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.
All treatments were fertilized with P and K according to
nutrient demand, and each unit of experimental treatment
was fertilized with 2.5 g of phosphate (P2O5) and 6.25 g of
potash (K2O), with both applied at the seedling stage. Required
irrigation was also applied from the outlet of a pump by using
plastic pipes