optimum working life of tractor and farm machinery employed in potato production in hamadan province was assessed through data envelopment analysis. an input oriented model was applied to determine the optimized machinery system. in this model inputs were the lifetime of tractor as well as seven involved machines including moldboard plow, potato planter, chemical fertilizer spreader, tractor mo...

to study the effects of different tillage systems on yield and some characteristic of wheat and also some soil properties in wheat dry land area, six experiments were performed in cold, moderate and semi-warm climatic conditions of kermanshah province in west of iran, in a randomized complete block design with five replications. experimental treatments were consisted of no-tillage, reduced till...

in this research, the effects of combine renovation as a mechanic harvest evaluation index of wheat were studied. results show that this renovation has decreased wheat losses by 1368 thousand tons which worth 2462400 million rials. two scenarios were investigated. first, under real condition with earmark of government subsidies for purchasing machines, was studied at both guaranteed and world p...

a deterministic model was employed to simulate various progeny testing programs compatible with the conditions of holstein dairy cattle population in iran. in simulated programs, the selection intensity of bulls was increased by increasing the ratio of cow population in mate with young bulls. selection accuracy in the programs was fixed because of the fixed progeny group. economic efficiency (t...

eremurus and forage are main by-products in the khazangah rangelands of makoo region. eremurus is harvested and used by local people in a period of 30 days during the spring in this region. at this study, eremurus and forage have been evaluated financially and the data were obtained through field work using unstructured interviews as well as direct observation. the harvested eremurus value was ...

Maize (Zea mays L.) production requires large amounts of nitrogen (N) thatdirectly affect production cost. Poultry litter can be used as an alternative source ofN. To optimize its use, poultry litter requires technical and economic feasibilityanalyses. Crop simulation models have proven to be efficient tools to support thistype of research. The objectives of this study were to determine yield a...