Samples of the soil columns (top 40 cm) were mixed and
Samples of the soil columns (top 40 cm) were mixed and
screened with 20 mesh sieving. Then they were mixed with
clean river sand in a ratio of 3:1 by volume of topsoil to sand.
The mixed soil nutrient contents were as follows: organic
matter 7.1 g kg−1
, total nitrogen (N) 0.62 g kg−1
, mean available
mineral phosphorous (P) 46 mg kg−1
, and exchangeable
potassium (K) 59 mg kg−1
.