Effects of soil substrate quantity and nitrogen fertilizer on soil chemical properties and nutrients uptake by cocoa (Theobroma cacao Linn.) seedlings in Togo

A problem for container tillers is managing container substrate and plant fertility. A comparative study in nurseries on the effects of soil quantity in pot and nitrogen fertilizer on the chemical properties of residual soil and the nutriments uptake by cocoa seedlings were led in a Randomized Complete Block Design. Two types of pots with different capacities (1055 cm3 and 2021 cm3) without any contribution and four nitrogen doses applied in pots of 2021 cm3, were used. The two nurseries were managed under the same conditions. Data were collected on the soil samples at the beginning and the end of experiment then analysed. The results showed that the cocoa seedlings effectively used the soil nutriments reserves but there was no significant difference (p>0.05) between the seedlings nutrition in the two types of sachets, nor with the nitrogen application. The major nutriments budget showed that the sold of N, K and Mg were negative whereas those of P and Ca were positive. Calcium profits were so stable whereas P profits were gradual according to the increasing amount of N. Thus, it is possible to grow cocoa seedlings on soil contained in pots of 1055 cm3 (coffee pot) while ensuring a balanced nutrition of the seedlings.