (100% at sowing and 0% at jointing/booting).  The SRF (43% N, 240 kg ha^–1) was only used as fertilizer at sowing.  Split N application significantly (P<0.05) affected wheat grain yield, yield components, aboveground biomass (ABM), water use efficiency (WUE) and nitrogen partial factor productivity (NPFP).  The N50–50 and SRF treatments respectively had the highest yield (8.84 and 8.85 t ha^–1), ABM (20.67 and 20.83 t ha^–1), WUE (2.28 and 2.17 kg m^–3) and NPFP (36.82 and 36.88 kg kg^–1).  This work provided substantial evidence that urea-N applied in equal splits between basal and topdressing doses compete economically with the highly expensive SRF for fertilization of winter wheat crops.  Although the single-dose SRF could reduce labor costs involved with the traditional method of manual spreading, the drip fertigation system used in this study with the N50–50 treatment provides an option for farmers to maintain wheat production in the NCP.     

渗灌水肥耦合对同心圆枣生长发育的影响

[目的]本文旨在探究不同水肥耦合处理下旱区同心圆枣各因子的变化,阐明不同水肥耦合对促进枣树生长发育的影响.[方法]本文以8年生成龄枣树为研究对象,设置不同灌溉定额(W1:2250m3/hm2、W2:3000m3/hm2、W3:3750 m3/hm2)、施氮水平(N1:240 kg/hm2、N2:300 kg/hm2、N...     

Alternate partial root-zone irrigation with high irrigation frequency improves root growth and reduces unproductive water loss by apple trees in arid north-west China

Alternate partial root-zone irrigation (APRI) can improve water use efficiency in arid areas. However, the effectiveness and outcomes of different frequencies of APRI on water uptake capacity and physiological water use have not been reported. A two-year field experiment was conducted with two irrigation amounts (400 and 500 mm) and three irrigation methods (conventional irrigation, APRI with high and low frequencies). Root length density, stomatal conductance, photosynthetic rate, transpiration rate, leaf water use efficiency, midday stem and leaf water potentials were measured. The results show that in comparison with conventional irrigation, APRI with high frequency significantly increased root length density and decreased water potentials and stomatal conductance. No differences in the above indicators between the two APRI frequencies were detected. A significantly positive relationship between stomatal conductance and root length density was found under APRI. Overall, alternate partial root-zone irrigation with high frequency has a great potential to promote root growth, expand water uptake capacity and reduce unproductive water loss in the arid apple production area.     

小麦垄作栽培的肥水效应及光能利用分析

小麦垄作栽培中以垄沟内小水渗灌代替传统平作的大水漫灌 ,化肥以垄沟内集中条施代替传统平作的撒施 ,相对增加了施肥深度 ,由此灌溉水的利用率较传统平作提高 1 8 9%～ 3 2 2 % ,氮肥利用率提高1 2 7%～ 1 3 7%。垄作栽培由于改善了田间通风透光条件 ,光能利用率较传统平作提高 1 0 0 %～1 3 2 %。     

Effects of deep vertical rotary tillage on the grain yield and resource use efficiency of winter wheat in the Huang-Huai-Hai Plain of China

Tillage represents an important practice that is used to dynamically regulate soil properties,and affects the grain production process and resource use efficiency of crops.The objectives of this 3-year field study carried out in the Huang-Huai-Hai(HHH) Plain of China were to compare the effects of a new deep vertical rotary tillage (DVRT) with the conventional shallow rotary tillage (CT) on soil properties,winter wheat (Triticum aestivum L.) grain yield and water and nitrogen use efficiency at different productivity levels,and to identify a comprehensive management that optimizes both grain yield and resource use efficiency in the HHH Plain.A split-plot design was adopted in field experiments in the winter wheat growing seasons of 2016–2017 (S1),2017–2018 (S2) and 2018–2019 (S3),with DVRT (conducted once in June 2016) and CT performed in the main plots.Subplots were treated with one of four targeted productivity level treatments (SH,the super high productivity level;HH,the high productivity and high efficiency productivity level;FP,the farmer productivity level;ISP,the inherent soil productivity level).The results showed that the soil bulk density was reduced and the soil water content at the anthesis stage was increased in all three years,which were due to the significant effects of DVRT.Compared with CT,grain yields,partial factor productivity of nitrogen (PFP_N),and water use efficiency (WUE) under DVRT were increased by 22.0,14.5 and 19.0%.Path analysis and direct correlation decomposition uncovered that grain yield variation of winter wheat was mostly contributed by the spike numbers per area under different tillage modes.General line model analysis revealed that tillage mode played a significant role on grain yield,PFP_N and WUE not only as a single factor,but also along with other factors(year and productivity level) in interaction manners.In addition,PFP_N and WUE were the highest in HH under DVRT in all three growth seasons.These results provided a theoretical basis and technical support for coordinating the high yield with high resource use efficiency of winter wheat in the resource-restricted region in the HHH Plain of China.     

微喷水肥一体化对冬小麦产量和水分利用效率的影响

为探明不同微喷灌施氮方式对冬小麦产量及水分利用效率的影响,以‘济麦22’为材料,在底施纯氮105kg/hm~2条件下,2016年春季设置追施纯氮45(N1)、90(N2)和135kg/hm~2(N3),每个追氮量采用微喷灌拔节期一次性追施(JS)和分别在拔节、孕穗、开花和灌浆期4次等量追施(4T)2种方式,测定冬小麦的产量和水分利用效率。结果表明:1)微喷灌条件下,随施氮量的增加,冬小麦产量先增加后降低,以N2处理产量最高;相同施氮量下,分次施氮处理产量显著高于拔节期一次性施氮,产量的增加主要由于显著提高千粒重;2)拔节期一次性施氮提高冬小麦开花期群体叶面积指数,而分次施氮处理灌浆期的叶面积指数显著高于拔节期一次性施氮,相同施氮量下分次施氮延缓灌浆中后期旗叶的衰老,从而有利于花后干物质积累和粒重的提高,但过多施氮导致粒重下降,总干物质积累量减少;3)不同施氮量处理间水分利用效率以N2处理最高,相同施氮量下分次施氮处理水分利用效率显著高于拔节期一次性施氮处理。综上所述,与拔节期一次性施氮相比,微喷灌采用分次施氮显著提高冬小麦的产量和水分利用效率,微喷水肥一体化N2处理下分次施氮为最佳的高产高效氮肥运筹模式。     

不同生育期水分亏缺和施氮对冬小麦产量及水分利用效率的影响

【目的】研究不同生育期土壤水分亏缺和施氮对冬小麦产量及水分利用效率的影响,探讨小麦生长的水分亏缺敏感期和合理施氮量。【方法】以冬小麦小偃22为试验材料,设置4个氮肥水平和11个水分亏缺处理,采用盆栽试验,研究不同生育期水分亏缺和施氮水平对冬小麦水分利用效率、产量及其构成要素的影响。【结果】不同生育期土壤水分亏缺和施氮水平对冬小麦产量和水分利用效率有一定影响。与全生育期不亏水处理相比,返青期水分亏缺处理冬小麦干物质显著降低了7.70%,产量、水分利用效率显著增加了4.95%和7.56%;拔节期、抽穗期水分亏缺处理冬小麦干物质显著降低了13.69%,15.88%,产量显著降低了5.69%,8.06%,且对有效穗数、穗粒数也有显著降低作用;灌浆期水分亏缺对冬小麦产量影响不显著,但耗水量显著减少了5.44%,水分利用效率显著增加了8.02%。与全生育期不亏水处理相比,返青期+拔节期、返青期+抽穗期、返青期+灌浆期、拔节期+抽穗期、拔节期+灌浆期、抽穗期+灌浆期水分亏缺处理冬小麦干物质和产量均有显著降低,其中返青期+拔节期、拔节期+抽穗期水分亏缺处理冬小麦干物质显著降低了17.44%,17.57%,产量显著降低了11.60%和14.52%,水分利用效率显著降低了8.02%和7.56%,且对有效穗数、穗粒数也有显著降低作用。施氮对冬小麦产量和水分利用效率有显著促进作用。中氮处理(0.3 g/kg,N2)冬小麦产量最高,耗水量较低,水分利用效率较高。【结论】冬小麦对拔节期、抽穗期、返青期+拔节期、拔节期+抽穗期水分亏缺很敏感,中氮处理具有最高的产量和较高的水分利用效率。     

秸秆还田与水分管理对双季水稻氮素吸收及氮肥?利用率的影响

秸秆还田是促进农田养分循环的重要方式,也对提升农田地力有较好效果。以南方典型双季稻田为研究对象,设置三个秸秆还田水平和两种水分管理方式的两因子田间定位试验,于定位试验开展后的第5年通过测定早稻和晚稻季稻田土壤无机氮、微生物生物量氮动态、植株吸氮量动态以及收获期主要土壤肥力因子、水稻产量和植株各部分氮素累积量,分析秸秆还田与水分管理制度下水稻氮素吸收和氮肥利用率的特征及其影响因素。结果表明:秸秆还田提高了土壤有机碳和全氮含量以及土壤p H,长期淹水较之间歇灌溉降低了土壤有机碳、全氮和全磷含量。在氮肥用量一致条件下,早稻季秸秆还田降低了分蘖期土壤氮素有效性,导致水稻生育期内氮素吸收量显著下降,且显著降低水稻籽粒产量及氮肥利用率;氮肥利用率较对照下降2.0~7.6个百分点,且随秸秆还田量的增加而降低。晚稻季秸秆还田提高了生育期内土壤氮素有效性,显著提高了水稻生育期内氮素吸收量,增加水稻产量且显著提高氮肥利用率;氮肥利用率较对照提高8.6~13个百分点,且随秸秆还田量的增加而增加。研究表明,间歇灌溉和长期淹水灌溉两种水分管理方式对水稻氮素吸收、籽粒产量及氮肥利用率的影响差异不显著。早稻季秸秆还田配合长期淹水灌溉将加剧水稻产量和氮肥利用率下降。双季稻稻田实行间歇灌溉下的早稻季秸秆不还田、晚稻季秸秆全量还田(6 t/hm2)有利于获得较高水稻产量和氮肥利用率。     

施氮量对黄土高原旱地冬小麦产量和水分利用 效率影响的整合分析

【目的】明确氮肥在黄土高原地区不同种植条件下对冬小麦生产的影响及各条件下合理的施氮量。【方法】通过文献检索共获得82篇大田试验文献,包含355个独立研究的1 169组观测数据,采用整合分析比较氮肥在黄土高原不同区域、不同年均温、不同年降水量及不同耕层有机质含量下对冬小麦产量和水分利用效率的影响,并采用回归分析探究各分组产量和水分利用效率与施氮量间的关系。【结果】施氮整体上显著提高了黄土高原冬小麦产量和水分利用效率,相对增长率分别为66.09%和72.38%（P＜0.05）。施氮后西北部产量相对增长率（69.27%）高于东南部,水分利用效率增长率（65.53%）低于东南部;西北部在施氮量212 kg·hm ^-2时产量达到最高,东南部需多施15 kg·hm ^-2才能获得最高产量;西北部施氮232 kg·hm ^-2时水分利用效率最高,而东南部水分利用效率在施氮224 kg·hm ^-2时基本趋于稳定。施氮后年均温≤10℃地区产量和水分利用效率的相对增长率（79.12%,75.00%）均高于＞10℃地区;年均温＞10℃地区施氮189 kg·hm ^-2和187 kg·hm ^-2时产量和水分利用效率分别达到最高,而年均温≤10℃地区施氮225 kg·hm ^-2时产量才趋于最大,水分利用效率在施氮239 kg·hm ^-2时达到最高。施氮后在年均降水≤600 mm地区产量相对增长率（70.48%）更显著,而水分利用效率则在年均降水＞600 mm时更显著;年均降水≤600 mm地区在施氮量235 kg·hm ^-2和244 kg·hm ^-2时,产量和水分利用效率分别达到最高,年均降水＞600 mm地区实现高产的施氮量为250 kg·hm ^-2。施氮后耕层有机质含量≤12 g·kg ^-1条件下,产量和水分利用效率的相对增长率（78.24%, 86.55%）均高于＞12 g·kg ^-1条件,前者在施氮量226 kg·hm ^-2和212 kg·hm ^-2时产量和水分利用效率分别达到最高,而后者获得最高产量和最高水分利用效率的施氮量分别为163 kg·hm ^-2和175 kg·hm ^-2。【结论】在黄土高原,冬小麦在东南部和西北部获得高产的合理施氮量分别为227 kg·hm ^-2和212 kg·hm ^-2;年均温＞10℃地区合理施氮量为187 kg·hm ^-2,年均温≤10℃地区为239 kg·hm ^-2;年均降水＞600 mm地区合理施氮量为250 kg·hm ^-2,年均降水量≤600 mm地区为235 kg·hm ^-2;耕层有机质含量≤12 g·kg ^-1条件下的合理施氮量为226 kg·hm ^-2,高于12 g·kg ^-1时则为163 kg·hm ^-2。     

膜下沟灌水氮耦合对温室番茄根系分布和水分利用效率的影响

【目的】研究膜下沟灌水氮耦合对温室番茄根系分布和水分利用效率的影响,以获得较优的灌溉施氮模式。【方法】2011-09-2012-02在甘肃石羊河流域,以番茄品种"保罗塔"为供试材料,采用田间试验,设置1 485,2 080m3/hm2 2个灌水水平和225,410和630kg/hm2 3个施氮水平,进行完全随机区组设计,共6个处理,研究膜下沟灌水氮耦合对番茄根系分布和水分利用效率的影响。【结果】温室番茄根系主要集中在60cm以上的土层,随着土层深度的增加,根长密度呈指数下降;施氮过低或过高均可以导致番茄根系长度、产量和水分利用效率显著减小。在施氮量较低(225～410kg/hm2)时,随着灌水量的增加,番茄根系长度显著增加;当施氮量较高(630kg/hm2)时,番茄根系长度显著减小。当施氮量相同时,随着灌水量的增加,番茄产量显著增加,而水分利用效率显著降低。番茄产量与根系表面积呈显著正相关关系。【结论】在西北干旱地区,低水中氮(灌水量为1 485 m3/hm2、施氮量为410kg/hm2)处理为较理想的水氮耦合模式。     

覆膜时期和施氮量对陇东旱塬玉米产量和水氮利用效率的影响

[目的]以抗逆性强的紧凑型玉米品种先玉335为供试作物,研究施氮量、覆膜时期及其互作对陇东旱塬玉米生理指标、产量性状及水氮利用效率的影响,以期为陇东旱塬区玉米高产高效栽培提供理论依据.[方法]2012年11月至2019年11月,连续设置覆膜时期(春季覆膜和秋季覆膜)和施纯N量(0、75、150、225、300、375、...     

泾惠渠灌区不同水氮供应对冬小麦氮素吸收运转的影响

【目的】研究泾惠渠灌区不同水氮供应对冬小麦植株氮素吸收运转的影响,为泾惠渠灌区提供合理的灌水施肥运筹方式。【方法】在泾惠渠灌区,通过田间小区试验研究不同灌水(W_(90)和W_(120),即灌水定额为90和120mm)和施氮(底肥60和120kg/hm~2,追肥0,60和120kg/hm~2,即施氮的底追肥处理组合为N_(60/0),N_(60/60),N_(60/120);N_(120/0),N_(120/60),N_(120/120))对冬小麦籽粒产量、各部位氮素积累量、氮素利用效率等的影响。【结果】除净积累量对籽粒氮的贡献率及氮素收获指数外,灌水和施氮对冬小麦籽粒产量、各器官氮素积累量、氮素转移量、氮素利用效率、氮肥农学利用效率均有显著影响。低水处理(W_(90))的籽粒产量、氮素积累量、氮肥农学利用效率显著高于高水处理(W120),其中产量增幅为4.88%~7.44%,植株氮素积累量增幅为6.15%~18.66%,氮肥农学利用效率增幅为19.48%~35.94%。随施氮量的增加,冬小麦籽粒产量、氮素积累量均呈显著增长趋势,其中籽粒产量表现为N_(0/0)(5 653.68kg/hm~2)N_(60/0)(6 777.71kg/hm~2)N_(60/60),N_(120/0)(7 165.63kg/hm~2)N_(60/120),N_(120/60)(7 376.92kg/hm~2)N_(120/120)(7 659.88kg/hm~2);氮素积累量表现为N_(0/0)(188.97kg/hm~2)N_(60/0)(229.49kg/hm~2)N_(60/60),N_(120/0)(275.23kg/hm~2)N_(60/120),N_(120/60)(310.00kg/hm~2)N_(120/120)(327.40kg/hm~2);当施氮量过高时,继续增加施氮量对冬小麦籽粒产量和氮素积累量的调节作用不显著。总施氮量相同的条件下,适当提高追肥的施氮比例,有利于提高产量、各器官氮素积累量及各营养器官氮素转移量,其中N_(60/60)与N_(120/0)处理相比,W_(90)和W_(120)灌水水平下籽粒产量分别提高3.92%和4.44%,各器官氮素积累量提高11.43%~27.99%,各营养器官转移量提高18.37%~71.81%;N_(60/120)与N_(120/60)处理相比,各营养器官转移量提高15.06%~39.63%。【结论】综合考虑籽粒产量、氮肥农学利用效率和氮素利用效率等因素,灌水定额为90mm、底肥施氮量60kg/hm~2、追肥施氮量120kg/hm~2,即W_(90)N_(60/120)为本试验条件下泾惠渠灌区冬小麦的最佳水氮组合。     

膜下滴灌施肥对樱桃产量品质和土壤肥力的影响

为寻求膜下滴灌施肥条件下果树栽培的最佳水肥调控阈值,以樱桃为试验材料,灌水量和施肥量各设3个水平(即设计灌溉定额的70%、85%和100%及推荐滴灌施肥量的60%、80%和100%),传统畦灌冲施为对照,为寻求膜下滴灌施肥条件下樱桃栽培的最佳水肥调控阈值进行了研究。结果表明:灌水量、施肥量和水肥交互作用对樱桃的产量品质和土壤养分含量等指标有不同程度的影响。相比传统畦灌冲施方式,膜下合理滴灌施肥能得到更佳的产量品质和土壤肥力,能有效提高樱桃树的水分利用效率和肥料偏生产力。其中,最佳水肥组合是中水高肥(W_2F_3),其产量(3 174.61kg/hm~2)、纵径(23.15mm)、可溶性总糖含量(17.82%)和水分利用效率(9.69kg/kg)达到最高,可滴定酸较低(0.41%),主要吸水吸肥土层(20~40cm)的全氮含量最高,其他品质、速效养分和有机质等指标也处较高水平。该研究为果园拟定高效高产的滴灌施肥制度提供了数据支撑。     

灌溉频率对滴灌小麦土壤水分分布及水分利用效率的影响

通过田间试验,研究了不同灌水频率对滴灌小麦农田土壤水分分布及小麦水分利用效率的影响。结果表明:从整个生育期来看,在灌水量375 mm条件下,高频灌溉(每4天1次)处理0～40 cm土层含水率和土壤贮水量较高,而深层（40～100 cm）土壤较低;低频灌溉(每10天1次)处理有利于水分的下渗和侧渗,深层土壤含水率和土壤贮水量较高,但水分补给不及时,表层土壤含水率和贮水量偏低;总体上中频灌溉(每7天1次)处理有利于水分在土壤剖面中的均匀分配,有利于作物生长。中频灌溉产量和水分利用效率都最高,分别比高频灌溉和低频灌溉产量增加7.6%和13.5%,水分利用效率增加2.6%和9.9%。在当地自然气候条件下,滴灌小麦采用375 mm灌溉量和每7 d 1次的灌溉频率是较适宜的灌溉模式。     

水氮互作对石羊河流域春小麦群体产量和水氮利用的影响

【目的】探讨西北旱区春小麦最佳的水氮耦合形式。【方法】在甘肃石羊河流域绿洲区采用田间试验,研究不同生育阶段的水量分配以及氮肥处理对春小麦群体产量和水氮利用的影响。【结果】施氮量、拔节期和抽穗期灌水对干旱区春小麦的产量影响显著;施氮量168 kg/hm2,并于拔节期灌水90 mm、抽穗期灌水70 mm,小麦可获得较高的籽粒产量。水氮对小麦地上干物质累积量的影响与对籽粒产量的影响相似,但抽穗期灌水对地上干物质累积量影响不显著。在施氮量224 kg/hm2、抽穗期和灌浆期灌水均为50 mm的条件下,小麦可获得较高的收获指数。在生产中考虑提高小麦收获指数时,首先应保证较高的籽粒产量。分蘖期和灌浆期灌水均为30 mm时,小麦的水分利用效率高达2.424 kg/m3,但产量降低约45%。施氮量对小麦地上干物质和籽粒氮素累积量影响显著;拔节期灌水90 mm、施氮量168 kg/hm2时,小麦籽粒的氮素累积量最大。【结论】石羊河流域春小麦最优灌水施氮模式为:施氮量168 kg/hm2,全生育期灌水4次,拔节期灌水90 mm,分蘖期、抽穗期、灌浆期均灌水60 mm。     

华北平原不同施氮量与施肥模式对作物产量与氮肥利用率的影响

合理施肥是保证作物高产、减少面源污染的重要措施,以华北平原为研究区域,基于7个长期施肥试验,探讨不同施氮量及施肥模式（不施肥CK、化肥NPK、有机肥M、有机无机配施NPKM）对作物产量及氮肥利用率的影响。结果表明,作物产量与施肥量之间整体呈抛物线趋势,作物产量最高值均出现在NPKM处理。不同施肥模式对作物产量有一定影响,NPKM与NPK处理小麦产量无显著差异,且显著高于M、CK处理;NPKM、NPK、M处理玉米产量无显著差异,均显著高于CK处理。氮肥利用率随着施氮量增加呈下降趋势,不同施肥模式对氮肥利用率有一定影响,小麦季NPKM与NPK处理氮肥利用率无显著差异,且高于M处理,玉米季NPKM、NPK、M处理之间氮肥利用率均无显著差异。综合分析施氮量与有机肥替代率两因素对小麦产量的影响,在华北平原,利用有机肥替代化肥潜力可观,且不会显著降低作物产量,甚至增产,但为避免显著减产,在考虑提高有机肥替代率时,需要满足总施氮量的需求。     

轮作体系下麦/油减量施氮与水稻氮肥运筹对作物产量和氮素吸收的影响

为了研究麦/油-稻轮作体系麦/油减量施氮与水稻氮肥运筹对作物产量、氮素吸收和氮肥偏生产力的影响,于2017—2018年开展麦-稻轮作和油-稻轮作的田间试验,在麦/油季设置常规施氮(小麦,N 150 kg·hm^-2;油菜,N 180 kg·hm^-2)、减量施氮(小麦,N 120 kg·hm^-2;油菜,N 150 kg·hm^-2)2个处理,在水稻季N 150 kg·hm^-2用量基础上设置3个运筹M1~M3,基肥、分蘖肥、穗肥的用量比分别为2∶2∶6、3∶3∶4和4∶4∶2。结果表明:在麦-稻轮作体系下,小麦季减量施氮小麦产量、地上部生物量和地上部氮素吸收量分别显著(P<0.05)降低15.36%、14.21%和17.14%,小麦氮肥偏生产力显著(P<0.05)增加5.79%。小麦季常规施肥处理下,M3运筹的水稻产量最高,而减量施氮处理下,M2运筹的水稻产量、地上部氮素吸收量和氮肥偏生产力最高。在油-稻轮作体系下,油菜季减量施氮显著(P<0.05)降低了油菜的产量和地上部氮素吸收量,降幅分别为14.28%和16.76%。无论油菜季减氮与否,M3运筹的水稻产量、地上部生物量和氮肥偏生产力均最高。