Effect of Suspended Load on the Physico-Chemical Characteristics of Soil on the Hirmand Flood Plain

Flood plalins are usually affected by the quantity and quality of the suspended load of the floodwater that inundates those areas. This is made possible by pumping the turbid water for irrigating the cropland adjacent to the river. This study was performed to assess the effects of addition of the suspended load carried by the Hirmand River on some physico-chemical properties of the farm fields irrigated by the pumped turbid water. It was observed that there was no statistically significant difference in the sand percentage, pH and Ca and Mg concentration between the irrigated and the control area. However, K, C, N, organic matter content and water saturation percentage showed a highly significant difference (p<0.01) between the two treatments. Moreover, SAR, ESP, and P concentration and silt and clay content of the irrigated area showed higher quantities at the (P<0.05) significance difference. Soil texture changed from loamy sand in the control area to loamy in the irrigated cropland. The turbid water irrigation of the sandy flood plain of the Hirmand River has improved most of the physico-chemical characteristics of the cropped area. Therefore, this irrigation method may be termed a desertification control technology.