امكانسنجي توسعه كشت يونجههاي يكساله در غرب ايران با استفاده از سامانه اطلاعات جغرافياي

Potential Assessment of Annual Medic Cultivation and Extension in Iran by GIS

Annual medics by their potential benefits such as soil conservation, soil fertility improvement, weed control and forage production can play a significant role in providing a sustainable food security in dry and semi-dry lands in the world. Annual medics are part of the Iranian flora in which 14 domestic species of them have been identified so far. This study performed in west of the country, with a latitude of 28 to 37 degree and a longitude of 45 to 55 degree in 2005. This study did by using the data obtained from 50 synoptic weather stations, 12 species cultivated in two station, topography maps, vegetation cover maps, soil maps with 1:100000 scale which were incorporated and analyzed by ILWIS software. The results indicated that the favorable regions (by moisture and temperature) for annual medics germination and establishment could be categorized in four groups; 1-without limitation, 2-without limitation in spring, 3-without limitation in fall and 4- with limitation in spring and fall. There are also four groups of soil classified as good, fair, poor and very poor for annual medic cultivation and development in the country. The results showed that total area of 22.32 million hectares suitable for annual medic germination and development in the country, 9.36 million hectares (23.14%) is suitable only for spring germination, 5.26 million hectares (13.1%) for spring and autumn germination and 8.72 million hectares (21.8%) only for autumn germination, respectively. The annual medic can be utilized for biological nitrogen fixation. Its special plant characteristic makes it match with wheat leyfarming