Journal of Soil and Plant Interactions

---

Abstract This research was performed in a completely randomized block design with four replications to investigate zinc (Zn) and manganese (Mn) nutrition effects on greenhouse tomato (Lycopersicon esculentum Mill. cv. HAMRA) in a perlite-containing media. Experimental treatments were: (1) control (Mn and Zn-free nutrient solution), (2) application of Mn in a concentration equal to the full Hoagland’s nutrient solution (4.06 mg/l), (3) application of Zn in a concentration equal to the full Hoagland’s nutrient solution (4.42 mg/l), (4) application of Mn and Zn in concentrations equal to the 50% Hoagland’s nutrient solution (2.03 mg/l Mn + 2.21 mg/l Zn), and (5) application of Mn and Zn in concentrations equal to the full Hoagland’s nutrient solution (4.06 mg/l Mn + 4.42 mg/l Zn). Results showed that the highest fresh-fruit yield, fruit and leaf dry matter and content of Mn and Zn in fruit were obtained from single or combined application of Mn and Zn in concentrations equal to the full Hoagland’s nutrient solution. In addition, Zn and Mn nutrition significantly affected the fruit concentrations of crude protein, nitrogen and phosphorus, while the effect of these treatments on fruit size of tomato was not significant.

---

Hydroponic growth systems are expanding due to their advantages such as maximum yield, healthy crop production and reduced labour requirement. Vegetable in each stage of the plant growth needs adequate nutrients in different growing media. The objective of this study was to examine the effect of some growth media on N, K and Mg uptake by greenhouse cucumber. This study was carried out in the research greenhouse of Islamic Azad University-Khorasgan branch, using a completely randomized design with 5 treatments, 4 replications and 10 plants in each replication. The Five different growth media consited of pure cocopeat, perlite-cocopeat (50-50 v/v), perlite-cocopeat-peatmoss (50-20-30 v/v and 50-30-20) and perlite-peatmoss. Physical and chemical properties and some nutrients concentrations such as N, K and Mg as well as fruit yield were examined. Although no significant difference was found among the studied growth media in the fruit yield of cucumber, the highest yield was obtained for cocopeat. Significant difference (P < 0.05) was observed in the plant biomass among the growth media. The highest biomass was obtained for the cocopeat and perlite-cocopeat media. No significant difference was found among the growth media in concentrations of N, K and Mg although the highest concentrations of N and K in the second and third stages of sampling were obtained in cocopeat. Shoot concentration of Mg at the first and second stages of sampling was more than the critical deficiency level. The best concentration of Mg was obtained in cocopeat. In general, the best nutrient concentration and yield were found in cocopeat substrate which can be used as an appropriate growing cucumber media for in soilless culture.

---

Most plant species are sensitive to high ammonium concentrations. In this experiment the sensitivity of lettuce and spinach to ammonium was investigated. In a factorial experiment with framework of a completely randomized design with two factors, nitrogen form (ammonium and nitrate) and plant species (lettuce and spinach), and three replications seeds were germinated in a mixture of perlite, sand and clay in soil-maid pots. After two weeks, the seedlings at two true-leaf stage were then transferred to buckets containing 4 L of aerated nutrient solution. The four plants were growing together. The treatments were ammonium and nitrate at 5 mM. In comparison to nitrate, ammonium reduced the growth of both species. Concentration of K, Mg, and Na decreased with ammonium in both species. The reduction of K and Mg concentrations in ammonium-fed plants may have a role in ammonium toxicity. Ammonium nutrition of both species caused an increase in P at roots and shoots. Higher P content at ammonium-fed lettuce and spinach plants may be due to creation of cations and anions balance in plants. Chlorophyll a and b were higher in ammonium-fed than nitrate-fed plants.

---

This experiment was conducted to determine the effect of salinity and nitrogen on growth and yield of tomato and concentration and total uptake of some nutrients in different parts of plant in hydroponics culture. Nitrogen (N) was used at 0, 1.5 and 3% levels as NH4Cl and NH4H2PO4 and salinity consisted of 0, 30 and 60 mM as NaCl and CaCl2 (2:1 w/w). A completely randomized design experiment was carried out under greenhouse conditions. Results showed that fruit fresh weight increased with N application but salinity treatment decreased fruit yield. Maximum fresh weight was observed in treatment with 3% N and without any salinity application, whereas minimum fresh weight was obtained with 30 mM salinity and without any N application. Application of 30 and 60 mM salinity increased fruit phosphorous concentration significantly (P<0.05), but it did not affect shoot and fruit concentration. Nitrogen application increased fruit, shoot and root phosphorous concentration significantly. Root, shoot and fruit N uptake increased with N application (without salinity) whereas at high salinity level, increase in N uptake was lower than at low salinity level. Salinity increase without N decreased fruit phosphorous and manganese uptake, root copper, zinc and manganese concentration and shoot manganese uptake. Furthermore, results showed that at low salinity level, N application can alleviate the negative effects of salinity on growth and yield of plant.

---

A pot experiment was conducted in Isfahan University of Technology research greenhouse to investigate the effects of sewage sludge, compost and cow manure on growth and uptake of Fe, Zn, Mn and Ni in tagetes flower. A completely randomized research with three treatments (sewage sludge, compost and cow manure at 25 Mg ha-1) and three replicates was performed. Application of organic wastes significantly increased organic matter and CEC of the soil. Application of compost significantly increased DTPA-extractable Fe, Zn, Mn and Ni of the soil. The use of organic wastes increased tagetes flower growth. The growth of plant was highest in the compost treatment. Results indicated that Fe, Zn, Mn and Ni uptake by plant shoot, and the percentage of metals translocated to the shoot was greater in the compost treatment compared to other treatments. In general, the application of compost for tagetes flower had a positive impact on plant growth parameters and micronutrients uptake.

---

Salinity plays an important role in the reduction of tomato growth, especially in arid and semi-arid regions. Nitrogen (N) may increase tomato tolerance to salt stress by increasing plant growth. In order to investigate the interaction effect of salinity and nitrogen on tomato growth, fruit quality, and micronutrient concentration in tomato plants, a hydroponic experiment was conducted in a completely randomized design with three replications. Treatments included 3 salinity levels (0, 30 and 60 mM), and 3 nitrogen rates (0, 1.5, and 3 mM). Results indicated that salinity decreased tomato height, shoot and fruit fresh weight, and increased citric acid in tomato fruit and consequently caused blossom-end rot in tomato fruit. However, salinity improved fruit quality (flavor). The use of N increased plant height, shoot, and fruit fresh weight compared to control. By application of N to saline nutrient solution, plant height increased. Salinity increased concentration of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) in roots, as`well as Fe and Cu in fruit. Increasing N rates in nutrient solution increased micronutrients concentration in tomato roots. Interaction of 60 mM salinity and N decreased micronutrients concentration in root, compared to control. Our tentative conclusion shows that the addition of N to the nutrient solution may decrease detrimental effect of salinity on the growth of tomato plants.

---

To study the effects of potassium and zinc on decreasing the cadmium (Cd) toxicity on growth and physiological parameters of tomato (Lycopersicon esculentum Mill.) a greenhouse experiment was conducted in a soilless system with complete randomized block factorial design. Zinc (Zn) was applied in three levels: 88.8, 177.6 and 355.2 µg L-1 as the first factor. The second factor was potassium (K) with three levels of 255, 510 and 1020 mg L-1. The base solution (Hoagland solution) contained 20 mM cadmium in all the treatments. The results showed that Zn treatments had significant effect on some growth indices including RGR, RLGR, LWR, LWCA, dry weight of aerial parts and soluble sugar content. Increasing the Zn level caused 7.7, 7.7, 3.3, 4 and 31.3% decrease in RGR, RLGR, LWR, LWCA and sugar content, respectively. The K treatments had significant effects on LAR, SLA, LWR, LWCA, NAR and root fresh weight. The LAR, SLA and LWR were increased 7.7, 15.3 and 6.9%, respectively. It was concluded that Zn had synergistic effect with Cd in tomato, and therefore co-existence of Zn and Cd reduced crop growth. Whereas, K application had antagonistic effect with Cd, and caused an increase in LAR and SLA. Interaction of K and Zn was not significantly effective on the measured parameters.

---

Despite of increasing request for greenhouse vegetables, there is quite limited information on their nutritional quality. This study was carried out to investigate nutritional status of macronutrients (Ca, Mg, P and K) and micronutrients (Fe, Mn, Cu and Zn) in greenhouse cucumber and bell pepper in Isfahan province. After selecting 25 greenhouses, the concentration of macronutrients and micronutrients was measured in soil and edible parts of cucumbers and bell peppers. The results showed that mean concentration of P and K in the soils was much higher than their critical deficiency level. Mean concentration of DTPA-extractable Fe, Zn, Cu and Mn of the soils was 12.0, 4.9, 1.9, and 14.5 mg kg-1. Mean fruit Mg, P and K concentrations in the cucumber and bell pepper were greater than their sufficiency level, while more than 75% of the greenhouse cucumbers were Ca deficient. Also more than half of the greenhouse cucumbers and about 20% of greenhouse bell peppers had Mn deficiency. Also more than 60% of greenhouse cucumbers were Fe and Zn deficient. According to the results, high concentration of some macronutrients such as P and K, and widespread deficiency of Ca and micronutrients in greenhouse production, is probably due to nutritional mismanagement, unbalanced fertilizer application, unstable greenhouse conditions and environmental pollution risks.

---

To determine the effect of application of phosphorus (P) and organic matter on soil-plant P relationship at different growth stages of spinach, an experiment was conducted at greenhouse conditions. Treatments consisted of two levels of organic matter (0 and 2% of sheep manure) and three levels of P as Ca(H2PO4)2 (0, 20 and 60 mg P kg-1soil). Soil and plant samples were collected at five growth stages (the first sampling was in the fourth week after emergence, and the other samplings were each one week after the first sampling). The results showed that crop yield increased with the increase of soil P at all growth stages, whereas it had no significant effect on plant P content. In the 4th week of growth, plant P increased with an increase of soil P, and it remained relatively unchanged in the 5th week. But it decreased significantly in the 6th to 8th week. Concentration of plant nutrients depends not only on soil nutrients concentration but also on plant age and availability of other nutrients. In some stages of the plant growth, the growth rate might be too fast such that total uptake of the nutrients is not enough to maintain the necessary concentration. Plants required adequate P at early growth stages for optimum growth. Phosphorus uptake was increased with plant growth in all samples. Soil P content was higher in all organic matter treatments (especially in the 6th week after emergence). Phosphorus uptake in samples with organic matter, and no addition of P, was more than the samples which received P. This might be due to mineralization of organic P added to the soil.

---

Abstract In order to study the effects of different levels of nitrogen (N) and molybdenum (Mo) in nutrient solution on quantitative and qualitative traits and nitrate concentration of cucumber (Sultan cv.), a factorial hydroponic-experiment with completely randomized design and three replications was conducted in the greenhouse of Soil Science Department, Zanjan University, in 2009. The concentrations of N in nutrient solution were 238 and 310 mg/L, and Mo was used at the rates of 0.01, 0.1 and 1 mg/L. The results showed that the effects of N and Mo levels were significant (P≤0.01) on plant yield and growth indices such as average weight, length and diameter of fruit and chlorophyll content of leaf. The chlorophyll content of leaf increased but fruit yield and average weight, length and diameter of fruits decreased as the N concentration of the nutrient solution increased. Increasing the Mo level in the nutrient solution decreased the growth indices and yield of cucumber. The highest fruit yield was obtained when the concentration of Mo in the nutrient solution was 0.01 mg/L. But it didn’t have significant difference with 0.1 mg/L treatment. However, the yield decreased significantly as the Mo concentration increased to 1 mg/L. The effects of N and Mo levels of nutrient solution were significant (P ≤ 0.01) on nitrate concentration of the fruits. As the N level of nutrient solution increased, the nitrate concentration of cucumber fruit increased from 1356 to 2122 mg/kg (on dry weight basis), and exceeded the toxicity limit of 1500 mg/L. Increasing the concentration of Mo of the nutrient solution from 0.01 to 0.1 mg/L decreased nitrate concentration of fruits from 1961 to 1703 mg/kg, without decreasing the fruit yield. With an increase in N concentration of the nutrient solution, the fruit concentrations of N, potassium and calcium increased, but those of phosphorus, magnesium and Mo decreased significantly. Also, as the concentration of Mo in the nutrient solution increased, the concentrations of iron, manganese and in fruit increased and that of copper decreased.

---

Abstract Optimum level of calcium (Ca) in saline soils is a critical factor in controlling the toxic effect of some ions, especially in plants sensitive to sodium (Na) and chlorine (Cl) damage. To evaluate the effect of salinity and supplementary calcium (S-Ca) on vegetative growth, fruit yield and concentration of some nutrients in roots, shoots, and fruits of strawberry (Fragaria ananaassa Duch) cv. Selva, a greenhouse experiment was carried out in 5×3 factorial experiment arranged in a completely randomized design with three replications. Treatments included three levels of salinity (0, 20, and 40 mM as NaCl) and five levels of supplementary Ca (0, 5, and 10 mM added to nutrient solution, 0.5 and 1% foliar application as CaCl2). The results showed that addition of NaCl to nutrient solution, negatively affected root and shoot dry weight and fruit fresh weight. Reduction of shoot dry weight and fruit fresh weight were higher than those of roots. Application of S-Ca not only did not improve the vegetative growth and fruit yield, but rather decreased them. Salinity (NaCl) treatments increased the concentration of Na in roots, shoots and fruits but application of 5 and 10 mM S-Ca levels decreased Na concentration in roots. By addition of NaCl to nutrient solution, the shoot Ca concentration was decreased in some treatments, but roots and fruits’ Ca concentration was not affected. Application of S-Ca increased Ca concentration in all organs of strawberry plants. By application of NaCl, potassium (K) concentration was decreased in roots, but increased in fruits and was not affected in shoots. K concentration did not change in roots in the S-Ca applied treatments, but decreased in shoots and increased in fruits. Simultaneous application of salinity and S-Ca decreased roots’ magnesium concentration in all treatments and shoots and fruits’ concentration in some treatments. In general, although supplementary Ca increased its concentration in different plant organs, but was not effective in alleviation of the negative effects of salinity on vegetative growth and fruit yield of strawberry plants.

---

Abstract Addition of sewage sludge (SS) in soil causes increasing soil organic matter, which in turn improves soil physical properties, and could supply part of the nutrients required by plants. For comparison of SS application and chemical fertilizer treatment (CFT) on yield and concentration of some macro and micro nutrients in spinach, a greenhouse factorial experiment, arranged in a completely randomized design (CRD), was conducted with three replications. The first factor included SS levels (0, 10, 20, 40 and 80 gr kg-1) and the second factor was soil textural classes (clay loam, sandy loam and sandy). A CFT was also used to compare its affect with that of SS levels. Results showed that addition of all levels of SS caused significant increase in the weight of spinach shoots in three soil textures. Application of all SS levels caused significant increase of nitrogen (N), phosphorous (P), iron (Fe), zinc (Zn), copper (Cu) and manganese (Mn) concentration in spinach shoots. With SS application, none of the nutrients’ concentration in spinach reached the toxic level. The amounts of cadmium (Cd) and lead (Pb) were not detectable in shoots. However, in frequent application of SS, especially at high levels, it is necessary to measure and detect these elements in plants. Effect of fertilizer in increasing yield and concentration of nutrients was less than the 40 and 80 gr kg-1 SS treatments. Considering the Fe and Zn deficiency in calcareous soils, application of SS can be effective for combating this deficiency. Prior to any recommendation of SS application, the results of this research need to be verified under field conditions.

---

Nickel (Ni) is the most recently discovered essential element for higher plants. But there is limited information about the effect of this element on yield and nitrogen (N) metabolism of different plants. In this research, the interaction of Ni supplement and N source was studied on nitrate accumulation and growth of lettuce (Lactuca sativa L. cv. Baker) in solution culture. In a greenhouse experiment, lettuce plants were exposed to two Ni levels (0 and 0.04 µM in the form of NiCl2) and three N levels (5, 10, and 20 µM in the form of urea and ammonium nitrate). The plants were harvested 6 weeks after transplanting and the fresh weight of shoots and roots, total N concentration, nitrate concentration and Fe content of shoots were determined. The results indicated that shoot and root fresh weight of nitrate-fed plants were higher than urea-fed plants. Ni nutrition significantly enhanced the yield of urea-fed plants. The shoot nitrate concentration in nitrate-fed plants was significantly greater in comparison with urea-fed plants. On the other hand, nitrate concentration in the shoots of lettuce plants decreased significantly with Ni nutrition. Ni supplementation in urea-fed plants increased the shoot Fe content. The shoot concentration of total-N in the urea-fed plants increased with the Ni supplement. While, Ni had no significant effect on shoot concentration of total-N in the nitrate-fed plants. Addition of low levels of Ni to the nutrient solution, particularly to the urea-containing solution, improved the yield of lettuce. In addition, these plant leaves are safer for human consumption because the shoot nitrate content is significantly reduced by application of Ni.

---

Phytic acid is the main source of organic phosphorus in grains of legumes and cereals. It has great ability of bonding with metals and minerals such as iron, zinc and calcium. As a result, the solubility of these elements and their absorption capability by human will be reduced. This greenhouse research was carried out with the aim of studying the variations of phytic acid to zinc molar ratio and evaluation of nutrients’ concentration in different varieties of red bean (Phaseolus calcaratus L.) under balanced fertilization conditions (based on soil test) in different timings after flowering stage. Treatments included: 5 varieties of red bean (Akhtar, Naz, Derakhshan, Goli and Sayyad), two levels of fertilizer (control and balanced fertilization) and 3 times of sampling (12, 22 and 32 days after flowering T1, T2 and T3, respectively) in a factorial arrangement with complete randomized blocks design. Phosphorous, potassium, iron and zinc concentration and phytic acid to zinc molar ratio in grains of different red bean cultivars were determined. The results of analysis of variance showed that the effect of cultivar, fertilizer and sampling time on concentration of zinc, iron, potassium, phosphorous and phytic acid to zinc molar ratio in grain was significant (P<0.01). Also, the highest concentration of zinc in grain was measured in Goli cultivar at T3 timing. The phytic acid to zinc molar ratio in balanced-fertilization treatment was recorded for Goli cultivar at T1, T2 and T3 timings as 11.1, 10.49 and 7.99, respectively. In general, the results of this research showed that balanced fertilization reduced phytic acid to zinc molar ratio. This can be effective in enhancing humans’ health by improving the absorption capability of required nutrients. More investigations under field conditions are recommended.

---

Soil salinity may cause nutrients imbalance in plants. Addition of some nutrients to saline soils may alleviate negative effects of salinity on plant growth and yield. In order to evaluate the effect of salinity and phosphorus on growth and chemical composition of two varieties of spinach (Khardar and Virofly Duch) a greenhouse experiment was carried out in a factorial arrangement 2×3×2 in a completely randomized design with three replications. Treatments consisted of three levels of salinity (0.6, 3.8 and 8 dS/m as NaCl) and two levels of phosphorus (40 and 80 mg per kg soil as mono-calcium phosphate). Results indicated that concentration and total uptake of sodium (Na), chloride (Cl) and magnesium (Mg) were higher in Khardar than in Virofly however, concentration and total uptake of nitrogen (N), potassium (K), iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu) were lower than in Virofly. Concentration and total uptake of calcium (Ca) and phosphorus (P) were similar in two varieties of spinach. Application of 80 mg P increased dry weight of Khardar but had no significant effect on dry weight of Virofly. Addition of P, significantly increased total uptake of N, P, Ca, Mg, Zn, Cu, Na and Cl in Khardar, and total uptake of P and Cu in Virofly. Phosphorus decreased uptake of N, Ca, Mg, Na and Cl in Virofly. Application of NaCl significantly increased fresh weight of both varieties of spinach and dry weight of Virofly. Salinity decreased uptake of N in Khardar but increased it in Virofly. In both spinach varieties, salinity decreased uptake of Ca and Mg, but increased uptake of Zn, Na and Cl. Both spinach varieties are considered relatively salt-tolerant plants, due to the fact that NaCl improved their growth.

---

Cadmium (Cd) is one of the toxic heavy metals which can be absorbed by plants and have detrimental effects on plant growth and nutrients uptake. In order to investigate the effect of Cd on some vegetative growth parameters, nitrogen (N), phosphorus (P) and Cd uptake in aerial parts of seven rice cultivars, a pot experiment with three soil-applied Cd levels (0, 45, and 90 mg Cd/kg soil) and seven rice cultivars (Ghasrodashti, Khazar, Anbarboo, Dasht, Hassani, Taroom and Kadoos) was conducted in a completely randomized design with three replications. Results revealed that Cd addition to soil had negative effect on some growth parameters, so that application of 90 mg Cd/kg soil decreased mean relative growth (RGR), wet and dry weights, shoot height, and number of lateral, main, and total tillers of seven rice cultivars by 64.7, 65.8, 65.6, 35.4, 13.3, 88 and 40% as compared to those of control, respectively. Hassani and Ghasrodashti cultivars had the highest shoot wet and dry weights, height, and RGR, and Khazar and Tarom cultivars had the lowest ones, compared to other cultivars. Addition of Cd to soil significantly increased shoot Cd uptake, but decreased shoot N and P uptake, as compared to those of control. Hassani and Khazar cultivars had the highest and lowest N and P uptake, respectively. Our tentative conclusion is that Hasani cultivar was superior cultivar compared to other studied cultivars due to its greater performance. Therefore, Hassani and Khazar cultivars could be considered as tolerant and sensitive cultivars, respectively, to Cd toxicity.

---

Sewage sludge (SS) as a source of macro- and micro nutrients has been utilized in many countries for crop and vegetable production. To compare the influence of SS with chemical fertilizer on macro- and micro nutrients bioavailability in three textural classes of a calcareous soil after harvesting spinach (Spinacia oleracea L.), a factorial experiment was carried out in a completely randomized design with two factors and three replications under glasshouse conditions. The first factor was SS levels (0, 10, 20, 40, and 80 mg per kg soil) and the second factor was soil textural classes (sandy, sandy loam, and clay loam). A chemical fertilizer treatment was used for comparison with the applied SS treatments. Results indicated that total nitrogen (N) and available phosphorus (P) was significantly higher in SS amended soils compared to fertilizer treatment. Effect of increasing soil potassium (K) due to addition of SS was less than P and N, which is probably due to low content of K in SS. Soil DTPA extractable iron, zinc, copper, and manganese were significantly increased in SS treatments in all soil textures and were higher than fertilizer treatment. Based on nutrients’ bioavailability in soil after harvesting spinach, especially at high rates of SS, addition of most nutrients is not necessary for the next crop. Concentration of DTPA extractable cadmium (Cd) and lead (Pb) was not detectable in all treatments. Therefore, because of low contents of Cd and Pb in the utilized SS, reaching to a toxic level of these elements in soil is unexpected. However, if high levels of SS are applied frequently, soil test is recommended for monitoring heavy metals concentration in amended soils. Prior to any SS recommendation, the results of this research need to be verified under field conditions.

---

Silicon (Si) is a beneficial nutrient for growth of crops such as cucumber. It seems that Si improves antioxidant capacity of plants and reduces damages induced by environmental stresses and metal toxicity. This research aimed to investigate the interaction of Si and cadmium (Cd) on growth, dry matter yield and catalase (CAT) activity, as an antioxidant enzyme, in cucumber. This hydroponic experiment was carried out at the greenhouse of Soilless Culture Research Centre, Isfahan University of Technology, Isfahan, Iran, and was set up in a completely randomized factorial design in triplicates. Treatments consisted of two Cd levels (0 and 5 µM), two Si levels (0 and 1 mM) and two cucumber cultivars (greenhouse cultivar called Negin and field cultivar called Super Dominus). Cadmium had no significant effect on the fresh and dry weight of shoots in both studied cucumber cultivars, while significantly decreased the root fresh and dry weights. Effect of Si on shoot dry weight differed in cultivars. Si nutrition significantly increased shoot dry weight of Super Dominus cultivar, but was not effective on shoot dry weight of Negin cultivar. Catalase activity was affected by the presence of Si and Cd, such that Cd reduced the activity of CAT in both cucumber cultivars. In contrast, CAT activity in Negin cultivar was increased by addition of Si to the nutrient solution. It seems that addition of Si to cucumber growth media can improve antioxidant capacity of plant under Cd toxicity, although this effect is cultivar-dependent.

---

To evaluate the effect of salinity (S) and vermicompost (V) on yield and concentration of nitrogen (N), phosphorus (P), potassium (K), iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), calcium (Ca), magnesium (Mg), sodium (Na) and chlorine (Cl) of spinach shoots cv. Virofly, a pot experiment was conducted in greenhouse, and arranged as factorial in a completely randomized design with three replications. Treatments included three V levels (0, 1 and 2%, w/w) and four S levels (0, 1, 2 and 3 g NaCl per kg soil). Electrical conductivity of the soil for these four S levels was 0.7, 4.5, 8 and 11.5 dS/m, respectively. Results showed that the highest yield of spinach shoots was obtained in 10% V treatment. Application of sodium chloride (NaCl) had no significant effect on shoot yield. Therefore, under the present experimental conditions, S threshold level for "Viroflay" cultivar was at least 11.5 dS/m, which is much higher than the level reported in literature for spinach (2 dS/m). Application of V increased concentration of N, P, K, Fe and Mg in spinach shoots, but decreased concentration of Mn, Zn, Cu, Ca, Na and Cl. Application of NaCl had no significant effect on the concentration of P, Fe, Mn, Ca and Mg. But, with the addition of NaCl, concentration of N, Zn, Cu, Na and Cl was increased in spinach shoots. In the absence of NaCl, application of V had no significant effect on Na concentration, but increased Cl concentration. Whereas, at 3 g NaCl level, application of V significantly decreased Na and Cl concentrations of shoots, compared to the application of NaCl alone. Therefore, application of V not only can increase plant growth, but also could be an effective solution to mitigate the negative effects of high concentrations of Na and Cl on growth of spinach, cv. Virofly, in saline soils.

---

In order to investigate the effects of different forms of nitrogen in nutrient solution on photosynthesis rate and quantitative properties of rose cv. Dolcvita, an experiment was conducted in a randomized complete blocks design with seven ratios of urea: NH4+: NO3- (0-100-0, 0-50-50, 0-0-100, 50-0-50, 25-25-50, 15-15-70 and 0-0-100) and three replications, in a hydroponic greenhouse which grows rose flower. The rooted plants of rose cv. Dolcvita were potted filled with perlite and cocopeat (50:50) substrates. Then, quantitative properties such as plant stalk height, bud length, diameter of bud and stem, leaf area index, vase life, fresh weight of stalk, leaf greenness and photosynthesis parameters were measured. The results showed that increasing the ammonium in nutrient solution reduced the photosynthesis rate, water use efficiency and leaf mesophyll efficiency. The highest stalk height was obtained from 25-25-50 and 0-0-100 treatments (88.3 cm and 86.9 cm), respectively. The highest fresh weight of stalk was obtained in 0-0-100 treatment. Application of 50-0-50 treatment increased leaf greenness as compared to other treatments. When ammonium was increased in nutrition solution, the vase life was reduced. The highest and lowest vase lives were obtained from 25-25-50 and 100-0-0 treatments (17.6 and 11.1 days), respectively.