technical and economic evaluation of rice harvesting methods in shirvan-chrdavol region

rice is a main food for iranian people and has an important role in providing food security. regarding the population growth, increase of rice production and reduction of losses have special importance in prevention of rice import. rice losses in the harvest stage are the highest through the whole production period of this crop and hence the reduction of these losses is necessary. provision of this purpose depends on on-time harvesting and separation of grains from chaff with the least grain losses, and choosing a suitable harvesting method. the choice of harvesting method depends on various factors in each region; thus, different harvest methods in each region must be compared while conducted in the same conditions. in order to recommend the beast harvest method in shivan-chardavol region, three harvesting methods (manually, rice-specific combine harvester and conventional cereals combine harvester) were considered as three experimental treatments and four different parts of this region considered as experimental blocks. the experimental design was randomized complete block design. this study was carried out on anbarboo variety and the measured factors were: effective farm capacity, percent of total losses, percent of harvesting losses, number of workers and harvesting cost. the results of this study indicated that the total difference of factors was significant at the 1% error level among all treatments. the effective farm capacity in harvesting by cereals combine harvester was more than other treatments. the lowest percent of loss was observed for harvesting by rice-specific combine harvester (2.32%) and the highest percent of loss was obtained for cereals combine harvester (3.816%). the manual harvesting method had the highest harvesting cost and the lowest cost was found to be associated with the rice specific combine harvester. therefore, from the results of this study, the use of this combine harvester is recommended for rice harvesting in this region.