The trace element selenium (Se) is a crucial element for many living organisms, including soil microorganisms, plants and animals, including humans. Generally, in Nature Se is taken up in the living cells of microorganisms, plants, animals and humans in several inorganic forms such as selenate, selenite, elemental Se and selenide. These forms are converted to organic forms by biological process, mostly as the two selenoamino acids selenocysteine (SeCys) and selenomethionine (SeMet). The biological systems of plants, animals and humans can fix these amino acids into Se-containing proteins by a modest replacement of methionine with SeMet. While the form SeCys is usually present in the active site of enzymes, which is essential for catalytic activity. Within human cells, organic forms of Se are significant for the accurate functioning of the immune and reproductive systems, the thyroid and the brain, and to enzyme activity within cells. Humans ingest Se through plant and animal foods rich in the element. The concentration of Se in foodstuffs depends on the presence of available forms of Se in soils and its uptake and accumulation by plants and herbivorous animals. Therefore, improving the availability of Se to plants is, therefore, a potential pathway to overcoming human Se deficiencies. Among these prospective pathways, the Se-biofortification of plants has already been established as a pioneering approach for producing Se-enriched agricultural products. To achieve this desirable aim of Se-biofortification, molecular breeding and genetic engineering in combination with novel agronomic and edaphic management approaches should be combined. This current review summarizes the roles, responses, prospects and mechanisms of Se in human nutrition. It also elaborates how biofortification is a plausible approach to resolving Se-deficiency in humans and other animals.
In modern days, rapid urbanisation, climatic abnormalities, water scarcity and quality degradation vis-à-vis the increasing demand for food to feed the growing population necessitate a more efficient agriculture production system. In this context, farming with zeolites, hydrated naturally occurring aluminosilicates found in sedimentary rocks, which are ubiquitous and environment friendly, has attracted attention in the recent past owing to multidisciplinary benefits accrued from them in agricultural activities. The use of these minerals as soil ameliorants facilitates the improvement of soil’s physical and chemical properties as well as alleviates heavy metal toxicity. Additionally, natural and surface-modified zeolites have selectivity for major essential nutrients, including ammonium (NH4+), phosphate (PO42−), nitrate (NO3−), potassium (K+) and sulphate (SO42−), in their unique porous structure that reduces nutrient leaching. The slow-release nature of zeolites is also beneficial to avail nutrients optimally throughout crop growth. These unique characteristics of zeolites improve the fertilizer and water use efficiency and, subsequently, diminish environmental pollution by reducing nitrate leaching and the emissions of nitrous oxides and ammonia. The aforesaid characteristics significantly improve the growth, productivity and quality of versatile crops, along with maximising resource use efficiency. This literature review highlights the findings of previous studies as well as the prospects of zeolite application for achieving sustenance in agriculture without negotiating the output.
Peanut (Arachis hypogaea L.) is adorned as the one of the important sources of vegetable oil, protein, vitamins and several minerals, which could mitigate the nutritional gap worldwide. However, peanut cultivation in winter suffers from low temperature stress and knowledge lacuna regarding the optimum dose nitrogen. Therefore, the present investigations were carried out during the winter seasons 2015–2016 and 2016–2017 at the district seed farm of Bidhan Chandra Krishi Viswavidyalaya, an agricultural university in West Bengal, India (23°26’ N, 88°22´ E, elevation 12 m above mean sea level) to facilitate the comprehensive study of plant growth, productivity and profitability of an irrigated peanut crop under varied levels of nitrogen: with and without a rhizobium inoculants and with and without polythene mulch. Quality traits and nutrient dynamics were also itemized. Fertilizing with 100% of the recommended dose of nitrogen combined with rhizobium inoculant and polythene mulch significantly enhanced peanut plant growth, yield and yield-attributing traits, while resulting in the maximum fertilizer (i.e., nitrogen, phosphorus and potassium) uptake by different plant parts. The greatest number of root nodules occurred in the treatment that received 75% of the recommended dose of nitrogen with rhizobium supplementation under polythene mulch, while 50% of the recommended dose of nitrogen with no rhizobium resulted in maximum fertilizer nitrogen use efficiency. Applying the full recommended dose of nitrogen with the rhizobium inoculants and mulch resulted in maximum profitability in the peanut crop.
Peanuts (Arachis hypogaea L.) are the world’s fourth-most important source of edible oil and the third-most valuable source of high-quality vegetable protein; they also contain carbohydrates, fatty acids, vitamins, and minerals essential for good human nutrition. Peanuts area particularly valuable crop in tropical and subtropical regions. While the demand for peanuts is increasing globally, there is a significant gap in nitrogen supply and demand in peanut production systems. To alleviate this, nitrogen fertilizers are often applied indiscriminately; this practice leads to the deterioration of indigenous soil fertility and to a long-term decline in crop productivity. Considering these aspects of soil health, a field study was conducted over two consecutive winter (November–March) seasons in 2015–2016 and 2016–2017 at the research farm of the agricultural university Bidhan Chandra Krishi Viswavidyalaya in West Bengal, India. This study examined supplementing different levels of nitrogen fertilizer with rhizobium and soil mulch in an irrigated peanut crop. The effects of these management interventions were evaluated in terms of crop productivity, nutrient dynamics, soil moisture, and the soil microbial activity. Peanuts grown with the 100% recommended dose of nitrogen, which was applied with rhizobium and grown under polythene mulching, recorded the highest average pod yield (3.87 and 3.96 t ha−1 in 2015–2016 and 2016–2017) and average kernel yield (2.88 and 2.99 t ha−1) in both growing seasons. This treatment also resulted in the greatest accumulation of nitrogen, phosphorous, and potassium by the peanut plants. In contrast, the maximum soil moisture distribution and the greatest total root zone moisture content were observed in the treatment with only rhizobium under the polythene mulch (i.e., no nitrogen was applied). The populations of soil bacteria and rhizobia were highest in the treatment where nitrogen fertilizer was applied to the crop at 75% of the recommended rate combined with rhizobium and under polythene mulch. After two cropping seasons, the peanut crop grown under polythene mulch with rhizobium and with nitrogen fertilizer applied at either the full recommended rate or 75% of this rate performed best in terms of crop productivity, soil nutrient dynamics, and soil moisture.