Book of Extended summaries ISDA

International Conference on Reimagining Rainfed Agro-ecosystems: Challenges &
Opportunities during 22-24, December 2022 at ICAR-CRIDA, Hyderabad
soil matrix generally precludes the use of the traditional, deterministic modelling approach to
predict flow and transport at the field scale thus it is often very difficult to estimate solute transport
by a preferential flow. Different methods have been used for evaluating or quantifying the
characteristics of macropores and preferential flow. Various researchers found that food-grade dye
Brilliant Blue FCF has been an excellent dye tracer for soil water flow and solute transport owing
to the high-water solubility, limited toxicity, similar transport property to water, low adsorption in
sand soil, and distinct visibility. A better understanding of preferential water flow would benefit
for the understanding of the ecological and hydrological functions of soil. So, the overall goal of
this study was to investigate the role of preferential flow, as affected by different land use, on the
subsurface movement of water in a micro-watershed. A micro-watershed at Hayathnagar,
Hyderabad, India, was taken up to generate detailed information on soil preferential flow.
Hayathnagar micro-watershed is situated in Hayathnagar village, Rangareddy district of Telangana
lying between 17 ° 20’18.00’’to17 ° 21’8.94” N latitude and 78 ° 35’26.14’’ to 78 ° 36’4.89’’ E
longitudes. The total area of the micro-watershed is 154 ha. The area has been divided into 3
units upper-reach, middle and lower-reach. The area under upper-reach is 54 ha, middle-reach is
60 ha and the lower-reach is about 40 ha.
The study shows significant effect of preferential flow on the nutrient movement down the profile
in the different land-use. At the upper reach, SOC for all the land-use systems was between 0.4 to
0.5% in flow path while in the soil matrix it was found to be between 0.25 to 0.35%, similar results
were observed for middle reach. Soil microbial biomass carbon was 50 to 70 % higher in flow path
than in the soil matrix. These findings lead us to understand that there exist a completely different
channels in the soil letting nutrients and microbes to travel within the horizons in soil.
Upper reach
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