We studied a Mediterranean species (Erica arborea L.) growing in a CO(2) spring in Italy that was naturally exposed for generations to a gradient of atmospheric CO(2) concentrations. The CO(2) concentration gradient to which different individual plants were exposed was determined by an indirect method based on radioisotope analysis. The stable carbon isotope ratio of sampled leaves was determin...

This research sought to link Andean soil knowledge and farmer categorization of soil fertility to soil science characterization of soils, and use these to understand the impacts of phosphorus (P) fertilization of legumes using rock phosphate and soluble P fertilizer in 17 smallholder-managed sites with varying soil properties. We found that farmer high/low categorization of soils corresponded t...

Soil carbon and nitrogen contents play an important role in sustaining soil physical and chemical quality and help to have healthy environments. The continues conversion of rangelands to arable lands has the potential to change carbon and nitrogen sequestration. In this study to evaluate the effects of land use change on soil organic carbon and nitrogen stock, forty samples collected from north...

In lowland rice farming, water control is the most important management practice that determines the efficacy of other production inputs such as nutrients, herbicides, pesticides, farm machines, microbial activity, mineralization rate, etc. Poor drainage that keeps soil saturated is detrimental to crops and degrades soil quality. In many rice irrigation systems, drainage mechanisms and practice...

We investigated the variation in leaf nitrogen to phosphorus ratios of tropical tree and liana seedlings as a function of the relative growth rate, whole-plant water-use efficiency, soil water content and fertilizer addition. First, seedlings of 13 tree and liana species were grown individually in 38-l pots prepared with a homogeneous soil mixture. Second, seedlings of three tree species were g...

this study was performed in order to investigate the changes in vegetation and soil properties in compartment no.317 (managed forest) and no.318 (control forest) of jamand district of golband forest in mazandaran (noshahr). for this purpose, random-systematic sampling method with regular grid of 100×200 m was used to locate samples. the plot size was 400 m2 considering to tree and shrub species...

Physiological investigations of nitrogen content and relation between nitrogen and chlorophyll content at some wheat cultivars were carried out at the outset of the flowering phase. Dependence of nitrogen content from mineral elements in the soil was established at the same time. Investigations were guided on unfertilized soil and four fertilization variants (N, NPK, NP and NK). The results ind...

This paper reports a study of the effect of three nuclear and one thermal power plants on the microbial ecology of soils. Populations of bacteria, actinomycetes, fungi, cellulolytic microbes, phosphate-solubilizing microbes and nitrogen-fixing microbes in the soil in the vicinity of each plant were studied. Soils were acidic at three sites, and moisture contents of the power plant soils were lo...

rehabilitation of arid and semi-arid regions by tolerant native plant cover is a primary concern to create a sustainable balanced ecosystem. thus, the existing plant species of the region should be recognized together with a comprehensive survey and study of the environmental factors such as climate and soil conditions which affect the establishment of these plant species. this paper attempts t...