Study of Methods of Rain Harvesting and Season Planting in Initial Establishment of Astragalus squarrosus in Yazd Province (Case Study: Kalmand Bahadoran Rangelands)

Astragalus squarrosus is a species of shrub without spine and palatable. This plant distributes in sandy dunes of arid and hyper arid regions in central, south-eastern and north-eastern desert of Iran. In this study the effect of rain harvesting treatments including furrow, pitting and crescent pond and planting season on initial establishment of A. squarrosus in Kalmand Bahadoran was evaluated. This region in terms of soil type, condition of rainfall and temperature is similar of the main habitat of this species. The seeds were planted at two season late fall as autumn sowing and late winter as spring sowing season. Also, the seeds were scratch according to germination studies in the lab. The scratched seeds were compared in split plot design with main treatment of planting season in the autumn of 2013 and 2014 and winter of 2013 and 2014. Subsequent treatments of pitting, furrow, crescent pond in three blocks were compared. In the spring, the number of established plants in each plot was counted and analyzed. Based on the results, fall planting been more successful than spring planting. Also, furrow treatment with 11.5% seed establishment had better results in seed establishment than other treatments. Also, the results of season and treatment interaction showed that 27% of seeds were planted in furrow during autumn 2013. But seeds in any of the treatments were not grown in winter 2014. Generally, low seed establishment suggests that rain storage combined with seeding in areas with average rainfall less than 100 mm faces with a high risk. In these areas, methods of potted seedlings combined with rain harvesting should be examined.