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No Thumbnail AvailableProjectProgramme / project reportSoil quality considerations in the selection of sites for aquaculture
Establishment of African Regional Aquaculture Centre
1987Also available in:
No results found.Soil quality is an important factor in fish pond productivity as it controls pond bottom stability, pH and salinity of overlying water and concentrations of plant nutrients required for the growth of phytoplankton, which is the base of food chain of the fish. A satisfactory site for constructing fish ponds is that where the soil is very deep, with low salinity levels and neutral pH, water infiltration is very low, mineralization of organic matter takes place rapidly, nutrients are adsorbed and r eleased slowly over a long period. Moderately heavy textured soils because of their high surface area and surface charge density posses the above characteristics. Too heavier textured soils such as pure clay may not be satisfactory as they have very high adsorptive property and thereby act as a sink for nutrients like phosphorus which may not be easily released to the overlying water. These soils may also give problems of developments of deep cracks when dry (on draining the ponds) thereby allow ing seepage losses of water. In order to have a clear understanding of the various physicochemical and biological processes which are controlled by the soil in the ponds and to make decisions on the suitability of sites for aquaculture as well as effective managements of the soils for increased productivity of the ponds, one needs to have a good background knowledge of the nature and properties of the soil. This chapter presents basic information on soils, their characteristics and their appli cations to aquaculture. The physicochemical characteristics of water as they affect aquaculture. are discussed separately elsewhere. The science of aquaculture has many similarities with that of agriculture though it is of recent development compared to the latter. Many of the ideas in aquaculture are derived from the experiences in agriculture. -
No Thumbnail AvailableProjectProgramme / project reportSite selection for aquaculture: Climatic factors
Establishment of African Regional Aquaculture Centre
1987Also available in:
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No Thumbnail AvailableProjectProgramme / project reportSite selection for aquaculture: plankton and benthos
Establishment of African Regional Aquaculture Centre
1987Also available in:
No results found.The organisms in the aquatic environment can be devided into three large groups - the plankton, nekton and benthos. In the benthos are included sessile, creeping or burrowing organisms found in the bottom of water bodies. The nekton is composed of swimming animals such as the fish and in the plankton is included all of the floating or drifting organisms. The term plankton was proposed by Victor Hesner in 1887 to designate that “heterogeneous assemblage of organisms which float and move at the wi ll of the waves and other water movements”. Much of the available information on plankton and benthos existing refer to those in natural water bodies, often large lakes and seas, which are described well in text books of limnology and marine biology - oceanography. These are also certainly of aquaculture importance in special cases, especially coastal aquaculture (“Pen and cage culture”) and also in extensive aquaculture, beginning with “stocking of open waters”, both natural and man-made. O ur interest here is to increase the richness of the water bodies by water quality assessment (physical and chemical feature of water, we already referred to in chapter 8 and 9 and also biological productivity, referred to in chapter 10), to judge their suitability for aquaculture. While biological productivity of a water body can be obtained by measurement of primary productivity, a good index of biological productivity is the measure of abundance of plankton and benthos.
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Book (series)FlagshipThe State of Food Security and Nutrition in the World 2021
Transforming food systems for food security, improved nutrition and affordable healthy diets for all
2021In recent years, several major drivers have put the world off track to ending world hunger and malnutrition in all its forms by 2030. The challenges have grown with the COVID-19 pandemic and related containment measures. This report presents the first global assessment of food insecurity and malnutrition for 2020 and offers some indication of what hunger might look like by 2030 in a scenario further complicated by the enduring effects of the COVID-19 pandemic. It also includes new estimates of the cost and affordability of healthy diets, which provide an important link between the food security and nutrition indicators and the analysis of their trends. Altogether, the report highlights the need for a deeper reflection on how to better address the global food security and nutrition situation.To understand how hunger and malnutrition have reached these critical levels, this report draws on the analyses of the past four editions, which have produced a vast, evidence-based body of knowledge of the major drivers behind the recent changes in food security and nutrition. These drivers, which are increasing in frequency and intensity, include conflicts, climate variability and extremes, and economic slowdowns and downturns – all exacerbated by the underlying causes of poverty and very high and persistent levels of inequality. In addition, millions of people around the world suffer from food insecurity and different forms of malnutrition because they cannot afford the cost of healthy diets. From a synthesized understanding of this knowledge, updates and additional analyses are generated to create a holistic view of the combined effects of these drivers, both on each other and on food systems, and how they negatively affect food security and nutrition around the world.In turn, the evidence informs an in-depth look at how to move from silo solutions to integrated food systems solutions. In this regard, the report proposes transformative pathways that specifically address the challenges posed by the major drivers, also highlighting the types of policy and investment portfolios required to transform food systems for food security, improved nutrition, and affordable healthy diets for all. The report observes that, while the pandemic has caused major setbacks, there is much to be learned from the vulnerabilities and inequalities it has laid bare. If taken to heart, these new insights and wisdom can help get the world back on track towards the goal of ending hunger, food insecurity, and malnutrition in all its forms. -
BookletHigh-profileFAO Strategy on Climate Change 2022–2031 2022The FAO Strategy on Climate Change 2022–2031 was endorsed by FAO Council in June 2022. This new strategy replaces the previous strategy from 2017 to better FAO's climate action with the Strategic Framework 2022-2031, and other FAO strategies that have been developed since then. The Strategy was elaborated following an inclusive process of consultation with FAO Members, FAO staff from headquarters and decentralized offices, as well as external partners. It articulates FAO's vision for agrifood systems by 2050, around three main pillars of action: at global and regional level, at country level, and at local level. The Strategy also encourages key guiding principles for action, such as science and innovation, inclusiveness, partnerships, and access to finance.
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Book (stand-alone)Technical bookClimate-Smart Agriculture Sourcebook 2013
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No results found.The purpose of the sourcebook is to further elaborate the concept of CSA and demonstrate its potential, as well as limitations. It aims to help decision makers at a number of levels (including political administrators and natural resource managers) to understand the different options that are available for planning, policies and investments and the practices that are suitable for making different agricultural sectors, landscapes and food systems more climate-smart. This sourcebook is a reference tool for planners, practitioners and policy makers working in agriculture, forestry and fisheries at national and subnational levels. The sourcebook indicates some of the necessary ingredients required to achieve a climate-smart approach to the agricultural sectors, including existing options and barriers. Read the executive summary here.