Response of different colour plastic mulches on water dynamics under drip fertigated greenhouse capsicum (Capsicum annuum)

Abstract

The study analyses spatio-temporal distribution of soil moisture pattern under colored plastic mulches inside the ventilated greenhouse. The experiment was conducted at Centre for Protected Cultivation Technology, Indian Agricultural Research Institute, New Delhi. Water distribution in the root zone of capsicum (Capsicum annuum L.) was simulated for three colored plastic mulches (silver, yellow and black) and unmulched condition (control) with three level of irrigation (100% ETc, 80% ETc and 60% ETc). It was found that for two levels of irrigation (100% and 80% ETc) highest yield was obtained, so for these two irrigation levels simulation of water dynamics was done by the Hydrus-2D model. The irrigation cycle was 72 h (i.e. 3 days) and indicates that moisture was readily available in the vicinity of root zone. Simulation study showed that water content for sandy loam soil was more in the second layer of soil (15 to 30 cm) and was near the field capacity. The R2-value obtained for silver plastic mulch at 100% of ETc was highest (0.91 to 0.94) and the second highest R2-value is for yellow plastic mulch at 80% of ETc (0.89 to 0.91). The results showed that at 100% of ETc, silver color mulch has comparatively more water content than other treatments. Simulation studies showed that silver plastic mulch optimised the water content in the vicinity of capsicum root zone for 1 lh-1 dripper discharge. So, silver plastic mulch was efficiently utilized, as the capsicum root zone was found within 20 to 30 cm depth. This indicates that the Hydrus-2D can be used effectively for predicting soil moisture distribution covered with plastic mulch.