An Asian Journal of Soil Science

Ajeet Kumar ¹, C. S. Choudhary ¹, Diwakar Paswan ¹, Brijesh Kumar ², Anjana Arun ¹

Affiliations
1 Regional Research Station, Agwanpur, Saharsa (Bihar), IN
2 Department of Soil Science and Agricultural Chemistry, Mandan Bharti Agriculture College, Agwanpur, Saharsa (Bihar), IN

Abstract

Phosphorus is the second important key element after nitrogen as a nutrient in terms of quantitative plant requirement. Although phosphorus is abundant in soils (organic and inorganic forms), its availability is restricted as it occurs mostly in insoluble forms. The phosphorus content in soil is about 0.05 per cent (w/w) but only 0.1 per cent of the total phosphorus is available to plant because of poor solubility and its fixation in every type of soil. An adequate supply of phosphorus during early phase of plant development is important for laying down the primordia of plant parts. It plays significant role in ischolar_main ramification, thereby imparting vitality to plant. It also helps in seed formation and in early maturation of crops. Poor availability or deficiency of phosphorus markedly reduces plant size and growth. Phosphorus accounts about 0.2 - 0.8 per cent of the plant dry weight. To satisfy crop requirements, phosphorus is usually added to soil as chemical fertilizer, however, synthesis of chemical fertilizer is highly energy intensive processes, and has long term impacts on the environment in terms of eutrophication, soil fertility depletion, carbon footprint. Moreover, plants use only a small amount of phosphorus, because about 80-90 per cent of added phosphorus is precipitated by metal-cation complexes, and rapidly fixed in soils. Such environmental concerns have led to the search for sustainable way of phosphorus nutrition of crops. In this regards phosphate-solubilizing microorganisms have been seen as best eco-friendly means for phosphorus nutrition of crop. Although, several bacterial (Pseudomonas and Bacilli) and fungal strains (Aspergillus and Penicillium) have been identified as PSM. Their performance under in situ conditions is not reliable and therefore, needs to be improved by using co-inoculation techniques. This review focuses on the diversity of PSM, mechanism of P solubilization, role of various phosphatase, impact of various factors on solubilization, the present and future scenario of their use and potential for application of this knowledge in managing a sustainable agricultural system.

Keywords

Soil Phosphorus, PSM, Solubilization, Biodiversity, Biofertilizers, Siderophores, TCP, Organic Acids.

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Ajeet Kumar ¹, Diwakar Paswan ¹, C. S. Choudhary ¹, Brijesh Kumar ¹, Anjana Arun ¹

Affiliations
1 Regional Research Station, Agwanpur, Saharsa (Bihar), IN

Abstract

The paper attempts to explore research findings focusing on the climate change impact on organic agriculture and its impact on climate change through scientific literature review. This review reveals that climate change and agriculture are closely linked and interdependent. Compared to conventional agriculture, organic agriculture is reported to be more efficient and effective both in reducing GHGs (CO₂, CH₄ and N₂O) emission mainly due to the less use of chemical fertilizers and fossil fuel. Organic agriculture also reported to be climate change resilience farming systems as it promotes the proper management of soil, water and biodiversity by acting as a good options for adaptation to climate change. But, due to lack of proper research, the contribution of organic agriculture for climate change adaptation and mitigation is yet to be known. It is argued that organic agriculture positively contributes to offset negative impacts of climate change, but there is inadequate systematic data to substantiate this fact.

Keywords

Adaptation, Climate Change, Greenhouse Gases Mitigation, Organic Agriculture.

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