EFFECT OF ORGANIC AMENDMENTS ON SOME PHYSICAL PROPERTIES OF LUVISOLIC SOILS IN RELATION TO EMERGENCE OF RAPESEED IN A GROWTH CHAMBER

Abstract

Organic amendments at 2.5% of soil weight were applied to three Luvisolic soils in the greenhouse. After five successive crops, soil crust strength as indicated by modulus of rupture measurements was reduced by the amendments. Modulus of rupture values were highly related (R² = 85.4%) to plant counts of Target rape (Brassica napus L.) in the growth chamber. Modulus of rupture determinations were made independently on oven-dried samples and showed that the effect of soil moisture on crust strength among treatments was negligible. Plant emergence was increased as much as threefold by the amendments. Treatments increased field and available moisture capacities of soils but had little effect on moisture retained at 0.35 and 15.8 bar tensions.