The study of the effect of different plant
spacing on runoff, soil erosion and soybean yield was
conducted in Yandev, Gboko, Benue State, Nigeria. The
site for the experiment was manually cleared of its
natural vegetation. The experiment was performed on
nine 2m x 1m micro plots of fine tilt and slope 3%.
Boundaries of burnt bricks were built round each
micro-plot to prevent the entry of runoff from adjacent
plots and land. Collecting pits were excavated at the
lower end of each micro-plot in the direction of the
slope and plastic bucket collectors of 40 litres were
installed to catch runoff and soil erosion sediments from
the micro plots. The size of each micro plot was 2m2
The experiment consisted of three treatments replicated
three times. Treatment one (T1) with plant spacing of
20cm x 20cm, treatment two (T2) with plant spacing of
30cm x 30cm and treatment three (T3) with plant
spacing of 40cm x 40cm. Runoff and soil erosion data
were determined after each rain storm by measuring
the runoff with a 1000ml measuring cylinder. The soil
erosion was determined by measuring the oven dried
soil erosion sediment with an electronic weighing
balance. The soybean yield was determined by weighing
the harvested and sun dried soybean grain at a moisture
content of 12.6% using an electronic weighing balance.
The values of the runoff from the different treatments
are 202.50 m3
/ha for treatment one (T1) with plant
spacing 20cm x 2cm, 221.00 m3
/ha for treatment two
(T2) with plant spacing 30cmx30cm and 238.50 m3
for treatment three (T3) with plant spacing 40cmx40cm.
The mean soil erosion values were 16.87 kg/ha for
treatment one (T1), 48.03 kg/ha for treatment two (T2)
and 142.20 kg/ha for treatment three (T3).
Keywords : Plant spacing, Runoff, Soil erosion, Soybean yield.