Spinach Shoot Research Articles

Comparative of Shoot and Root Growth of Water Spinach (Ipomoea aquatica) Cultivated in Mars Global Simulant MGS-1 with or without Addition Earth Soil Illuminated by LED light in Indoor Environment

Mars has been a target for human colonization for centuries. When the time comes for humans to settle Mars, they will need food for survival. It is implausible to send a lot of fresh food to Mars. Therefore, we could instead cultivate plants at the site itself, using Martian soil in an indoor environment. In this study, we evaluated the shoot and root growth of water spinach (Ipomoea aquatica) in Mars Simulant or combination of Mars Simulant with earth soil at indoor environment using LED lighting. The result showed that water spinach can grow on earth soil and Mars Global Simulant MGS-1 for 28 days (about 4 weeks) without any addition of nutrients aside from water. Growth in earth soil is much better than on Mars Global Simulant MGS-1, and even 75 % Mars Global Simulant MGS-1: 25 % earth soil is slightly better than 100 % Mars Global Simulant MGS-1. The growth of water spinach shoots in Mars Simulant was compared to poor water spinach root growth in Mars Simulant. Our results provided the insight that it is possible to grow water spinach in Mars Simulant indoors and to boost its growth, physical properties and chemical composition of Mars Simulant improvement was needed.

Biochar and Cd Alter the Degradation and Transport of Kasugamycin in Soil and Spinach

Biochar has been widely studied to reduce multiple contaminant sources in one matrix (e.g., several heavy metals in soils), yet less attention has been paid to accelerating pesticide degradation while in the presence of any heavy metals, such as when kasugamycin (KSM) and cadmium (Cd) are both present in soil. While KSM has low toxicity compared to other pesticides, it can be a potential health risk when applied to vegetable crops, especially when KSM is used or overapplied to achieve rapid reductions in insect and disease pressure. The degradation behavior of KSM (2 kg ha−1) in the presence of Cd (20 mg kg−1) and biochar (5% by wt.) when growing spinach (Spinacia oleracea) was studied. The biochar increased spinach shoot and root biomass by 51.0–54.8% and 24.4–39.0%, respectively, compared to the KSM treatment only. Compared to the treatments that did not receive biochar, the biochar application increased the KSM degradation in the soil by 8.4–68.4% and, subsequently, less KSM was absorbed by the spinach roots (18.0–48.4%) and shoots (33.0–33.2%). The KSM degradation rate, as a function of soil depth, was enhanced in the presence of Cd. The biochar also effectively decreased the KSM concentration with soil depth, reducing downward KSM migration. The KSM degradation, increased by the biochar, led to smaller organic moieties and some macromolecular organic phases. In soils that are contaminated with Cd and where vegetables are raised, biochar may be used as an environmentally friendly proponent for increasing KSM degradation, reducing KSM downward transport and, thus, protecting environmental and human health.

Examining the role of AMF-Biochar in the regulation of spinach growth attributes, nutrients concentrations, and antioxidant enzymes in mitigating drought stress

Drought stress is one of the serious threats to crop production. It causes significant deterioration of crop growth and yield by inducing oxidative stress. The biochar and arbuscular mycorrhizae fungi (AMF) can be an effective technique to overcome drought stress. Activated carbon biochar (BC) has the potential to improve soil water holding capacity while AMF inoculation can increase root surface area for better uptake of water. However, their combined application as an amendment against drought still needs scientific justification. That's why the current study was conducted using a combination of AMF and BC on spinach under no drought stress and drought stress. The treatments included i.e., 0, 0.25%, and 0.50%AMF-BC. The experiment was replicated thre times using completely randomized design (CRD). Results showed that 0.5%AMF-BC increase spinach shoot fresh weight (20.34%), shoot dry weight (21.23%), shoot length (3.37%), root fresh weight (16.10%), root dry weight (14.51%), and root length (38.03%) over control under drought stress. The 0.50%AMF-BC increased chlorophyll a (15.33%), chlorophyll b (30.17%), total chlorophyll (18.85%), photosynthetic rate (35.59%), transpiration rate (26.53%), stomatal conductance (13.97%) and internal CO2 concentration (37.15%) compared to control under drought stress. The improvement in N, P, and K concentration in root and shoot verified the efficacious functioning of 0.50%AMF-BC compared to control under drought stress. In conclusion, 0.50%AMF-BC is recommended for the mitigation of drought stress in spinach.

The Interplay of Sulfur and Selenium Enabling Variations in Micronutrient Accumulation in Red Spinach.

Aside from its importance in human and animal health, low levels of foliar-applied selenate (SeO4) can be advantageous in the presence of sulfur (S), contributing to improved growth, nutrient uptake, and crop quality. A hydroponic experiment in a growth chamber explored the interactive influence of Se and S on micronutrients and several quality indices, such as soluble sugars, organic acids, and total protein concentrations in spinach (Spinacia oleracea L.). Three levels of S (deprivation, adequate, and excessive) with varying quantities of Se (deficient, moderate, and higher) were examined in combination. Under S starvation and along with S nourishment in plant parts, Se treatments were found to cause noticeable variations in plant biomass and the concentrations of the examined elements and other quality parameters. Both Se levels promoted S accumulation in S-treated plants. Although the Se treatment had the opposite effect in shoots, it had a favorable impact on minerals (apart from Mn) in roots grown under S-limiting conditions. The S and Se relationship highlighted beneficial and/or synergistic effects for Mn and Fe in edible spinach portions. Reducing sugars were synergistically boosted by adequate S and moderate Se levels in roots, while in shoots, they were accumulated under moderate-or-higher Se and excessive S. Furthermore, the concentration of the quantified organic acids under S-deficient conditions was aided by various Se levels. In roots, moderate Se under high S application enhanced both malic acid and citric acid, while in the edible parts, higher Se under both adequate and elevated S levels were found to be advantageous in malic acid accumulation. Moreover, by elevating S levels in plant tissues, total protein concentration increased, whereas both moderate and high Se levels (Se1 and Se2) did not alter total protein accumulation in high S-applied roots and shoots. Our findings show that the high S and medium Se dose together benefit nutrient uptake; additionally, their combinations support soluble sugars and organic acids accumulation, contributing ultimately to the nutritional quality of spinach plants. Moreover, consuming 100 g of fresh red spinach shoot enriched with different Se and S levels can contribute to humans' daily micronutrients intake.

Morupule fly ash as amendments in agricultural soil in Central Botswana

The potential of Morupule fly ash as a soil amendment was evaluated using spinach and rape vegetables planted successively in Palapye soils added with 0 fly ash (FA), 5% FA, 10% FA, and 15% FA (w/w) in combination with four nutrient sources as no fertilizer (-NF), compost (+COMP) at 20 tones ha −1 , inorganic NPK (+NPK) and a combination of 1 2 NPK and 1 2 compost (+NPK+COMP). Spinach was grown first for 40 days followed by rape as a second crop planted on the same pots and treatments after harvesting spinach. The application of FA increased the pH, EC, and the total concentration of As, Cu, and Pb of soil while compost increased the total Zn. The available concentration of Cr, Cu, Mn, Ni, and Pb were significantly reduced by FA. FA increased the yield of spinach and rape, especially in 10FA+NPK+COMP. The heavy metal concentration in the shoots of spinach and rape were below the maximum acceptable limits (MAL) for vegetables in 10FA+NPK and 10FA+NPK+COMP treatments. Overall, an application rate of 10% FA combined with compost and fertilization gave the highest yield and safe level of As, Cr, Cu, Mn, Ni, Pb, and Zn in the edible shoots. • First report on using Morupule fly ash as an amendment in agricultural soils in Botswana. • A combined with compost and inorganic fertilizer improved the growth and yield of spinach and rape grown successively. • Fly ash amendments reduced the available concentration of Cr, Cu, Mn, Ni, and Pb in soil. • Fly ash at 10% application combined with compost and inorganic fertilizer produced spinach and rape safe for human consumption.

Lead stabilization in a polluted calcareous soil using cost-effective biochar and zeolite amendments after spinach cultivation

Biochar has been shown to be an effective organic soil amendment for the in situ immobilization of Pb. Little research has been done on the effects of biochar and zeolite interactions on Pb immobilization in contaminated calcareous soils. Therefore, the aim of this study was to investigate the effect of different levels of zeolite (2% and 4% w/w) and biochar (3% w/w) prepared from compost and poultry manure on the concentration of Pb in spinach shoots and Pb stabilization in contaminated calcareous soil after spinach cultivation using sequential extraction and release kinetics procedures. The results of this study show that the application of biochars derived from compost and poultry manure significantly decreased the Pb mobility factor (MF) (2.8% to 4.6%) and the release of cumulative diethylenetriamine pentaacetate (DTPA)-extractable Pb (16.8% to 20.1%) in calcareous soil. This benefit was further enhanced by the combined addition of zeolite (MF reduction of 4.4% to 8.4%; cumulative Pb release reduction of 24.8% to 28.6%). The enhancement of soil Pb immobilization is attributed to the properties of the amendments, such as high pH (10.0 to 11.0), ash content (39.0% to 43.5%), and P content (0.25% to 0.43%). The results of the soil Pb sequential extraction and Pb release kinetics were highly and significantly correlated with spinach shoot Pb concentration. Soil chemical data showed that the application of municipal waste biochar with 4% zeolite (MB+Z 2 ) was the most effective treatment for immobilizing Pb (8.4% reduction in MF, 28.6% reduction in cumulative DTPA-extractable Pb), which is in agreement with the results of the spinach shoot Pb concentration (89.0% reduction in uptake).

Is Aquaponics Beneficial in Terms of Fish and Plant Growth and Water Quality in Comparison to Separate Recirculating Aquaculture and Hydroponic Systems?

Aquaponics is a technique where a recirculating aquaculture system (RAS) and hydroponics are integrated to grow plants and fish in a closed system. We investigated if the growth of rainbow trout (Oncorhynchus mykiss) and baby spinach (Spinacia oleracea) would be affected in a coupled aquaponic system compared to the growth of the fish in RAS or plants in a hydroponic system, all systems as three replicates. We also investigated the possible effects of plants on the onset of nitrification in biofilters and on the concentration of off-flavor-causing agents geosmin (GSM) and 2-methylisoborneol (MIB) in rainbow trout flesh and spinach. For the fish grown in aquaponics, the weight gain and specific growth rates were higher, and the feed conversion ratio was lower than those grown in RAS. In spinach, there were no significant differences in growth between aquaponic and hydroponic treatments. The concentration of GSM was significantly higher in the roots and MIB in the shoots of spinach grown in aquaponics than in hydroponics. In fish, the concentrations of MIB did not differ, but the concentrations of GSM were lower in aquaponics than in RAS. The onset of nitrification was faster in the aquaponic system than in RAS. In conclusion, spinach grew equally well in aquaponics and hydroponic systems. However, the aquaponic system was better than RAS in terms of onset of nitrification, fish growth, and lower concentrations of GSM in fish flesh.

High Nutrient Concentrations of Hydroponic Solution Can Improve Growth and Nutrient Uptake of Spinach (Spinacia oleracea L.) Grown in Acidic Nutrient Solution

Hydroponic leafy green production offers high productivity and quality of crops but requires good management of pH and electrical conductivity (EC) to optimize the nutrient uptake. Nutrient solution pH is typically managed between 5.5 and 6.5, whereas lowering pH to more acidic range (e.g., <5.0) can potentially mitigate problematic waterborne diseases. Plant response to low pH is species specific and generally involves direct effect of increased hydronium ions and indirect effects of pH-dependent factors, such as low cations availability. To develop a new hydroponic nutrient management strategy, ‘Corvair’ spinach plants were grown under pH 4.0, 4.5, 5.0, and 5.5 of a hydroponic nutrient solution using a deep-water culture system in a growth chamber. Spinach shoot and root mass after 19 to 20 days declined with lowering pH. At the lowest pH of 4.0, plants displayed stunted overall growth and severely inhibited root development. Plant growth and morphology at pH 4.5 or 5.0 were normal but small, suggesting that growth reduction at these pH was likely a result of reduced nutrient uptake. Plant tissue analyses showed decreased N, P, K, Mg, S, Cu, Fe, Mn, and Zn concentration as pH decreased. When the strength of nutrient solution was increased three times at a low pH 4.5 to improve the overall nutrient availability, spinach shoot and root fresh weight with high nutrient concentrations (EC 3.4 dS·m−1) significantly improved but was still lower than those in the control (pH 5.5 and EC 1.4 dS·m−1), respectively. Plant tissue analysis showed that lowering pH to 4.5 significantly reduced tissue concentrations of P, K, Ca, Mg, S, Cu, Mn, and Zn compared with those in the control. Under low pH and increased EC treatment (pH 4.5 and EC 3.4 dS·m−1), all dry leaf nutrient concentrations were similar or higher than those of the control, except Mg and Zn, which showed a lower concentration than the control with a weak significance (P < 0.06). This suggests that additional optimization of nutrient formula might further improve the spinach growth at low pH. Together, our results will help to develop a new and low-cost nutrient management methodology to produce leafy greens hydroponically.

Influence of Urea on Some Growth Responses and Nutrients of Spinach (Spinacia oleracea L.) under Different Levels of Soil Salinity

Introduction: Salinity is an environmental problem in the world, especially in arid and semi-arid regions. High amounts of salts like sodium chloride (NaCl) in the soils and water have destructive effects on yield of plants. The harmful effects of salinity on plant growth are related to the low osmotic potential of the soil solution (water stress), the nutritional imbalance, the specific ion effect (salt stress), or the combination of these factors. The relationship between salinity and plant mineral nutrition is complicated. Under salinity stress, occurs the sodium and chlorine accumulation, resulting in ionic imbalance and the deficiency symptoms of nutrients in plants. The sodium (Na+) competes with the uptake of potassium (K+), calcium (Ca2+) and magnesium (Mg2+) by plant, and the chlorine (Cl-) with the uptake of nitrates (NO3-), phosphates (PO43-) and sulfates (SO42-). Materials and Methods: In order to evaluate the tolerance of spinach cv. “virofly” to salinity levels in application with different nitrogen rates, a greenhouse experiment was conducted as completely randomized design based on factorial arrangement with three replications at Shiraz University Agricultural Faculty. Treatments include four levels of salinity (without salinity, 1, 2 and 3 gr of sodium chloride per kg of soil, equivalents to 0.7, 4.5, 8 and 11.5 dS/m in saturated solution extract of soil, respectively), and five levels of nitrogen (unfertilized, 75, 150, 225 and 300 mg N/kg of soil) as urea source. Nitrogen treatments were applied in two installments in water soluble (half before planting and another half, 20 days after planting). In order to prevent sudden stress, saline treatments were applied gradually after complete plant establishment with irrigation water. The irrigation of the pots was carried out with distilled water and at field capacity. After 56 days of sowing, in every pot the spinach shoots were discarded near the surface of the soil and the required parameters were measured. Results and Discussion: The application of 4.5 and 8 dS/m salinity had no significant effect (≤0.05) on the relative yield and spinach leaf area, but 11.5 dS/m salinity significantly (≤0.05) decreased relative yield and spinach leaf area compared to without salinity level, 4.5 and 8 dS/m. Nitrogen application (75 and 150 mg/kg of soil) alleviated negative effect of salinity on yield and leaf area. Application of 225 and 300 mg N/kg of soil with 11.5 dS/m salinity significantly decreased the relative yield of spinach. The highest and lowest shoot water content changes in salinity conditions were observed in no-nitrogen application and 150 mg N/kg application, respectively, which shows that the application of nitrogen in the medium level controls the water changes in the spinach plants. In this study, increasing the amount of nitrogen at all levels of salinity, elevated the shoot water content. The tolerant plant species in the face of environmental stresses maintain the water content of their cells in the higher levels. Therefore, it can be said that the maintenance of high leaf water content is an important mechanism for tolerance to salinity, and the cultivars that can hold more water in their leaves under stress conditions, will have more tolerance to salinity stress. Linear regression (R2 = 0.8198) showed that in the salinity levels of 4.5 to 11.5 dS/m, there is a negative relationship between the yield and the chlorine to nitrogen ratio (Cl/N) of spinach shoots, so that with increasing Cl/N, the spinach shoot yield decreased by gradient of -3.077. Application of nitrogen up to 225 mg/kg of soil gradually reduced the ratio of K/Na, Ca/Na and Mg/Na, however, the application of 300 mg N/kg of soil had no significant effect on these ratios. The application of different levels of salinity gradually reduced the K/Na, Ca/Na and Mg/Na ratio. Conclusion: The threshold of salinity of spinach cv. “virofly” was about 8 dS/m in our study, this was above the threshold mentioned (2 dS/m) for spinach in most sources. The application of nitrogen in medium level as urea can improve the negative effects of salinity in spinach but intensive nitrogen fertilization may increase the negative effects of salinity on plant yields.

Growth and metal uptake of spinach with application of co-compost of cat manure and spent coffee ground

Cat manure (CM) possesses high level of nutrients for growing food crop. However, animal manure may contain toxic elements that may contaminate food crop. Spent coffee ground (SCG) may be used to reduce mobility of heavy metals and reduce crop uptake. In this study, SCG was composted with CM for 31 days to produce a co-compost (SCG-CM) for growing spinach (Spinacia oleracea). The growth rate of spinach was assessed until its maturity, and the metal uptake of spinach shoot was determined thereafter using inductively coupled plasma-optical emission spectroscopy (ICP-OES). The effect of soil treatment with SCG-CM on the height and elemental composition of spinach were compared with that of chicken manure compost (CMC). The prepared composts were primarily organic matter (72.9–81.4 % w/w) with the rest are ash (13.3–23.4 % w/w) and moisture (1.2–2.6 % w/w). Zinc content in SCG-CM (1261 ± 0.1 mg/kg) is significantly higher than that of soil and CMC (p < 0.05) and has exceeded the maximum permissible limit set by European Union Standard (2002) and the Malaysian Compost Quality Standard and Guidelines (2000). Matured spinach reached maximum plant height after 33 days. The amendment of SCG-CM significantly increased the height of spinach (32 ± 6 cm) compared to that of CMC (13 ± 1 cm) (p < 0.05). However, contents of Zn, Cu, Pb and Cd were not increased for spinach grown in the SCG-CM-amended soil, and the level of those elements are below permissible limit set by the Malaysian Food Act 1983 and Food Regulations 1985. This study shows that SCG-CM is effective in improving yield without causing accumulation of toxic trace elements in spinach.

Residual organochlorine pesticides in the salad vegetables cultivated in Lagos, Nigeria and their human health risks

Concerns are mounting over the health risks associated with the use of harmful pesticides to control crop pests. In this study, the salad vegetables and soil samples from three farms in Lagos, Nigeria were evaluated for organochlorine pesticide residue concentrations using gas chromatography-mass spectrometry (GC-MS). Eighteen organochlorine pesticides were detected in the vegetable and soil samples. In Idi-Araba farm, α-BHC had the highest concentration (0.06±0.07 mg/kg) in lettuce shoots, Endosulfan I had the highest concentration (0.29±0.26 mg/kg) in spring onion. P, P-DDE and L-cyhalothrin had the highest concentrations (0.08±0.03 and 0.08±0.08 mg/kg, respectively) in spinach shoots. In Tejuosho farm, L-cyhalothrin, PF-38, and chlorothalonil had the highest concentrations (0.50±0.71, 0.13±0.07, and 0.03±0.01 mg/kg, respectively) in lettuce shoots, spring onions, and spinach, respectively. In Alapere farm, Endosulfan I had the highest concentration (0.03±0.02 mg/kg) in lettuce shoots, Aldrin had the highest concentration (0.02±0.01 mg/kg) in spring onion shoots, and L-cyhalothrin had the highest concentration (0.04±0.05 mg/kg) in spinach shoots. The concentrations of these pesticides were higher than the maximum residual limit prescribed by the European Union (EU) Commission. Moreover, the hazard index (HI) calculated for spring onion and spinach from Idi-Araba farm and lettuce from Tejuosho farm exceeded one (HI>1). These results may be a reflection of what obtains in other countries where harmful pesticides are still being used. Therefore, governments and stakeholders should raise awareness to discourage farmers from the use of organochlorines and other harmful pesticides.

Reducing chromium uptake through application of calcium and sodium in spinach.

In peri-urban areas, the use of wastewater for crop production is a common practice due to water scarcity. Moreover, in the recent years, large quantity of wastewater generation and discharge as industrial effluent in water resources is another issue for reduction of water quality. The leather industries are significantly contributing chromium (Cr) in effluent, whereas, other industries may have salt and cationic load in their discharges are mixed up. Therefore, it is mandatory to study the interactive effect of different effluent constituents on crop plants. In this connection, a pot culture experiment was conducted at the ICAR-Indian Institute of Soil Science, Bhopal to compute the effect of application of calcium (Ca) and sodium (Na) ions on Cr uptake by spinach crop in Vertisol of central India. Three levels of Cr (0, 50, 100 mg kg-1), calcium (0, 2, 4 mM), and sodium (0, 40, 80 mM) were applied in combinations. The spinach variety All Green was used as a test crop and harvested at full maturity. Results showed that application of Ca and Na reduced the Cr uptake in spinach crop. The reduction of Cr uptake was more in the root than shoot. Applied calcium acted as an essential plant nutrient and enhanced the crop biomass. Sole applications of Na adversely affected the crop biomass and Cr uptake in both root and shoot of spinach. In conclusion, application of Ca fertilizers reduced the Cr toxicity in spinach and could be used as a strategy for the safe utilization of tannery industrial effluents for crop production.

Growth and physiological response of spinach to various lithium concentrations in soil.

Lithium (Li) exploitation for industrial and domestic use is resulting in a buildup of the element in various environmental components that results in potential toxicity to living systems. Therefore, a soil culture experiment was conducted to evaluate the effects of increasing concentration of Li (0, 20, 40, 60, and 80 mg kg-1 soil) on spinach growth, the effects of Li uptake, and its effects on various physiological attributes of the crop. The results showed that lower levels of Li in soil (20 mg Li kg-1) improve the growth of spinach plants, while a higher concentration of applied Li enhanced the pigment contents. Higher concentrations of Li in soil interfered with potassium and calcium uptake in plants. Moreover, increasing Li concentration resulted in higher activities of antioxidant enzymes activity in spinach shoots. From these results, it is concluded that spinach shoot accumulated higher concentrations of Li without showing any visual toxicity symptoms. Therefore, the study concludes that Li ion was mostly deposited in leaves rather than in roots which may cause potential human health risk on the consumption of Li-contaminated plants. Therefore, the cultivation of leafy vegetables in Li-affected soils should be avoided to reduce the potential human health risks.

Bioactive compounds and antioxidant activity of Feijoa (Feijoa sellowiana berg) cultivated in subtropical zones of Georgia

Increasing demand for irrigation water and scarcity of fresh water has caused significant increase in the reuse of urban and industrial wastewater throughout the world. Heavy metals in wastewaters are the main factors in the contamination of water and soil. The objective of this study was to evaluate the effect of application of pumice as soil amendment on the uptake of Cd by spinach (Spinach oleracea L.) under irrigation with wastewater (containing 10 mg/L Cd). The experiment was conducted as a completely randomized design in a greenhouse with 3 replications in the research station of Isfahan University of Technology. Different levels of pumice (0, 4% and 8% w/w soil) were added to the soil. Results indicated that the addition of 4% and 8% of pumice in soil, decreased 30.19% and 46.17% Cd uptake in plants, respectively. The transfer factor into roots and shoots of spinach were significantly reduced (p < 0.05) in pumice treatments compared to the control. The percentage of DTPA extractable Cd in soils amended with pumice significantly decreased (p < 0.05) and this resulted in lower Cd accumulation in plants. Irrigation with wastewater containing Cd decreased the yield in comparison to irrigation with freshwater. So, it seems that pumice, as a cost-effective adsorbent, poses potential for immobilization and reduction of phytoavailability of Cd in polluted soils.

Can Lead and Nickel Interaction Affect Plant Nutrient Uptake Pattern in Spinach (Spinacia oleracea)?

Increasing lead (Pb) and nickel (Ni) pollution through geogenic and anthropogenic activities is a major concern to evolve a sustainable crop and to meet the food requirement of a growing population. Interaction effects of metal ions may affect the essential plant nutrients concentration and their uptake by crops. For this, a pot culture experiment was conducted with four levels (0, 100, 150 and 300 mg kg−1 dry soil) of each Pb and Ni in combinations that were spiked into black cotton soils (5 kg pot−1) of Central India. Spinach crop was raised as test crop. The essential plant nutrients and heavy metal concentration in spinach were measured. Experimental results showed that increasing the concentration of Pb in soil significantly (p = 0.05) reduced the concentration of micronutrients (Fe, Zn, Cu, Mn) as well as macronutrients (P, K, S) in the plant parts. Application of Ni did not significantly increase the concentration of plant nutrients in root and shoot of spinach. The magnitude of Pb toxicity was high as compared to the magnitude of Ni toxicity in both root and shoot. This type of research studies helps in the formulation of waste water management policies, mostly in developing countries to protect the natural resources with respect to sustainable crop management.

Tyrophagus neiswanderi (Acari: Acaridae) as a Pest of Greenhouse Spinach in Antalya, Turkey

Tyrophagus neiswanderi (Johnston & Bruce 1965) generally lives in stored products as saprophyte and on dead bodies of arthropods living in the soil, organic fertilizers, mushroom houses, greenhouses, algae and plant scraps. In this study, however, it was observed in roots and shoots of spinach (Spinacia oleracea L.) plants originated from greenhouse commercial crop in 2016-2017, in cultivated areas around Antalya, Turkey. This is the first record of T. neiswanderi occurring in spinach plants under greenhouse conditions in Antalya, Turkey.

Reduced arsenic availability and plant uptake and improved soil microbial diversity through combined addition of ferrihydrite and Trichoderma asperellum SM-12F1.

Arsenic (As) accumulation in agricultural soils is prone to crop uptake, posing risk to human health. Passivation shows potential to inactivate soil labile As and lower crop As uptake but often contributes little to improving the microbiota in As-contaminated soils. Here, the combined addition of ferrihydrite and Trichoderma asperellum SM-12F1 as a potential future application for remediation of As-contaminated soil was studied via pot experiments. The results indicated that, compared with the control treatment, the combined addition of ferrihydrite and T. asperellum SM-12F1 significantly increased water spinach shoot and root biomass by 134 and 138%, respectively, and lowered As content in shoot and root by 37 and 34%, respectively. Soil available As decreased by 40% after the combined addition. The variances in soil pH and As fractionation and speciation were responsible for the changes in soil As availability. Importantly, the combined addition greatly increased the total phospholipid fatty acids (PLFAs) and gram-positive (G+), gram-negative (G-), actinobacterial, bacterial, fungal PLFAs by 114, 68, 276, 292, 133, and 626%, respectively, compared with the control treatment. Correspondingly, the soil enzyme activities closely associated with carbon, nitrogen, and phosphorus mineralization and antioxidant activity were improved. The combination of ferrihydrite and T. asperellum SM-12F1 in soils did not reduce their independent effects.

Nutrient uptake and growth of spinach as affected by cow manure co-composted with poplar leaf litter

PurposeWastes were composted and applied as the soils amendment to improve soil fertility and crop productivity. The study aimed at assessing the nutrient uptake and growth of spinach (Spinacia oleracea L.) grown in soils amended with cow manure after a co-composting process.MethodsSandy loam and silt loam soils were amended with cow manure after co-composting with poplar leaf litter at 1:0, 1:1, 1:2 and 1:3. The compost was applied to soil at the rate of 20 t ha−1. Spinach was grown for 8 weeks and then harvested to measure plant shoot biomass. Spinach shoot samples were digested and nutrient contents in the shoots were determined.ResultsCo-composted manure significantly improved the growth and nutrients availability to the spinach. Dry biomass, P and K contents in spinach shoot varied among manure: leaf litter ratios: 1:0 < 1:1 < 1:2 < 1:3. Conversely, N, Zn, Fe, Cu and Cd contents in spinach shoot reduced with the manure amendment with increasing amount of leaf litter. Water extractable micro-elements in the post-harvest soils were found in the order of Zn > Fe > Cu > Cd. Co-compost amendments increased the P and K availability except N, NO3 and NH4 in the post-harvest soils. Trace elements in the post-harvest soils reduced with leaf additives in the compost.ConclusionsCo-composted cow manure with leaf litter proved to be superior in terms of bioavailability of plant nutrients over the composted manure without leaf litter. This may also assist in mitigating the environmental contamination of heavy metals in the farm lands.

Influence of Organic Manure and Lime on Cadmium Mobility in Soil and Uptake by Spinach (Spinacia oleracea L.)

ABSTRACTSpinach grown in cadmium (Cd)-contaminated soils accumulates Cd compounds in toxic concentration contaminating the food chain leading to the chronic toxic effects on human and animal health. A study was conducted in a Cd-contaminated soil to examine the ameliorative effect of lime and organic manure on the mobility of Cd and its uptake in spinach. Application of lime or organic manure or both decreased the Cd concentration in soil and shoots and increased chlorophyll content of leaves. As compared to the control treatment, combined application of lime and organic manure decreased the level of Cd in soil by 54.7%, in spinach shoot by 61.3%, and the transfer factor of Cd by 35.0% and increased in leaf chlorophyll content by 29.4%. Combined application of lime and organic manure emerged as a viable option in reducing the mobility of Cd in contaminated soil for growing spinach.

Effect of pH Upper Control Limit on Nutrient Solution Component and Water Spinach Growth under Hydroponics

In this study, experiment with four levels of nutrient solution pH control upper limit was conducted to explore the optimal nutrient solution pH management scheme under hydroponics by evaluating the nutrient solution characters i.e., pH, Electric Conductivity (EC), nitrate, soluble phosphorus (soluble-P), water spinach growth and quality. The results showed that the nutrient solution pH was 8.2 and unsuitable for water spinach growth under the treatment with no pH regulation during the experimental period. The pH could be maintained within a reasonable range for water spinach growth by adding nitric acid to nutrient solution. Meanwhile, the availability of cations and soluble-P were improved. The water/nutrition uptake was also promoted. Through nutrient solution pH control, the plant height, leaf number and fresh/dry shoot weight increased by 34.66-55.70%, 12.42-13.66%, 39.18¬-101.72% and 13.78-74.03%, respectively. It indicated that pH regulation could improve water spinach growth, promote allocation of photosynthetic product to shoot and increase the effective yield. The nitrate content of water spinach shoot increased, but which was lower than the critical value of 3000 mg/kg FW. Vitamin C content decreased under the treatment which 6.5 of pH control upper limit was set. There were no significant differences in soluble sugar and crude protein content among the four treatments. Considering the yield and quality of water spinach, the suitable nutrient solution pH control upper limit was 7.0.