The objective of this experiment was to assess the effects of organic or chemical nutrient solutions on the growth and composition of lettuce (Lactuca sativa L.) in greenhouse production. Hoagland and Arnon nutrient solution, an organic hydroponics solution, and no fertilization were factored with lettuce cultivars of different phenotypes, iceberg, romaine, loose head, and loose leaf. Lettuce growth was higher with Hoagland and Arnon solution than with the organic fertilizer or with no fertilization. The organic fertilizer increased growth above no fertilizer applied. Hoagland and Arnon solution gave the highest concentration of nitrogen, potassium, magnesium, and iron in the lettuce whereas lettuce grown with the organic fertilizer had the highest phosphorus. Plant nutrient accumulation differed slightly among the cultivars. Hoagland and Arnon solution produced high nitrate in leaves. Nitrate concentrations with organic or no fertilization were low. Loose head or loose leaf cultivars had higher nitrate than romaine or iceberg.

The responses of lettuce (Lactuca sativa L. ‘Arroyo’) to organic nitrogen (N) fertilizers were investigated in a greenhouse. Fertilizers were blood meal (BLO), feather meal (FM), cottonseed meal, alfalfa meal, sewage sludge, compost, cow manure, a chemical fertilizer, and a treatment without fertilizer. Amounts of N from fertilizers were 100, 200, 400, or 800 mg per pot. Lettuce yield was higher for plants receiving fertilizers than with no fertilizer and increased with increased N applications, but high applications of BLO or FM suppressed yields. Nitrogen and nitrate increased in leaves as N supply increased with all fertilizers. Small changes in leaf nutrient contents other than N occurred among or with increased application of the various fertilizers. The soil carbon dioxide release and ammonia volatilization were high from fertilizers with high N concentrations. Organic fertilizers with high N increased lettuce growth at lower applications than those with low N content.

Leaf morphology and anatomy are important criteria to evaluate plant tolerance to salinity stress. Therefore, in this study the morphophysiological responses of strawberry (Fragaria’× anansa Duchesne “Camarosa”) plants treated with nanosilicon (nSiO₂) were investigated under salt-stress conditions. The plants in a complete nutrient solution designed for strawberry were exposed to salt stress (0, 25, or 50 mM NaCl) and treated with nanosilicon before (0, 50, or 100 mg L⁻¹) or after (0 or 50 mg L⁻¹) floweringConcentrations of sodium (Na), chlorine (Cl), and calcium (Ca) increased in plants exposed to salt stress, whereas silicon (Si), potassium (K), and phosphorus (P) decreased. In the presence of nanosilicon, strawberry plants absorbed K, P, and Ca from the nutrient solution and transferred the nutrients to leaves effectively. Only a little amount of Ca, Cl, or Na was transferred to leaves with presence of nanosilicon. The adverse effects of salinity on phyllochron, flowering, and fruit set, and fruit production parameters were suppressed by application of nanosilicon. Analysis by optical microscopy revealed that salt stress limited the number of parenchyma cells, leaf thickness, epidermis cell thickness, and mesophyll thickness, thereby leading to restrictions in chlorophyll content and photosynthetic efficiency. Nanosilicon application reduced negative effects of salinity by improving cell wall thickness, providing higher content of water, and leading to increased chlorophyll content and fluorescence. Overall, these observations indicated that application of nanosilicon can suppress the adverse effect of salinity on anatomical and physiological changes of strawberry plants.

The material obtained through hydrothermal alteration of K-feldspar rock in alkaline conditions is a potential source of soluble potassium (K), but agronomic testing is needed to verify its capacity to supply K to crops. A (NH₄)₂SO₄-based bioassay was used to test the capacity of the material to supply K to tomato plants (Lycopersicon esculentum Mill.) growing in a mixture of silt loam, peat moss, and sand. Potassium chloride (KCl) and unaltered K-feldspar rock powder also were tested for comparison. The fresh weight and K composition of the plants increased as doses of KCl or hydrothermal material increased, but not with increases in K-feldspar rock. Development of stem lesions, which develop as symptoms of K deficiency in the presence of (NH₄)₂SO₄, were eliminated by KCl or hydrothermal material but not by feldspar rock. A beneficial effect may occur due to the calcium (Ca) supplied or with adjustment of soil acidity by the hydrothermal material. The hydrothermal material is a K fertilizer at least as effective as KCl since it yields the same or better plant weight.

Effects of varying the ammonium:nitrate ratios in nutrient solutions and effects of calcium carbonate buffering on plant mass and accumulation of potassium and calcium were studied with two lettuce (Lactuca sativa L.) cultivars, Two Star and Red Deer Tongue, in a greenhouse hydroponics experiment. The supply of ammonium-N ranged from 0% to 100% of the total nitrogen in the nutrient solution at 0.015 M total N supplied as nitrate and ammonium. Proportions of ammonium-N greater than 50% of total N nutrition severely curtailed growth and calcium and potassium accumulation for both cultivars. Growth and composition of the two cultivars did not differ in response to nitrogen nutrition. The acidity of the nutrient solution increased as the proportion of ammonium increased. Application of calcium carbonate buffering improved growth in solutions containing ammonium, but plants did not attain the amount of growth and nutrient accumulation achieved with solely nitrate nutrition.

Increasing the amount of nutrients in plant-based foods will help to improve the nutritional status of people in the World. Faba bean (Vicia faba L.) as a staple food in developing countries has the potential to provide many nutrients in human diets. The objective of this study was to characterize the nutrient concentrations in leaf, pod, and seed of faba bean varieties. A field study was conducted with six faba bean varieties. Variation in the elemental concentrations of nutrients and protein occurred among varieties and different parts of the plants. The highest concentrations of nitrogen, phosphorus, potassium, zinc, or copper and protein were in the seeds. However, the highest accumulation of calcium, magnesium, iron, or manganese was in the leaves. We recommend that faba bean can be considered as a valuable crop in the diet of nutrient-deficient consumers due to high concentration nutrients in edible parts of the plant.