Maize (Zea mays L.) is an important food crop popular in Kenya and its production has a direct influence to nutrition and economic security. The high demand for this food crop has resulted to innovation of new farming practices to increase its production. Therefore, this experiment was set up at Meru University Demonstration Farm in randomized complete block (RCBD) split plot design during June - October 2022 (S1) and November - March 2023 (S2). Two land preparation methods were used conservational and conventional (CA and CT). The organic amendments were 2.5 t ha-1 BSF, 5.5 t ha-1 BSF, 8.5 t ha-1 BSF, 2.5 t ha-1 BSF + Biochar, 5.5 t ha-1 BSF + Biochar, 2.5 t ha-1 BSF + Trichoderma 125 g ha-1, 5.5 t ha-1 BSF + Trichoderma 125 g ha-1, 5 t ha-1 FYM, 100 kg N ha-1 DAP and control. Data collected was on soil bulk density, soil moisture, vegetative growth and yields. There was significance (p<0.05) difference between the two land preparation method on soil moisture retention. Organic amendments influenced the soil moisture retention and soil bulk density reduction significantly (p<0.05). Plots with 8.5 t ha-1 BSF and 100 kg N ha-1 DAP increased the vegetative growth by 37%, application of Trichoderma increased the vegetative growth by 7%. CA increased the vegetative growth by 6% and 4% as compared to CT. 8.5 t ha-1 BSF increased the vegetative growth by 21% and 19%. CA increased the yields by 6% in S1 and 14% in S2 compared to CT. Trichoderma increased the yields of maize by 12% and 11%. Increase in maize yield and vegetative growth is due to increased soil moisture condition in CA. Addition of BSF manure and biochar improved the soil moisture retention, reduced soil bulk density and improvement in soil nutrient content which led to an increase in growth and yield.