English

Abstract

This research was conducted on a degraded Ultisol at the Eastern farm of Michael Okpara University of Agriculture, Umudike during 2014 and 2015 planting seasons, to determine the effect of different rates of sawdust and poultry manure application on soil physicochemical properties of acid sandy Ultisol, and growth and yield of cocoyam. The treatments comprised of two organic amendments at five levels each: Sawdust (0, 2, 10, 15 and 20 t/ha) and poultry manure (0, 2, 4, 6 and 8 t/ha), which were combined to produce 24 treatment combinations and a control. The treatments were assigned randomly to the plots and incorporated into the soil two weeks before planting. The treatment combinations were laid out in Randomized Complete Block Design (RBCD) and replicated three times in a factorial experiment. Data were collected on plant height, number of leaves, leaf area, corms, cormels and total yield. Soil samples were collected with core samplers for physical properties such as soil bulk density and total porosity using soil auger at 0 to 15 cm, at the end of the experiment for chemical analysis such as soil pH, organic carbon, available phosphorus, total nitrogen, exchangeable acidity and total exchangeable cations such as K+, Ca2+, Mg2+, and Na+. The soil physicochemical properties were significantly improved with mostly higher rates of sawdust and poultry manure over control, which positively modified cocoyam growth and yield. The cocoyam leaf area, plant height, number of leaves, corms, cormels and total cocoyam yield increased significantly with application of 8 t/ha PM. The total cocoyam yield amounted to 17.73 t/ha in 2014 and 15.15 t/ha in 2015. Results of this research showed that agro-wastes such as poultry manure and sawdust have the potentials for increasing cocoyam production and soil fertility.  Key words: Sawdust, poultry manure, bulk density, total nitrogen, soil fertility.