Soil Fertility, Weed Biomass And Cassava (Manihot Esculenta Crantz) Performance Under Different Mulch Types

Although, empirical evidence from many parts of the world indicates significant and positive effects of mulching on improving soil conditions, crop yield, as well as suppression of weeds, with resultant improved agricultural productivity. However, in Southwestern Nigeria, there is paucity of published scientific data and research information on the relative effectiveness of mulch types on improving soil conditions, cassava root yield and reducing weed biomass. Consequent upon this, a two – year field experiment was designed and executed at the Teaching and Research Farm of the Ekiti State University, Ado – Ekiti, Ekiti State, Nigeria, during 2010 and 2011 cropping seasons to assess effects of mulch types on soil fertility, weed biomass and cassava (Manihot esculenta Crantz) performance. The experiment was laid out in a randomized complete block design with three replicates. The different mulch types included: Rice straw mulch (RSM); polythene mulch (PM) and no mulch (NM), which served as the control. The results obtained indicated existence of significant (P = 0.05) differences between the two mulch types as regards their effects on soil fertility, weed biomass and cassava root yield performance. At the end of 2010 cropping season, mulching resulted in significant increases in soil organic carbon (SOC) from 0.56 g kg-1 for NM to 0.69 and 0.83 g kg-1 for PM and RSM, respectively. Similarly, at the end of 2011 cropping season, mulching resulted in significant increases in SOC from 0.40 g kg-1 for NM to 0.56 and 0.89 g kg-1 for PM and RSM, respectively. At the end of 2010 cropping season, mulching significantly increased total N from 0.30 g kg-1 for NM to 0.40 and 0.49 g kg-1 for the respective PM and RSM. At the end of 2011 cropping season, mulching significantly increased total N from 0.25 g kg-1 for NM to 0.32 and 0.56 g kg-1 for the respective PM and RSM. Mean values of cassava root yield data across the two years of experimentation indicated that, mulching resulted in significant increases in cassava root yield from 7.77 t ha-1 for NM to 10.49 and 11.94 t ha-1 for PM and RSM, respectively. In contrast, mulching significantly decreased weed population density from 90.8 weeds m-2 for NM to 60.5 and 76.8 weeds m-2 for the respective PM and RSM.