Se Ha-1 Research Articles

Foliar Sprays of Multi-Nutrient Fertilizer Containing Selenium Produce Functional Tomato Fruits with Higher Shelf Life.

Selenium (Se) is a nutrient whose daily intake is often below the recommended levels in people. Biofortification with Se is a method to increase this intake by raising the Se concentration in tomato fruits, an effect dependent on sources and modes of application. Additionally, Se application can promote the enhancement of other compounds in tomato fruits, altering their metabolism, which may increase the fruit's shelf life. This study aimed to determine how different strategies of applying a multi-nutrient fertilizer containing Se (SeMNF) can increase the Se content and other bioactive compounds and enhance the shelf life of tomato (Solanum lycopersicum L.) fruits. Different foliar fertilization strategies involving the use of SeMNF were evaluated in field trials conducted on commercial tomato crops. Indeterminate-growth tomatoes were used, and different Se doses and application strategies were tested. Harvesting was conducted in three phases according to fruit ripening. Each harvested fruit was assessed for the Se content, macro and micronutrients, total phenolic compounds, vitamin C, antioxidant activity, carotenoids, pH, total titratable acidity, and total soluble solids in tomato fruits. Doses of 15 g ha-1 of Se, split into three applications, increased the Se content in the fruits at 1 and 2 harvests. The application of SeMNF at Se doses above 10 g of Se ha-1 increased firmness, days of ripening, and the nutritional quality of the tomatoes (higher contents of carotenoids (+39%), lycopene (+33%), antioxidant activity (+16%), total phenolic compounds (+38%), and vitamin C (+14%) in a dose-dependent effect of the application strategy used. These results contributed to an increase in the shelf life of tomatoes, consequently reducing food waste.

Comprehensive evaluation of factors influencing selenium fertilization biofortification.

Dietary selenium (Se) deficiency, stemming from low Se concentrations in agricultural products, threatens human health. While Se-containing fertilizers can enhance the Se content in crops, the key factors governing Se biofortification with Se fertilization remain unclear. This study constructed a global meta-analysis dataset based on field experiments comprising 364 entries on Se content in agricultural products and 271 entries on their yield. Random forest models and mixed effects meta-analyses revealed that plant types (i.e., cereals, vegetables, legumes, and forages) primarily influenced Se biofortification, with Se fertilization rates being the next significant factor. The random forest model, which included variables like plant types, Se fertilization rates, methods and types of Se application, initial soil conditions (including Se content, organic carbon content, and pH), soil types, mean annual precipitation, and temperature, explained 82.14% of the variation in Se content and 48.42% of the yield variation in agricultural products. For the same agricultural products, the increase in Se content decreased with higher rates of Se fertilization. The increase in Se content in their edible parts will be negligible for cereals, forages, legumes, and vegetable crops, when Se fertilization rates were 164, 103, 144, and 147 g Se ha-1, respectively. Conversely, while low Se fertilization rates enhanced yields, high rates led to a yield reduction, particularly in cereals. Our findings highlight the need for balanced and precise Se fertilization strategies to optimize Se biofortification benefits and minimize the risk of yield reduction. © 2024 Society of Chemical Industry.

Biofortification of upland rice using selenium-enriched urea: Evaluation of potential genotypes

This objective of this study was to evaluate the ability of upland rice genotypes to absorb selenium (Se) in the form of selenate (SeVI) and translocate it to grain using Se-enriched urea in topdressing fertilizer and to investigate its effects on the agronomic attributes of rice. For this, twenty upland rice genotypes were evaluated in a split-plot design in two areas, where each experimental plot was divided into subplots. One subplot was treated with application of Se-enriched urea (80 g of Se ha-1), while the other subplot was used as a control treatment and fertilized normally with urea. The evaluated traits were plant height, thousand grain weight, hulling yield, whole grain milling yield, grain yield, Se content, and intake in the polished grain. The results suggest that the application of Se-enriched urea increased the whole grain milling yield of rice in both areas. Genetic variability was among the upland rice genotypes in terms of their ability to increase Se in the grain when Se-enriched urea was applied, with all genotypes biofortified and a maximum Se content of 2.30 mg kg-1 in the grain. These results indicate that it is possible to increase the Se content in rice grains by application of Se-enriched urea fertilizer. This increase in Se content results to a higher daily intake of Se (µg person-1 day-1). This strategy could help to minimize the deficiency of this nutrient in the population, particularly in regions where Se is not very representative in cultivated soils.

Foliar Application of Selenium Associated with a Multi-Nutrient Fertilizer in Soybean: Yield, Grain Quality, and Critical Se Threshold.

Selenium uptake and its content in soybean grains are affected by Se application methods. This study evaluated the impact of Se foliar application combined with a multi-nutrient fertilizer (MNF) on soybean, establishing a Se threshold to better understand the relationship between Se content in grains and yield of two genotypes (58I60 Lança and M5917). Two trials were conducted in a 4 × 2 factorial design: four Se rates (0, 10, 40, 80 g Se ha-1) and two methods of foliar Se application (Se combined or not with MNF). Foliar fertilizers were applied twice, at phenological stages of beginning of pod development and grain filling. Grain yield increased with the application of MNF, yet Se rates increased Se contents linearly up to 80 g Se ha-1, regardless of the use of MNF. Lança and M5917 genotypes had grain Se critical thresholds of 1.0 and 3.0 mg kg-1, respectively. The application of Se favored higher contents of K, P, and S in grains of genotype Lança and higher contents of Mn and Fe in grains of genotype M5917. Our findings highlight the importance of addressing different Se fertilization strategies as well as genotypic variations when assessing the effects of Se on soybean yield and grain quality.

Effect of the Addition of Selenium and some Competing Anions on Selenium Concentration in Maize Growing in some Soils in Central Iraq

The effect of selenium and some competing anions to the soil on selenium concentration in maize growing in AL-Herria (clay )soil and Khan al-Nass (Sandy Loam )soil was studied. four levels ( 0, 20, 40 and 60 )gm Se ha-1 and three levels of Sulfur and (0, 45, 90 )Kg S ha-1 and phosphate in doses of (0, 90, 180) Kg P ha-1 were added to the soil. Maize plant content of selenium increased significantly, with increasing soil applications of selenium in both soils. While the plant content of selenium was decreased from (79.75 to 76.32 and 72.09 μg Se gm-1)and from (47.08 to 44.04 and 41.2 μg Se gm-1)with addition of as and 90 kg S ha -1 to Al-Herria and khan al-Nass soils respectively. Plant selenium content was also decreased from 79.75 to 76.32 and 72.09 and from 46.38 to 44.28 and 41.64 μg Se gm-1 with soil application of 90 and 180 kgP ha-1 to Al-Herria and khan al-Nass soils respectively. Increasing addition of and phosphorus censed decreasing of selenium content of corn plant in both soils.

Impact of selenium biofortification on production characteristics of forages grown following standard management practices in Oregon.

Low selenium (Se) concentrations in soils and plants pose a health risk for ruminants consuming locally-grown forages. Previous studies have shown that Se concentrations in forages can be increased using soil-applied selenate amendments. However, the effects of foliar selenate amendments applied with traditional nitrogen-phosphorus-potassium-sulfur (NPKS) fertilizers on forage yields, and nutrient contents, and agronomic efficiencies are unknown. Using a split plot design, we determined the effects of springtime sodium selenate foliar amendment rates (0, 45, and 90 g Se ha-1) and NPKS application (none, NPK for grasses/PK for alfalfa, and NPKS/PKS fertilization at amounts adapted to meet local forage and soil requirements) on forage growth and N, S, and Se concentrations, yields, and agronomic efficiencies. This 2-year study was conducted across Oregon on four representative forage fields: orchardgrass (Dactylis glomerata L.) in Terrebonne (central Oregon), grass-clover mixture in Roseburg (southwestern Oregon), and both grass mixture and alfalfa (Medicago sativa L.) fields in Union (eastern Oregon). Grasses grew poorly and were low in N content without NPK fertilization. Fertilization with NPK/PK promoted forage growth, increased forage N concentrations, and had to be co-applied with S when plant available S was low. Without Se amendment, forage Se concentrations were low and further decreased with NPKS/PKS fertilization. Selenate amendment linearly increased forage Se concentration without adversely affecting forage yields, N and S concentrations, or N and S agronomic efficiencies. Importantly, S fertilization did not interfere with Se uptake in Se amended plots. In conclusion, co-application of NPKS/PKS fertilizers and foliar sodium selenate in springtime is an effective strategy to increase forage total Se concentrations, while maintaining optimal growth and quality of Oregon forages.

Effects of Amount and Chemical Form of Selenium Amendments on Forage Selenium Concentrations and Species Profiles.

Selenium (Se) agronomic biofortification of plants is effective for alleviating Se deficiencies in human and livestock populations. Less is known about how higher selenate amendment rates, or how foliar compared with granular selenate amendments affect forage Se concentrations. Therefore, we compared the effects of a higher sodium selenate foliar amendment rate (900 vs. 90g Se ha-1), and two selenate amendment methods (liquid foliar sodium selenate vs. granular slow-release Selcote Ultra® at 0, 45, and 90g Se ha-1) on Se concentrations and Se species in forages across Oregon. The 10 × amendment rate (900g Se ha-1) resulted in 6.4 × higher forage Se concentrations in the first cut (49.19 vs. 7.61mg Se kg-1 plant DM, respectively) compared with the 90gha-1 amendment rate, indicating that forages can tolerate higher selenate amendment rates. Most Se was incorporated as SeMet (75%) in the harvested portion of the forage (37mg Se kg-1 forage DM of the first cut) and only a limited amount was stored in the selenate reserve pool in the leaves (~ 5mg Se kg-1 forage DM). Higher application rates of selenate amendment increased forage Se concentrations in first and second cuts, but carry over in subsequent years was negligible. Application of foliar selenate vs. granular Selcote Ultra® amendments, between 0 and 90g Se ha-1, both resulted in a linear, dose-dependent increase in forage Se concentration. Amendments differed in their Se incorporation pattern (Se%), in that, first cut forage Se concentrations were higher with foliar selenate amendment and second, third, and residual (following spring) cut forage Se concentrations were higher with granular Selcote Ultra® amendment. Given the linear relationship between forage Se concentrations and whole-blood Se concentrations in livestock consuming Se-biofortified forage, we conclude that targeted grazing or other forage feeding strategies will allow producers to adapt to either selenate-amendment form.

Selenyum Uygulamalarının Silajlık Mısırın Verim Parametreleri Üzerine Etkileri

In this study, the effects of sodium selenite and sodium selenate applications on laying, plant appearance, number of worm cobs, random number of plants, plant height, cob/plant ratio, leaf/stem ratio of silage maize plant were investigated. Selenium was applied at eight different levels (0-5-10-15-25- 50-75-100 g Se ha-1). Selenite was applied to the soil in liquid form before planting seeds, and selenate was applied to the leaf when the corn plant was 50-70 cm tall. Selenium applications did not statistically affect lying, plant appearance, worm cob number, randomized plant number and plant height values. Selenite applications affected the cob/plant ratio and leaf/stem ratio values statistically, the interaction of the year X subject was significant. In 2013, there was a statistical difference between the subjects, the highest values were obtained with 52% from 5 g Se ha-1 application, with 45% and 47% from 10 g Se ha-1 and 25 g Se ha-1 applications, respectively. Selenate applications did not affect the cob/plant ratio values statistically, but the leaf/stem ratios were affected, the highest values were obtained with 43% from 100 g Se ha-1 applications. It is known that selenium applications do not affect the yield and other plant properties in plants, but increase the selenium concentration of the grain or plant. However, some studies show that selenium application affects positively the plant as our study. It is thought that the effect of selenium in plant development may vary depending on the type and variety of the plant, many factors increase the selenium activity, especially outside the soil and climatic conditions, the application time, rate and method, the form of selenium and the plant species are effective.

Selenium toxicity in upland field-grown rice: Seed physiology responses and nutrient distribution using the μ-XRF technique.

Selenium (Se) is an essential element for human and animal, although considered beneficial to higher plants. Selenium application at high concentration to plants can cause toxicity decreasing the physiological quality of seeds. This study aimed to characterize the Se toxicity on upland rice yield, seed physiology and the localization of Se in seeds using X-ray fluorescence microanalysis (μ-XRF). In the flowering stage, foliar application of Se (0, 250, 500, 1000, 1500, 2000 g ha-1) as sodium selenate was performed. A decrease in rice yield and an increase in seed Se concentrations were observed from 250g Se ha-1. The storage proteins in the seeds showed different responses with Se application (decrease in albumin, increase in prolamin and glutelin). There was a reduction in the concentrations of total sugars and sucrose with the application of 250 and 500g Se ha-1. The highest intensities Kα counts of Se were detected mainly in the endosperm and aleurone/pericarp. μ-XRF revealed the spatial distribution of sulfur, calcium, and potassium in the seed embryos. The seed germination decreased, and the electrical conductivity increased in response to high Se application rates showing clearly an abrupt decrease of physiological quality of rice seeds. This study provides information for a better understanding of the effects of Se toxicity on rice, revealing that in addition to the negative effects on yield, there are changes in the physiological and biochemical quality of seeds.

FOLIAR APPLICATION OF SELENIUM, ZINC AND COPPER IN ALFALFA (Medicago sativa L.) BIOFORTIFICATION

Biofortification of forage crops has an important role in improving the quality of plants used for animal nutrition. The field experiments were conducted in three consecutive years in Subotica, Serbia, in order to investigate the effect of Se, Zn, and Cu foliar fertilization on the yield, Se and Zn contents and nutrient efficiency, as well as on other mineral compositions of alfalfa hay. The treatments were as follows: i) control without fertilization, ii) 5 g Se ha-1, iii) 10 g Se ha-1, iv) 0.5 kg Zn ha-1, v) 1 kg Zn ha-1, vi) the combination of these two elements (0.5 kg Zn ha-1 and Se 10 g ha-1) and vii) 2% Cu solution. The application of Se, Zn, and Cu had no effect on dry yield or on crude protein, P, K, Ca, Mg, Fe, Mn, Mo, and Co contents in alfalfa hay. However, Se, Zn, and Cu fertilization significantly increased the contents of Se, Zn, and Cu in alfalfa hay. The results showed that Se and Zn contents in plant biomass were significantly correlated with the applied doses of Se (r=0.99) and Zn (r=0.99). The production years of alfalfa and the weather conditions proved to be significant factors in fertilization efficiency.

Zea mays L. Grain: Increase in Nutraceutical and Antioxidant Properties Due to Se Fortification in Low and High Water Regimes

This work aimed to investigate the effect of selenium (Se) and irrigation on the grain yield, on the forms of Se, phenols, and carotenes, and on some antioxidant activities of maize ( Zea mays L.) grains. To reach this goal, a 2 year experiment was undertaken. Maize was fertigated with sodium selenite at the rate of 200 g of Se ha-1 and grown under two water regimes. While the irrigation did not show a clear effect on the selected parameters, Se fertigation increased the contents of inorganic and organic Se forms, xanthophyll, and salicylic acid. Furthermore, while Se fertigation decreased the hydroxycinnamic acid content, generally higher antioxidant activities were found in Se-treated grains than in the control. These findings suggest that Se fertigation increases most of the nutraceutical values of maize grains, which therefore might improve human and livestock health and could increase the maize grain shelf life and its byproducts.

Agronomic biofortification of maize and beans in Kenya through selenium fertilization.

Deficiency in calcium, zinc, selenium, and iodine remains a major health issue in Africa. A selenium (Se) status survey conducted in central Kenya highlands revealed a high risk of dietary Se deficiency. This study investigates the effect of soil and foliar Se fertilizer application on Se concentration in maize and bean grains. It further tests the combination of Se fertilizer with phosphorus and nitrogen fertilizers, and with zinc and iodine fertilizers. Selenium fertilization results in a significant increase in Se concentration in grains. For the soil application, Se concentration increases on average by 3µgkg-1 in maize and by 10µgkg-1 in beans, for each gram of Se applied as sodium selenate. Foliar Se fertilization is more effective and increases Se concentration in grains on average by 18µgkg-1 in maize, and by 67µgkg-1 in beans. Total soil phosphorus/availability appears as an important factor influencing soil Se availability. Addition of phosphorus fertilizers positively affects the impact of Se fertilization in locations with low soil P, Fe, and Al. A Se + Zn + I fertilizer combination does not affect the impact on Se concentration in grains. Fertilizing beans alone is found to be more efficient compared to fertilizing only maize. In locations at high risk of dietary Se deficiency, foliar application at 10g Se ha-1 on beans or 31g Se ha-1 on maize is sufficient to achieve adequate daily dietary Se intake. The study points towards a multi-mineral agronomic biofortification, based on a site-specific biofortification strategy.

Effect of different doses and application methods of sodium selenate on selenium status in maize for silage

A two-year field study was conducted to determine the effect of different Se fertiliser application methods and application rates on the selenium content in maize plants. Selenium as sodium selenate was added into soil (10 g and 20 g Se ha-1) or sprayed on maize plants (20 g Se ha-1). Maize plants from control treatment contained 0.018 and 0.020 mg Se kg DM-1 in the first and the second year of the study. Foliar application exhibited superior effect by increasing selenium content in the plants up to 0.343 mg kg DM-1 in the first year, and 0.249 mg kg DM-1 in the second. Soil selenium application was less effective; selenium content in maize plants varied from 0.018 to 0.019 mg kg DM-1 in the first and from 0.018 to 0.145 mg kg DM-1 in the second year, respectively. Strong linear correlation (r=0.71) was found between selenium content in the plants and in grains. Selenium recovery rates were significantly higher in case of foliar treatment compared to soil application.

The effect of fertilizing forage with sodium selenate on selenium concentration of hay, drain water and serum selenium concentrations in beef heifers and calves

The objectives of this trial were to determine the effect of fertilizing grass/alfalfa pastures with sodium selenate on selenium (Se) concentration of hay, drain water and serum Se concentrations in heifers and their calves. A 9.7-ha grass alfalfa hay field was split into four strips, two of which were fertilized with 10g Se ha-1 on 2002 Apr. 20. Hay was harvested from the field on 2002 Jul. 01 and 2002 Aug. 25. Drain water from the field was collected at monthly intervals from 2002 Apr. 20 to 2002 Aug. 20. Thirty-six first calf heifers in the third trimester of gestation were assigned randomly to one of nine pens and pens were assigned randomly to one of three treatments in a completely random design. Treatments were: (1) a basal diet of Se fertilized hay and a mineral mix containing 180 mg Se kg-1 (+Se hay +Se mineral), (2) a basal diet of Se fertilized hay and a mineral mix containing no Se (+Se hay −Se mineral), and (3) a basal diet of non-Se fertilized hay and a mineral mix containing 180 mg Se kg-1 (−Se hay +Se mineral). Blood samples were collected via coccygeal venipuncture at the initiation of the trial and at calving. Twelve hours after birth a blood sample was collected from each calf via jugular venipuncture. Selenium fertilization increased (P < 0.05) Se concentration in the hay 12-fold in the first cutting and fourfold in the second cutting. Selenium was only detectable in the drain water 1 mo after fertilization (0.55 µg Se kg-1). Intake of Se was greatest (P < 0.05) for +Se hay +Se mineral heifers, intermediate for −Se hay +Se mineral heifers, and lowest for +Se hay −Se mineral heifers. Serum Se concentration of heifers was greater (P < 0.05) in +Se hay +Se mineral than in +Se hay −Se mineral heifers. Serum Se concentration of calves was higher (P< 0.05) in the +Se hay +Se mineral, intermediate in +Se hay −Se mineral calves, and lowest in −Se hay +Se mineral calves. Fertilization with sodium selenate can be used as an alternative method to provide Se to beef cattle in geographic regions where Se supplementation is required. Key words: Beef cattle, selenium, supplementation, fertilization

Selenium fertilizers for pastures grazed by sheep. 2. Wool and liveweight responses to selenium

Two forms of selenium fertilizer, Na2 Se04 (quick release) and BaSe04 (slow release), prepared by Mintech of New Zealand, were applied in 1987 to pasture at Bakers Hill in Western Australia at 10 g Se ha-1. Merino wethers grazing the pasture over the following 3 years had significant increases in liveweight and wool production even though the control sheep showed no clinical symptoms of selenium deficiency. Sheep treated with selenium intra-ruminal pellets that also grazed the selenium-fertilized pasture showed no signs of toxicity and also had significant increases in liveweight and wool production. There was no significant increase in wool fibre diameter from the selenium treatments. Responses to blood selenium indicated that whole blood selenium should be maintained at a minimum value of 60 8g Se L-1 or a minimum plasma concentration of 40 8g Se L-1 to avoid subclinical selenium deficiency.

Selenium fertilizers for pastures grazed by sheep. 1. Selenium concentrations in whole blood and plasma

Two forms of prilled selenium fertilizer from Mintech N.Z., Na2 SeO4 (Selcote�) and BaSe04 incorporating a slow-release technology, were applied to pasture once at 10 and 20 g Se ha-1 in 1987 at Bakers Hill, Western Australia. The pasture was grazed at 10 sheep ha-1 for 3 years. In the first year, half the sheep were also treated with a selenium intra-ruminal pellet. The Selcote fertilizer produced a rapid rise in pasture selenium concentration, resulting in a similar response in the concentrations of selenium in the whole blood and plasma which reached their maximum values within 7 weeks of commencing grazing. The selenium concentration then declined until, after 15 months, there was insufficient selenium in the pastures to increase the selenium status of sheep. In contrast, the slow-release formulation provided adequate selenium in each of the 3 years with sheep reaching their maximum plasma selenium of 80 8g Se L-1 in the second and third year. At relatively low values for whole blood selenium (< 75 pg Se L-1), supplying an additional selenium source had an additive effect on selenium concentration in the blood, but at higher concentrations (> 350 8g Se L-1) additional sources of selenium only marginally increased the whole blood concentration of selenium. Plasma was a more sensitive indicator of the selenium content of pasture in the short term than whole blood. The results indicate that either Selcote or the BaSe04 fertilizer provides an effective alternative to current strategies for supplying Se to grazing animals.