Effects of landscape homogeneity on starling roost distribution

The possible effects of landscape structure on starling roost distribution were investigated in western France using GIS analysis at different radii (2, 4, 8 and 10 km). Composition (11 land use classes) and configuration (patch size, diversity index) of the landscapes surrounding 97 roost sites used by starlings from 1981 to 2002 and surrounding 50 random points not used as roost sites were compared. Significant results suggested that starling roosts were established preferentially in the centre of an agricultural landscape where large units of pastures and arable land predominated and where natural areas were lacking both in large patches (forests or wetland classes) and in small patches such as woods in the mixed land class. A varied farmland landscape with natural areas and small patches should be promoted to limit the starling damage in wintering regions and also to favour their reproduction in regions where it has declined.     

Bipolar charged aerosol agglomeration and collection by a two-zone agglomerator

ＩｎｔｒｏｄｕｃｔｉｏｎＢｅｃａｕｓｅｏｆｔｈｅｌｏｗｅｆｆｉｃｉｅｎｃｙｏｆｔｈｅｅｌｅｃｔｒｏｓｔａｔｉｃｐｒｅｃｉｐｉｔａｔｏｒ (ＥＳＰ)ｆｏｒｃｏｌｌｅｃｔｉｎｇｔｈｅｓｕｂｍｉｃｒｏｎｐａｒｔｉｃｌｅｓ ,ｔｈｅｅｌｅｃｔｒｉｃａｌａｇｇｌｏｍｅｒａｔｉｏｎｍｅｔｈｏｄｈａｓｌｅｄｔｏａｎｉｎｃｒｅａｓｉｎｇｉｎｔｅｒｅｓｔｉｎｒｅｄｕｃｉｎｇｔｈｅｅｍｉｓｓｉｏｎｏｆｔｈｅｆｉｎｅｐａｒｔｉｃｌｅｓ .Ｍａｎｙａｕｔｈｏｒｓｈａｖｅｓｔｕｄｉｅｄｅｌｅｃｔｒｉｃａｌａｇｇｌｏｍｅｒａｔｉ…     

Sustainable resource management coupled to resilient germplasm to provide new intensive cereal–grain–legume–livestock systems in the dry savanna

Sustainable resource management is the critical agricultural research and development challenge in sub-Saharan Africa. The accumulated knowledge on soil management gathered over the last 10 years, combined with solid crop improvement and plant health research at farmers’ level, has brought us to a stage where we can now address with confidence the intensification of cereal–grain–legume-based cropping systems in the dry savanna of West Africa in a sustainable and environmentally positive manner.Two sustainable farming systems that greatly enhance the productivity and sustainability of integrated livestock systems have been developed and implemented in the dry savanna of Nigeria. These are: (i) maize (Zea mays L.)–promiscuous soybean [Glycine max (L.) Merr.] rotations that combine high nitrogen fixation and the ability to kill large numbers of Striga hermonthica seeds in the soil; and (ii) miflet [Eleusine coracana (L.) Gaerth] and dual-purpose cowpea [Vigna unguiculata (L.) Walp.]. Improvement of the cropping systems in the dry savanna has been driven by the adoption of promiscuously nodulating soybean varieties (in particular TGx 1448-2E) and dual-purpose cowpea. The rate of adoption is very high, even in the absence of an efficient seed distribution system. The number of farmers cultivating the improved varieties increased by 228% during the last 3 years. Increased production of promiscuous soybean has been stimulated by increased demand from industries and home utilization. Production in Nigeria was estimated at 405,000 t in 1999 compared to less than 60,000 t in 1984. Economic analysis of these systems shows already an increase of 50–70% in the gross incomes of adopting farmers compared to those still following the current practices, mainly continuous maize cultivation. Furthermore, increases in legume areas of 10% in Nigeria (about 30,000 ha in the northern Guinea savanna) and increases of 20% in yield have translated into additional fixed nitrogen valued annually at US$ 44 million. This reflects, at the same time, an equivalent increase in land-use productivity, and with further spread of the improved crops, there are excellent prospects for additional economic and environmental benefits from a very large recommendation domain across West Africa.     

The macro implications of a complete transformation of U.S. agricultural production to organic farming practices

A national interregional linear programming model of U.S. agriculture is used to evaluate and compare two conventional and three organic production alternatives. The objective is to estimate the effects on production, supply prices, land use, farm income, and export potential, of a complete transformation of U.S. agriculture to organic practices. Crop yields and production costs are estimated for 150 producing regions for seven crops under both conventional and organic methods. Results indicate that compared with conventional methods, widespread organic farming leads to a decrease in total production, lower export potential, higher supply prices, higher value of production, lower costs of production, and higher net farm income. The United States domestic crop demand can be met with organic methods, but would be more expensive. Some interregional shifts in crop production would also occur.