Organic carbon dynamics and changes in some physical properties of soil and their effect on grain yield of maize under conservative tillage practices in Abakaliki, Nigeria

In Nigeria and other Sub-Saharan Countries of Africa, erosion is pervasive and major source for loss of soil and productivity. This has necessitated continued search for appropriate soil management technologies to ensure sustained and profitable crop production. An experiment was carried out using maize (Zea mays L.) to evaluate organic carbon dynamics and changes in some physical properties of soil and grain yield of maize under conservative tillage practices on an ultisol in Southeastern Nigeria. The study consisted of three conservative tillage practices which were laid out in the field using randomized complete block design replicated seven times. Data were analyzed using statistical analysis for agricultural science. Results showed that tillage reduced seedlings emergence by 5 days compared to zero tillage. Highest grain yield of maize, significantly higher by 4 and 20% was obtained in deep tilled plot when compared to yields in shallow and zero tilled plots. Deep tilled plot had 2-9% significantly lower bulk density and 20-36, 1-8 and 27-55% higher total porosity, gravimetric moisture content and saturated hydraulic conductivity when compared to shallow tilled and zero tilled plots. Deep tilled plot had 15 and 55% significantly organic carbon when compared to their counterparts in shallow and zero tilled plots. Conservative tillage practices are recommended for sustainable and profitable production of maize crop in Nigeria. Key words: Edaphic, grain yield, organic carbon, soil properties, tillage practices.