EFFECTS OF SOME NATURAL SOIL AMENDMENTS AND WATER REQUIREMENTS ON THE GROWTH AND CHEMICAL CONSTITUENTS OF SOME LAWNS (PASPALUM VAGINATUM, L.)

The aim of this research was to improve properties of calcareous soil by adding two natural soil conditioners (sand + compost) with different rations, i.e., calcareous, calcareous + composted leaves (3:1 v/v), calcareous + sand (3:1 v/v) and calcareous + sand + composted leaves (1.5:1.5:1 v/v/v))  combined with  three rates of irrigation 5.00 l/m2  as severe stress, 10.00 l/m2  as moderate stress and 15.00 l/m2  as normal stress) on Paspalum. The experimental design was a split-plot design. Natural soil amendments were listed as the primary component, with various irrigation rates included as a subfactor. Resulted from media consisting of calcareous + sand + composted leaves (1.5:1.5:1 v/v/v) with the addition of the third level (15.00 l/m2) of irrigation rate, gave the highest reduction for the time required to give covering complete (44.916 days) and produced the maximum increase in total fresh (989.772 g/m2) and dry weight (221.492 g/m2) of vegetative growth, fresh weight of rhizome (379.854 g/m2) and dry weight (85.551 g/m2). Also, highest significant increase in the total chlorophylls (258.595 mg/100 g L.F.W.), carotenoids (60.779 mg/g L.F.W.) and total carbohydrates (267.384) in rhizomes at 15.00 l/m2 with the growing medium of calcareous + sand + composted leaves (1.5:1.5:1 v/v/v). Natural soil amendments (sand, plant compost) reduced the harmful effects of stress and improved plant resistance to water stress when using irrigation at the moderate stress rate of 10.00 l/m2. Accordingly, it could be recommended that high-quality lawns (P. vaginatum, L.) be produced by growing Paspalum in a mixture of calcareous + sand + composted leaves (1.5:1.5:1 v/v/v) as the best natural soil amendments and irrigation with the rate of 10 as moderate stress and/or15.00 l/m2.