Modem agriculture

Alabouvette C, Backhouse D, Steinberg C, Donovan N J, Edel-Hermann V and Burgess L W (2004), Microbial diversity in soil - effects on crop health , in Schjpnning P, Elmholt S and Christensen B T, Managing Soil Quality - Challenges in Modem Agriculture, CAB International, Wallingford, 121-138. 

The availability of selenium to plants may be lessened by modem agricultural practices, eventually contributing to selenium deficiency in animal consumers. For example, fertilizers containing nitrogen, sulfur, and phosphorus all influence selenium uptake by plants through different... 

Modem agriculture uses worldwide about 2.5 million tons of pesticides annually (Wijnands 1997), and out of such quantity only about 0.4% reaches the targeted pests, according to Pimentel (Pimentel 1995), while losses through volatilization are on the order of 80-90% (Taylor and Spencer 1990). 

Modem agriculture training has often biased people s attitudes toward using indigenous soil knowledge. 

Many fertilizers are based on ammonia compounds. Modem agriculture requires more nitrogen in soils than is normally replaced by the nitrogen cycle, hghtning, decaying plants and animals, and other natural means... 

Besides the direct and indirect risks associated with the consumption of agricultural products by humans in general, several risks are specific to the consumption of animal produce from modem agriculture. These have received considerable public attention in the past, i.e. antibiotic and hormone residuals, or just recently, such as Bovine Spongiform Encephalopathy (BSE). 

Mandelbaum, R.T., N. Shapir, and L. Kautsky (1997). Biological atrazine destruction mediated by bacteria. In D. Rosen, E. Tel-Or, Y. Hadar, and Y. Chen, eds., Modem Agriculture and the Environment. Dordrecht, The Netherlands Kluwer Academic Publishers, pp. 501-521. 

Contributing authors include university, government and industry scientists, extension specialists, and growers who have offered their unique insight into the history and development of the triazines and their impact on modem agriculture. We thank each of them for their contribution to the held and to our book. We also are grateful to the thousands of scientists involved in research, education and extension work who have helped to advance the understanding of weed science over the past 50 years. 

Exposure to toxicants from terrestrial sources is very common because of the intimate association between animals and plants that live on the land with soil. Modem agricultural practices call for the application of large quantities of herbicides and other pesticides to plants and soil residues of these substances may readily enter living organisms. Soil is the repository of a variety of air pollutants, especially airborne particles that settle onto soil. Improper disposal of industrial wastes and toxic substances washed from or blown off of hazardous waste sites has contributed to exposure of soil. 

Because of the productivity demanded in modem agriculture to feed the millions of increasing world population, the use of different pesticides has become a necessity to contain a host of crop and household pests. A major benefit of pesticides is their ability to contain hosts of pests on commercial crops, food crops, lawn, and turf in and around household surroundings. Hop destruction by locust infestation in Africa is an example. Insecticides also are used for control of vector-bome diseases such as typhus and malaria. 

Almost all of this pesticide production is introduced into the environment by direct application to agricultural crops, livestock, soil, forests, water sources, homes, gardens, and to all types of environment for controlling parasites and vectors of disease to protect the public health. While—as commonly claimed—only about 5% of the arable area of the world has been so treated, these limited areas may be heavily treated. For example, in 1962 in California alone, 12,000,000 acres were sprayed or dusted. Over 1,800,000 pounds of 14 different pesticides were applied in 1963 to 700,000 of these acres, planted in cotton in the San Joaquin Valley, resulting in 2.6 pounds per acre in one year or 25 mg. per square foot per year. Over the past 20 years, therefore, many millions of pounds of DDT alone have been used there. Although few agricultural areas in the world are so intensively treated, substantial amounts of pesticide chemicals are always used wherever modem agriculture is practiced. 

The greater efficiency of modem agricultural practice liberates land that can be used for recreational purposes in the United States in 1983, sufficient food was produced from 117 ha, whereas in 1950 the production of the same quantity of food required 243 ha. 

Like nitrates, phosphates are included in the indicative list of main pollutants (Water Framework Directive, 2000/60/EC) because of their contribution to eutrophication. Phosphorus is an essential nutrient for all plants and in modem agriculture this element has to be supplied to the crops as fertilizer. Wind erosion, surface mnoff and leaching constitute the main pathways for transport of phosphoms from terrestrial to aquatic ecosystems. The process is accelerated by agriculture, animal husbandry and anthropogenic discharges. 

Modem agriculture depends upon man s ability to cycle minerals that are nutritionally important through crops, poultry, and animals. In particular, the absorption of these minerals by green plants and their subsequent role in the formation of organic compounds are basic to almost all forms of life. 

There are two types of trace metal supplements the pharmaceutical prepared formulation and the non-pharmaceutical formulation. The metals present in pharmaceutical preparations are chelated or bonded to organic compounds to achieve maximum beneficial effects to the body. Manufacturers claim that supplements are needed to augment the deficiencies caused by our modem agricultural methods and that healthy people also need them. 

Chen, Y., and Stevenson. F. J. (1986). Soil organic matter interactions with trace elements. In The Role of Organic Matter in Modem Agriculture, ed. Chen, Y.. and Avnimelech, Y., Nijhoff, Dordrecht, The Netherlands, 73-116. 

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