Phytophthora nicotianae transmission and growth of potted kalanchoe in two recirculating subirrigation systems

Recirculating subirrigation systems are frequently exposed to the risk of plant pathogens transmission, which may deteriorate the growth and quality of the plants. The transmission of Phytophthora nicotianae was examined using Kalanchoe blossfeldiana cv. New Alter in two recirculating subirrigation systems, a nutrient-flow wick culture (NFW) system and an ebb and flow (EBB) system. When the nutrient solution was infested, the pathogen was recovered from roots in both subirrigation systems. However, foliar blights and browning of roots appeared 4 and 7 weeks, respectively, after inoculation in the EBB system. Only a little discoloration appeared in the NFW system. The fresh and dry weights were lower in the EBB system than in the NFW system. When growing medium was inoculated, the pathogen was unable to be isolated from the plants in the NFW system. However, disease symptoms appeared in the EBB system 4 weeks after inoculation, and the pathogen was observed in the basal leaves and roots. Similar to the infested nutrient solution, the plant growth in the EBB system was inhibited. These results suggested that when the nutrient solution was infested, pathogen transmission could occur in plants in both systems, although differences existed with regard to disease symptoms and the time it took for symptoms to appear. However, we observed that when growing medium was inoculated the pathogen was not transmitted to adjacent plants in the NFW system using wick.     

The influence of drip irrigation or subirrigation on tomato grown in closed-loop substrate culture with saline water

In closed-loop soilless culture, one of the most relevant problems may be the accumulation in the recirculating nutrient solution of ions contained in irrigation water that are not or scarcely absorbed by the plants (e.g. Na, Cl) In order to verify the possibility to reduce the rate of recirculating water salinisation by means of subirrigation, an experiment was carried out in the spring of 2002 and 2004, with tomato plants (cv. Jama) grown in glasshouse and watered by conventional drip irrigation (D) or by subirrigation (trough bench system; S). The plants were cultivated in pots filled with a peat-perlite substrate for approximately 3 months and fed with complete nutrient solution, which was prepared with fresh water containing 10 mol m⁻³ NaCl; the nutrient solution in the collecting tank was replaced when the value of electrical conductivity (EC) exceeded 6.0 dS m⁻¹. Water and nutrient crop use, salt accumulation in the substrate, and fruit yield were monitored. In S culture, the composition and EC of the recirculating nutrient solution changed slightly, while in D treatment there was a fast water salinisation that made it necessary to flushed out the nutrient solution in six different occasions, with consequent loss of water and fertilisers. In S culture, the upward water movement in the substrate, coupled with selective mineral uptake by the roots, caused salinity build-up in the upper region of the substrate, which was associated with Na⁺ accumulation. No significant influence of irrigation methods on fruit yield and quality was observed. These findings suggest that subirrigation can be a tool to reduce the water consumption and nutrient runoff in closed-loop substrate culture of tomato conducted with saline water.     

The influence of irrigation system and nutrient solution concentration on potted geranium production under various conditions of radiation and temperature

Zonal geranium (Pelargonium × hortorum ‘Real Mintaka’) were grown in closed soilless systems to evaluate the effects of irrigation system (drip and subirrigation) and nutrient solution concentration (half and full) under various conditions of radiation and temperature (winter and summer) in terms of substrate electrical conductivity (EC_s), growth, quality, crop evapotranspiration (ET_c) and growth index water use efficiency (WUE_GI) and nutrient uptake. At he end of the cultural cycle the highest EC_s in the upper and lower layers were recorded in the spring season on plants grown in subirrigation using a full nutrient solution concentration. The highest shoot biomass, leaf area, plant growth index, and quality index were recorded in the winter season on plants grown in both drip-irrigation and subirrigation using half and full nutrient solution concentration, whereas the lowest value was observed in the spring season on plants grown with subirrigation using the full nutrient solution concentration. The highest maximum air temperature recorded during the first 20 days after transplanting in the spring growing season was presumably responsible for the reduction in shoot biomass production, growth and quality index, and in time of geranium flowering compared to the plants grown in the winter season. The ET_c was 44% higher in spring than in winter season treatment, while the effect of the irrigation system was less pronounced with an increase in 11% in the subirrigation treatment compared with the drip-irrigation system. WUE_GI was not stable and showed a seasonal variability. Solar radiaton (R_s), air temperature (T_a) and vapour pressure deficit (VPD) were greatly higher in the spring season, which influenced WUE_GI negatively. The WUE_GI improved especially when R_s, T_a and VPD were below 12 MJ m², 20 °C and 0.6 kPa, respectively. The highest N, and Mg uptake were recorded in the winter season, especially on plants grown with subirrigation at 2 dS m⁻¹. The highest P, K, and Ca uptake values were measured during winter season using subirrigation system, and on plants grown under full strength nutrient solution. The variation of the nitrate concentration and EC in the nutrient solution during the spring growing cycle was less pronounced in the subirrigation than with a drip-irrigation system which represents an important aspect for the simplification of the closed loop management of the nutrient solution.     

Growth,yield, fruit quality and nutrient uptake of hydroponically cultivated zucchini squash as affected by irrigation systems and growing seasons

Zucchini plants (Cucurbita pepo L.) were grown in closed soilless systems to analyze the effects of two of the most promising and used irrigation systems (drip and subirrigation) and two cropping seasons (spring-summer and summer-fall) in terms of substrate EC, growth, yield, fruit quality (dry matter, carbohydrates, protein, Vitamin C, nitrates and mineral composition), total nutrient uptake, mineral solution composition and water use efficiency (WUE). Plants grown with subirrigation had a high electrical conductivity in the upper and lower layers of the pots in both growing seasons, especially in the spring-summer season. In the spring-summer season, zucchini yield (total and marketable) was 18% lower with the subirrigation than with the drip-irrigation system, but the fruit quality was higher (dry matter, glucose and fructose concentrations), while no significant difference of total and marketable yield were recorded between irrigation systems during summer-fall season. In both growing seasons, and after 76 days of solution recycling, the variation of nutrients (N, P, K, Mg and Na) in the solution composition at the end of the experiment was lower with the subirrigation than with the drip-irrigation systems. Compared with the spring-summer season, plants grown in the summer-fall season exhibited a 35 and 33% lower total and marketable yield, respectively, but offer several benefits: earlier production (10 days), and higher fruit quality (higher concentration of glucose, fructose, sucrose, starch, P, K, and Mg), and water use efficiency. To produce 1 kg of marketable fruits 29 L of nutrient solution were necessary in the summer-fall season and 42 L in the spring-summer season. From an environmental point of view, growing zucchini during the summer-fall season represents an important practice to improve WUE especially in areas where water conservation is a concern.     

Subirrigation vs drip-irrigation: Effects on yield and quality of soilless grown cherry tomato

Summary

This research was carried out with the aim of comparing drip-irrigation with the trough bench technique of growing a cherry tomato crop, in terms of i) pH and EC of the substrate, ii) production and quality of the fruits and iii) efficiency in the use of the water. In the latter system, pots of opaque plastic with different characteristics were also used: i) with six bottom holes for subirrigation and without risers on the bottom; ii) with four bottom holes and with 3 mm risers on the bottom; iii) with a furrow cross on the bottom and with eight holes and 3 mm risers. This last pot was also used for the drip-irrigation. With both the fertigation methods the EC of the substrate showed a similar pattern over time in the lower and middle layers (always below 3 dS m^–1), whereas in the upper layer of the substrate it increased during the growing cycle with higher values with subirrigation compared with drip-irrigation, reaching 7.7 and 3.4 dS m^–1, respectively. The pots without risers used for the subirrigation showed the highest variations and values of EC of the recirculating nutrient solution, and the pots with risers and four holes the lowest. Tomato yield was lower with subirrigation than with the traditional free drainage drip-irrigation technique, but the quality was higher (dry matter, total soluble solids, and titratable acidity). Furthermore, with subirrigation the most frequent size class of the fruits was that with a diameter between 25 and 35 mm (considered optimal for cherry tomato), while with the open cycle it was that greater than 35.mm. No significant differences emerged between the three pot types. The water efficiency of the system was greater with subirrigation than with drip-irrigation. To produce 1 kg of fruits, 41 l of nutrient solution were necessary with the subirrigation (closed system) and 59 l with the drip-irrigation (open system).     

Closed cycle subirrigation with low concentration nutrient solution can be used for soilless tomato production in saline conditions

Closed cycle soilless techniques can be adopted to minimize water and fertilizer losses in greenhouse cultivation. There is a general lack of information regarding the soilless cultivation of vegetables with closed cycle subirrigation techniques, specifically when using saline water. In this study, a trough bench subirrigation system (SUB), with two fertilizer concentrations (“100%”, containing 9.8 mol m⁻³ N-NO₃, 1.6 mol m⁻³ P-H₂PO₄, 8.7 mol m⁻³ K⁺, 2.8 mol m⁻³ Ca⁺, 1.8 mol m⁻³ Mg⁺, 4 mol m⁻³ S-SO₄, and “70%”, containing 70% of the macronutrient concentration) in the nutrient solution (NS), was compared with open cycle drip-irrigation (DRIP with “100%” NS). For all the three treatments, NS was prepared using rain water (0.05 dS m⁻¹) and adding NaCl (1 g L⁻¹), in order to simulate moderate saline irrigation water. The effect of the treatments on tomato (Solanum lycopersicum L.) plant growth, yield, fruit quality, water use efficiency (WUE) and fertilizer consumption was evaluated. Substrate and recirculating NS composition were also studied. Subirrigation, regardless of NS concentration, reduced plant height (by 30 cm), leaf area (by 1411 cm²), total fresh and dry weight (by 429 and 48.5 g plant⁻¹, respectively) but not dry matter percentage of the whole plant, with respect to DRIP. Yield was reduced when plants were subirrigated with the higher concentrated NS, but no differences with open cycle DRIP were recorded when the lower NS concentration was used in SUB. Fruit quality was not affected by irrigation system or NS concentration. The higher WUE was obtained with subirrigation. NaCl accumulated similarly over the crop cycle in recirculating NS of both SUB treatments and in growing substrates of all the three treatments. Higher salt concentration was found in subirrigated substrates, in particular in the upper part of the substrate profile. Fertilizers accumulated in the subirrigated substrates when the higher NS concentration was used, but not when the NS concentration was reduced by 30%. The results of this study indicate that tomato can be grown successfully in a closed cycle subirrigation system, using saline water, by reducing the fertilizer NS concentration normally used with traditional open cycle systems.     

Spatial and temporal oxygen distribution measured with oxygen microsensors in growing media with different levels of compaction

Oxygen microsensors were used to determine oxygen profiles in situ from the top to the bottom layer of the growing medium for potted plants of Rosa sp. ‘Dior’. The growing medium was peat- based and compacted uniformly to 3 different bulk densities of 0.14, 0.18 and 0.23 g cm⁻³ (0, 20 and 40% compacted, respectively). The water distribution in the pot was determined as water content (g cm⁻³) in the top, middle and bottom layers of the peat. Oxygen content was also determined after a standard subirrigation cycle and after excessive irrigation where the bottom of the pots were left waterlogged for 24 h. Measurements were carried out at 5.5 weeks during the production phase and at 12 weeks at the end of the production. The results showed that with increasing compaction and density, more water was transported to the upper layers of the pot. After a standard irrigation cycle there was no effect of the level of medium compaction on the oxygen distribution, whereas after excessive irrigation, the oxygen contents at the bottom of the pots were strongly reduced and the level of compaction significantly affected oxygen availability. The most compacted medium had the lowest oxygen content at 5.5 weeks, with anoxic conditions in the bottom 30 mm. Plant quality measured as fresh weight, dry weight, height and number of shoots with flowers and buds was not affected by the different levels of compaction. The use of oxygen microsensors provided a new insight into the spatial and temporal distribution of oxygen in growing media and how this was affected by the physical characteristics of the growing media.     

Effects of different mulches and irrigation methods on root growth,nutrient uptake,water-use efficiency and yield of strawberry

Field studies were conducted for two consecutive years under sub-temperate climatic conditions at Nauni in district Solan of Himachal Pradesh (30°52′N, 77°11′E 1175 asl) on loamy sand Inceptisols to investigate the effect of different mulches (hay: HM, black polyethylene: BP) on root growth, nutrient uptake, water-use efficiency (WUE) and yield of strawberry cv. Chandler under drip (DI) and surface irrigation (SI) systems. Unmulch (UM) and rainfed treatments were kept as control. Higher soil moisture content was registered under both the mulch materials during entire crop growth period. However, it was greater under BP mulch as compare to HM. The moisture conservation increased by 2.80–12.80% under BP mulch as compared to UM. HM treatment, irrespective of irrigation method increased the minimum soil temperature (2.8–5.2 °C) and reduced the maximum soil temperature (2.7–5.8 °C) as compared to UM. BP mulch increased the minimum soil temperature from 0.4 to 2.5 °C. Application of irrigation moderated the soil (minimum 2.6 and maximum 1.4 °C) temperature. Both the mulch materials were effective in enhancing root growth, nutrient uptake, WUE and yield. Application of mulch enhanced the root growth (63%), nutrient uptake (179.20%), WUE (84.40%) and yield (343%) under DI. However, respective increase under SI was 23.60, 83.80, 109.40 and 219.20%. Under DI, 51% of irrigation water was saved and about 19% higher fruit yield was obtained as compared with SI treatment. Linear regression model could significantly describe the variations in nutrient uptake (N, P and K) and WUE of strawberry under sub-temperate climatic conditions, root mass density was better indicator for estimating nutrient uptake of strawberry.     

栽培槽大小对日光温室架式栽培番茄生长发育、水肥利用和产量品质的影响

利用封闭式循环供液高架栽培系统,研究了栽培槽大小(横切面宽度×深度:20cm×10cm,20cm×15cm,20cm×20cm)和钵栽(直径12cm×高10cm,基质容积1L)对架式栽培番茄(3穗果摘心)生长发育、水肥利用及产量品质的影响。结果表明:与钵栽相比,槽栽促进番茄植株生长,增加产量,但开花和采收时间延迟,果实品质下降,水肥利用效率降低;随着栽培槽体积的增大,植株生长旺盛,干物质积累量增加,但水肥利用效率降低,果实品质下降,不同大小栽培槽处理间水分利用效率和单株产量差异不显著。综合产量、品质及水肥利用效率等指标,番茄架式栽培槽大小以20cm×10cm为宜。     

Comparative effects of deficit irrigation (DI) and partial rootzone drying (PRD) on soil water distribution,water use,growth and yield in greenhouse grown hot pepper

This study was conducted to compare two water-saving practices, deficit irrigation (DI) and partial rootzone drying (PRD), and examine how they affected soil water distribution, water use, growth and yield of greenhouse grown hot pepper compared to commercial irrigation (CI). Control (CI) in which irrigation water was applied to both sides of the system when soil water content was lower by 80% of field capacity; deficit irrigation (DI50, DI75) in which 50% and 75% irrigation water of CI supplied to both sides of the root system; 1PRD with half of the root system exposed to soil drying and other half kept well-watered with 50% irrigation water of CI, and 2PRD with 50% irrigation water of CI supplied, half to fixed side of the root system. The results showed mean soil volumetric water content of DI75, DI50, 1PRD and 2PRD were lower by 21.06%, 28.32%, 24.48% and 34.76%, respectively than that of CI after starting the experiment. Water consumption showed some significant effect of irrigation treatments during the growing period of drought stress application, and therefore decreased in DI75, DI50, 1PRD and 2PRD to a level around 75% and 50% of CI. All the DI and PRD treatments resulted in a reduction of total dry mass of 7.29–44.10%, shoot biomass of 24.97–47.72% compared to CI, but an increase in the root–shoot ratio of 12.50–35.42% compared to the control and with significant differences between 2PRD, 1PRD, DI50 and CI. The yield of 1PRD was significantly reduced by 23.98% compared to CI (19,566 kg hm⁻²) over a period of 109 days after transplanting. However, the 1PRD treatment had 17.21% and 24.54% additional yield over the DI50 and 2PRD treatments and had 52.05% higher irrigation water use efficiency (IWUE) than CI treatment. At harvest, although there was a significant difference recorded as single fruit weight and single fruit volume were reduced under the DI and PRD treatments, total soluble solids concentration of fruit harvested under the water-deficit treatments were higher compared to CI. Stomatal conductance measured in fresh leaf was the lowest under 1PRD treatment relative to CI and other treatments. The low stomatal conductance of fresh-leaf issue observed in the work supported the root signaling mechanism reported earlier in plants having undergone partial root drying cycles.     

日光温室番茄畦上覆膜沟灌增产和节水效果分析

以番茄品种东圣1号为试材,以传统沟灌为对照,研究了畦上覆膜沟灌(膜上沟灌和膜下沟灌)对番茄生长、产量及水分生产效率的影响。结果表明:在灌水量减少的情况下,膜上沟灌保持根区0～40cm土层墒情的能力高于其他灌溉方式;膜下沟灌更有利于番茄的生长发育,植株长势较好,并且较传统沟灌显著增产11.34%;相对于传统沟灌,膜上沟灌和膜下沟灌分别节约灌溉用水31.33%和27.00%,水分生产效率提高50%以上。     

交替根区滴灌对西瓜生长、产量、品质及水分利用效率的影响

为探索设施西瓜栽培的最优灌水策略,以“早佳8424”西瓜为研究对象,在早春塑料大棚栽培模式下,以常规滴灌为对照,设置3个交替根区滴灌处理(灌水上限分别为70%、80%、90%田间持水量),研究不同灌溉模式对西瓜生长、产量、品质、养分吸收及水分利用效率的影响。结果表明：交替根区滴灌处理(灌水上限和下限分别为90%和60%田间持水量)的综合性状最好,其主蔓长、叶绿素相对含量(SPAD值)、平均单果质量、产量及果实中心可溶性固形物含量、全氮含量、全钾含量均较对照显著提高;理论产量达48 217.5 kg/hm²,水分利用效率达78.21 kg/m³,较对照分别增长11.09%和35.50%;且较对照节水33.01%,具有明显的节水效果和较高的水分利用效率,不仅促进了西瓜生长、品质提升以及养分吸收,同时可以实现高产、节水,有效提升灌溉水分利用效率。     

负水头供不同营养液对温室樱桃番茄生长和产量的影响

采用负水头灌溉装置,通过调节装置的供水吸力值来持续稳定地控制栽培基质的湿度,供给不同浓度磷酸二氢钾（KH₂PO₄）营养液配方进行樱桃番茄基质栽培试验,研究营养液中不同磷酸二氢钾浓度对樱桃番茄株高、茎粗、产量、水肥利用效率和根系活力的影响。结果表明：在负水头供水控水技术条件下,适当提高营养液中磷酸二氢钾浓度,有利于增加樱桃番茄株高、茎粗,效果显著;同时可以提高果实产量、水分利用效率和N、K利用效率以及根系活力。负水头供给营养液樱桃番茄栽培生产中,2.5 S处理即340 mg•L^-1的KH₂PO₄浓度可作为推荐用量。     

CCROP—Simulation model for container-grown nursery plant production

Container Crop Resource Optimization Program (CCROP) is an integrative model which simulates the growth and water and nutrient requirements of a woody ornamental shrub grown in small (2.8–11.4 L) containers in a field environment with overhead sprinkler irrigation. The model was developed for producers, producer advisers and researchers to support best management practice decision-making in container nursery production. We describe the primary processes simulated by CCROP particularly how they differ from traditional crops grown in-ground and assess the ability of CCROP to simulate measured values for a range of irrigation and fertilizer trials and transplanting dates. Results of model testing with 11 trials indicate that CCROP provided reasonable outcomes for biomass and leaf area growth as well as evapotranspiration, runoff (container drainage plus un-intercepted irrigation and rainfall) and nitrogen loss.     

潮汐灌溉供液高度对黄瓜穴盘苗生长发育与水肥利用的影响

在潮汐灌溉条件下,以黄瓜品种中农18号为材料,分别在夏季和冬季进行穴盘育苗,比较1、2、3 cm供液高度对基质的吸水速率、黄瓜穴盘苗表观生长指标、根系活力、水分及氮素利用率的影响。结果表明:随着供液高度增加,基质吸水速率逐渐加快;夏季和冬季育苗供液高度为2 cm和3 cm时,穴盘苗的株高、叶面积、茎叶鲜质量和干质量均高于1 cm供液高度,3个供液高度间的根体积、根系鲜质量和干质量、根冠比、壮苗指数无显著差异,但3 cm供液高度的穴盘苗根系活力显著降低,供液和回液体积以及肥料施用量最大;而夏季育苗2 cm供液高度时,穴盘苗的水分利用率较高,且氮素利用率最大。基于穴盘苗表观生长指标与水肥利用率,夏季和冬季黄瓜潮汐穴盘育苗的适宜灌溉高度均为2 cm。     

杜鹃无土栽培基质配方的研究

 采用发达国家已经大量应用的潮水式(Ebb&Flow)底面灌施营养液栽培系统，以盆栽杜鹃品种‘Mission Bell’作为试材，筛选出适合杜鹃盆花无土栽培 基质配方。混有草炭的M1(体积比：草炭土3+蛭石3+珍珠岩3)、M2(草炭土3+蛭石3+砻糠3)和M4(草炭土2+蛭石2+珍珠岩2+著糠2+腐叶土2)基质配方栽培的植株表现较好，尤以M1处理，即‘草炭土3+蛭石3+珍珠岩3’的等量配方为最优，而椰壳并不适合盆栽杜鹃的植株生长。土壤的理化分析和植物体分析结果表明，营养液灌溉处理后基质的pH值基本相同，但EC值的增幅很大，是由封闭系统内营养液中盐分累积所致；盆内基质中的矿质营养元素和阳离子交换量也明显增加；植物体的营养元素含量水平普遍较高，非常符合杜鹃类植物的生长条件与特殊需求。     

Effects of oxygen-enriched nutrient solution on greenhouse cucumber and pepper production

A series of experiments were conducted with greenhouse cucumber and pepper plants to determine the effects of oxygen enrichment of the irrigation water on yield and fruit shelf-life. The experiments were carried out in soilless culture in research greenhouses. Depending on the experiment, treatments included sub-ambient (2 mg L⁻¹), ambient (5–6 mg L⁻¹), medium (16 mg L⁻¹) and high (30–40 mg L⁻¹) levels of oxygen in the supply tank. Cucumber plants were grown in yellow cedar sawdust and pepper plants in either sawdust or perlite. Oxygen enrichment resulted in a promotion of cucumber yield in only one experiment; in two other experiments, none of the oxygen treatments, including those at sub-ambient levels, had an effect. There were no effects of oxygen enrichment on pepper yield. However, in both cucumber and pepper, fruit shelf-life was extended in oxygen-enriched treatments. In terms of system efficacy, oxygen levels in the irrigation water were measured at the dripper and found to decrease by 20–67% of initial values compared to the supply tank values, depending on the initial oxygen concentration and on the experiment. Oxygen concentrations decreased even further to virtually ambient levels when measured in the drain water or in the substrate reservoir. Cucumber plant growth was promoted under conditions which facilitated consistently high oxygen in the root zone, achieved through heavy irrigation (1 min in two) with oxygen-enriched nutrient solution of plants grown in saturated substrate (pumice). However, those extreme irrigation rates would not be practical for commercial cucumber or pepper production. Overall, this study demonstrates that oxygen enrichment of porous substrates under typical hydroponic conditions is difficult and possibly because of this, effects on yield are infrequent. However, fruit shelf-life may be improved.     

水肥耦合对设施番茄肥料减施效应的影响

为了探索水肥耦合在设施番茄上的应用效果及其对肥料减施的贡献，采用田间试验，设置6个处理，研究了水肥耦合条件下底肥减施20%和40%、灌溉量减少15%的条件下对设施番茄产量、品质和土壤养分的影响。结果表明：中水中肥（W2F2）处理产量最高，显著高于其他处理，产量比高水中肥（W1F2）处理提高2.0%，比常规处理（W1F1）提高4.1%。中水中肥处理番茄可溶性固形物、维生素C、土壤有机质、碱解氮、有效磷、速效钾含量比常规处理分别提高1.5%、5.8%、6.5%、6.3%、4.5%、10.6%。说明中水中肥处理（80%常规施肥+滴灌至田间持水量的85%，每公顷每次施用51kg大量元素水溶肥随水滴灌4次）不仅能提高设施番茄产量，还能在一定程度上提高番茄品质和土壤养分含量，是设施番茄肥料减施最佳处理。     

A comparative study of young ‘Thompson Seedless’ grapevines under drip and furrow irrigation. I. Root and soil water distributions

Soilwater distribution, soilwater extraction, and root distributions were determined for young grapevines (Vitis vinifera L. cultivar ‘Thompson Seedless’) grown under drip and furrow irrigation near Fresno, CA, USA. Soilwater content and extraction was determined to a depth of 0.9 m by neutron scattering from an array of nine access tubes installed throughout one-quarter of the soil volume available to each vine. Root distribution was determined from root intersections with vertical planes established parallel and perpendicular to the vine row. Drip irrigation was applied daily according to estimated evapotranspiration, and furrow irrigation was managed according to 50% depletion of the plant available soil water. Drip and furrow irrigated vines showed similar water status and shoot growth patterns. There was a confined soil wetted zone beneath the emitter discharge that largely coincided with a confined and shallow root system of drip irrigated vines. In contrast, furrow irrigated vines had a deeper and more widespread root system. Differences between water applied and soilwater content 3 days after irrigation suggested large water losses by evaporation during that period for furrow irrigated vines. Consumptive use of furrow irrigated vines was 12.5% greater than drip irrigated vines, but similar irrigation efficiencies were obtained for both irrigation systems when soilwater status was carefully monitored. Water applications for both irrigation systems were less than 50% of the longterm mean for irrigation deliveries to farms in the area. Thus, the results indicate that a significant potential for water savings exists in the San Joaquin Valley by means of irrigation management. It is concluded that relatively high and similar irrigation efficiency can be obtained with both drip and furrow irrigation of young grapevines in arid and semiarid regions when careful management is used.     

设施黄瓜水肥一体化技术研究

设施黄瓜生产对土壤水分和营养元素养分条件要求比较严格,目前传统灌溉施肥方式,不能满足设施黄瓜生产对水肥的合理需求。针对以上问题,开展了设施黄瓜灌溉和施肥方式、不同生育期水肥用量、肥料种类、营养成分搭配等水肥一体化综合技术研究工作。根据研究结果,水肥一体化灌溉施肥技术比常规施肥节省肥料37.7%,节省水资源65.6%,节水节肥效果明显,建议研究推广此项技术。