Reducing the tillage of agricultural soils can increase early-season crop-P uptake. Consistent increases in plant-P have been found in both fieldand laboratory-systems with undisturbed (U) compared to disturbed (D) soil. A concomitant stimulatory effect on colonization of roots in U soil by arbuscular mycorrhizal (AM) fungi has been found in some cases, but in others the colonization has been s...

introduction legumes after cereals are the second source of human food and in iran they are the second most important food after the wheat. legumes protein is four times as much as that of grains and 10 to 20 times as much as that of glandular plants. in addition, beans are planted in iran in a wide area and knowing optimal farming factors can be an important step in increasing them. one of the...

weeds in wheat (triticum aestivum l.) fields have always been a big problem in iran and worldwide and must be managed by non-chemical especially cultural methods. a field experiment as factorial based on a randomized complete block design with four replications in a 1000 m2 field in research farm of shirvan college of agriculture was conducted during 2007-2008. treatments included wheat densiti...

Accurate pricing of crop insurance policies relies on forecasts probability densities yields. Yield are dynamic, time series data yields often limited, and yield spatially correlated. We examine linear pooling potentially related, but almost surely misspecified, density forecasts. The pooled combine from other spatial units based out-of-sample forecast performance. result in more accurate premi...