Different effects of sheep manure conditioner on runoff and soil loss components in eroded soil

• Reducing soil erosion is necessary for ecological balance in watershed scale.
• There are many biological and mechanical ways to control soil erosion.
• We compared the effects of manuring on soil loss in plot scale.
• The manure effectively affected study variables under different rainfall intensities.

Conservation of the soil surface by organic and inorganic amendments or stabilizers is often adopted to reduce runoff and splash erosion. The manure as an organic amendment is a resource which can be utilized for crop production and soil conservation. However, the effect of manure on mitigating soil erosion on eroded soil has not been yet considered. The present study attempted to determine the efficiency of manure with rate of 0.3 kg m− 2 in changing the splash erosion, runoff, sediment concentration and soil loss under laboratory conditions. The study has been conducted for a sandy-loam soil taken from summer rangeland, the Alborz Mountains, Northern Iran with simulated rainfall intensities of 30, 50, 70 and 90 mm/h and the slope of 30% in three replicates for each treatment. The obtained data from 36 splash cups showed that the manure could reduce the splash erosion in all studied rainfall intensities and also the maximum reduction occurred in rainfall intensity of 30 mm/h. The results also showed that the manure affected differently in changing splash erosion, runoff and soil loss characteristics. The maximum changing for splash erosion, time to runoff, sediment concentration and soil loss was observed in the rainfall intensities of 30, 50, 90 and 90 mm/h, respectively. The results showed that the time to runoff had more effect in rainfall intensity of 50 mm/h with rate of — 115.95%. The maximum reducing runoff coefficient, sediment concentration and soil loss occurred in rainfall intensity of 50, 90 and 90 mm/h with rates of 8.98, 14.65 and 13.14%, respectively.