Effect of corn cob biochar and irrigation on maize production in a maize cowpea intercrop

Abstract

Biochar has the potential of improving soil properties to increase crop yield and also to sequester carbon to mitigate climate change, however, very few farmers in Ghana are aware of the potential use of biochar and supplementary irrigation in crop production. A field study was carried out at University of Cape Coast to evaluate the effect of corn cob biochar amended soil with or without irrigation on the growth and yield of maize. A split plot design was used for the study. There were 12 treatments and were replicated four times with irrigation as the main plot and biochar as the sub plot. Three irrigation regimes (no irrigation, deficit irrigation and full irrigation) and four biochar application rates (0 t ha-1, 10 t ha-1, 20 t ha-1 and 20 t ha-1 + 60 kg P) were assessed for their effect on earliness to maturity (number of days to tasseling, silking and physiological maturity), barrenness, yield and nutrient composition of maize grain and stover. Biochar amended soil and irrigation levels increased plant height, number of leaves, leaf area, stem diameter, and number of nodes compared to plants on plots without irrigation but amended with the same levels of biochar. Biochar amended plots without irrigation produced maize with increased percentage barrenness, number of days to tasseling, silking and physiological maturity compared to plants on similar plots with deficit and full irrigation. Highest grain yield of 8.81 t ha-1was obtained on plots treated with full irrigation and 20 t ha-1 + 60 kg P. The canopy of the maize hinders the amount of sunlight to reach the cowpea to produce dry matter through photosynthesis. Biochar work best in maize production under supplementary irrigation.