A number of tests to study the yield response of cotton and soybean to several fertility programs, under conventional, no-till, and stale-seedbed production systems were established at the Cotton Branch Station near Marianna, Ark. Soil samples (0 to 6 inches) were collected prior to planting and extracted using the Mehlich3 procedure (extraction ratio of 1:7), with nitrate-N measured with a sel...

Throughout the world there is a strong evidence to support the link between poverty and soil conditions. In subsistence agriculture the wealth of people on low fertility sandy soils is much lower than those living on rich volcanic soils. But there are great differences between regions in the world and this talk focuses on historical developments in soil research in tropical and temperate region...

Soil organic C or organic matter has been studied under various plant communities. In comparisons of similar soils having either grassland or forest vegetation, surface horizons of the forest soil may have lower levels of soil C (Ugolini and Schlichte, 1973; Almendinger, 1990) or higher levels (Jenny, 1980). Even between forest types, soil C may vary. Alban (1982) found the forest floor in a Po...

With the newly arisen ecological awareness in the agriculture the sustainable use and development of the land is getting more important. With the sustainable use of soil in mind, we are developing a decision support system that helps making decisions on managing agricultural systems and is able to handle both conventional and genetically modified crops as a part of the ECOGEN project. The decis...

Soil science is a relatively new discipline which has mainly developed since the 1880s. It uses terms, methods and processes borrowed from other basic disciplines like climatology, geology, chemistry, physics and biology, but with a direct application to soils. At present, it is difficult to speak about one single science but as soil sciences, as they cover several fields including: pedology (o...

plant life and food production for human closely depend on fertile and healthy soil. knowledge about qualitative properties of soil and its potential production can contribute us in the plantation, fertilization, utilization and land management. in addition, rangelands cover a very large portion of the earth's surface and play an important role in food security and other ecosystem services. the...

Predators often exert multi-trophic cascading effects in terrestrial ecosystems. However, how such predation may indirectly impact interactions between above- and below-ground biota is poorly understood, despite the functional importance of these interactions. Comparison of rat-free and rat-invaded offshore islands in New Zealand revealed that predation of seabirds by introduced rats reduced fo...

The carbon/nutrient balance hypothesis suggests that leaf carbon to nitrogen ratios influence the synthesis of secondary compounds such as condensed tannins. We studied the effects of rising atmospheric carbon dioxide on carbon to nitrogen ratios and tannin production. Six genotypes of Populus tremuloides were grown under elevated and ambient CO(2) partial pressure and high- and low-fertility s...

Improving soil fertility/productivity and reducing environmental impact of nitrogen (N) fertilization are essential for sustainable agriculture. Quantifying the contribution of various fertilization regimes to soil N storage and loss has been lacking in a wide range of spatiotemporal scales. Based on data collected from field experiments at three typical agricultural zones in China, soil N dyna...