Effects of applying different levels of P fertiliser on growth and yield of soybean varieties in Mozambique

Soybean (Glycine max L. Merrill) can be successfully grown in many provinces in Mozambique using low agricultural input. Soybean cultivation in Mozambique has expanded as a result of its nutritive and economic importance and diverse domestic usage. It is believed that soybean production will increase as more farmers become aware of the potential of the crop for cash/food and also for soil fertility improvement. An experiment was established and run from December 2012 to May of 2013 in Lichinga and Nampula Research Stations to find out effects of applying different levels of fertiliser on growth and yield of soybean varieties (TGX-1835-10E and Serenata) in three sites of differing soil fertility status. Treatments were arranged in a randomized complete block design with three replications per site. Treatments were two soybean varieties consisting of Serenata and TGX-1835-10E and six rates of fertilizer application: 1. Control N-P2O5-K2O 0-0-0 (kg/ha), 2. N-P2O5-K2O 0-48-0 (kg/ha), 3. N-P2O5-K2O 24-0-24 (kg/ha), 4. N-P2O5-K2O 24-24-24 (kg/ha), 5. NP2O5-K2O 24-48-24 (kg/ha) and 6. N-P2O5-K2O 24-72-24 (kg/ha). Soybean harvest data included plant height, 100 seeds weight and yield per plot. Hundred grain weight was recorded from 100 seed sample. Yield per plot was determined by weighing the grain obtained after threshing all the harvested pods of the net area and the weight converted to tons ha-1. Results showed that the Serenata plants grown in Nampula gave higher yield (1.54 t/ha) compared to Lichinga at 1.38 t/ha while TGX plants grown in Nampula gave lower yield (1.38t/ha) compared to Lichinga with 1.58 t/ha. Optimum yield of the soybean was achieved at treatment six N-P2O5-K2O 24-72-24 (kg/ha) in both varieties giving 1.59 t ha-1 for Serenata and 1.68 t ha-1 for TGX in Lichinga compared to 1.77 ton ha-1 for Serenata and 1.72 t ha-1for TGX in Nampula.