Soil composition

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  • The acre-yields of crops on dry-farms, even under the most favorable methods of culture, are likely to be much smaller than in humid sections with fertile soils. The necessity for frequent fallowing or resting periods over a large portion of the dry-farm territory further decreases the average annual yield.

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  • Chapter 37 - Soil and plant nutrition. This chapter define soil texture and soil composition; explain why plants cannot extract all of the water in soil; define cation exchange and describe how plants can stimulate the process; discuss the problems of topsoil erosion and farm irrigation in arid regions; suggest actions that can help mitigate these problems;...

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  • Failure to adequately define [sample] support has long been a source of confusion in site characterization and remediation because risk due to long-term exposure may involve areal supports of hundreds or thousands of square meters; removal by backhoe or front-end loader may involve minimum remediation units of 5 or 10 m2; and sample measurements may be taken on soil cores only a few centimeters in diameter. (Englund and Heravi, 1994) The importance of this observation cannot be overstated.

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  • Sodium concentration in irrigation water replaces calcium by the process of Base Exchange, therefore reduces soil permeability. Furthermore, excess salinity in groundwater used for irrigation decreased plants osmotic activity and interfere water absorption and nutrients from the soil. Nearly 5% of groundwater from the study site exceeds the desirable limit (1000 mg L-1) of chloride. The natural source of chloride is due to the weathering of phosphate mineral apatite present in granites.

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  • Thus, it remedies soil degradation, desertification, and deforestation. Jatropha is native of tropical America, but now flourish in many parts of the tropics and sub-tropics in Africa/Asia. Various parts of the plant are of medicinal(both human and veterinary purposes) value for instance, and are under intensive scientific investigation. The oil is a strong purgative, widely employed as an antiseptic for cough, skin diseases, and a pain reliever from rheumatism. Jatropha latex can heal wounds and also has antimicrobial properties (Openshaw, 2000).

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  • The space program’s missions to Mars have confirmed that the soil composition on that planet is similar to that on our planet. (A) (B) (C) (D) to that on our planet to our planet with the soil on our planet to this composition on our planet (E) to our planet’s soil’s composition 4. According to life-insurance company statistics, nine out of ten alcoholics die before the age of seventy-five, as opposed to seven out of ten nonalcoholics.

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  • This publication has been designed to share IFAD’s experience with a broader public. It uses examples of instruments, processes and practices selected from IFAD’s project portfolio. The theme of IFAD’s 2001 portfolio review was the environment and natural resource management. Environment and Natural Resource Management: IFAD’s Growing Commitment draws extensively on that progress report, which was presented at the Seventy-Second Session of the IFAD Executive Board in April 2001.

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  • Sewage sludge as an uncalled for product of wastewater treatment poses the challenge to society of disposing of it, but at the same time gives us the opportunity of beneficial use by closing the cycle of nutrients: sludge derived from agricultural activity must return to soil if a sustainable and ecologically sound management of these materials is desirable (SEQUI et al. 2000). At present the major ways of disposing of sewage sludges are deposition, landfill and incineration, only part of the sludges are used in agriculture. ...

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  • Human activities are affecting the global environment in myriad ways, with numerous direct and indirect effects on ecosystems. The climate and atmospheric composition of Earth are changing rapidly. Humans have directly modified half of the ice-free terrestrial surface and use 40% of terrestrial production. Our actions are causing the sixth major extinction event in the history of life on Earth and are radically modifying the interactions among forests, fields, streams, and oceans.

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  • A number of abiotic stresses impose damage to crop and provokes reduction of yield productivity. Amongst several abiotic stresses, water deficit and soil salinity are the most commonly investigated owing to the extent of cultivated area affected by them. Water scarcity and increase competition for water resources involving several sectors of the production segment (agriculture, industry, hydroelectric energy, etc.

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  • The objective of waste water treatment is to prevent large quantities of substances to reach and impact the environment in high doses and concentrations. Areas of high population densitiy naturally are areas were production of sewage sludge is high (see Figure 1-1). Presently about 8 million t of sewage sludges (MAGOAROU 2000) are produced each year in the EU member states (Table 1-1). Its high content of organic materials, of nitrogen and phosphorous suggest their use as soil conditioner and fertilizer in agriculture.

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  • The object of cultivating the soil is to raise from it a crop of plants. In order to cultivate with economy, we must raise the largest possible quantity with the least expense, and without permanent injury to the soil. Before this can be done we must study the character of plants, and learn their exact composition. They are not created by a mysterious power, they are merely made up of matters already in existence. They take up water containing food and other mat[Pg 12]ters, and discharge from their roots those substances that are not required for their growth. ...

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  • There is currently no independent authoritative statement on the nature and importance of differences in content of nutrients and other nutritionally relevant substances (nutrients and other substances) in organically and conventionally produced foodstuffs. This systematic review of the available published literature was designed to seek to determine the size and relevance to health of any differences in content of nutrients and other substances in organically and conventionally produced crops and livestock products.

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  • The history, culture and community values of East Africans are embedded in agriculture. It is the most important source of livelihoods for millions of East Africans. The sustainable management of the agriculture production process is therefore crucial if livelihoods are to be sustained. Organic agriculture is a holistic production management system, which promotes and enhances agro- ecosystem health, including bio-diversity, biological cycles and soil biological activity.

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  • Foreword for Cary Conference X, “Ecosystem Function in Heterogeneous Landscapes.” Among the most difficult problems in the life sciences is the challenge to understand the details of how ecosystems/watersheds/landscapes function. Yet, the welfare of all life, not just the human species, depends upon the successful functioning of diverse and complicated ecosystems, each with various dimensions and compositions.

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  • Regioregular polythiophene-based conductive copolymers with highly crystalline nanostructures are shown to hold considerable promise as the active layer in volatile organic compound (VOC) chemresistor sensors. While the regioregular polythiophene polymer chain provides a charge conduction path, its chemical sensing selectivity and sensitivity can be altered either by incorporating a second polymer to form a block copolymer or by making a random copolymer of polythiophene with different alkyl side chains.

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  • Diverse human-produced organic chemicals can enter surface and groundwater through human activities, including pesticide use and industrial processes, and as breakdown products of other chemicals (Carr and Neary 2008). Many of these pollutants, including pesticides and other non-metallic toxins, are used globally, persist in the environment, and can be transported long ranges to regions where they have never been produced (UNEP 2009).

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  • Alterations to fire regimes have resulted in many changes to the biological communities including changes in vegetation composition and structure and vegetation type conversions or ecosystem migrations. This text details many of these changes, explains how fire has changed as an ecosystem process, and provides insights for determining the direction that the changes might take in the future.

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  • The Modular Wetlands device to be tested is located in a non typical situation. Unlike a storm event that typically contains higher concentration during the first 2 hours our site has a fairly consistent flow of wash water that is estimated to be consistent through out the day. For this reason, composite samples were taken over a two hour period. The intent of the sampling was to establish a composite pollutant sample. This was done by dividing all of the containers and bottles to be filled for testing into ten equal parts. The grab sample was taken...

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  • Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Effects of the clear-cutting of a Douglas-fir plantation (Pseudotsuga menziesii F.) on the chemical composition of soil solutions and on the leaching of DOC and ions in drainage waters...

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