Effects of nitrogen fertigation frequency on yield and nitrogen retention in drip-irrigated cotton

Fertigation techniques have been widely used in drip-irrigated cotton. The timing of nitrogen (N) fertilizer injections then becomes a management question producers need guidance on. This study investigated the effect of nitrogen (N) fertigation frequency on drip-irrigated cotton. Experiments were conducted in the Southeastern Anatolia Region of Turkey in 2011 and 2012. A split-plot experimental design was applied. The main plots contained two different lateral spaces: A, one drip-line (lateral) per row; and B, one lateral for every two rows. Sub-plots were designed with different frequencies of fertigation as follows: a, the application of fixed amount of N at each irrigation cycle (5 days); b, the application of fixed amount of N every two irrigation cycles (10 days); and c, the application of one-fifth of the total N between the first irrigation and first flowering, two-fifths between the first flowering and formation of the first boll, and one-fifth between the formation of the first boll and last irrigation cycle. One-fifth of the total N was applied to the soil at sowing in all treatment regimens. The maximum cotton yield (4120 kg ha^?1) and highest total N content (2.57–2.94%) in the leaves were obtained with one lateral for every two rows and the application of fixed amount of N every two irrigation cycles (10 days). One-fifth of the total N might be applied to the soil at sowing, and the remaining N should be applied in equal doses (an average of 7 fertigations) every two irrigation cycles (10 days) by fertigation. However, further research fertigation methods for cotton, including the amount of N that needs to be applied and the use of different injection systems, is required.     

Influence of nitrogen nutrition on nitrate levels of strawberry leaf blades and petioles

Hydroponic and field experiments were conducted to assess the optimum nitrogen (N) levels in strawberry leaves for the appropriate management of its N nutrition under field or protected cultivation. Unlike the common view that leaf petiole is the right plant organ to sample for strawberries, the study showed that the leaf blade, of the most recently fully expanded leaf, is more responsive and therefore a better indicator of the N supply changes in the strawberry plant. This was attributed to the distinctive characteristic of strawberry plants to accumulate high concentrations of nitrates in leaf blades when there is luxury consumption of N.     

Relationship between rainfall-adjusted nitrogen nutrition index and yield of wheat in Western Australia

Abstract

Insufficient nitrogen applications may contribute to yield gaps in low rainfall environments of Western Australia (WA). This study tested a nitrogen nutrition index (NNI) for wheat tailored for low rainfall regions, which is based on rainfall-scaled dilution curves. We analyzed yield, shoot biomass, and nitrogen concentration from 32 field trials in WA. An empirical rainfall threshold of 400?mm (summer?+?growing season rainfall) returned two parallel dilution curves accounting for the reduction of critical N in drier and lower yielding conditions. Scatterplots of relative yield and rainfall-adjusted NNI returned a robust boundary function that may lead to greater adoption by growers. The NNI defined in this research study can be applied and further tested by growers in WA, but may also apply to other low rainfall environments, to close nitrogen related yield gaps.     

Effect of phosphogypsum application on the growth and Ca uptake of Komatsuna Brassica rapa L. cv. Natsurakuten

(pp. 1–7)
Application of phosphogypsum PG and limestone to Andisol were compared in terms of their effects on the growth and uptake of Ca in Komatsuna Brassica rapa L. cv. Natsurakuten. The studies were carried out in soil pot cultures, and both PG and limestone were applied to the Andisol at the rates of 0, 0.30, 0.75, 1.50 g kg⁻¹ in the form of CaO.

• 1) 

  Limestone application resulted in an increase in the soil pH. On the other hand, no change was observed in the case of PG application at pH 6.1 ± 0.1 regardless of the application rate. Both soil EC and water-soluble Ca increased in proportion to the PG application rate, and this increase was approximately 5 times greater than that observed when limestone was applied at 1.50 g kg⁻¹. The w-Ca/ex-Ca ratio (water-soluble Ca: 1 M acetic acid-extractable Ca) was clearly increased from 0.12 up to 0.26 in PG, while the value was slightly decreased from 0.12 to 0.05 in limestone.

       
  
  

地面灌溉技术参数对氮素运移分布影响的研究进展

地面灌溉是应用最广泛的灌水方法，通过优化地面灌溉设计和管理减少水氮淋失，正在成为研究的热点问题，该文对有关成果进行了综述。由于地面灌溉的尺度较大，加之土壤水力参数和溶质运移参数的空间变异，使得地面灌溉施肥条件下溶质(N)运移分布的田间试验研究，无论在技术上还是在投入上都具有一定难度。有关沟灌、畦灌和水平畦田灌溉施肥时水氮分布的田间试验结果指出，肥料(N)分布没有入渗水深分布均匀，且与土壤初始含水率、流量、土壤入渗参数、田面糙率和施肥时机等因素密切相关。在模拟研究方面，文献中报道的模型有纯对流模型、对流-弥散模型、基于活塞流的水平衡模型和传递函数模型等。鉴于地面灌溉条件下水氮运移的复杂性，在水氮运移分布的数学模拟、灌水技术参数和施肥方式对水氮淋失的影响以及灌溉施肥质量评价指标体系等方面尚需要进一步研究。     

施氮模式对夏玉米产量和籽粒灌浆的影响

为进一步明确夏玉米在基肥和拔节期施肥的基础上增施吐丝肥的增产机理,于2011年在中国农业大学吴桥试验站布置了田间试验。共设置4种施氮模式:即模式Ⅰ,施氮量90 kg·hm-2(播前90 kg·hm-2);模式Ⅱ,施氮量190 kg·hm-2(播前150 kg·hm-2+拔节40 kg·hm-2);模式Ⅲ,施氮量250 kg·hm-2(播前90 kg·hm-2+拔节160kg·hm-2);模式Ⅳ,施氮量300 kg·hm-2(播前50 kg·hm-2+拔节150 kg·hm-2+吐丝100 kg·hm-2)。本研究对比分析了不同施氮模式对夏玉米产量和籽粒灌浆的影响。结果表明,在施基肥和拔节肥的基础上,再追施吐丝肥,与不施吐丝肥的模式相比,其吐丝后11~20 d、21~30 d、31~40 d内,每天增加的枯叶数分别减少0.01~0.02片、0.01~0.05片、0.02~0.04片;吐丝后穗位叶SPAD值的峰值有所提高,灌浆中后期SPAD值下降延缓;模式Ⅳ与模式Ⅲ相比灌浆速率峰值提高8.5%,籽粒体积得到显著提高。夏玉米吐丝后籽粒的吸氮量显著提高(模式Ⅳ籽粒吸氮峰值分别是模式Ⅰ、Ⅱ、Ⅲ的1.65倍、1.45倍、1.31倍),氮收获指数增加2.5~13.3个百分点,穗粒数增加。与穗粒数相比,吐丝期增施氮肥(模式Ⅳ)对千粒重的促进更显著,可改善夏玉米产量因子和部分穗部性状,与模式Ⅰ、Ⅱ、Ⅲ相比,分别增产200 kg·hm-2、300 kg·hm-2、400 kg·hm-2。夏玉米增施吐丝肥可以延缓吐丝后光合面积下降,从而为籽粒灌浆提供较多的源,最终提高粒重和产量。     

施氮对不同肥力土壤小麦氮营养和产量的影响

【目的】农田养分供应是由土壤基础肥力和肥料投入共同决定的,不同土壤肥力下土壤养分供应能力和特征也不同。本文研究了河南省高、低肥力田块下,不同施氮量对小麦主要生育时期植株氮素营养和土壤硝态氮及产量的影响,以期为河南省同类生产条件下氮肥的合理施用和产量的提升提供参考和依据。【方法】2015—2016年,以小麦品种矮抗58为供试材料进行大田试验,分别设置0、120、225、330 kg/hm^2 4个施氮处理(表示为N0、N1、N2、N3),在开花期到成熟期调查施氮量对土壤硝态氮及产量的影响;在开花期、花后10天和花后20天,测定施氮量对小麦旗叶到倒4叶的叶片氮含量、SPAD值和氮素积累量,以及对植株和所有叶片氮含量的影响。【结果】从开花期到成熟期土壤中硝态氮含量随着施氮量的增加而增加,高肥力田块的土壤硝态氮含量显著高于低肥力田块的土壤硝态氮含量。施氮能显著增加低肥力田块产量,但是高肥力田块的产量均高于低肥力田块,与不施氮相比,低肥力田块的产量最大增幅是高肥力田块产量最大增幅的2.63倍。N1和N2处理下,在开花期和花后10天倒2叶的SPAD值高肥力田块显著高于低肥力田块,但在花后20天低肥力田块显著高于高肥力田块。在N1、N2和N3处理下,旗叶的氮含量在花后10天高肥力田块显著高于低肥力田块,但在花后20天则显著相反。开花期到花后20天,对于低肥力田块旗叶的氮素积累量对上4叶的贡献率最大(N0除外),最高达52.6%;高肥力田块,旗叶和倒2叶对上4叶的氮素积累量贡献率处在同等重要的位置,最高分别达39.9%和39.7%。花后10天到花后20天,高肥力田块不同叶位的氮素转运量和转运率均高于低肥力田块(N0除外)。【结论】增施氮肥可以通过提高土壤硝态氮含量来提高土壤供氮能力,高肥力田块的叶片转运量和转运率比低肥力田块高,低肥力田块通过提高施氮量增加的产量低于高肥力田块下的产量,因此,需改善农田基础肥力来提高产量。通过对高、低肥力条件下产量的分析发现,达到最高产量时的施氮量分别为213kg/hm^2和287 kg/hm^2。     

氮肥和品种及种植密度对春玉米机械化收获性状及产量的影响

机械化收获是提高农业生产效率的重要措施,但机械化收获受倒伏、籽粒脱水特性和收获籽粒含水率等的影响。为探讨春玉米形态结构与抗倒伏性之间的关系、籽粒脱水进程和收获籽粒含水率对品种、施氮量和种植密度的响应,该研究以先玉335和陕单609为试验材料,设置0、180和225 kg/hm² 三个氮肥水平、6.5×10⁴和8.5×10⁴ 株/hm² 两个种植密度,通过2 a大田试验研究品种、种植密度和氮肥对株高、茎粗、穗位系数、抗折强度、弯曲力矩、倒伏系数、灌浆末期籽粒脱水速率、收获籽粒含水率、产量和生物量等的影响。结果表明：不施氮条件下,株高和茎粗对倒伏系数影响较大;施氮条件下,倒伏系数主要受弯曲力矩、抗折强度和株高影响。施氮显著降低陕单609的倒伏系数（P<0.05）,施氮处理下陕单609的株高和茎粗较不施氮处理分别增加8%～21%和26%～45%,抗折强度和弯曲力矩分别增加157%～277%和72%～114%,倒伏系数降低30%～47%。施氮可降低籽粒脱水速率,推迟脱水进程,显著增加收获籽粒含水率（P<0.05）。施氮处理籽粒含水率较不施氮处理提高7%～9%。高密度处理收获籽粒含水率比低密度处理低3%（P<0.05）。先玉335的籽粒脱水速率快,收获籽粒含水率比陕单609低7%（P<0.05）。与不施氮处理相比,施氮处理产量和生物量分别显著提高92%和63%（P<0.05）。与低密度处理相比,高密度处理产量显著增加12%（P<0.05）。综上所述,春玉米的倒伏性、灌浆后期籽粒脱水速率及收获籽粒含水率受品种特性影响,也受施肥、栽培措施和气候条件的显著影响。选育籽粒脱水快的品种、适当增加种植密度并合理统筹氮肥施用量可以提高春玉米机械化收获适宜性。     

Influence of nitrogen nutrition on growth,nitrate reductase and nitrite reductase of seedlings of maize (Zea mays L. cv LG12)

The effects of three N levels on etiolated and green leaves of Zea mays were studied. It was found that the activity of both nitrate reductase (NR) and nitrite reductase (NiR) was affected, although differently, and the former showed higher sensitivity. NR activity rose with N increase, but different values in the three groups of seedlings appeared only after the second day in light/darkness; both nitrate and light were necessary to obtain a high level of activity. The interference of the N supply on NiR was observed only in seedlings grown in light. Seedling growth was also affected and the leaf weight appeared to correspond with the level of N supplied. In seedlings grown in darkness, the nitrate accumulated in the leaf increased with the decrease of the supplied N, whereas in light/darkness the opposite occurred. Different values of the leaf protein in the three seedling groups appeared only under light/dark and after the second day and by SDS‐PAGE they were found to be quantitative.     

利用15N标记研究氮素水平对大豆根瘤生长的影响

为了明确氮肥对大豆根瘤生长的影响,以东农47为试验材料,采用15N 标记和砂培的方法,进行了氮素营养水平对大豆根瘤生长及与根瘤固氮相关性的研究。结果表明,随外源氮水平增加,根瘤干重呈先增加后降低的变化趋势,当营养液氮浓度为50 mg/L时,有利于根瘤的生长;根瘤生长需要一定量启动氮,启动氮的作用维持到第3片复叶完全展开时（V3）对大豆根瘤的生长最有利;在盛荚期 （R4）和鼓粒始期 （R5）补充外源氮的供给抑制根瘤的生长。根瘤干重与植株中根瘤氮积累量、根瘤氮比例呈极显著正相关,根瘤干重与植株中氮积累量呈显著正相关。     

适宜灌水施氮方式提高制种玉米产量及水氮利用效率

为通过不同灌水施氮方式调控干旱区作物收获指数提高资源利用效率,以制种玉米"金西北22号"为供试材料,进行了为期2 a的田间试验。试验采用灌水方式（交替灌水、固定灌水、均匀灌水）与施氮方式（交替施氮、固定施氮、均匀施氮）完全随机组合设计,测定生育期内作物耗水量（evapotranspiration,ET）和成熟期植株的生物量、籽粒产量及其构成（穗长、穗粗、行粒数和千粒质量等）和作物吸氮量,折算收获指数（harvest index,HI）、水分利用效率（water use efficiency,WUE）和氮利用效率（nitrogen use efficiency,NUE）。结果表明,灌水施氮方式只对行粒数有显著影响。ET只受灌水方式影响,交替灌水较其他灌水方式显著减小ET。WUE表现为：灌水方式相同时,交替施氮和均匀施氮大于固定施氮;施氮方式相同时,交替灌水>均匀灌水>固定灌水。玉米的吸氮量、HI和NUE与WUE表现出相似的规律。2013年交替灌水均匀施氮下制种玉米的HI、WUE和NUE最大,较均匀灌水均匀施氮分别增加5.46%、11.41%和19.73%。交替灌水交替施氮（水氮同区）的表现与交替灌水均匀施氮相似。2014年的结果与2013年一致。综上,交替隔沟灌溉均匀施氮和交替隔沟灌溉交替施氮（水氮同区）有利于提高制种玉米的产量和水氮利用效率。     

Effects of nitrogen application frequency via subsurface drip irrigation on corn development and grain yield

Subsurface drip irrigation (SDI) has not only potential for water conservation, but also for improving nutrient use efficiency. Two nitrogen (N) application frequencies (every week versus every two weeks, via SDI) were compared in 2012 and 2013 on a Cozad silt loam in North Platte, Nebraska. The weekly treatment was fertigated every week for seven weeks in a row; the bi-weekly treatment was fertigated in weeks 1, 3, 5 and 7. Both treatments received the same total amount of N. There was a positive grain yield response to N application, but no advantage was found to a greater frequency of N application. Corn (Zea mays L.) grain yields and other indicators of corn growth and development (canopy-intercepted light, vegetation indices, indicators of chlorophyll content of corn plant leaves) were not affected by N application frequency.     

Effects of nitrogen fertilization method and tillage system on squash growth,nutrient uptake and fruit yield

Abstract

Squash, cv Dixie, grown on a Lakeland sand was subjected to factorial combinations of 3 tillage systems and 2 N application methods during 1979 and 1980. Fruit yield was greatest with a combination of moldboard plow tillage and application of 22 kg N/ha preplant and 18 kg/ha increments of N by fertigation 2, 3, 4, 5 and 6 weeks after planting. Plant growth and nutrient uptake were greatest and N available for potential contamination of the ground‐water was least with subsoil‐bed tillage and N application by fertigation. Disc harrow tillage with 67 kg N/ha preplant and 45 kg N/ha 4 weeks after planting resulted in 42% less yield, 61% less plant growth, 29 to 64% less nutrient uptake and more than 5 times as much N available for potential contamination of the groundwater as the best practices.     

Variation of nitrogen accumulation and yield in response to phosphorus nutrition of soybean (Glycine max L. Merr.)

Phosphorus (P) is essential macronutrient for soybean [Glycine max (L.) Merr.] growth and function. The objective of this study was to determine effect of phosphorus nutrition (including phosphorus nutrition level and interruption of phosphorus supply) on nitrogen accumulation, nodule nitrogen fixation and yield of soybean plants by ¹⁵N labeling with sand culture. The results showed that they all presented a single peak curve with improvement of phosphorus nutrition level, when phosphorus concentration of nutrient solution was about 31 mg/L, they all reached the maximum and effect of phosphorus nutrition level on nodule nitrogen fixation was lower than that on yield formation level. Interruption of phosphorus supply during soybean growth period, nitrogen accumulation and nodule nitrogen fixation were seriously inhibited, and yield was decreased significantly when interruption of phosphorus supply during V₃-R₁ and R₁-R₅ period, while interruption of phosphorus supply during R₅-R₇ period had no significant effect on nitrogen accumulation, nodule nitrogen fixation and yield. So soybean nitrogen metabolism and yield were sensitive to phosphorus nutrition in the V₃-R₅ period, those were not sensitive to phosphorus nutrition after R₅ period.     

Effect of nitrogen on yield,quality, and irrigation water use efficiency of drip fertigated grafted watermelon (Citrullus lanatus) grown on a calcareous soil

A two-year field experiment was conducted during the growing seasons 2016 and 2017 to investigate the response of drip fertigated watermelon to different rates of nitrogen (0, 10, 20, 30, and 40?g/m³ N) applied in the form of ammonium sulfate (AS). The combined effect of nitrogen (N) and sulfur (S) was investigated. Irrigation water use efficiency (IWUE) under the different N levels was, also, evaluated. N levels in the irrigation water induced a significant effect on yield parameters (total and commercial yields, dry matter yield, plant yield, and fruit number). Increasing the level of N also induced significant increases in fruit length and fruit fresh weight. IWUE was also significantly improved at high levels of N. Fertigation using modern techniques can be considered an efficient method in the delivery of N to the crop at N levels of 30–40?g/m³, as ammonium sulfate.     

Effects of tied-ridge,nitrogen fertilizer and cultivar on the yield and nitrogen use efficiency of sorghum in semi-arid Ethiopia

Moisture deficit, poor soil fertility and lack of improved varieties constrained sorghum production in north-eastern Ethiopia. An experiment was conducted in 2002 at Kobo and Sirinka in north-eastern Ethiopia to study the possible effects of seedbed, nitrogen fertilizer and cultivar on the yield and N use efficiency (NUE) of sorghum. The experiment was carried out in a split–split plot design with seedbed (tied-ridge vs. flatbed planting) as main plots, N fertilizer (0, 40 and 80 kg N ha^?1) as subplots and sorghum cultivars (Jigurti, ICSV111 and 76T1#23) as sub-sub plots, with three replications. At Kobo, the seedbed by cultivar interaction affected all parameters. Nitrogen fertilization increased biomass yield and NUE at both locations and grain yield at Sirinka. Cultivars showed different performance where ICSV111 and 76T1#23 were superior in grain yield, N uptake and concentration, N harvest index and NUE of grain (NUEg) compared with Jigurti. Thus, planting ICSV111 and 76T1#23 in tied-ridging and with N fertilization at Kobo and in flatbed and with N fertilization at Sirinka is recommended. This study revealed that tied-ridging is not a solution in all areas where moisture deficiency is a problem. Its effectiveness is affected by rainfall amount and soil type.     

几种有机和无机氮肥对草莓生长及其氮素吸收分配影响的差异

通过不同生育时期植株各部位的氮素分析,研究了不同商品有机肥和有机无机复混肥对大田草莓(FragariaAnanassa.c.v.Dutch.)植株生长及氮素吸收分配的影响。结果表明,施用不同肥料品种均可促进植物氮素吸收,提高氮素积累速率,促进氮素向果实中分配。在施等量氮素养分条件下,草莓器官的氮素吸收状况对不同氮肥品种反应不一。尽管无机肥处理的氮素积累速率和地上部全氮含量较高,但施用商品有机肥较无机氮肥或有机无机复混肥更能促进草莓生长发育和草莓果实产量的增加,说明无机氮不宜作为草莓基肥一次性施用。结果还表明,施肥处理氮素的日均积累量平均为10.8.mg/plant,而不施肥处理仅为5.1.mg/plant。在果实采收末期,不同处理草莓各器官的氮素分配趋势为果实茎和叶柄叶片根系。施用纯有机肥(OFA和OFB),果实中吸收的氮素超过植株吸收总量的一半,分别占53.5%和51.7%,无机氮肥处理(UN)和有机无机复混肥处理(OIF)的果实氮素分配率分别只有46.1%和39.8%。     

氮素对温室黄瓜开花后干物质分配和产量影响的模拟研究

了解氮素对干物质分配和产量的定量影响是实现温室黄瓜氮肥优化管理的前提.该研究通过黄瓜雌性无限生长型品种"戴多星"(Cucumis sativas.'Deltastar')不同定植期和开花后不同氮素处理试验,定量分析了氮素施用水平对该类型黄瓜开花后干物质分配和产量的影响,并建立了开花后分配指数和采收指数与盛果期叶片氮浓度的关系方程.在此基础上,建立了氮素对黄瓜开花后干物质分配和产量影响的预测模型,并用独立的试验数据对模型进行了检验.结果表明,模型对茎干物质量、叶干物质量和果实干物质量及黄瓜产量(鲜质量)预测值与实测值之间基于1:1直线之间的决定系数R2分别为0.945、0.943、0.990、0.955;相对预测误差RE分别为13.0%、12.3%、9.2%、16.8%.本模型可预测不同氮素水平下温室黄瓜地上部各器官干物质量和产量,可以为中国温室黄瓜生产的氮肥优化管理决策提供参考.     

Effect of nitrogen application on growth and yield of pumpkin

Evaluation of any crop response to different nitrogen amounts is important for determining the amount that can be considered as optimum from economical and environmental point of view. This study was conducted to (1) evaluate the growth and yield of pumpkin (Cucurbita pepo L.) under different nitrogen rates and (2) determine the nitrogen use efficiency (NUE) of pumpkin in two growing seasons (2013 and 2014). In both growing seasons, nitrogen fertilizer (at three rates including 50, 150, and 250 kg ha^?1) was band-dressed on the planted side of each furrow, coinciding with 4–6 leaves stage and flowering. Crop performance over 2 years was evaluated by measuring shoot dry matter, crop growth rate (CGR), leaf area index (LAI), leaf area duration (LAD), intercepted PAR (PAR_i), radiation use efficiency (RUE), shoot nitrogen uptake, water use efficiency (WUE), NUE, and fruit and seed yield. The results showed that in both growing seasons, the highest growth and yield of pumpkin were obtained by applying 250 kg N ha^?1 (using urea fertilizer containing 46% nitrogen). Increased nitrogen rate from 50 to 250 kg ha^?1 resulted in 87.3%, 27.0%, 62.1%, 87.5%, and 84.5% increase in shoot dry weight, RUE, WUE, fruit yield, and seed yield of pumpkin, respectively, across both growing seasons. However, higher application nitrogen rate decreased the NUE of pumpkin, i.e., the NUE decreased by 62.5% when the nitrogen rate increased from 50 to 250 kg ha^?1. The effect of nitrogen applied in 2014 growing season on growth and yield of pumpkin was higher than that in 2013 growing season, which might be due to more suitable weather condition. In conclusion, the nitrogen rate of 250 kg ha^?1 produced the highest amount of fruit and seed yield in pumpkin.     

分根灌溉下水氮耦合对草莓果实品质及产量的影响

本文采用盆栽分根固定干湿灌溉试验研究了水氮耦合对草莓果实品质及产量的影响。试验设置水分和氮肥2个因素,草莓根区设置湿润与干旱(A/B)两个区域,湿润一侧(A)全生育期内土壤相对含水量均为80%±5%,干旱一侧(B)土壤相对含水量设置为20%±5%(重度水分胁迫)、35%±5%(中度水分胁迫)、50%±5%(轻度水分胁迫)3个处理水平;施氮量设置0.5 g(N)×kg~(-1)(低氮)、0.75 g(N)×kg~(-1)(中氮)、1 g(N)×kg~(-1)(高氮)3个处理水平,对照处理(即常规生产模式,CK)A/B两区域均为80%±5%土壤相对含水量、中氮[0.75 g(N)×kg~(-1)]水平。研究结果表明:1)分根干湿灌溉显著减少了草莓全生育期灌溉水量,提高了草莓的水分利用效率(WUE),全生育期内干旱一侧(B)土壤相对含水量为20%±5%、35%±5%和50%±5%的水分处理总灌溉水量分别为14.77 L×株~(-1)、16.62 L×株~(-1)和18.47 L×株~(-1),较CK处理(24.62 L×株~(-1))分别减少40.0%、32.5%和25.0%;以中度水分胁迫中氮水平的草莓水分利用效率(WUE)最高,为13.55 g×L-1,较CK处理提高47.1%,而产量没有明显减少;耦合分根干湿灌溉和施氮处理,轻度水分胁迫中氮水平下草莓果实产量最高,较CK处理提高4.4%。2)从对草莓果实品质影响角度分析,中氮及中度水分胁迫处理的草莓果实中Vc含量、可溶性糖含量、有机酸含量和糖酸比分别比CK处理增加63.3%、12.5%、3.9%和8.3%。综合考虑不同水氮耦合处理对草莓果实品质、产量、水分利用效率及对农业环境安全的影响,以湿润一侧(A)保持土壤相对含水量为80%±5%、干旱一侧(B)保持土壤相对含水量为35%±5%,且0.75 g(N)×kg~(-1)施氮水平为设施草莓生产适宜的水肥管理模式。