Effect of soil application of urea and ammonium sulpha te on some physiological aspects and chemical compositions of sorghum plants [electronic resource].

Includes references.

The present study was carried out in pots during growing season of 2003 in a greenhouse at the Experimental Station, Department of Biology, Faculty of Education, Sana'a University, Yemen, to study the effect of soil application of urea and ammonium sulphate on some physiological aspects and chemical compositions in roots and shoots of Sorghum bicolor L. plants. Each nitrogen source (urea or ammonium sulphate) was applied at two concentrations (0.2% and 0.4% solution) separately or in combinations (urea at 0.2 + ammo sulphate at 0.2% and urea at 0.4% + ammo sulphate at 0.4%). Three samples were taken at 40, 50 and 60 days after sowing (corresponding to 10, 20 and 30 days after starting the treatments) for estimating dry weight, water content, direct reducing, total reducing value, polysaccarides. total carbohydrates; phosphorus content, nitrogenous content and proline in roots and shoots as well as photosynthetic pigments content in leaves of sorghum plants. The obtained results indicated that, for roots high significant increases in dry weight, water content and direct reducing value were gained due to applying urea + ammonium sulphate at 0.4% in the first and second samples and applying urea + ammonium sulphate at 0.2% in the third one. Total carbohydrates significantly increased due to application of ammonium sulphate at 0.4% in the second and third samples, as well as urea + ammonium sulphate at 0.4% in the first sample. Organic and total phosphorus significantly increased due to application of urea at 0.2% in the first and second samples. Urea at 0.4% achieved the highest significant value in total soluble N, protein-N, total -N and proline in first sample. Meanwhile, urea + ammonium sulphate at 0.2% resulted in high increases in total- N and protein - N in the second and third samples. Likewise application of urea + ammonium sulphate at 0.4% caused the highest significant value in total soluble - N in the second sample compared with control and other treatments in roots of sorghum plants.

Summary in Arabic.

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