abstract this study was conducted under cold climate condition in khorasan during 2006-2008 growing seasons to evaluation of soil fertility in wheat-based double cropping systems under different rate of nitrogen and return of crop residues. a randomized complete block design with split-split plot arrangement and three replicates was used. main plots were five crop rotations namely: wheat-wheat,...

crop rotation affect on crop nitrogen uptake and nitrogen use efficiency (nue). crop rotations with high nue decrease energy use and increase level of sustainability in agro ecosystems. the objectives of this research were to determine the suitable double cropping system for enhancing nue and evaluate the effects of crop rotation, n fertilizer rate and return of crop residue on nue. this study ...

the study was performed for assess the environmental factors affecting weed species diversity and composition of wheat (triticum aestivum l.) fields in jajarm, north-khorasan of iran, in 2009. the crop management (herbicide, amount of nitrogen applied and preceding crop type) and edaphic factors (ph, texture and content of phosphorus) of 16 fields were collected. shannon’s diversity index, spec...

this study was conducted under cold temperate climate condition in khorasan during 2006-2008 growing seasons to determine the suitable wheat-based double cropping systems for increase nitrogen agronomic efficiency. a randomized complete block design in split-split plot arrangement with three replicates was used. main plots were crop rotation with five different rotations including wheat:wheat, ...

In Europe, the framework for sugar beet (Beta vulgaris L.) production was subject to considerable changes and for the future it is expected that sugar beet cultivation might concentrate around the sugar factories for economic reasons. Based on data from a national sugar beet farmers' survey and multi-year crop rotation trials, the effects of cropping interval (number of years in between two sub...