Maseko, Stephen Phuz’ukuvela2026-02-092026-02-091996https://www.suaire.sua.ac.tz/handle/20.500.14820/7307DissertationThe effect of soil texture and shade on soil water evaporation using microlysimeters of different sizes was investigated. The rate of evaporation from the different sized microlysimeters was studied to see which evaporates the most. The days after irrigation were monitored to see if evaporation would increase or decrease. The effect of the depth of the microlysimeters was also studied to find out which depth evaporates more between the shallow depth microlysimeters (SDM) (10 cm), and the deeper depth microlysimeters (DDM) (20 cm). Two periods of the day, morning period (MP) and afternoon period (AP) were also studied to determine which one had more evaporation. The study, which was conducted from October to December 1994, was carried out in two sites with contrasting soils viz; (a) Ismani, in Iringa region selected for its clayey soils, and (b) Hombolo, in Dodoma region which had sandy soils. For the experiment, two plots were used, one shaded and the other unshaded. Shading was obtained by using a shade screen (a black net) which provided a shade of about 50 per cent. Sixty mm of irrigation water was applied on both plots at the same time. Results show that sandy soils evaporated significantly (P<0.05) more water, up to about 20 per cent, than clayey soils. Shading significantly (P<0.05) reduced evaporation by 5 to 10 per cent. The 10 cm diameter microlysimeters lost more water than the 5 cm diameter ones. This was prominent in clayey soils (P<0.05) than in the sandy soils, at the initiation of the experiment. However, towards the end of the study the difference was reduced. It was also observed that evaporation significantly decreased as the soil progressively dried after irrigation. The second day’s evaporation was reduced by almost 50 per cent. The rest of the days’ evaporation was steady at about 10 to 20 percent of the first day. There was no significant difference between the SDM and DDM. It seems depth (10-20 cm) does not significantly affect evaporation. The periods of the day showed some significant difference. In clayey soils significantly (P<0.05) more water was lost in the MP than in the AP. However, the reverse was true for the sandy soils.enSoil water evaporationMicrolysimetersSoil textureThesis