Comparison between effects of open grazing and manual harvesting of cultivated summer rangelands of northern Iran on infiltration, runoff and sediment yield

The effects of grazing and cultivation management on infiltration, runoff and sediment yield on storm basis were quantified for summer rangeland in the Matash mountains (Talesh Region), northern Iran. The infiltration experiments were made using double cylinder infiltrometer with five replicates within each study treatment. The runoff generation and sediment yield were measured using standard plots (1·83 m x 22·18 m) in three replications.The peak and the terminal instantaneous infiltration, and runoff and sediment rates were compared using independent and paired sample t-test in two aforesaid treatments, respectively. The terminal and the peak instantaneous infiltration rates of 39·6 and 342·9 mm/h showed a respective significant increase (p < 0·001) of 32 and 39 per cent in cultivated areas compared to those in open grazing treatments. The results of runoff analysis also showed that there was a significant difference (p < 0·001) in runoff generation in two above-mentioned areas. The runoff water was also found to be 5·63-folds more in case of open grazing treatment in comparison with that generated by cultivated plots. A significant difference (p < 0·001) in sediment yield between two study treatments was also proved by the results obtained through sediment yield study. The soil loss in open grazing treatment was found to be 26·6 times more than of that occurred in cultivated plots. Copyright © 2007 John Wiley & Sons, Ltd.