Soil organic matters are considered as the animal and plant residues and active components of soils. The cultivation practices will cause the quick removal of organic matters in soils even in those which are not affected by erosion. This study was carried out to assess the level of soil humus in the pilot area, to investigate the positive or negative effect of humus level on soil and to introdu...

Biochar application can influence soil nitrogen (N) cycle through biological and abiotic processes. However, studies on comprehensive examination of the effects biochar microbially mediated N-cycling processes (N mineralization, nitrification, denitrification, fixation) N fate (i.e., plant uptake, N2O emission, leaching) are warranted. Therefore, aim this study was to examine transformation, mi...

For 5 yr we monitored the fertility of a volcanic-ash derived Inceptisol at a site in the humid tropics of Costa Rica. After forest felling and burning, we established four treatments in a randomized block design with six blocks: a sequence of monocultures (two crops of maize [Zea mays] followed by cassava [Manihot esculenta], then the tree species Cordia alliodora), successional vegetation, a ...

Functional traits can drive plant responses to short- and long-term stressful conditions, with potential effects on species persistence in local habitats, changes in population size and structure, and potential species range shifts in changing environments. We investigated whether ecophysiological traits in a rare cycad vary along environmental gradients and with ontogeny to understand intra-sp...

• In nitrogen (N)-limited systems, the response of symbiotic N fixation to elevated atmospheric [CO 2 ] may be an important determinant of ecosystem responses to this global change. Experimental tests of the effects of elevated [CO 2 ] have not been consistent. Although rarely tested, differences among legume species and N supply may be important. • In a field free-air CO 2 enrichment (FACE) ex...

This paper describes a method of soil erosion and soil movement measurements using 137Cs as a tracer. This technique has been used successfully employed for more than 30 years. Caesium-137 is a valuable tracer to study soil erosion. Its chemical and biological movement in soil is limited. Practically all redeposition of caesium-137 in soil after fallout occurs with soil particles due to strong ...

Earthworms mix soil layers and incorporate organic matter into the soil. This mixing allows the dispersion of the organic matter through the soil and makes the nutrients held in it available to plants and improves the fertility of the soil. Earthworms when present improve the soil physical, chemical and biological properties and acts as soil conditioner. They do so by fragmentation, aeration, b...

cyanobacteria were collected and identified in five paddy fields with different soil textures of golestan province in iran. it was determined that nostoc ellipsosporum and nostoc muscorum were dominant in all sites among 20 species. to assess the ability of atmospheric nitrogen fixation by the species, their pure cultures were provided by growing on bg-11 solid culture medium. subsequently, eac...

The slow-growing genus Bradyrhizobium is biologically important in soils, with different representatives found to perform a range of biochemical functions including photosynthesis, induction of root nodules and symbiotic nitrogen fixation and denitrification. Consequently, the role of the genus in soil ecology and biogeochemical transformations is of agricultural and environmental significance....

The use of legumes as green manure can potentially increase crop productivity in saline environments and thus contribute to the sustainability of agricultural systems. Here, we present results from a field experiment conducted in the Netherlands that addressed the efficiency of nitrogen (N) fixation by a legume at varying salinities. We grew Melilotus officinalis in an agricultural field using ...