M.Tech

Automation in irrigation management refers to those innovations which
partially or fully replace manual intervention from watering operations. Automized
irrigation includes automation at regional level or farm level. Recently, technological
advances have been made in soil water sensors for efficient and automatic operation of
irrigation system by which exact quantity of required water can be supplied to the crop.
Automatic soil water sensor-based irrigation seeks to maintain a desired soil water
range in the root zone that is optimal for plant growth.The present study was conducted
to evaluate the suitability of drip automation systems for optimal irrigation scheduling.
The field experiment was done in the rain shelter in the research plot of Nodal Water
Technology Centre, College of Horticulture, Vellanikkara, during the months of
October 2014–March 2015. The experiment was done for tomato variety Akshaya in
rain shelter with 4 treatments of irrigation levels. The experiment was laid out in CRD
with 3 replications. The main objectives of the study were to evaluate the performance
of sensor based automated drip irrigation systems, scheduling irrigation for tomato
based on the best performing drip automation system and to evaluate the cost
economics of drip automation system with optimal irrigation scheduling. Irrigation
was provided using sensors through drip automation system at 40 per cent, 50 per cent
and 60 per cent moisture depletion levels (MDL) from the available moisture content.
Control was irrigated at the rate of 2 l/plant/day. Crop growth parameters such as height
of the plant, number of days to first flowering, number of days to initial budding,
number of days to first harvest, root length and root dry weight were observed. During
all the stages, plant height significantly varied in all treatments. All the parameters were
found to be better in 50 per cent MDL treatment compared to other treatments. Yield
parameters such as number of fruits and total yield were recorded. There was no
significant difference in number of fruits per plant in all the treatments. Yield was
significantly higher in 50 per cent MDL than that of other treatments. Water use
efficiency was significantly different in all the treatments. WUE in T2 and T3 was on
par which showed better performance than other treatments. The analysis of the data
of soil moisture content at 2 and 6 hours after irrigation was monitored at distances of
0, 15 and 30 cm from the emitter laterally and at a depth of 0, 10, 20 and 30 cm from
the surface. Soil moisture contour maps for the longitudinal section of the soil were
plotted using computer software “Teraplot 1.3.02” version. The pattern was more
uniform for T2 (50 per cent MDL) two hours after irrigation. Benefit cost (B/C) ratio
for each treatment was calculated. The maximum benefit cost ratio of 2.57 was noted
in T2. Hence it can be concluded that for tomato (Akshaya) grown in rain shelter, 50
per cent MDL can be fixed as the optimum level for scheduling irrigation. As 60 per
cent moisture depletion also gave good yield and WUE on par with 50 per cent level,
60 per cent MDL can also be suggested for scheduling irrigation in water scarce areas.