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Agricultural chemistry - evaluation of an agricultural science in presence and future
1994
Welte, E. (Kiel Univ. (Germany). Inst. fuer Pflanzenbau und Pflanzenzuechtung)
Agricultural chemistry is the science dealing with the interactions between the yields of plants and factors affecting growth. It aims to improve the quantitative and qualitative yield by means of determining the supply of the needed growth factors. Agricultural chemistry is divided in two parts: science of plant nutrition and science of fertilization. Agricultural chemistry is now in a second area. The aim is not to fight against hunger, rather to secure the supply of plant nutrients from nutrient fluxes. It is now time to come out of the darkness which false policy led agriculture and agricultural chemistry into. It is the task of both organic and conventional agriculture to preserve the resources of soil and plant as a resource for cultivating land in the European tradition.
Afficher plus [+] Moins [-]Management of National Agricultural Research Systems in Selected Arab Countries: An Overview
1994
International Service for National Agricultural Research
Developing an agricultural engineering department in Cameroon
1994
Bagnall, L.O. | Berinyuy, J. | Fonteh, M. | ,
Forage for bees in an agricultural landscape
1994
Matheson, Andrew
Genetic resources in Suriname, an agricultural perspective
1994
Goedhart, E.R.A. (Agricultural Experiment Station, Paramaribo (Suriname). Palm Research Centre)
After some general information about the population, climate, pedology and agriculture of Suriname further information is given about; the genetic resources and their availability, perspectives for the future concerning for instance biodiversity conservation, the agricultural outlook and different aspects of the workplan for genetic conservation activities
Afficher plus [+] Moins [-]Forage for bees in an agricultural landscape
1994
Matheson, A. (ed.) (International Bee Research Association, 18 North Road, Cardiff, CF1-3DY (United Kingdom))
Explaining diversity in agricultural organization: an agency perspective.
1994
Roumasset J.A.
Naturally Occurring Radionuclides in Agricultural Products: An Overview Texte intégral
1994
Hanlon, Edward A.
Low levels of naturally occurring radionuclides exist in phosphatic clays, a by-product of phosphatic mining and beneficiation processes. Concerns about these radionuclides entering the human food chain were an immediate research priority before the phosphatic clays could be reclaimed for intensive agricultural purposes. Efforts included the assembly of a large body of data from both soils and plants, part of which were produced by the Polk County (Florida) Mined Lands Agricultural Research/Demonstration Project (MLAR/DP). Additional detailed studies involving dairy and beef cattle (Bos taurus) were conducted by researchers working with the MLAR/DP. A national symposium was conducted in which data concerning the MLAR/DP work and other research projects also dealing with naturally occurring radionuclides in agriculture could be discussed. The symposium included invited review papers dealing with the identification of radionuclide geological origins, the geochemistry and movement of radionuclides within the environment, mechanisms of plant uptake, entry points into the food chain, and evaluation of dose and risk assessment to the consumer of low levels of radionuclides. The risk to human health of an individual obtaining 0.1 of his or her dietary intake from crops produced on phosphatic clays increased by 1 in 5 × 10⁶/yr above a control individual consuming no food grown on phosphatic clays. Leaf tissues were found to be generally higher than fruit, grain, or root tissues. The natural range in radionuclide content among various food types was greater than the difference in radionuclides content between the same food produced on phosphatic clays vs. natural soils. Florida Agric. Exp. Stn. no. R-02497.
Afficher plus [+] Moins [-]Evaluation of Rhodamine WT as an adsorbed tracer in an agricultural soil
1994
Two column breakthrough tests and a series of 88 batch-equilibrium isotherms were conducted to quantify adsorption parameters for the fluorescent dye Rhodamine WT (Acid Red 388), in contact with a Nicollet loam soil. Results from batch-equilibrium isotherms performed at a 2:1 (water:soil) ratio showed that dye adsorption reached an equilibrium after 10 min on a shaker table. Regression equations were developed to predict distribution coefficients (Kd) for Rhodamine WT (RWT) adsorption to the soil based on soil organic carbon and the ionic strength of the RWT solution. A linear isotherm fitted the batch-equilibrium data for RWT in the concentration range evaluated (25-8000 microgram 1(-1)). Kd values obtained from the regression equation generated from the batch-equilibrium isotherms were input to a one-dimensional convection dispersion model. The predicted results were compared with the experimental results obtained from two repacked column breakthrough curves. RWT adsorption was less than predicted in the first column (in which the breakthrough curve was terminated after 45 pore volumes), but greater than predicted for the second column (which was terminated after 420 pore volumes). The reason for the discrepancy was attributed to the plateau-shaped breakthrough curve observed for RWT and differences in the ionic compositions of the two RWT solutions used to conduct the two column breakthrough curves. RWT did not appear to be a reliable adsorbed tracer if quantitative prediction is needed. Breakthrough curves for atrazine and trifluralin, two herbicides present in the second column, showed atrazine adsorption to be less and trifluralin absorption greater as compared with RWT, as was predicted from their respective organic carbon partitioning coefficients (Koc).
Afficher plus [+] Moins [-][Agromatics. Application of informatics in an agricultural enterprise]
1994
Grenon, D.
La agromatica es la aplicacion de los principios y tecnicas de la informatica y la computacion a las teorias y las leyes del funcionamiento y el manejo de los agrosistemas. Su objetivo es el de servir como apoyo operativo en el diagnostico de los problemas y en el diseno y la evaluacion de las alternativas de solucian, es decir: transformarse en una metodologia de accion util en la resolucion de los problemas de las empresas agroproductivas
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