Influence of Five Years of Tillage and Poultry Manure Application on Soil Properties and Ginger (Ziginber officinale Roscoe) Productivity

Tillage and use of organic manure are essential agronomic practices that affect soil properties and have a direct impact on soil sustainability and crop productivity. Hence, a five-year (2012 to 2016) field trial was carried at two sites (Owo — site 1 and Uso — site 2), in the forest-savanna transition zone of southwest Nigeria to assess the effect of tillage and poultry manure on soil physical and chemical properties, growth and yield of ginger (Zingiber officinale Roscoe). The study was a 2 × 5 × 5 factorial experiment with three replicates. The treatments were five tillage methods; zero tillage (ZT), manual ridging (MR), manual mounding (MM), ploughing plus harrowing (P+H), and ploughing plus harrowing twice (P+2H) and five levels of poultry manure (PM) (0, 5.0, 10.0, 15.0, 20.0 t ha−1). Soil bulk density (BD) increased, while soil water content (WC) decreased with increase in tillage intensity, whereas soil OM, N, P, K, Ca, and Mg reduced with increase in tillage intensity, thus ZT conserved soil OM and nutrients the most, and increased nutrient uptake. Soil OM and nutrient concentrations was lowest under the P+2H treatment due to leaching, oxidation, and increased biological activity. The ZT, MR, and MM treatments prompted quicker growth and higher rhizome yield. As PM increased from 0 to 20.0 t ha−1 soil BD and WC tend to improve and soil pH, OM, N, P, K, Ca, and Mg increased. The 15.0 t ha−1 PM gave the highest soil K, Ca, and Mg values. Site 1 had significantly higher growth and yield parameters of ginger compared with site 2. Growth and yield parameters of ginger increased with increase in PM level up to 15.0 t ha−1. Among all tillage cum manure treatments, ZT+15.0 t ha−1 PM gave the highest values of growth and yield parameters of ginger.