To determine the appropriate drip irrigation mode for southern desert aged red jujube when changing flood irrigation into drip irrigation

the effect of different irrigation quotas (900

1 050

1 200 mm) and irrigation times (10

14

18) on soil salt distribution of 0-200 cm in the whole red jujube growth period and yield after using drip irrigation are examined using the two factor combination test design. The results showed that every process in the horizontal direction performed as follows: the soil salt content became higher with the increasing distance to the tree trunk

and the increased irrigation quota could increase the soil salt content remarkably in the 0-20 cm soil layer at 60 cm distance to the trunk; the increased irrigation frequency could reduce the soil salt content significantly in the 0-80 cm soil layer at 60 cm distance to the trunk. The soil salinity appeared as an“S”shaped distribution in the vertical direction

and an obvious accumulation phenomenon in the surface soil. Different irrigation quotas showed a low salinity zone (<2 g/kg) in the vertical direction

and the depth of the low salinity zone would increase with the increasing irrigation quota. Compared with the drip irrigation

the soil salinity of the flood irrigation was not changed much in the horizontal direction

and there was no obvious salt accumulation phenomenon. During the whole growth period

the soil salinity peak appeared in June of the new shoot period or July of the flowering stage. As for the 0-200 cm soil layer

the salt leaching effects of the irrigation treatment with 10 times and 1 200 mm and the treatment with 14 times and 900 mm were similar to the flood irrigation. The flood irrigation treatment was only obviously better than the drip irrigation in the 0-100 cm soil layer. The effect of irrigation times on soil salt content of 0-200 cm was weaker than the irrigation quotas. After changing into drip irrigation

neither the too low nor the too high irrigation quota was conducive to improve the yield of red jujube. Eighteen times and 1 050 mm irrigation showed a not only reasonably salt distribution but also the highest yield (7 549 kg/hm2) and water use efficiency

increased by 12.87% in yield and 30% in water saving compared with the other treatments. Thus

it can be used as the local drip irrigation regime of red jujube for the water-saving

high yield and high efficiency purpose.