Zhenli He – författare

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.

The red soils of China are highly weathered, inherently infertile and very susceptible to erosion. However, they represent China's last available soil resource that could be brought into agricultural production, a fact that assumes great importance in view of China's huge and still-increasing population. These soils are typical of similar red soils that occur throughout tropical and sub-tropical South America, Africa and south east Asia, so that if the red soils of China could be successfully utilized then this would have wider implications for agriculture in other countries. Previous attempts to cultivate Chinese red soils have met with little success and it has become apparent that they cannot sustain arable cropping systems without the most careful management. This book describes recent research outlining the physical, chemical and mineralogical nature of the soils, the various constraints that combine to inhibit their practical use, and the traditional and novel approaches that may be used to overcome these constraints.Building upon previous work and using examples from other countries, the book illustrates these approaches, shows appropriate land uses for the red soils of China and how the fertility of the soils evolves with time under these land uses. Whether these technical and scientific advances will be taken up by the Chinese farmer will depend to a large extent on the prevailing socio-economic conditions.

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.

This collection features four peer-reviewed literature reviews on soil erosion in agriculture.The first chapter identifies different types of soil degradation, focussing primarily on soil erosion by water. The chapter explores the impact of soil erosion processes on soil properties that relate directly to crop growth, including soil depth, water-holding capacity, carbon content and nutrient reserves.The second chapter reviews advances in techniques used to assess and measure soil erodibility by water, such as computer aided tomography. The chapter considers the role of static and dynamic soil properties in the erosion process, as well as the challenges that have developed as a result of climate change.The third chapter assesses the impact of heavy metal contamination on soil and its consequent role in the degradation of soil health. The chapter describes the sources, impacts, indicators and remediation of heavy metal contamination, as well as the development of improved soil management practices, including effective pollution control strategies.The final chapter discusses the implementation of integrated strategies under Conservation Agriculture (CA) farming systems to restore soil productivity in degraded agricultural lands in tropical and subtropical regions in Brazil. The chapter additionally considers the adoption of CA as a tool to prevent and reverse instances of soil degradation.

This collection features four peer-reviewed reviews on major contaminants in agricultural soils.The first chapter discusses emerging technologies for remediating soil polluted with polycyclic aromatic hydrocarbon and their contamination routes. The chapter also addresses techniques for their identification and tracking, persistence and bioaccumulation in the soil and risks to and effects on human health and soil health.The second chapter provides a comprehensive overview of the pathways through which antibiotics reach the soil, the processes that influence their fate within the soil and the techniques and efforts used to predict their behaviour and fate. The chapter also offers insights from specific case studies and discusses future research directions to address environmental challenges.The third chapter addresses the risks associated with using treated wastewater in irrigation systems for crop production, including an elevation in soil water osmotic pressure, the addition of toxic ions and organic contaminants to the soil and the deterioration of the physical and hydraulic properties of soil.The final chapter reviews the impact of heavy metal contamination on soil health, focussing on its effects on soil biogeochemical processes, nutrient cycling and soil functions in crop production, environmental quality and food security. The chapter also discusses common indicators of soil contamination and remediation techniques.