Clearing tropical forests of the Amazon Basin for pasture alters rates of soil nitrogen cycling. Previous studies have shown that rates of soil net N mineralization and net nitri®cation are lower in established pastures than in forests. We compared soil inorganic N concentrations, rates of net and gross mineralization and net and gross nitri®cation in a chronosequence and an experimental slash-...

Denitrification in pasture soils is mediated by microbial and physicochemical processes leading to nitrogen loss through the emission of N2O and N2. It is known that N2O reduction to N2 is impaired by low soil pH yet controversy remains as inconsistent use of soil pH measurement methods by researchers, and differences in analytical methods between studies, undermine direct comparison of results...

Dry matter production data for pure lucerne, overdrilled lucerne and pasture ark presented for 14 sites on pumice soils. On average, the annual dry matter yield of lucerne, harvested at early basal shoot movement, was 50% higher than from pasture, ranging froti 128% higher on a drought-prone soil where the pasture was dominant browntop to 33% on a more moisture-retentive soil type where the pas...

Greenhouse gas (GHG) fluxes and soil organic carbon (SOC) accumulation in grassland ecosystems are intimately linked to grazing management. This study assessed the carbon equivalent flux (Ceq) from 1) an irrigated, heavily stocked, low-density grazing system, 2) a nonirrigated, lightly stocked, high-density grazing system, and 3) a grazing-exclusion pasture site on the basis of the GHG emission...

The lower montane zone of northwestern Ecuador, like many parts of the tropics, is undergoing rapid conversion from native forest vegetation to crop and pastureland. The current landscape is a mosaic of agricultural land, forest fragments and secondgrowth vegetation in various stages of development. While there is abundant research documenting the e€ects of land-use change in the lowland tropic...

Quantitative knowledge of stabilizationand decomposition processes is necessary to understand, assess and predict effects of land use changes on storage and stability of soil organic carbon (soil C) in the tropics. Although it is well documented that different soil types have different soil C stocks, it is presently unknown how different soil types affect the stability of recently formed soil C...

The aim of our work was to survey and state the representative values and range of the microbial biomass carbon (Cmic) and microbial respiration activities in arable soils of three types (Chernozem, Luvisol, Planosol) and in pasture grassland soil (Cambisol). In arable soils no significant differences between the soil types were found concerning the content of Cmic. Way of soil use significantl...

This paper examines changes in carbon (C) pools associated with land-use, synthesizing data from two experiments dealing with different aspects of tree plantation establishment in Central Panamá. First, we analysed soil profiles in a grazed pasture and an adjacent 5-year-old teak (Tectona grandis) plantation. There were small differences in soil C mass in the top 10 cm of the pasture and the pl...

The requirement for ‘cobalt (Co) of ruminants grazing pastures on the pumice soils of the Central Plateau was established in the late 1930s and Co topdressing to increase the Co intake of animals became commonplace from the mid-1950s. An on-farm survey in 1978-79 indicated that Co inputs could be halved because of adequate reserves of soil Co accumulated since the 1950s. However, the economic d...