Titlebook: Advances in Soil Science; B. A. Stewart Book 1987 Springer-Verlag New York Inc. 1987 Deforestation.agriculture.forest.soil.soil science.tr

FAWN

云状

https://doi.org/10.1007/978-3-642-78448-4ritive elements. These soils are an important resource in that much of the world’s grain and livestock are produced on them. The extensive agricultural development is a consequence of not only the general absence of forest cover, making conversion to agriculture relatively simple, but the natural fe

Panacea

D. P. Landau,K. K. Mon,H.-B. Schüttlerall, by leguminous nitrogen fixation. Although animal wastes, nonsymbiotic fixation, and atmospheric deposition can be significant sources of N, a large fraction of the first can be traced to legume sources and the latter two are generally insufficient to maintain productivity of cropland. In the Me

木质

Conference proceedings 19941st editionon to its fertilizing value, this organic material is likely to improve the soil physical condition. The gradual decrease in the organic matter content in cultivated soils, which may lead to deterioration of the soil physical status and erosion, is particularly worrying in warm areas, where organic

臭名昭著

Complexity in Rayleigh-Bénard Convectioncrop production. Much of this land is best described as dryland. It is important to distinguish between dryland agriculture in particular and rain-fed agriculture in general. Clearly, they both exclude irrigation. The emphasis for rain-fed agriculture, however, is often on disposal of excess water,

不幸的人

Advances in Soil Sciencehttp://image.papertrans.cn/a/image/149783.jpg

Obscure

Advances in Soil Science978-1-4612-4790-6Series ISSN 0176-9340

确定的事

使入迷

978-1-4612-9157-2Springer-Verlag New York Inc. 1987

神经

0176-9340 well to meeting the increased need for food and fiber. While the population growth during this period averaged almost 2% annually, the production of grain increased at an even faster rate. From 1950 to 1973, grain production increased 3. 1% annually, but slowed to about 2% from 1973 to 1984. There­