| To ascertain the root properties of helianthus and mechanism of yield decreasing under different salinity of irrigation water,root properties and yield of helianthus irrigated by water whose salinity is 3 g/L,4 g/L,5 g/L and 6 g/L respectively on the condition of field experiments with fresh water treatment as the control.The results show that in company with the increase of salinity of irrigation water,total dry matter,mean diameter and surface area of root in 0～40 cm soil horizon decrease gradually.Distribution ratio of root in different soil horizons have been influenced after irrigated by saline water.Compared with fresh water treatment,the yield of 3 g/L treatment reduces slightly,and that of 4 g/L,5 g/L and 6 g/L treatment reduces by 5.58%,20.14% and 38.75% respectively,which is a reaction of root properties. |