in the present study, five log-normal models, normal model (n), and two four- parameter models namely gompertz (g) and fredlund (fr) were tested on 71 psd data from 10 soil textural classes. the jaky (j) and fr models had the smallest and largest r2 values for all of the soils, respectively. the results of comparing the n and simple log-normal (sl) models showed that the accuracy of the n model...

Biochar application to agricultural soils is rapidly emerging as a new management strategy for its potential role in carbon sequestration, soil quality improvements, and plant growth promotion. The aim of our study was to investigate the effects of biochars derived from white clover residues and poultry manure on soil quality characteristics, growth and N accumulation in maize (Zea mays L.) and...

Rice (Oryza sativa L.) is one of the essential foods of the human diet; advances in agronomic crop management can improve productivity and profitability as well as reduce adverse environmental impacts. Nitrogen rates in Chile are generally based on crop yield without considering other agronomic factors. The objective of this experiment was to determine the effect of increasing N rates on plant ...

In tropical regions, soil acidity and low soil fertility are the most important yield-limiting factors for sustainable crop production. Using legume cover crops as mulch is an important strategy not only to protect the soil loss from erosion but also to ameliorate soil fertility. Information is limited regarding tolerances of tropical legume cover crops to acid soils. A greenhouse experiment wa...

introduction: nitrogen (n) is one of the most important growth-limiting nutrients for dryland wheat. mineral nitrogen or ammonium (nh4+) and nitrate (no3−) are two common forms of inorganic nitrogen that can serve as limiting factors for plant growth. nitrogen fertilization in dryland area can increase the use of soil moisture, and improve wheat yields to some extent. many researchers have been...

in order to evaluate the effect of nitrogen absorption and use efficiency in relay intercropping for winter wheat and maize, a field experiment was conducted during 2008-2009 at the agricultural research station of ferdowsi university of mashhad, iran. a randomized block design with three replications was used. treatments included four combinations of relay intercropping of wheat and maize (thr...

Rapid fermentation of food waste can be used to prepare soil conditioner. This process consumes less time and is more cost-effective than traditional preparation technology. However, the succession of the soil microbial community structure after long-term application of rapid fermentation-derived soil conditioners remains unclear. Herein, dynamic rapid fermentation (DRF) of food waste was perfo...

Influence of arbuscular mycorrhizal fungi (AMF) (Glomus etunicatum, G. intraradices and Glomus versiforme) and external phosphorus supplement (8 and 35 mg P Kg-1 soil) on leaf P, Zn, Cu and Fe nutrition of 4-month-old tea(Camellia sinensis) was studied in an glass house pot experiment. The highest leaf P concentration (up to 59.43% increase) was found in G. versiforme inoculated seedlings gro...

in order to evaluate nitrogen fixation ability and nutrients uptake in three cultivars of common bean (phaseolus vulgaris l.) inoculating with some types of inoculants containing different strains of rhizobium leguminosarum; bv. phaseoli an experimental design was conducted in khoramdarah region in 2006 and 2007. in this investigation three types of biological fertilizers including rb117, rb123...

We studied nitrogen (N) cycling pools and processes across vegetation and elevation gradients in. the southern Appalachian Mountains in SE USA. Measurements included bulk deposition input, watershed export, throughfall fluxes, litterfall, soil N pools and processes, and soil solution N. N deposition increased with elevation and ranged from 9.5 to 12.4 kg ha-' yr-'. In all sites canopies retaine...