2. Materials and methods
2.1. Site description
Present experiment was executed in the ravine land in the research farm
of ICAR- Indian Institute of Soil and Water Conservation, Research
Centre, Vasad, Anand, Gujarat, India. This location falls under
“Gujarat plains and Hills Region” agro-climatic zone of India. The
climate of the region was characterized with hot, partly-arid type. The
mean yearly precipitation and temperature was 983 mm and 25°C,
respectively. The mean monthly weather variables from 2017 to 2020 have
been presented in Fig. 1. July-September months receives 90% of total
annual precipitation and rest months are dry. The run-off plots were
prepared on degraded ravine lands having 14% slopes. This landscape was
characterized by undulating terrains dominated by sporadic trees, shrubs
and grasses due to poor soil moisture and fertility. The soils of the
experimental site were low in SOC (<0.5 %) and N (96 kg
ha-1), with alkaline soil reaction (pH 8.0).
2.2 Treatment details
Investigation location was prepared by eliminating weeds, unwanted trees
and spiny bushes to secure uniformity in the plots and to impose SMSTs.
Consistent plots of 72 m length x 24 m width, along the slope were
prepared at the investigation site each unconnected by earthen bund
(˜30 cm height). Out of these four plots, two were
converted to bench terrace in four uniform sub-plots to minimize slope
length (Fig. 2d). One control plot was maintained with natural slope of
14%. In trench plot, 96 trenches of size 2x0.5x0.5m were dug in
staggered manner across the slope (Fig. 2e). The execution of SMSTs was
followed by planting of Sapota in 2010 to evaluate their potential for
rehabilitation of ravine lands. Thus, there were three SMSTs treatments
used to cultivate sapota along with control viz., i)
intercropping of cowpea and castor on bench terrace (SCCBT), ii) bench
terrace without any intercrops (SBT), iii) staggered trenches on slope
(SSTS) and iv) natural slope (SS) as control.