有限性灌溉对设施草莓产量及水分利用效率的影响

在日光温室环境及盆栽条件下,通过与全灌(FI)比较,研究了亏缺灌溉(DI)及分根交替灌溉(PRD)对草莓产量和灌水利用效率(IWUE)的影响.试验从开花期开始到果实成熟期结束.共分5个处理,全灌(FI);分根灌溉PRD分2个处理水平,即PRD1和PRD2;限制灌溉DI也分两个处理水平,即D11和D12.与F1处理相比,DI1和DI2处理的叶水势和气孔导度明显偏低,单株叶面积、鲜果重、平均单果重也显著低于FI处理.但水分利用效率却比FI处理的高(分别高15.8%和29.3%);PRD1处理的叶水势与FI处理的相当.且高于其它处理,而气孔导度比FI,DI1和D12处理的明显降低,与PRD2处理的相近.PRD1处理的鲜果重、平均单果重与FI处理的相当,比DI1,DI2和PRD2处理的显著提高;与FI处理相比,DI1,DI2,PRD1和PRD2处理分别节水31.5%,50.0%,31.5%和50.0%,水分利用效率分别提高了15.8%,29.3%,44.4%和84.4%,从草莓产量和水分利用效率各指标可以看出,PRD1处理比DI1,DI2和PRD2处理表现出明显的优势,其综合效益最佳.     

部分根区干燥灌溉条件下土壤温度和玉米N吸收改善研究

Soil temperature is a major effective factor on the soil and plant biological properties. Irrigation can affect soil temperature and thereby induces a temperature effect on plant growth, which may result in an economic increase due to higher yield and plant nutrition. A field experiment was carried out to investigate the effects of three irrigation strategies including full irrigation (FI), partial root-zone drying (PRD) and deficit irrigation (DI) on soil temperature and the consequent results on the grain yield and N uptake of maize (Zea May L.). Soil temperature was measured by time domain reflectometry (TDR) sensors during the 2010 growing season. Irrigation treatments were applied from 55 to 107 d after planting. The PRD treatment caused soil temperature to be in a favorable domain for a longer period (for over 60% of the measuring dates) as a consequent result of water movement to deeper soil layers compared with the other treatments; the PRD treatment also reduced soil temperature at deeper soil depths to below the maximum favorable soil temperature for maize root growth, which resulted in deeper root penetration due to both water availability and favorable soil temperature. Compared to the FI treatment, the PRD treatment increased root water uptake by 50% and caused no significant reduction in total N uptake, while this was not observed in the DI treatment partially due to the negative temperature effect of DI on plant growth, which consequently affected the water and nutrient uptake. A longer vegetation period in the PRD treatment was observed due to higher leaf N concentrations and no significant reduction in maize grain yield occurred in the PRD treatment, compared with those in the FI treatment. Based on the results, having 15.2% water saving during the whole growing season, the PRD irrigation would positively affect soil temperature and the water and nutrient uptake as a consequent, which thereby would prevent significant reduction in maize grain yield.     

Irrigation effects on quality, phenolic composition, and selected volatiles of virgin olive oils cv. Leccino

Field-grown olive trees (Olea europaea L. cv. Leccino) were used over two growing seasons to determine the effect of deficit irrigation regimes on virgin olive oil (VOO) quality. Drip irrigation was managed to maintain a predawn leaf water potential (PLWP): (a) higher than -1.1 MPa (full irrigation: FI); (b) between -1.0 and -3.3 MPa (deficit irrigation: DI); (c) higher than -4.2 MPa (severe deficit irrigation: SI). The fruit yield and oil yield of DI trees were over 90% of those of FI treatments in both years, respectively, whereas yields of SI trees ranged from 61 to 76%. The irrigation regime had minor effects on the free acidity, peroxide value, and fatty acid composition of VOO. The concentrations of phenols and o-diphenols in VOO were negatively correlated with PLWP. The concentrations of the dialdehydic form of decarboxymethyl elenolic acid linked to (3,4-dihydroxyphenyl)ethanol (3,4-DHPEA-EDA), the isomer of the oleuropein aglycon (3,4-DHPEA-EA), and the dialdehydic form of decarboxymethyl elenolic acid linked to (p-hydroxyphenyl)ethanol (p-HPEA-EDA) were lower in FI than in SI treatments. The concentrations of lignans (+)-1-acetoxipinoresinol and (+)-1-pinoresinol were unaffected by the irrigation regime. The tree water status had a marked effect on the concentration of volatile compounds, such as the C(6)-saturated and unsaturated aldehydes, alcohols, and esters.     

Improved soil–plant water dynamics and economic water use efficiency in a maize field under locally water stress

Soil–plant water dynamics is a major driving factor on crop yield which could be improved under optimal irrigation strategy. The soil water dynamics under partial root-zone drying (PRD) and its consequent effects on maize economics returns were investigated in a two-year field study in the research field of Sari Agricultural Sciences and Natural Resources University. Irrigation treatments included full irrigation (FI) and two PRD treatments including PRD₁ and PRD₂, receiving 100%, 75% and 55% of crop water demand at each irrigation event, respectively. TDRs were used for measuring soil water contents on a daily basis. Economic analysis was done based on net present value (NPV), benefit-to-cost ratio (B/C) and internal rate of return (INRR) indices. Applying PRD₁ treatment increased soil wetting front advance by 110–330% compared those for other treatments which caused 50% increase in root water uptake. Improved soil water dynamics under PRD1 prevented a significant reduction in maize grain yield, leading to 37.7%, 6.14% and 192% increase in NPV, B/C and INRR, respectively, under PRD₁ than those for FI treatment. Thus, PRD₁ was the most economic water-saving irrigation strategy under which 25% of irrigation water would be saved due to a better utilization of soil water supply.     

调亏灌溉对滴灌成龄香梨果树生长及果实产量的影响

调亏灌溉对果树节水、提高果实产量和品质具有一定效果。2009-2010年,在新疆库尔勒巴州农业科学研究所进行试验,研究滴灌调亏时间及土壤水分亏缺程度对树龄24a的成龄库尔勒香梨果树生长及产量的影响。果实细胞分裂期、果实缓慢膨大期、果实细胞分裂期至缓慢膨大期,分别进行中度土壤水分亏缺与重度土壤水分亏缺灌溉。中度土壤水分亏缺的灌水量为美国A级蒸发皿蒸发量(Ep)的60%,重度土壤水分亏缺的灌水量为Ep的40%。其它时段灌水量与对照相同,为Ep的80%;对照处理整个生育期灌水量均为Ep的80%。灌溉周期为7d。结果表明,前2个生长阶段的调亏灌溉均抑制了香梨树的营养生长,提高了香梨果实产量和灌溉水利用效率。各调亏处理的夏季修剪量比对照减小了8.4%～43.2%。2a内,细胞分裂期重度调亏处理,产量分别比对照增加了15.5%和19.2%,较对照节水9.7%和8.1%;果实缓慢膨大期中度调亏处理,产量分别比对照增加了14.0%和18.0%,较对照节水13.2%和11.3%;果实细胞分裂期及果实缓慢膨大期的重度调亏处理,产量分别比对照减少了15.4%和13.2%,较对照节水34.7%和28.4%。调亏灌溉对香梨果实品质无显著影响。结果对成龄库尔勒香梨灌溉管理具有指导意义。     

Effects of Deficit Irrigation and Fertilizer Use on Vegetative Growth of Drip Irrigated Cherry Trees

ABSTRACT

The effects of deficit irrigation and fertilizer use under drip irrigation (DI), on vegetative growth of mature cherry trees were studied in two field experiments. Treatments for the assessment of deficit irrigation consisted of two drip line arrays: double drip lines (T1) and loop (T2) as main treatments. Three irrigation levels: irrigation at 100% of crop evapotranspiration (ETc or I1), 75% ETc or I2, and 50% ETc or I3, constituted the sub-treatments. To assess soil fertility practices, the main treatments consisted of T1 and single drip line (T3) arrays; sub-treatments were two fertilizer regimes: basic fertilizer recommendation plus 0.5 m³ sheep manure per tree (F1) and basic fertilizer recommendation plus 1300 g potassium sulfate, 350 g of zinc (Zn), 140 g of iron (Fe), and 600 g ammonium phosphate (F2). Total irrigation amount, which was applied routinely in control treatment (7466.7 m³ha^{? 1}), was less than the crop water requirement (8764.5 m³ ha^{? 1}). A significant correlation between both the length of young branches and canopy volume with annual applied irrigation water was observed. Mean canopy volume under T1 was 26.0 m³ tree^{? 1}, which was significantly less than 28.6 m³ tree^{? 1} under T2. Water use efficiency (kg m^{? 3}) was increased by water stress, but there was no significant yield reduction from I1 to I2. Concentration of Fe, phosphorus (P), potassium (K), and magnesium (Mg) in leaf samples increased with the use of double drip lines array compared to use of single drip line array and it was higher under F2 fertilizer level. The concentration of calcium (Ca) in leaf samples was higher than critical level in all treatments. We conclude that I2 irrigation level and F2 fertilizer management was the most efficient practice for cherry trees in the study area.     

Response of red pepper to deficit irrigation and nitrogen fertigation

The main objective of this investigation was to evaluate the response of red pepper grown in a subhumid climate to different irrigation and nitrogen levels. Open-field trials were conducted in the Marmara Region, Turkey. Plants were subjected to three water levels [full irrigation (FI) = 100% crop evapotranspiration (ETc) and two deficit irrigations (DIs)= 66 and 33% ETc restoration] and four levels of N (0, 80, 160, and 240 kg N ha^?1) during the 2012, 2013, and 2014 growing seasons. A split-plot experimental design was used. The highest values of biomass and marketable yield (MY) were observed under FI. DI significantly increased the fruit soluble solids content. The biomass yield, MY, and fruit weight significantly improved with increasing nitrogen levels. The 240 kg N ha^?1 treatment under FI provided the maximum net income. Increasing N supply under DI conditions enhanced the water-use efficiency based on both biomass yield and MY. These results indicate that with respect to the yield, the net income, and the water productivity of red pepper, the FI with a nitrogen supply of 160–240 kg ha^?1 is recommended for drip irrigated and N-fertigated red pepper under subhumid climate conditions.     

负压灌溉提高紫叶生菜的水分利用效率和根际微生物多样性

【目的】针对目前设施农业中常用的灌溉方式容易造成土表水分蒸发和水肥流失,且不能按照作物所需自动供水供肥的现状,本研究探讨了负压灌溉提高紫叶生菜的产量和品质,以及水分利用效率和土壤微生物群落多样性的机理。【方法】在温室内进行盆栽试验,以紫叶生菜(Lactuca sativa L.)为试验材料,设置3个灌溉处理:常规灌溉、滴灌和负压灌溉。收获后,测定了紫叶生菜的产量,分析了品质(维生素C、可溶性糖、花青素和硝酸盐含量),植株的养分(氮、磷和钾)浓度和吸收量,监测了土壤水分含量动态的变化,计算了水分消耗量和水分利用效率,分析了根际土壤微生物的多样性指数和细菌在门分类上的群落结构组成。【结果】负压灌溉下显著提高紫叶生菜的产量和品质,负压灌溉比常规和滴灌处理的产量分别显著提高了68.1%和29.0%,也提高了维生素C、可溶性糖和花青素的含量,减少了硝酸盐含量。与常规灌溉相比负压灌溉显著提高了紫叶生菜氮、磷、钾的浓度和含量,分别提高13.0%、14.4%、38.4%和90.2%、92.6%、135.5%。紫叶生菜在负压灌溉下耗水量最少,为9900 cm3,比常规和滴灌处理分别减少了23.8%和23.8%;负压下水分利用效率比常规和滴灌分别显著提高了122.2%和70.5%。同时负压灌溉处理下动态的土壤含水量处于10.3%~11.3%之间,变异范围低于常规和滴灌处理9.2%~11.6%。通过高通量测序紫叶生菜根际土壤微生物群落发现,负压灌溉处理下微生物多样性指数最高,表现为OTU、Chao1和Shannon指标的数值显著高于常规和滴灌处理,其数值分别为1808、2437和8.48,分别比常规灌溉处理显著提高了15.2%、15.7%和3.16%。同时也改变了细菌在门分类水平上组成的相对丰度,在负压灌溉处理下比常规和滴灌处理分别提高了放线菌门(Actinobacteria),绿弯菌门(Chloroflexi),疣微菌门(Verrucomicrobia)和浮霉菌门(Planctomycetes)在细菌门分类上的相对丰度。【结论】本试验证明了负压灌溉系统通过土壤水肥平稳供应机制,实现了紫叶生菜高产优质且高效利用水分的目标。因此,负压灌溉系统相比常规和滴灌,显著提高了紫叶生菜的产量和品质、水分利用效率和根际微生物群落的多样性,为设施农业的可持续性发展提供科学依据。     

Physiological responses of pepper plant (Capsicum annuum L.) to drought stress

Water shortage is the most important factor constraining agricultural production all over the world. New irrigation strategies must be established to use the limited water resources more efficiently. This study was carried out in a completely randomized design with three replications under the greenhouse condition at Shahrekord University, Shahrekord, Iran. In this study, the physiological responses of pepper plant affected by irrigation water were investigated. Irrigation treatments included control [full irrigation (FI) level] and three deficit irrigation (DI) levels—80, 60, and 40% of the plant's water requirement called DI₈₀, DI₆₀, and DI₄₀, respectively. A no plant cover treatment with three replications was also used to measure evaporation from the soil surface. Daily measurements of volumetric soil moisture (VSM) were made at each 10-cm intervals of the soil column, considered as a layer. The differences between the measured VSM and the VSM in the next day and evaporation rate at the soil surface at the same layer of the bare soil with no plant cover treatment were calculated. Eventually, by considering the applied and collected water in each treatment, evapotranspiration (ET_C) and root water uptake in each layer per day were estimated. Furthermore, fruit number per plant, fresh fruit weight/day, root fresh/dry weights, shoot fresh/dry weights, root zone volume, root length and density, crop yield, and water use efficiency (WUE) were measured under different water treatments. The results showed that the maximum and minimum of all the studied parameters were found in the FI and DI₄₀ treatments, respectively. ET_C in the DI₈₀, DI₆₀, and DI₄₀ treatments were reduced by 14.2, 37.4, and 52.2%, respectively. Furthermore, applying 80, 60, and 40% of the plant's water requirement led to the reduction in crop yield by 29.4, 52.7, and 69.5%, respectively. The averages of root water uptakes in the DI₈₀, DI₆₀, and DI₄₀ treatments reduced by 17.08, 48.72, and 68.25%, respectively. WUE and crop yield also showed no significant difference in the FI and DI₈₀ treatments. Moreover, in the DI₈₀ treatment, the reduced rate of water uptake was less than the reduced rate of plant's applied water. According to these results, it can be concluded that 20% DI had no significant reduction on the yield of pepper, but above this threshold, there was an adverse effect on the growth and yield. Therefore, for water management in the regions with limited water resources, rate of plant's applied water can be decreased by around 20%.     

新疆膜下滴灌棉花早衰的根系生长发育特征

【目的】 膜下滴灌 (drip irrigation under mulch film, DI) 技术由于其高效节水的特点在新疆大面积推广使用,然而近期发现应用滴灌技术进行灌溉的作物根系出现了早衰,影响了地上部生长及产量的形成。本研究探讨了目前膜下滴灌技术体系棉花根系生长发育、空间分布的动态变化规律及地上部响应。 【方法】 采用田间试验方法,设置膜下滴灌、漫灌 (flood irrigation under mulch film, FI,对照) 两处理,采用 Monolith 法分 7 次采集根系,DT-Scan 软件测定根系长度,分析不同生育时期棉花根系在土壤空间中的变化特征,同时采集地上部样品并分器官测定干物质量。 【结果】 滴灌棉花根系表现出明显的浅层分布趋势:从播种后 96 d 开始,距地表 10 cm 范围内的根系长度明显大于漫灌处理,而 30—60 cm 土层则正好相反;在播种后 65～96 d 内,滴灌棉花根长增加速率明显低于漫灌;棉花生长发育后期 (播种后 125～160 d),滴灌处理棉花根系显著衰退,且主要集中在 0—40 cm 深度、距滴灌带 30—70 cm 土体范围内,播种后 160 d 与 125 d 相比,0—10 cm 土层下降了 13.8%,而 10—40 cm 衰退幅度更大 (22%),与此同时,漫灌处理除 0—10 cm 土层根长有所下降外 (7.7%),10 cm 以下依然保持增长状态 (10—40 cm 及 40—60 cm 层分别增加了 5.5% 与 10.2%);播种后 125 d,滴灌棉花地上部生长量明显高于漫灌,而根系正好相反,其冠根比较漫灌高,而在播种后 160 d 剧烈下降 (地上部叶片及蕾、铃的大量脱落所致 )。 【结论】 膜下滴灌棉花根系由于浅层分布,根系体积小,而地上部生物量过大,导致其在生长发育后期快速衰退。今后应研究适宜的水肥调控措施,以构建更早、更深的根系系统,控制生殖生长期内棉花的营养生长,实现膜下滴灌棉花的高产稳产。      

不同生育期调亏灌溉对酿酒葡萄耗水及果实品质的影响

不同程度的土壤干旱对酿酒葡萄的果实品质、产量和水分利用效率具有显著影响。明晰不同生育阶段干旱胁迫效应对酿酒葡萄土壤水分精准化管理和节水灌溉方案的制定具有重要的意义。本文于2014年在河西走廊中东部武威市凉州区清源镇威龙葡萄园产区开展了酿酒葡萄不同生育期、不同干旱胁迫程度的试验研究。在保持其他生育期土壤水分为正常灌溉(土壤水分阈值70%~75%)的情况下,在葡萄的萌芽期、抽蔓期、开花期、浆果膨大期和着色成熟期分别进行中度(土壤水分阈值60%~65%)和重度(土壤水分阈值50%~55%)的干旱处理,同时增设浆果膨大期的充分灌溉(土壤水分阈值80%~85%)处理,以全生育期的正常灌溉(土壤水分阈值70%~75%)作为对照,进行葡萄耗水特征和产量品质的测定。试验结果表明:不同处理土壤含水量垂直变化趋势一致,随土壤深度增加土壤含水量呈持续递增趋势;随着土壤深度递增,调亏灌溉对土壤含水量的影响越来越弱;40~60 cm土壤剖面,调亏处理含水量较对照减少幅度最大;浆果膨大期土壤剖面内含水量均低于其他生育期。不同处理酿酒葡萄耗水强度随时间变化趋势一致,萌芽期日耗水强度最小,为0.13~0.33 mm·d-1,而浆果膨大期耗水强度最大,为2.30~4.09 mm·d-1。萌芽期中度胁迫处理酿酒葡萄产量和水分利用效率最高,分别达到15 228 kg·hm-2和3.62 kg·m-3;浆果膨大期充分灌溉处理次之,而浆果膨大期重度胁迫处理最低,仅分别为7 128 kg·hm-2和2.26 kg·m-3。着色成熟期中度胁迫下,酿酒葡萄花青苷、还原糖、单宁、总酚含量比生育期正常供水处理高2.7%、6.56%、17.91%和23.23%,且有效抑制可滴定酸积累(P0.05),而其他处理与对照之间品质指标差异不显著。综合考虑产量、水分生产效率及果实品质等指标,最佳酿酒葡萄水分调控处理为着色成熟期中度胁迫,即着色成熟期土壤相对含水率为60%~65%、其余生育期土壤相对含水率为70%~75%。由此可见,在酿酒葡萄栽培时适时、适度的调亏灌溉既能显著提高水分生产效率,实现节水、高效用水的目的,又能提高果实品质,对河西走廊地区酿酒葡萄种植具有重要的意义。     

Productivity and Economics of Drip-Irrigated Banana (Musa Spp.) under Different Planting and Fertigation Techniques in Subtropical India

Banana is well known to be extremely demanding for water and nutrients, and supplemental application of these resources are prerequisites for higher yield. The study was undertaken to assess the effects of fertigation through drip on the growth, yield, quality, and economics of banana during 2007–2009. The experiment also aimed to find out a suitable method of planting for banana under drip irrigation system. Twelve treatments comprising two fertilizer sources, three fertilizer levels, and two planting systems were attempted. These treatments were compared with surface method of irrigation using conventional fertilizers applied as farmers practice. The results revealed that among the various treatments, 100% dose of water-soluble RDNPK and planting spacing of 1.5 × 1.5 m with drip fertigation recorded better values for growth characteristics. Banana fruit yield was significantly higher in normal planting (82.86 t/ha) than paired row planting (75.75 t/ha). The fruit yield increased significantly in water-soluble fertilizers (81.01 t/ha) as compared with “nitrogen (N)” fertigation (77.59 t/ha) and it also increased significantly with an increase in fertilizer levels (100% fertigation), but high costs of these fertilizers lowered the B:C ratio and net returns as compared with fertigation using conventional fertilizers. The drip irrigation gave 3–14.5% increase in banana fruit yield and 52% water saving over surface irrigation. The quality of banana fruits was not affected significantly due to any of the treatments.     

调亏灌溉促进涌泉根灌枣树生长提高产量

调亏灌溉是作物通过主动调节自身营养达到节水和提高果实产量等目的。该文通过微灌枣树试验,研究了涌泉根灌下调亏灌溉对山地枣树生长与产量的影响。2013年分别在萌芽展叶期和开花坐果期进行轻度、中度和重度3个调亏水平调亏处理试验。结果表明:轻度和中度水分亏缺均对枣吊的生长起到抑制作用,能够有效减少新梢生长及夏季修剪量,而对枣树果实的生长起到了促进作用,达到增产的目的。轻度、中度和重度水分亏缺与充分灌溉相比,枣吊长度分别减少了7.2%、13.2%和19.7%(P0.05)。枣树坐果期,果实生长缓慢,轻度、中度、重度调亏以及充分灌溉果实生长量分别为果实最终体积的14.5%、14.1%、13.8%和13.5%。与充分灌溉相比,轻度调亏的枣树最终产量提高了22.1%(P0.05)。可见,调亏灌溉会较为显著的影响枣树的最终产量。适宜的水分亏缺对枣树果实生长与产量有促进作用,且提高了水分利用率。     

Effects of Irrigation and Nitrogen Rates on Growth,Yield, and Quality of Muskmelon in Semiarid Regions

Abstract

Muskmelon (Cucumis melo L. cv. ‘Polidor’) were grown under field conditions to investigate the effects of different nitrogen (N) levels (0, 40, 80, and 120 kg ha^{? 1}) on plant growth, water use efficiency, fruit yield and quality (weight, sizes, and water-soluble dry matter), leaf relative water content, and macro nutrition under three different irrigation regimes. Irrigation was applied based on cumulative class A pan evaporation (Ep). Plant treatments were as follows: (1) well-watered treatment (C) received 100% replenishment of Ep on a daily basis, (2) water-stressed treatment (WS) received 75% replenishment of Ep at three-day intervals, and (3) severely water-stressed (SWS): treatment received 50% replenishment of Ep at six- day intervals. Plants grown under C at 120 kg N ha^{? 1} produced significantly higher biomass (175.6 g plant^{? 1}), fruit yield (36.05 t ha^{? 1}), fruit weight (2.25 kg fruit^{? 1}), and leaf relative water content (93.5%) under increasing N levels than did the two deficit irrigation treatments. The WS or SWS treatments caused reductions in all parameters measured except water-soluble dry matter (SDM) concentrations in fruits compared with those receiving unstressed (C) treatment. The WS irrigation regime with 80 kg ha^{? 1} N significantly improved the fruit yield and size, plant dry matter, leaf area, and IWUE compared with the SWS regime. Increased N significantly enhanced foliar N in the unstressed plants. Increasing N rate in the SWS treatment did not increase fruit yield with the same trend found in the WS and C treatments with increasing N levels. The yield reduction under severe water shortage was much more severe at high N rates. Water use (ET) at the C treatment at 120 kg ha^{? 1} N ranged between 160 and 165 cm, while SWS reduced ET to 90 cm at 0 and 40 kg ha^{? 1} N. Nitrogen supply modified water use at C and WS irrigation regimes. Muskmelon yield response to N rate was quadratic and differed with the level of irrigation. This moderate water deficit (SW) may be an alternative irrigation choice with a suitable N application rate for muskmelon growers in arid and semi-arid regions if the goal is to irrigate an agricultural area with limited water supply for more growers, but not if it is maximizing economic yield. Growers should accept a significant yield reduction in exchange for water conservation.     

Influence of plant water status on the production of C13-norisoprenoid precursors in Vitis vinifera L. Cv. cabernet sauvignon grape berries

The influence of irrigation strategy on grape berry carotenoids and C13-norisoprenoid precursors was investigated for Vitis vinifera L. cv. Cabernet Sauvignon. Two irrigation treatments were compared, one in which vines received reduced irrigation applied alternately to either side of the vine (partial rootzone drying, PRD) and a second control treatment in which water was applied to both sides of the vine. Over the two years of the experiments, PRD vines received on average 66% of the water applied to the controls. Initially, the PRD treatment did not alter midday leaf (psiL) and stem (psiS) water potential relative to the control, but decreased stomatal conductance (gs). Continued exposure to the PRD treatment resulted in treated grapevines experiencing hydraulic water deficit relative to the control treatment and induced lowered midday psiL and psiS, which was also reflected in decreased berry weight at harvest. In both irrigation treatments, the most abundant grape berry carotenoids, beta-carotene and lutein, followed the developmental pattern typical of other grape varieties, decreasing post-veraison. At certain points in time, as the fruit approached maturity, the concentration of these carotenoids was increased in fruit of PRD-treated vines relative to the controls. This effect was greater for lutein than for beta-carotene. PRD consistently caused increases in the concentration of hydrolytically released C13-norisoprenoids beta-damascenone, beta-ionone, and 1,1,6-trimethyl-1,2-dihydronaphthalene in fruit at harvest (24 degrees Brix) over two seasons. The effect of the PRD treatment on the concentration of hydrolytically released C13-norisoprenoids was greater in the second of the two seasons of the experiment and was also reflected in an increase in total C13-norisoprenoid content per berry. This suggests that the increases in the concentration of the C13-norisoprenoids in response to PRD were independent of water deficit induced changes in berry size and were not the result of an altered berry surface area to volume ratio.     

不同施肥条件和滴灌方式对青椒生长的影响

该文通过大田试验,比较了地下滴灌与地表滴灌及其不同施肥量对青椒生长的响应。试验设置地下滴灌和地表滴灌2个灌水处理和0、75、150、300 kg/hm2 4个施肥水平,灌水周期为4 d。另外设1个畦灌对照处理。结果表明,2 a中地下滴灌产量均高于地表滴灌,2007年平均高4%,2008年平均高13%。而地下滴灌耗水量低于地表滴灌,2007年平均低6.7%,2008年平均低7.3%。地下滴灌和地表滴灌0～40 cm土层的根系总根长分别是畦灌的2.44和1.46倍,且地下滴灌10 cm以下各层的根长占总根长的百分比,比地表滴灌高7%,这说明地下滴灌不仅促进作物根系的生长,而且使根系更多的扎入较深土层。地下滴灌150 kg/hm2施氮量为青椒的最优灌溉施肥策略。     

灌后通气处理对温室黄瓜生长和品质的影响

Rhizosphere aeration, irrigation with aerated water, and post-irrigation aeration would positively impact crop growth and yield. The objective of this study was to determine the effect of 4 post-irrigation aeration levels on plant growth, yield, irrigation-use efficiency （IUE）, and fruit market and nutritional quality of greenhouse cucumber under subsurface drip irrigation （SDI） and furrow irrigation （FI）. The post-irrigation aeration levels were 0.00, 0.50, 0.75, and 1.00 times half the estimated porosity of the plot rhizosphere. The experimental design was a two-faetor split-plot in randomized complete blocks with irrigation （FI and SDI） as the main treatments and 4 aeration levels as the sub-treatments. Ridge and furrow main plots （2.4 m ~ 2.4 m） with 4 ridges were replicated 5 times. Each of the 4 ridges （1.44 m2 in area） in the main plots was used as a sub-treatment plot. The results showed that post-irrigation aeration enhanced greenhouse cucumber plant growth, yield, IUE, and fruit market and nutritional quality. These parameters generally increased with increasing aeration levels under both FI and SDI. The aeration effect was generally higher under SDI than FI, and the IUE under SDI was almost twice that under FI. Further investigation would be required to elucidate the plant physiological mechanisms and soil processes responsible for the observed effects.     

不同土壤水分下限对大棚滴灌甜瓜产量和品质的影响

以厚皮甜瓜品种伊莉莎白为材料,研究大棚滴灌条件下营养生长期不同土壤水分下限(75%田间持水量,I75;65%田间持水量,I65;55%田间持水量,I55;45%田间持水量,I45)对甜瓜生长、产量、品质以及灌溉水分利用效率的影响,并以沟灌(G75)作为对照。结果表明,株高、茎粗、叶面积和地上部干重均随着营养生长期土壤水分下限的降低而减小。I75果实横径、皮厚和肉厚均最大,果形指数最小;I65果实纵径最大。果实品质方面,总可溶性固形物(TSS)含量为:I65>I55>I75>I45;可溶性糖含量为:I55>I65>I45>I75;维生素C(Vc)含量为:I55>I65>I75>I45;可溶性蛋白质含量为:I55>I65>I45>I75;游离氨基酸总量为:I45>I65>I55>I75。I75的产量和平均单果重最高;I65的灌溉水分利用效率最高,达到29.16kg/m3,相比沟灌对照提高76.4%,可节水58.1%,而平均单果重仅比对照下降3.2%。综合考虑产量和品质,可以选择65%田间持水量作为武汉地区厚皮甜瓜营养生长期适宜的土壤水分下限指标。     

Response of Leek (Allium porrum L.) to Different Irrigation Water Levels Under Rain Shelter

A pot experiment was conducted to investigate the effects of different water levels on water-use efficiency, yield and growth parameters of leek (Allium porrum L.) and was carried out in the practical research field of Ondokuz May?s University in Turkey. Different irrigation water levels were based on the weight changes of each pot and included 5 irrigation treatments [25% (I₂₅), 50% (I₅₀), 75% (I₇₅), 100% (I₁₀₀) and 118% (I₁₁₈) times of consumed water]. Decreases in irrigation water resulted in decreases in plant height, stem diameter, leaf and stem fresh weights, leaf and stem dry weights and leaf area, but did not significantly affect leaf number or chlorophyll content. A yield-response factor of 1.26 was obtained, implying that the leek crop was sensitive to water stress caused by deficit irrigation. Comprehensive analysis of yield, water use efficiency, and evapotranspiration, the I₇₅ treatment can be suggested for leek production in water-scarce regions.     

Effect of HCO $ _3^ - $ on rice growth and iron uptake under flood irrigation and drip irrigation with plastic film mulch

There has been a partial shift away from conventional flood irrigation (FI) practices for rice (Oryza stativa L.) production in water‐scarce northern China. Drip irrigation with plastic film mulch (DI‐PFM) can maintain high rice yields with significant water savings. However, rice seedlings often develop chlorosis when grown with DI‐PFM on calcareous soil. Bicarbonate is a concern with regard to chlorosis in calcareous soil. The objective of this simulation experiment was to determine the effect of irrigation method and irrigation water HCO $ _3^ - $ concentration on (1) soil pH and DTPA‐Fe concentration, (2) chlorophyll, total Fe, and active Fe concentrations of rice leaves, and (3) rice root and shoot biomass. The experiment consisted of four treatments: FI with water containing either 2 or 10 mM HCO $ _3^ - $ (referred to as FI‐2 and FI‐10, respectively) and DI‐PFM with water containing 2 or 10 mM HCO $ _3^ - $ (referred to as DI‐2 and DI‐10, respectively). The results show that the HCO $ _3^ - $ concentrations of the soil solution were greater under FI than under DI‐PFM, because more irrigation water was applied in the FI system. Soil pH increased as the HCO $ _3^ - $ concentration of the irrigation water increased. The increase in soil pH was greater in DI‐PFM than in FI. Soil DTPA‐Fe concentration, leaf SPAD values, leaf total Fe concentration, leaf active Fe concentration, shoot biomass, and root biomass decreased as the HCO $ _3^ - $ concentration of the irrigation water increased. The decreases were less under DI‐PFM than under FI. Overall, the results indicate that rice plants are more sensitive to the HCO $ _3^ - $ concentration of irrigation water under FI than under DI‐PFM.