Optimization of fertigation level and depth of lateral under subsurface drip irrigation for amaranthus

Abstract

The study “Optimization of fertigation level and depth of lateral under subsurface drip irrigation for amaranthus” was taken up with the objective to optimize the fertigation level and the depth of laterals under subsurface drip irrigation for amaranthus and workout the cost economics. The effect of different fertigation levels and depth of laterals under plastic mulch on the performance of Amaranthus (Amaranthus hypochondriacu, variety: kannara local) were studied. The observations on number of leaves, stem girth root length and yield were taken. The number of leaves, root length and yield showed significant difference between the treatments. The yield showed significant difference with different levels of fertigation and depth of laterals. Maximum yield of 8.51t/ha was observed for the treatment T2. The yield for treatments T1 was 7.41 t/ha and T3 was 7.2 t/ha. Even though, maximum yield was obtained in T2, as per the statistical analysis, difference in yield was not that much significant between T2 and T1 and T2 and T3. The treatment T3 is of 10 cm lateral depth with 80 per cent fertigation level. The study suggested that treatment T3 is better due to the fact that it gives higher crop yields with substantial saving in fertilizer usage. The benefit cost ratio treatment T2, 100% of fertigation requirement with lateral depth at 10 cm was 2.6. The benefit cost ratio for T1 was 2.2 and T3 was 2.18. The benefit cost ratio for control was minimum i.e., 1.39. Comparing with the benefit cost ratio between T2, T1 and T3, it was found that there was not much difference in ratios. Hence the treatment T3 i.e., 80% fertigation level with 10 cm lateral depth that shows comparatively better yield with benefit cost ratio of 2.18. The study shows that maximum fertilizer use efficiency was observed in case of T3 i.e., 80% fertigation level with inline laterals at 10 cm depth, compared to other treatments. Hence, subsurface drip irrigation of 10 cm lateral depth with 80 per cent fertigation level under plastic mulching for amaranthus is a good option as compared to 20 and 30 cm lateral depth with 80, 100 and 120% of fertigation levels.