The application of fractal geometry to describe soil structure is an increasingly useful tool for better understanding the performance of soil systems. Only a few studies, however, have focused on the structure of rhizospheric zones, where energy flow and nutrient recycling most frequently occur. We used fractal dimensions to investigate the characteristics of particle-size distribution (PSD) i...

Forests on calcareous substrates constitute a large fraction of the vegetation in Puerto Rico. Plant growth on these substrates may be affected by nutrient deficiencies, mainly P and Fe, resulting from high pH and formation of insoluble compounds of these elements. The occurrence of these forests in humid and dry areas provides an opportunity to compare nutrient relations, water use efficiency,...

Phytoremediation is a promising method for remediation of heavy metals (HMs) contaminated environments. However, the main failures are the limited bioavailabilty of HMs such as lead (Pb) in the soil and/or suppressed plant growth in contaminated sites. These limitations specifically occur in semi-arid zone environments such as calcareous soils. Arbuscular mycorrhizal fungi (AMF) and plant growt...

Fungi and fungal community play important roles in the soil ecosystem, and the diversity of fungal community could act as natural antagonists of various plant pathogens. Biological control is a promising method to protect plants as chemical pesticides may cause environment pollution. Pseudomonas fluorescens 2P24 had strong inhibitory on Rastonia solanacearum, Fusarium oxysporum and Rhizoctonia ...

With the global population predicted to grow by at least 25% by the year 2050, the sustainable production of nutritious foods will be necessary for human health and the environment. Iron (Fe) is an essential nutrient for both plants and humans. Fe is poorly soluble, especially at high pH levels, at which it is difficult for living organisms to accumulate sufficient Fe. In plants, Fe deficiency ...

To identify effective ways of increasing the yield crops grown in nutrient-poor calcareous soils, combined effects biochar addition and inoculation with plant growth promoting rhizobacteria (PGPR) arbuscular mycorrhizal fungi (AMF) on wheat soil properties were investigated under rhizobox conditions. Measured included pH, electrical conductivity (EC), organic matter content (OM), availability P...

We evaluated the changes of some soil microbiological characteristics due to the use of transgenic maize expressing Bacillus thuringiensis (Bt) toxin. A two-year field experiment was conducted (2003 and 2004). Two lines of transgenic Bt maize that express the Cry1Ab protein (event 176 and MON 810) and their near-isogenic non-Bt lines were used. Rhizosphere and non-rhizosphere soils were collect...

Fertilizer-induced reductions in CO(2) flux from soil ((F)CO(2)) in forests have previously been attributed to decreased carbon allocation to roots, and decreased decomposition as a result of nitrogen suppression of fungal activity. Here, we present evidence that decreased microbial respiration in the rhizosphere may also contribute to (F)CO(2) reductions in fertilized forest soils. Fertilizati...

Sensitive responses among bacterial and fungal communities to pyrogenic organic matter (PyOM) (biochar) addition in rhizosphere and bulk soils are poorly understood. We conducted a pot experiment with manure and straw PyOMs added to an acidic paddy soil, and identified the sensitive "responders" whose relative abundance was significantly increased/decreased among the whole microbial community f...