Ignatus, Agnes Nshemele2026-04-282026-04-282000https://www.suaire.sua.ac.tz/handle/20.500.14820/7494DissertationThis study was conducted at the Sokoine University of Agriculture (SUA) Farm, Morogoro, Tanzania, to assess the effect of synchronized mulching of Gliricidia sepiwn on soil nutrient status; nutrient uptake by maize and field performance of maize. The experiment was laid out in a 4 x 4 split-plot arrangement in a randomized complete block design with three replications. The different factors and their levels were as follows: Major factors (mulch application dates) i.e just before sowing (Ti), two weeks after sowing (Tz), four weeks after sowing (T3), six weeks after sowing (T4). Minor factors (mulch application rates) i.e Control (0 kg ha’1, dry wt per plot, Mi), 2.5 t ha'1 (2500 kg ha’1, 4 kg plot’1 M2), 5.0 t ha'1 (5000 kg ha'1, 8 kg plot’1 M3) and 10.0 t ha'1 (10000 kg ha’1, 16 kg plot’1 M4). Measurement and analysis included: net mineralization samples collected at 0, 1, 2, 4, 6, 8, 10 and 12 weeks after sowing of maize; height of maize plants at tasseling stage (i.e 6 weeks after sowing), and maize grain and stover yield at harvesting. Also nitrogen and phosphorus contents of maize leaves at tasseling and maize grain and stover at harvesting were determined. Results on N mineralization at all sampling periods showed significant differences (P<0.05) between mulching rate treatments except at weeks 1 and 4 for nitrate-N and at weeks 1 and 2 for ammonium-N. Nitrogen mineralization was not affected by the time of mulch application. Nitrate dominated the system throughout the whole growing period. Maize yield was not significantly (P)0.05) affected by time of mulch application in terms of grain and stover, but it was significantly affected by mulching rates. The trend was the higher the mulching rate, the higher the yield. Mulching time had no significant effect on maize growth and yield, however its effect was significant on grain P and stover N uptake. The interaction between time and mulching rate had no significant effect on maize growth, yield and nutrient uptake, except stover yield and stover P. It was concluded that, application of mulch 2 weeks after maize sowing or just before sowing should be adopted in order to optimise N uptake by the crop and thus increase yield. A mulching rate of 10 t ha'1 is recommended. However, mulching alone cannot sustain crop yield enhancement, and supplementation with fertilizers is necessary.enSoil nutrientsMaizeSynchronized mulchingGliricidia sepiumThesis