abstract wenner direct contact method is a method of estimating apparent electrical conductivity (eca) of agricultural soils in situ. this method can be affected by factors such as quality of electrodes in contact with soil, type of employed electric current, moisture content, clay content and compaction of soil. in this research, the effect of electrode type (rod and plate) and electric curren...

northern khorasan province is located in north-east iran. according to demarton coefficient, it is a semiarid region. arid and semi-arid or subhumid zones are characterized by temperature variations, low and erratic rainfall, periodic droughts and different associations of vegetative cover and soils. this article looks at current dry lands and general guidelines for finding the best area for dr...

to study of biological control of charcoal rot of melon caused by macrophomina phaseolina, 187 isolates of fluorescens pseudomonas isolated of rhizosphere and soil of melon plants. then 12 isolates belong to i, iii and v biovars of p. fluorescens and b biovar of p. putida were selected for greenhouse experiments based on inhibition amount. pseudomonas isolates inhibited mycelial growth signific...

Determining when applications of nitrogen (N), sulfur (S), potassium (K) and phosphorus (P) fertilizer are needed is important to maintain alfalfa yield and quality. The Western U.S. is diverse in terms of climate, soil types, irrigation water need and availability, historical nutrient use and alfalfa production systems. Therefore, few generalizations hold regarding the timing and location of N...

• Changes in P chemistry were determined 13–24 years after wood ash and N application. The speciation forest organic layer was assessed by X-ray micro-spectroscopy. As Ca-bound the dissolved, solubility Al- Fe-bound increased. high of treatment increased uptake trees. fertilization plants decreased easily available P. Application to forests can restore pools phosphorus (P) other nutrients, whic...