The effect of available water content and other physical and chemical properties of soil substrates on germination of cucumber

Abstract

The research work was conducted at the El-Dokki greenhouse site, Egypt in 1996. Three soil substrates and four substrate mixtures were tested in terms of physical, chemical properties and their effect on germination rate and ratio of cucumber seedling (cucumber satives c.v. pasandra ). The four tested mixtures were: peat + vermiculite (1.1 v/v ; p+v), peat + compost (1.1 v/v, p+c), compost + vermiculite, (1:1 v/v, c+v) and peat + compost + vermiculite,(l:l:l v/v; p+c+v). All tested mixtures exhibited low bulk density (0.185 - 0.389 g/cm ³), moderate porosity (66.2 - 85.4% v), high available air (48.4 - 66.9% v.v) and high available water (17.8 - 18.6% v). pH of the first mixture (p+v) was low (4.6) while the three other mixtures were within the natural level (6.44 - 7.12). Cation exchange capacity (CEC) was calculated as meq lOOg ^-1 and as meq^-1. The values of CEC were 35.38, 88.33, 37.9, 65.0 meq l00g^-1 respectively, while were 112.5, 163.4, 147.4 and 154.2 meq^-1, respectively. Germination percentage and germination rate were not significantly affected by substrate type while seedling height, dry weight, dry weight - fresh weight ratio and macro nutrient uptake were affected with superiority of p+v+c mixture.