Effect of dune sand mulch on water recharging into root zone using drip lines

Abstract

Surface drip irrigation has been used for agricultural production for more than three decades. Surface drip irrigation (SDI) can maintain sufficient water content in soil for seed germination and emergence, seedling development and plant growth. Insufficient water content in the root zone may cause crop failure. In this study, the effects of Tottori dune sand mulch on drip lines on water recharging into root zone was examined under drip irrigation. Two irrigation levels of 60 and 100% evapotranspiration, and three dune sand mulches of 0, 2 and 5 cm thickness on the drip lines were used in this experiment. The results indicated that water recharging into the root zone under 5 cm dune sand was highest among the three dune sand mulch treatments. The drip lines under the 2 cm dune sand mulch expanded and contracted resulting in protrusion from the sand mulch. An irrigation level of 100% evapotranspiration under the 5 cm dune sand mulch resulted in increase of dry matter yield of sorghum. From this study, it is concluded that to increase water recharging into the root zone (to the depth of 25 cm), the minimum thickness of dune sand mulch on the drip lines was 5 cm. Key words: Irrigation level, root zone, dune sand, surface drip irrigation, water recharging.