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At least 145 records · Page 8Linked to original sources
PubMed2004

[Conservation tillage systems in North America and their significance for China].

Soil degradation through erosion and desertification reduces soil productivity, and is a serious problem in agricultural production of China. To avert our arable land from further degradation, soil management must be shifted from degrading tillage to conservation practices. Over viewing the technology used in the 20th century for controlling soil degradation from erosion, conservation tillage developed in the United States and adopted in South America and Africa is one of the most successful measures to overcome soil degradation problems. This paper reviewed the historical development and the current situation of conservation tillage systems used in North and South America, with special reference to their effects on soil erosion control and soil quality. The increasing adoption of conservation tillage systems in North and South America and Africa followed an enhanced awareness of the increasing risk of soil erosion and the high cost of fuel associated with conventional tillage. Many crucial points for successfully adopting conservation tillage systems were emphasized, such as equipment/tool development and chemical weed control. Adopting conservation tillage could provide China with low-priced means of reducing soil degradation and improving soil and water quality.

Agriculture↗
PubMed2004

[Spatial pattern of two dominant shrub populations at transitional zone between oasis and desert of Heihe River Basin].

Based on the field investigation in a 500 m x 500 m plot and applying geo-statistical theory and methods, this paper described the spatial pattern of the coverage, density, height and volume of two shrub populations Nitraria sphaerocarpa and Reaumuria soongorica at the transitional zone between oasis and desert of Heihe River Basin. The average coverage of the two populations was 1.56 +/- 2.34% and 0.23 +/- 0.22%, and their average density was 1.5 +/- 1.8 clump x 100 m(-2) and 2.3 +/- 2.1 individual x 100 m(-2), respectively. The height of N. sphaerocarpa was 0.18 +/- 0.15 m, and its volume 0.10 +/- 0.18 m3. N. sphaerocarpa population exhibited strip distribution pattern, while R. soongorica population showed uniform distribution pattern. The nugget (c0)/sill (c0 + c) ratio of the semivariogram of the two populations was 0.08-0.12, which indicates that the random variance of spatial heterogeneity occupied 8%-12%. In semivariogram model, the range value (A0) of the coverage and density was 14.7 and 33.9 m for N. sphaerocarpa, and 25.2 m and 24.9 m for R. soongorica, respectively. As a whole, the random spatial heterogeneity existed at the scale of 10 m, and autocorrelated spatial heterogeneity existed at the scale of 34 m. The spatial heterogeneity of the coverage and density of the two dominant populations showed both isotropy and anisotropy, and the isotropy scope of R. soongorica population was larger than that of N. sphaerocarpa. The spatial pattern of N. sphaerocarpa population was controlled by two factors. The first was precipitation and surface runoff, and the second was oasisofication and desertification.

Conservation of Natural Resources↗
PubMed2004

Use of rural energy resources and eco-environmental degradation in Tibet.

Cattle dung, firewood, and crop straw have being used as survival necessities by farmers and herdsmen for thousands of years in Tibet. Until recently such biotic energy source still constitutes more than 92 per cent of total rural energy consumption due to lack of petroleum, coal and new alternative energy sources. As a result, environmental degradation such as land desertification, soil erosion, grassland degradation and soil fertility reduction is increasingly aggravated, the area of desertified land has increased 1467.5 km2 from 1991 to 1997. Degraded area of grassland has reached 2.60 x 10(7) hm2, increased by 116.1% from 1987 to 1996. To prevent further deterioration of eco-environment in Tibet great efforts should be made to make full use of ample solar energy, wind energy and other biotic energy of the Qinghai-Tibet Plateau. The solar cooking stoves and solar hothouse, expand forest area and replace existing abiotic energy sources with firewood forest should be popularized. This is an urgent task to protect the eco-environment of Tibet today.

Animals↗
PubMed2005

A field experimental study of lignin sand stabilizing material (LSSM) extracted from spent-liquor of straw pulping paper mills.

A new technique was introduced for sand stabilization and re-vegetation by use of lignin sand stabilizing material (LSSM). LSSM is a reconstructed organic compound with lignin as the most dominant component from the extracts of black-liquor issued by straw pulp paper mills. Unlike the polyvinyl acetate or foamed asphalt commonly used for dune stabilization, the new material is plant-friendly and can be used with virescence actions simultaneously. The field experimental study was conducted since 2001 in China's Northwest Ningxia Hui Autonomous Region and has been proved that LSSM is effective in stabilizing the fugitive dunes, making the arenaceous plants survive and the bare dune vegetative. The advisable solution concentration is 2% and the optimal field spraying quantity is 2.5 L/m2. The soil nutrients of the stabilized and greened dune, such as organic matter, available phosphorous and total nitrogen are all increased compared with the control treatment, which is certainly helpful to the growth of arenaceous plants. The technique is worthwhile to be popularized because it is provided not only a new method for desertification control but also an outlet for cleaning contaminants issued from the straw paper mills.

Lignin↗
PubMed2005

River contract in Wallonia (Belgium) and its application for water management in the Sourou valley (Burkina Faso).

Inspired by the experience of a river contract in Wallonia (Belgium) since 1990, the implementation of a first river contract has been initiated in a West African country, Burkina Faso. This application is not limited to a simple transposition of the Walloon model. The Burkina context calls for adaptation to the local environmental and socio-economical realities with an adequate partnership management. The importance of the mobilization around this project of institutional partners, as well as local collectivities, agricultural producers and water users in general reveals the great expectations of the actors concerning this new tool of water participative management. But will the latter be equal to the task? A first assessment has been drawn up one year after the launch. During the first year of the project, a participative diagnostic was implemented but the understanding of basic notions of water management such as 'river' (not translatable in the local language), 'watershed', 'contract' were not obvious. After the identification of functions and uses of water in the basin, an environmental survey was started. This approach allows study with the river committees of the priority actions to be developed as a first project of restoration of the gallery forest alongside the stream to fight against desertification. This project of integrated and participative management of water at sub-basin level is a concrete example of solidarity and exchange know-how between North and South in the context of a sustainable development.

Agriculture↗
PubMed1982

Population, environment, medicine and global sustainability.

The final two decades of this century see our planet in a highly perilous condition. This paper, after touching on the problem of nuclear proliferation, goes on to consider three other issues overpopulation, environmental depredation and the future of medical practice all of which are of high salience. The section on population concentrates on the time required for numbers to stabilize at two children per family. Europe is likely to attain stabilization before 2050, North America and the USSR by 2100. In the developing world South and East Asia could also be in balance by the beginning of the twenty-second century; but the situation in Africa vis-à-vis population growth is much more serious and stabilization cannot be anticipated until about 2150. Destruction of life support systems on a massive scale continues, particularly in developing countries. Much of Asia, Africa and Latin America is riddled with soil erosion; expanding populations of humans and livestock are proving a notable catalyst to desertification; the 'firewood crisis' is deepening as slowly but surely the earth is being deforested. There is little convincing evidence that the major aims of the World Conservation Strategy maintenance and responsible utilization of essential ecological systems, preservation of genetic diversity are being obeyed anywhere in the world. In the more sustainable society of the future engineering medicine with its proclivity for resource depletion will be less attractive. Rather will the emphasis be on prevention and on attempting to delineate the environmental factors known to be responsible for an increasing number of diseases. The likely pattern of morbidity and mortality in the twenty-first century is discussed. Geriatric medicine will hold pride of place; the incidence of cancer will rise markedly, and as an increasing number of Third World nations undergo the process of development diseases, which up till now have mainly affected affluent technological societies, it will spread throughout the planet.

Africa↗
PubMed1998

[Climatic changes and transmissible diseases].

Transmissible disease geography can be defined as the study of the spatial expression of pathogenic processes. The three main elements implicated in this study are environmental conditions affecting biophysical dynamics, political, economic, social, and cultural events, and evolution of pathogenic agents under the influence of the first two factors. A number of pathogenic areas or regions can be delimited in function of different combinations of these factors. These territories are subject to rapid change and variation. Meteorological changes and cycles are contributing factors. However the underlying mechanisms appear to be increasingly affected by human activity. Several disturbing signs have been attributed to man including desertification, drought, and global warming, but the cause-and-effect relationship is unsure. Much research is in progress but resulting data remains contradictory except insofar as to confirm the complexity of atmospheric phenomena. The natural geography of transmissible diseases is affected by these variations but it is mainly the expression of the dialogue between man and nature.

Climate↗