Effect of fertigation frequency on soil nitrogen distribution and tomato yield under alternate partial root-zone drip irrigation

Alternate partial root-zone drip fertigation (ADF) is a combination of alternating irrigation and drip fertigation,with the potential to save water and increase nitrogen (N) fertilizer efficiency.A 2-year greenhouse experiment was conducted to evaluate the effect of different fertigation frequencies on the distribution of soil moisture and nutrients and tomato yield under ADF.The treatments included three ADF frequencies with intervals of 3 days (F3),6 days (F6) and 12 days (F12),and conventional drip fertigation as a control (CK),which was fertilized once every 6 days.For the ADF treatments,two drip tapes were placed 10 cm away on each side of the tomato row,and alternate drip irrigation was realized using a manual valve on the distribution tapes.For the CK treatment,a drip tape was located close to the roots of the tomato plants.The total N application rate of all treatments was 180 kg ha^(-1).The total irrigation amounts applied to the CK treatment were450.6 and 446.1 mm in 2019 and 2020,respectively;and the irrigation amounts applied to the ADF treatments were 60%of those of the CK treatment.The F3 treatment resulted in water and N being distributed mainly in the 0–40-cm soil layer with less water and N being distributed in the 40–60-cm soil layer.The F6 treatment led to 21.0 and 29.0%higher 2-year average concentration of mineral N in the 0–20 and 20–40-cm soil layer,respectively and a 23.0%lower N concentration in the 40–60-cm soil layer than in the CK treatment.The 2-year average tomato yields of the F3,F6,F12,and CK treatments were 107.5,102.6,87.2,and 98.7 t ha^(-1),respectively.The tomato yield of F3 was significantly higher (23.3%) than that in the F12 treatment,whereas there was no significant difference between the F3 and F6 treatment.The F6 treatment resulted in yield similar to the CK treatment,indicating that ADF could maintain tomato yield with a 40%saving in water use.Based on the distribution of water and N,and tomato yield,a fertigation frequency of 6 days under ADF should be considered as a water-saving strategy for greenhouse tomato production.

Effects of Alternative Partial Root-zone Irrigation and Nitrogen Fertilizer on Plukenetia volubilis Seedlings

This study was aimed to investigate the effects of alternative partial rootzone irrigation and nitrogen fertilizer on the potted seedlings of Plukenetia volubilis.A total of 7 treatments were designed with three factors, i.e., irrigation amount, irrigation mode and nitrogen fertilizer. The growth, photosynthesis and water use efficiency were analyzed. The results showed that compared with those under full irrigation, the biomass and water consumption under alternative partial root-zone irrigation were reduced by 5% and 75%, respectively, and the water use efficiency was increased by 60%. Under severe drought conditions, the root cap ratio in the nitrogen fertilizer treatment group was increased by 30%; the leaf area index, photosynthetic rate and biomass under alternative partial root-zone irrigation were reduced by 38%, 9% and 18%, respectively. It indicates that under severe drought conditions, alternative partial root-zone irrigation is not suitable to be matched with application of nitrogen fertilizer. In short, under moderate drought conditions, alternative partial root-zone irrigation could reduce transpiration and improve water use efficiency, and it is an effective water-saving irrigation technology for the plantation of P.volubilis plants.

Alternate Furrow Irrigation: A Practical Way to Improve Grape Quality and Water Use Efficiency in Arid Northwest China

Field experiments were conducted for two years to investigate the benefits of alternate furrow irrigation on fruit yield, quality and water use efficiency of grape （Vitis vinifera L. cv. Rizamat） in the arid region of Northwest China. Two irrigation treatments were included, i.e., conventional furrow irrigation （CFI, two root-zones were simultaneously irrigated during the consecutive irrigation） and alternate partial root-zone furrow irrigation （AFI, two root-zones were alternatively irrigated during the consecutive irrigation）. Results indicate that AFI maintained similar photosynthetic rate （Pn） but with a reduced transpiration rate when compared to CFI. As a consequence, AFI improved water use efficiency based on evapotranspiration （WUEEr, fruit yield over water consumed） and irrigation （WUE~, fruit yield over water irrigated） by 30.0 and 34.5%, respectively in 2005, and by 12.7 and 17.7%, respectively in 2006. AFI also increased the edible percentage of berry by 2.91-4.79% significantly in both years. Vitamin C （Vc） content content of berry was increased by 25.6-37.5%, and tritrated acidity （TA） was reduced by 9.5-18.1% in AFI. This resulted in an increased total soluble solid content （TSS） to TA ratio （TSS/TA） by 11.5-16.7% when compared to CFI in both years. Our results indicate that alternate furrow irrigation is a practical way to improve grape fruit quality and water use efficiency for irrigated crops in arid areas.

Stem flow of seed-maize under alternate furrow irrigation and double-row ridge planting in an arid region of Northwest China

Maize is widely planted throughout the world and has the highest yield of all the cereal crops. The arid region of North- west China has become the largest base for seed-maize production, but water shortage is the bottleneck for its long-term sustainability. Investigating the transpiration of seed-maize plants will offer valuable information for suitable planting and irrigation strategies in this arid area. In this study, stem flow was measured using a heat balance method under alternate furrow irrigation and double-row ridge planting. Meteorological factors, soil water content （e）, soil temperature （Ts） and leaf area （LA） were also monitored during 2012 and 2013. The diurnal stem flow and seasonal dynamics of maize plants in the zones of south side female parent （SFP）, north side female parent （NFP） and male parent （MP） were investigated. The order of stem flow rate was： SFP〉MP〉NFP. The relationships between stem flow and influential factors during three growth stages at different time scales were analyzed. On an hourly scale, solar radiation （Rs） was the main driving factor of stem flow. The influence of air temperature （Ta） during the maturity stage was significantly higher than in other periods. On a daily scale, Rs was the main driving factor of stem flow during the heading stage. During the filling growth stage, the main driving factor of NFP and MP stem flow was RH and Ts, respectively. However, during the maturity stage, the environ- mental factors had no significant influence on seed-maize stem flow. For different seed-maize plants, the main influential factors were different in each of the three growing seasons. Therefore, we identified them to accurately model the FP and MP stem flow and applied precision irrigation under alternate partial root-zone furrow irrigation to analyze major factors affecting stem flow in different scales.

Influences of alternate partial root-zone irrigation and urea rate on water-and nitrogen-use efficiencies in tomato

Traditional water and fertilizer inputs are often much higher than the actual demands of tomato,which causes a reduction in water-and fertilizer-use efficiencies.To investigate the advantage of alternate partial root-zone irrigation(AI)on water-and nitrogen(N)-use efficiencies of tomato modified by water and N management,taking conventional irrigation(CI)as the control,the effects of AI on root morphology and activity,fruit yield and water and N use efficiency were studied using pot experiments.There were four combinations of irrigation levels and growing stages of tomato for AI,i.e.AI_(1)(high water(W_(H))from blooming to harvest stage(BHS)),AI_(2)(W_(H)from blooming to fruit setting stage(BFS)and low water(W_(L))at the harvest stage(HS)),AI_(3)(W_(L)at BFS and W_(H)at HS)and AI_(4)(W_(L)at BHS)at three urea rates,i.e.low urea rate(NL),middle urea rate(N_(M))and high urea rate(N_(H))in the form of urea.Irrigation quotas for W_(H)and W_(L)in AI at BFS or HS were 80%and 60%of that in CI,respectively.Compared to CI,AI decreased water consumption by 16.0%-33.1%and increased water use efficiency of yield(WUE_(y))and dry mass(WUE_(d))by 6.7%-11.9%and 10.2%-15.9%,respectively.AI_(1)did not decline yield,total N uptake(TNU)and N use efficiency(NUE)significantly.Compared to NL,N_(M)enhanced tomato yield,TNU,WUE_(y)and WUE_(d)by 28.5%,35.3%,22.6%and 16.3%,respectively.Compared to CINL,AI_(1)N_(M)reduced water consumption by 12.5%,but increased tomato yield,TNU,WUE_(y)and WUE_(d)by 35.5%,58.4%,54.4%and 53.7%,respectively.Therefore,AI_(1)can improve water use efficiency and total N uptake of tomato simultaneously at medium urea rate.

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 and500 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.

Evaluation of tomato fruit quality response to water and nitrogen management under alternate partial root-zone irrigation

A pot experiment was conducted to investigate the effects of different water and nitrogen supply amounts on the comprehensive assessment of tomato fruit quality and root growth parameters under alternate partial root-zone irrigation.Three upper irrigation limitations(i.e.70%(W1),80%(W2)and 90%(W3)of field capacity,respectively)and three N-fertilizer levels(i.e.0.18(N1),0.30(N2)and 0.42(N3)g/kg soil,respectively)were arranged with a randomized complete block design,and alternate partial root-zone irrigation method was applied.Results showed that fruit yields under deficit irrigation(W1 and W2)were decreased by 6.9%and 2.0%respectively compared with W3 under N1 level.Yields of tomato under W1N1 and W1N2 combinations were also reduced by 10.3%and 7.2%,respectively compared with W1N3 combination.Root dry weight,root length,root surface area and root volume were all increased in W1N2 treatment.According to two-way ANOVA,the root parameters except root dry weight,were extremely sensitive to water,nitrogen and the cross effect of the two factors.TSS(total soluble solids),SS(soluble sugars)and OA(organic acid)in the fruits increased with the decrease in irrigation water,OA and NC reduced with decreasing amount of nitrogen.Moreover,within an appropriate range,as more irrigation water and nitrogen were applied,the higher VC(vitamin C)and lycopene contents were identified in the fruits.Eventually,the combinational evaluation method(i.e.entropy method and gray relational analysis)showed that W2N2 ranked highest in comprehensive fruit quality.Therefore,considering the tradeoff between fruit comprehensive quality and yields,upper irrigation limitation of 80%θf and N-fertilizer of 0.30 g/kg soil with alternate partial root-zone irrigation was the optimal cultivation strategy for the greenhouse tomato in autumn-winter season in northwest China.

Biochar and alternate partial root-zone irrigation greatly enhance the effectiveness of mulberry in remediating lead-contaminated soils

Aims Soil lead contamination has become increasingly serious and phytoremediation can provide an effective way to reclaim the contaminated soils.This study aims to examine the growth,lead resistance and lead accumulation of mulberry(Morus alba L.)seedlings at four levels of soil lead contamination with or without biochar addition under normal or alternative partial root-zone irrigation(APRI).Methods We conducted a three-factor greenhouse experiment with biochar(with vs.without biochar addition),irrigation method(APRI vs.normal irrigation)and four levels of soil lead(0,50,200 and 800 mg·kg^(-1)).The performance of the seedlings under different treatments was evaluated by measuring growth traits,osmotic substances,antioxidant enzymes and lead accumulation and translocation.Important Findings The results reveal that mulberry had a strong ability to acclimate to soil lead contamination,and that biochar and APRI synergistically increased the biomass and surface area of absorption root across all levels of soil lead.The seedlings were able to resist the severe soil lead contamination(800 mg·kg^(-1) Pb)by adjusting glutathione metabolism,and enhancing the osmotic and oxidative regulating capacity via increasing proline content and the peroxidase activity.Lead ions in the seedlings were primarily concentrated in roots and exhibited a dose–effect associated with the lead concentration in the soil.Pb,biochar and ARPI interactively affected Pb concentrations in leaves and roots,translocation factor and bioconcentration.Our results suggest that planting mulberry trees in combination with biochar addition and APRI can be used to effectively remediate lead-contaminated soils.

根系分区交替灌溉不同灌水上限对西瓜和甜瓜生长及水分利用效率的影响

为了探究设施西瓜和甜瓜膜下根系分区交替灌溉效应,选取西瓜品种‘早佳8424’、甜瓜品种‘青甜脆’为试验材料,以土壤田间持水量的60%为灌水下限,田间持水量的70%、80%、90%、100%为灌水上限,研究不同灌水上限处理对设施西瓜和甜瓜生长、产量、品质、养分吸收、水分利用效率的影响。结果表明:根系分区交替灌溉条件下,西瓜、甜瓜最佳灌水上限处理是90%田间持水量,该处理下西瓜、甜瓜中心可溶性固形物含量、维生素C含量、果实中含氮、钾量均显著高于其他处理,灌溉水分利用效率较100%田间持水量灌溉上限处理分别显著提高40.56%、33.35%,且产量下降不明显,有助于西瓜和甜瓜生长、养分积累和品质提升,同时达到节水的目的。综上,本研究可作为山西晋中地区设施节水提质增效的一种灌溉模式推广应用。

分根区交替滴灌施肥频率对土壤水氮运移及番茄产量的影响

针对目前我国设施蔬菜实际生产过程中水肥调控不合理及水肥利用效率低的问题,本文通过温室试验研究了分根区交替滴灌施肥(ADF)条件下,不同施肥频率对土壤水分养分运移及番茄产量的影响,为番茄高效水肥调控提供理论依据。试验在ADF下设3个滴灌施肥频率处理F3(3 d)、F6(6 d)、F12(12 d)和1个常规滴灌施肥处理作为对照(CK,频率为6 d)。结果表明,在0~40 cm土层,高频滴灌施肥处理(F3)相比于低频处理(F12)生育期内两年平均土壤含水量和无机氮含量分别增加了7.9%和28.3%;在40~60 cm土层,F3和F6相比于F12处理,两年平均无机氮累积量分别降低了37.8%和23.0%。与F12处理相比,F6处理两年平均番茄生物量、吸氮量和产量分别显著增加16.9%、15.2%和22.6%,而F3和F6处理之间均无显著差异。在相同施肥量和滴灌施肥频率条件下,F6处理在减少40%灌水量的同时能够保持与CK相当产量。因此,适当提高滴灌施肥频率能够促进番茄生长及产量的形成,ADF较常规滴灌施肥具有较大的节水稳产效果。本研究推荐ADF条件下6 d一次的滴灌施肥频率可作为温室番茄生产中较为高效的水肥管理措施。

根系分区交替滴灌对棉花产量和水分利用效率的影响

为了探讨旱区农业节水新途径,在甘肃省石羊河流域下游荒漠绿洲区采用常规滴灌和分根区交替滴灌方式研究不同灌溉方式对大田棉花生长发育、产量、水分利用效率以及土壤水分分布的影响。结果表明,交替滴灌处理棉花叶片气孔开度减小,减少了奢侈的蒸腾损失,灌溉定额较小时根系分区交替滴灌对棉花的株高抑制作用较明显,灌水定额较大时限制作用不显著。根系分区交替滴灌技术在大田条件下可使籽棉产量比常规滴灌处理提高21.1%,总水分利用效率和灌溉水利用效率分别提高17.9%和20.9%。同等产量水平下与常规滴灌相比,交替滴灌可节省30.8%的灌水量。本研究表明根系分区交替滴灌是一种切实可行的节水灌溉技术,可在干旱缺水的棉花生产地区进一步研究和推广应用。

番茄垂向分根区交替控制滴灌室内试验及节水机理

开展了垂向分根区交替控制滴灌番茄试验研究,设中等水分处理和低水分处理的垂向分根区交替控制滴灌、中等水分处理的表面滴灌3个处理。结果表明:垂向分根区交替控制滴灌可以在作物上下根区层形成干湿交替的区域,在适宜水分条件下能够大大降低耗水强度,使耗水过程趋于平缓,有利于控制植株长势、壮大径杆直径,以及增加下层根系的比重与根冠比,番茄产量在无显著下降的情况下可实现节水46.5%。在较高的土壤水分下限条件下适时进行番茄垂向分根区交替控制滴灌能够有效降低设施农业的运行管理费用、增加番茄商品率及实现节约水资源的目的。

分根区交替灌溉对马铃薯水氮利用效率的影响

分根区交替灌溉已被证实是一种有效节水灌溉技术同时保持作物产量,但有关分根区交替灌溉提高作物氮素利用效率、降低对水土环境的影响机理还不是很清楚。为了探明地下滴灌条件下充分灌溉及分根区交替灌溉(APRI)对马铃薯水氮利用效率的影响,通过田间小区试验,对各处理马铃薯全生育期灌水量、植株体氮素残留、土壤氮素残留及水氮利用效率进行了比较分析。研究结果表明:收获后,APRI处理(E、I、K)与充分灌水处理产量(F、J、L)差异不大,但APRI处理灌溉水利用效率显著高于充分灌水处理(p=0.05);充分灌水处理不同土层(0～30cm和30～60cm)土壤中残留硝态氮、矿物质氮较APRI处理高;APRI处理(I、K)作物氮利用效率及农田氮利用效率显著高于充分灌水处理(J、L)(p=0.05)。因此,APRI处理不仅能够显著提高作物的水分利用效率,而且还能显著提高土壤矿质氮的活性,有利于作物对土壤氮素的吸收利用。

干旱荒漠绿洲区葡萄根系分区交替灌溉试验研究

为了探讨西北旱区葡萄节水优质高效灌溉模式,于2004～2006年在甘肃河西走廊石羊河流域干旱荒漠绿洲区进行了田间试验,研究了根系分区交替滴灌、固定部分根区滴灌和常规滴灌三种灌溉模式对鲜食葡萄产量、品质和水分利用效率的影响。研究结果表明,根系分区交替灌溉灌水量较常规滴灌减少1/2,其产量未有显著下降,而且显著提高了浆果V c含量,使果酸含量降低,可溶性固形物含量显著提高,成熟度明显改善。根系分区交替灌溉的水分利用效率较常规滴灌提高了37.36%。采用根系分区交替灌溉可以达到大量节水、提高葡萄品质和成熟度而不明显降低产量的目的,可以作为西北旱区果园有效的节水优质高效灌溉模式。

不同根区交替滴灌方式对赤霞珠葡萄幼苗根冠生长的影响

为探讨不同根区交替滴灌供水模式对赤霞珠葡萄幼苗生长的影响,筛选出适合中国干旱区酿酒葡萄生产的最佳滴灌供水模式和方法。该研究以酿酒葡萄品种赤霞珠（Vitis vinifera L.‘Cabernet Sauvignon’）为试验材料,分别测定左侧地下穴贮滴灌,右侧地表滴灌（SDI-DI）、两侧地下穴贮滴灌（SDI-SDI）、左侧地表滴灌,右侧地下穴贮滴灌（DI-SDI）、两侧地表滴灌（DI-DI）4种根区交替滴灌处理对赤霞珠葡萄幼苗根冠生物量、根系分布、根系活力及叶片生理功能的影响。结果表明：同一灌水条件下SDI-SDI、DI-SDI、SDI-DI能保持根冠比在较适宜水平（1-1.3）,DI-DI所受胁迫较大,根冠比增加,植株正常生长受到限制;根系水平分布上DI-SDI与SDI-DI根区左侧与根区右侧根量指标差异较大,DI-DI与SDI-SDI根区左右两侧根量指标差异较小,其中DI-SDI根区右侧根量指标分别比根区左侧高13.3%、10.5%、14.0%、22.1%;根系垂直分布上一侧为SDI的根区交替滴灌能促进根系下扎,提高土层深度20-60 cm处根系的根系活力,其中根区右侧SDI-SDI与DI-SDI处理根表面积、根体积在土层深度〉20-40 cm处分布最多,根表面积分别占右侧根总表面积的48.8%、49.2%,根体积分别占右侧根总体积的47.5%、46.3%;灌水量一定的条件下,灌水侧为SDI的根区交替滴灌能有效维持同一灌水周期内地上部叶片光合性能的稳定,保持叶片瞬时水分利用效率在较高水平,适宜降低表层根量增加深层根量可提高植株叶片的净光合速率和蒸腾速率。综合生产成本、田间实际操作与植株根冠生长差异,该试验条件下采用一侧地表滴灌、一侧地下穴贮滴灌的根区交替滴灌供水模式为最佳处理。

不同膜下滴灌方式对设施黄瓜生理特性及水分利用效率的影响

为了探明黄瓜膜下分根交替滴灌的节水效果,为设施黄瓜节水灌溉提供理论依据和技术参数,以‘津优3号’黄瓜为试材,采用随机区组设计,以土壤田间持水量的65%为灌水下限,田间持水量的90%为灌水上限,研究了分根交替滴灌(APDI)、固定1/2根区滴灌(FPDI)和传统滴灌(CDI)3种灌溉模式对黄瓜生长、生理特性、产量与品质及水分利用效率的影响,结果表明:(1)随灌溉处理时间的延长,3种灌溉模式的单株叶面积和株高的差异越来越显著,而茎粗和叶片数差异不显著;(2)与传统滴灌相比,分根交替滴灌模式下黄瓜叶片净光合速率略有下降而蒸腾速率显著降低,水分利用效率显著提高;(3)分根交替滴灌处理下黄瓜可溶性蛋白、可溶性糖含量与传统滴灌相比差异不显著,Vc含量却显著增加;(4)分根交替滴灌模式下黄瓜产量比传统滴灌下降1.5%,而灌水量减少17%,水分利用效率提高18.6%,节水效果显著。综上所述,分根交替滴灌可以在保证设施黄瓜产量没有显著下降的前提下,改善品质和显著提高水分利用效率,可作为设施节水提质增效的一种灌溉模式,推广应用前景广阔。

分根交替滴灌对管栽黄瓜光合作用及水分利用效率的影响

【目的】探讨分根交替滴灌对管栽黄瓜光合作用及水分利用效率的影响机理。【方法】以‘津优3号’黄瓜为试材,设分根交替滴灌(alternate partial root-zone drip irrigation,APDI)、固定1/2根区滴灌(fixed partial root-zone drip irrigation,FPDI)和传统滴灌(conventional drip irrigation,CDI)3个处理,随机区组排列,研究了不同滴灌方式对黄瓜生长、光合作用及水分利用效率的影响。【结果】分根交替滴灌(APDI)作物根区的干湿交替能够刺激根系的补偿生长,提高植物的根系活力。固定1/2根区滴灌(FPDI)黄瓜叶片相对含水量、水势和渗透势都显著低于传统滴灌(CDI),而细胞汁液浓度显著高于其他两个处理,说明FPDI在一定程度上影响了黄瓜对水分的正常吸收和转运,抑制其正常生长。与CDI相比,APDI显著降低了黄瓜叶片净光合速率和蒸腾速率,却显著提高了水分利用效率。APDI处理的PSⅡ有效光化学量子产量(Fv'/Fm')与CDI相比差异不显著,但较FPDI显著升高。FPDI处理的非光化学猝灭系数(NPQ)显著高于其他两个处理,说明固定一侧根系的干旱胁迫导致PSⅡ吸收的光能用于光化学反应的份额显著减少,从而使得光反应的能力和效率降低,过剩光能的热耗散显著增加。另外,APDI和FPDI虽然都不同程度地减少了耗水量和渗漏量,但FPDI黄瓜生长和光合作用均受到严重抑制,因此不适用于设施黄瓜的节水灌溉,而APDI处理在节水的同时能保证黄瓜正常生长及适宜的光合作用。【结论】分根交替滴灌(APDI)可作为设施节水高效灌溉的一种灌溉模式,具有广阔的应用前景。

控制性根系分区交替灌溉对玉米根区土壤微生物及作物生长的影响

【目的】研究不同的灌溉方法和灌水量对根区土壤微生物及作物生长的影响。【方法】利用盆栽试验对供试玉米采取3种灌水方式,即常规全部根系区域灌水(常规)、固定1/2根系区域灌水(固定)和交替1/2根系区域灌水(交替)。每种灌水方式设3种供水水平:充分灌水(充分)、轻度水分亏缺(轻度)、重度水分亏缺(重度)。测定土壤微生物数量、作物株高、茎粗及叶面积,记录每次灌水量。【结果】在同一灌水方式下,轻度的水分亏缺处理下土壤微生物数量占有一定的优势,有时甚至高于充分灌水处理。交替1/2根系灌水根系两侧土壤微生物数量分布均匀。作物充分灌水时,生长最旺盛,轻度亏缺次之,重度最次。【结论】轻度的水分亏缺能有效地改善土壤的水分、通气等条件,从而有利于土壤微生物的繁殖。在不同灌水方式下,由于交替1/2根系灌水使根系区土壤处于交替干燥和湿润,在提供生命活动所需水分的同时,使土壤孔隙处于良好的通气条件下,为土壤微生物提供了有益的生存条件,因此显示出其明显的优越性。充分灌水处理中,常规方式灌水所得干物质量达到最大。交替灌充分灌水处理耗水与常规灌重度水分亏缺相近,但其干物质量却相对常规灌增加了50%。交替灌的水分利用效率达到最优。

石羊河流域干旱荒漠绿洲区不同滴灌模式下葡萄茎液流变化及其与环境因子的关系

研究了石羊河流域干旱荒漠绿洲区交替滴灌(ADI)、固定滴灌(FDI)和常规滴灌(CDI)模式下葡萄茎液流的变化规律及其与气象因子和土壤含水率的相关关系.结果表明:研究区葡萄茎液流表现出与太阳辐射同步的昼夜变化节律;新梢生长期和开花期CDI处理的茎液流量显著大于其它两个处理;影响瞬时茎液流的主要气象因子是太阳辐射和气温,日茎液流量与平均气温和风速具有线性相关关系;不同灌溉方式下葡萄茎液流与气象因素的相关程度依次为:CDI>ADI>FDI;葡萄日茎液流量与参考作物蒸发蒸腾量(ET0)呈显著线性相关关系.与CDI相比,ADI节省50%水量,而茎液流总量仅降低6.56%,且其葡萄茎液流和水分传导具有明显的补偿效应.

两种新型灌溉制度——调控亏缺灌溉(RDI)和交替根区灌溉(APRI)在葡萄上应用的研究进展

葡萄是一种对水分十分敏感的果树,在我国大陆性季风气候下,合理的水分管理措施对葡萄产业的发展十分重要。笔者综述了在滴灌方式下,作为研究热点的2种灌溉制度——调控亏缺灌溉(PRD)和交替根区灌溉(APRI)的技术特点、对葡萄生长发育的影响以及在生产中实施的注意事项,为生产者们制定合理的灌溉制度提供了理论依据。制定合理的调控亏缺灌溉和交替根区灌溉制度可以减小植株无效的营养生长,促进根系生长,解决滴灌方式下根系上浮的问题,同时提高果实品质,维持甚至提高产量,还有利于树体营养的贮存。其中交替根区灌溉技术相对容易掌握,对产量影响不大,对生产者而言风险较小,适宜作为今后研究和应用的重点。此外,2种灌溉制度之间的系统比较也应作为今后的研究重点。