Soil Water Balance Studies in Subsurface Drip Irrigation for Amaranthus

Abstract

Subsurface drip irrigation (SDI) is an advanced and recent revolutionary variation of traditional drip irrigation where the tubing and emitters are buried beneath the soil surface. The field experiment was done at the institutional farm, KCAET, Tavanur. The experiment was aimed to optimize the depth of installation of laterals and spacing between laterals under subsurface drip system. This study also computed the deep percolation from different layers with different lateral depths. The soil moisture was taken from different depths and horizontal distance and soil moisture contour maps were plotted. The results showed that the moisture content increased with depth from the surface due to the less evaporation loss. Also, the amount of moisture was found to be decreased with time. Moisture content at the surface layer for 10 cm lateral was 14.5 per cent whereas the same for 20 cm lateral was 11.6 per cent. The maximum values of yield were observed for the treatment T 4 , and then T1 (which have 15 cm and 10 cm lateral depth respectively). The highest water use efficiency was for treatment T 4 with a value of 37.96 kg/ha-mm followed by treatment T 1 with 34.6 kg/ha-mm. In the statistical analysis, it was observed that, there were significant variations between treatments. The number of leaves was influenced by both spacing between laterals and depth of laterals. Stem girth was varied significantly by spacing between laterals. Both spacing between laterals and lateral depth had remarkable effect on crop height. Deep percolation was relatively less from the surface layers than from the deeper layers in higher lateral depths (i.e., 20 cm lateral depth).