Abstract:

Trials to test effectiveness of mucuna (Mucuna pruriens) in improving soil fertility for cotton (Gossypium hirsitum L.) production were conducted at the National Semi Arid Resources Research Institute (NaSARRI) and on farmers’ fields in Northern Uganda. During the 2008/2009 cotton season, trials were conducted at NaSARRI and Lira, whereas work was done in Gulu district during the 2010/2011 and 2011/12 cotton seasons. At NaSARRI and Lira, mucuna was intercropped with cotton at two densities (high and low) and periodically cut down to decompose under the cotton crop. Under the on-farm trials in Gulu, mucuna was planted and allowed to grow for 1-2 months before ploughing it down. Cotton was then planted on the post- mucuna plots for comparison with the control plots. Soil analyses before and after the growth of mucuna revealed changes in levels of various nutrients in the Gulu trials. Mucuna significantly (P<0.05) increased soil K but decreased Mg levels. Cotton yielded 1,195.0 kg/ha from the post-mucuna plots compared to 750.1kg/ha from the control plots in the Gulu trials. Mucuna cut from elsewhere and applied to cotton at NaSARRI significantly (P<0.05) increased cotton yields to 2472.2 kg/ha from 1,988.9 kg/ha under the no fertilizer controls (24.3 % increase). It can be concluded from the study that: (1) Mucuna is a potentially cheap and sustainable method of providing nutrients (especially K) to cotton and increasing seed cotton yields in areas where fertility is a limitation;. (2) Intercropping mucuna with cotton is not feasible and should be discouraged. (3) Mucuna needs to be established early and given sufficient time to form biomass before it may be ploughed back into soil and a subsequent crop planted