MSc

A field experiment was conducted at the Instructional Farm, Vellanikkara during September 1979 to May 1980 to study the effect of various Agro-Techniques on soil loss, surface runoff and soil moisture storage in hill slopes. The experiment was conducted with the main objective of studying the effect of groundnut intercropping as well as the different methods of planting of tapioca on reducing soil and water losses in hill slopes.
The experiment was laid out in a Randomised Block Design with five treatments and four replications. The treatments consisted of (1) tapioca alone in mounds, (2) tapioca in mounds with groundnut as intercrop, (3) tapioca alone in ridges across the slope, (4) tapioca in ridges across the slope with groundnut as intercrop and (5) uncultivated bare fallow as a control.
The experiment was conducted in field runoff plots of 24.3M x 2.7M size. The runoff from the field were collected directly into water proof polyethylene lined earthen tanks and measured after each rainfall.
Only rainfalls more than 12.5 cm were taken for the purpose of the study.
From the experiment it is observed that AIm index was better correlated with runoff as compared to other erosion indices. Similarly EI15 index was better correlated with soil loss.
Maximum runoff and soil loss occurred in uncultivated bare fallow. Among the various cultivation methods, tapioca in mounds registered maximum soil and water losses.
Groundnut intercropping as well as tapioca planting in ridges across the slope were effective in reducing soil and water losses.
Uncultivated bare fallow runoff plots recorded the maximum losses of N,P and K being 107.47kg, 28.476kg, and 82.479kg/ha respectively. Among the Agro-Techniques, tapioca in mounds recorded the maximum loss of N,P and K being 44.01kg, 14.845kg and 39.08 kg/ha respectively during the entire season. However, the nutrient losses from other plots were meagre.
Maximum retention of rainfall was recorded by tapioca in ridges across the slope with groundnut as intercrop.
The pH and conductivity of runoff water were not significantly influenced by different treatments.
During the dry periods maximum storage and minimum depletion of sub soil moisture were recorded by uncultivated bare fallow plot.
The growth and yield of tapioca were not significantly affected by the groundnet intercrop. Maximum yield of tapioca was recorded by the treatment of planting tapioca in ridges across the slope without intercrop.
The yield of the intercropped groundnet was not affected by various cultivation methods of tapioca.