A long-term project was initiated in order to stuq the et!ecta of sawdust Jlltll.ch and two .forms of a synthetic soil conditioner on the yield of vegetable crops. Data is in this thesis concerning experimental results of two years, 1953 and 1954. In addition, a report is given on a preliminary study which was conducted in 1952. In general, not enough research has been done on this project to formulate definite conclusions. However, certain tr.nds are apparent: 1. The soil treatments have caused no significant changes in the pH values of the soil. 2. The treatments have caused no wide fluctuations in the amounts of calcium, magnesium, phosphoric acid, or potash in the soil. 3. The potassium dichromate and sulphuric acid tests, used by the Soils Laboratory of this institution, did not indicate that the soil treatments increased the organic matter content of the soil. 4. In general, synthetic soil conditioners as used in this test have produced no significant effects. 5. Incorporation of sawdust into the soil mq result in nitrate deficiency. However, this deficiency can be readily corrected by the addition or fertilizers containing nitrogen. 6. Sawdust mulch has, in general, benefitted the production of vegetable crops. The beneficial effects are probably caused by conservation of soil moisture (including an increase in the percentage of moisture available to plants), and by reduction of soil temperature fluctuations. / Master of Science