Coastal areas are commonly defined as the interface or transition areas between land and sea, including large inland lakes. Overall, about 50–70 % of the global population live within 100 km of the coastline covering only about 4 % of earth’s land, thereby drawing heavily on coastal and marine habitats for food, building sites, transportation, recreational areas, and waste disposal. The people of these zones depend mainly on low productive agriculture due to several constraints such as prolonged water logging and drainage congestion in predominantly low-lying areas with heavy soils during the wet season, preponderance of saline and acid sulphate soils, scarcity of good quality irrigation water, particularly in the dry season, seawater intrusion into adjoining lands, and water pollution due to eutrophication, and others affecting the aquatic habitats, etc. Carbon sequestration in coastal areas, such as, marshes, lagoons, etc. has significant influence on soil quality, and the carbon pool in soils as well as their impacts on the environment. Over and above these, the coastal areas are prone to disasters due to climate change leading to colossal loss of lives and properties in many areas. Forestry and mangrove dynamics, in particular, because of their continuing diminishing nature, are also subjects of interest affecting the ecology of coastal zones requiring appropriate attention. The international symposium held in this context on ‘ Transforming Coastal Zones for Sustainable Food and Income Security ’ in virtual mode in March, 2021 offered scope to present and discuss various thematic areas by eminent scientists from all over the world. The proceedings of selected papers presented reflect cross-sectoral views of the areas highlighting, wherever necessary, a fusion of technologies, with the ultimate target to suggest livelihood security and sustainable development for the sensitive coastal zones. The book intends to share the knowledge with researchers, academicians, and various other stakeholders to address the complex problems of coastal regions, production constraints, social, economic, technical and environmental issues to draw out strategies for resilient agricultural technologies and improving livelihood security in coastal agro-ecosystems.

Cowpea (Vigna ungiculata L. Walp) is a major food and fodder legume in poor countries, particularly Sub-Saharan Africa countries. It is generally produced in sandy, acid soils, deficient in phosphorus (P) which severely limits its production. Because processed phosphate fertilizers are expensive and poorly available to farmers, rock phosphate is viewed as a cheap alternative phosphate source. The present study evaluated 696 U.S Core Collection and IITA cowpea accessions for adaptation to low soil P environments and for response to rock phosphate application. Subsequently, organic acid exudation by selected cowpea genotypes as a mechanism for P acquisition from Fe-oxide and Ca bound P was investigated. A low P soil from Nacogdoches pine forest was used to grow plants. There were two P treatments: 0 and 300 mg P/kg of soil as Tahoua (Niger) rock phosphate. At harvest, plant height, shoot and root dry weights were determined and total biomass and shoot-to-root ratios were computed. Shoot P contents of 100 selected accessions were measured. Sixteen accessions reflecting the wide array of responses observed were selected for the organic acid study. Plants were grown in a growth chamber hydroponically with no P and +P nutrient solutions for 3 weeks. Organic acids were collected in a CaCl2-KCl solution. The nature and quantity of the collected organic acids was determined. Cowpea accessions were significantly different in their ability to adapt to Pdeficiency stress and to acquire P from rock phosphate. The parameters most effective in separating the accessions were shoot mass and total biomass. This data will be potentially useful in the selection of cowpea germplasm for (1) adaptation to West African soils of low P fertility, and (2) ability to utilize P from poorly soluble rock phosphate. The predominant organic acid exuded by cowpea roots was a tricarboxylic acid not yet identified. There was surprisingly more exudation of this acid under +P than under -P conditions. Exudation was more highly correlated to roots than to shoots.

The world population is projected to reach nine billion by 2050, and in the coming years, global food demand is expected to increase by 50% or more. Higher crop productivity gains in the future will have to be achieved in developing countries through better natural resources management and crop improvement. After nitrogen, phosphorus (P) has more widespread influence on both natural and agricultural ecosystems than any other essential plant element. It has been estimated that 5.7 billion hectares of land worldwide contain insufficient amounts of available P for sustainable crop production, and P deficiency in crop plants is a widespread problem in various parts of the world. However, it has been estimated that worldwide minable P could last less than 40 years. For sustaining future food supplies, it is vital to enhance plant P use efficiency. To bring the latest knowledge and research advances in efficient management of P for economically viable and environmentally beneficial crop production in sustainable agriculture, Phosphorus Management in Crop Production contains chapters covering functions and diagnostic techniques for P requirements in crop plants, P use efficiency and interactions with other nutrients in crop plants, management of P for optimal crop production and environmental quality, and basic principles and methodology regarding P nutrition in crop plants. The majority of research data included are derived from many years of field, greenhouse, and lab work, hence the information is practical in nature and will have a significant impact on efficient management of P-fertilizers to enhance P use efficiency, improve crop production, promote sustainable agriculture, and reduce P losses through eluviations, leaching, and erosion to minimize environmental degradation. A comprehensive book that combines practical and applied information, Phosphorus Management in Crop Production is an excellent reference for students, professors, agricultural research scientists, food scientists, agricultural extension specialists, private consultants, fertilizer companies, and government agencies that deal with agricultural and environmental issues.