Accurate descriptions of P leaching are important because excess P applied to soils can enter surface water via leaching and subsurface transport, thereby negatively impacting water quality. The objectives of this study were to monitor P leaching in soils with a long-term history of waste application, relate soil solution P concentrations to soil P status, and quantify P leaching losses. Soil s...

There is a need to select high quality forage legumes that are acid soil-tolerant, drought resistant, and persistent under the close defoliation associated with intensive pasture systems in the humid tropics. A greenhouse pot study was conducted to determine forage legume seedling growth (10 week-old) and regrowth (5 weeks after clipping to an 8-cm residual stubble) responses of ‘Amarillo’ pere...

Earthworms play an important role in soil ecology and can serve as practical indicators in land quality evaluation. The abundance and distribution of earthworms were determined in 84 cropping and pasture soils in north-east Victoria and southern New South Wales (NSW), Australia. Overall, an average density of 89 earthworms mÿ2 was found, with an average species richness of 1±2 per site, indicat...

Introduction Cattle production on Brachiaria pastures is a primary use of cleared forestland in the western Brazilian Amazon. About 6.8 million hectares in the States of Acre and Rondônia have been deforested, where 75% of land is now grazed (IBGE, 1998). The principal pasture species are B. brizantha and B. decumbens with the latter in decline from spittlebug susceptibility (Deois incompleta; ...

CIAT is carrying out an agricultural land resource evaluation of Tropical America to create a base for the effective development and transfer of germplasm oriented technology. The study started in mid-1977 and now covers 850 million ha. It reduces land information to a common base in terms of land systems defined as repetitive patterns of climate, landscape and soils. These are delineated direc...

Soil microbial communities under three agricultural management systems (conventionally tilled cropland, hayed pasture, and grazed pasture) and two fertilizer systems (inorganic fertilizer and poultry litter) were compared to that of a w150-y-old forest near Watkinsville, Georgia. Both 16S rRNA gene clone libraries and phospholipid fatty acid (PLFA) analyses indicated that the structure and comp...

The similarities and differences in the structures of the nifH gene pools of six different soils (Montrond, LCSA-p, Vernon, Dombes, LCSA-c, and Thysse Kaymor) and five soil fractions extracted from LCSA-c were studied. Bacterial DNA was directly extracted from the soils, and a region of the nifH gene was amplified by PCR and analyzed by restriction. Soils were selected on the basis of differenc...