Effect of land preparation method and potassium application on the growth and storage root yield of cassava in an acid Ultisol

Abstract

A 2 year field trial was conducted in an Ultisol in the forest zone of southeastern Nigeria to ascertain if planting cassava ( Manihot esculenta, Crantz) on ridges 35–37 cm high had any significant advantage over flat planting in view of the extra cost of making ridges. The interaction of these methods of land preparation with cassava response to potassium was also investigated. The experiment was carried out on a sandy well-drained soil. Both storage root yield (SRY) and total dry matter yield (TDMY) were significantly higher in the first year (1990) than in the second year (1991), and were not significantly affected by the method of land preparation in both years. The optimum K rates for maximum SRY were 105 kg ha −1 and 124 kg ha −1 for flat and ridge planting respectively in 1990, and 89 kg ha −1 K for flat planting in 1991, the response being linear for plants on ridges. Increasing rates of K increased the efficiency of storage root production in 1991. As ridging had no significant advantage over flat planting, and the interaction of method of land preparation and K response was not significant, ridging for cassava production in non-waterlogged areas in the forest zone of southeastern Nigeria should be re-examined.