Influence of tillage on soil penetration resistance and maize performance in Ghana's coastal savannah agro-ecological zone

Tillage practices tend to influence soil physical characteristics and the performance of crops. This study assessed the impacts of different tillage systems (i.e. two conservation tillage systems (no-tillage (NT) and harrowing only (H)) and two conventional tillage systems (ploughing only (P) and ploughing followed by harrowing (PH)) on soil penetration resistance and their impact on abontem maize variety growth and yield. Initial measurements indicated higher penetration resistance in no-tillage plots at the onset of the growing season. The trend shifted towards having lower penetration resistance in no-tillage plots as the crop developed, particularly compared to conventional tillage systems such as PH. The NT treatment recorded lowest root system architecture while the maximum values were recorded in the harrowing only plots, especially with respect to average diameter, root length in the 4 mm diameter class, surface area, number of root tips and surface area. Further, the results showed that NT had the lowest germination rate (68%) as well as other growth parameters and yield, while the Ploughing alone resulted in the highest grain yield during the first season. However, when considering both seasons, the PH treatment consistently demonstrated superior agronomic performance. It recorded the highest values for key growth parameters, including Leaf Area Index (1.50–1.75), stem diameter (20–22.5 mm), and plant height (165–175 cm). Overall, PH achieved the greatest yields, with biomass ranging from 7.20 to 10.93 t ha -1 and grain yield from 4.619 to 5.67 t ha -1 . Despite its lower yields, NT showed the highest yield improvement (+1.11 t/ha), which is suggestive of its potential for improved crop performance in the long-term while that of the conventional practices like PH could be considered for short-term cultivation.