| Resume |
A study was carried out to compare the influence of four Guinea grass ecotypes
(Panicum maximum) differing in their morphological, physiological, and agronomical
traits on soil fertility in Soudanian region of West Africa. Plants were sown in a
randomized complete block design with four replicates and cultivated during three
successive years under a cut-and-carry regime without any fertiliser use. A natural
fallow served as the control. Soil samples were collected before and after cultivation,
and analyzed for pH, organic carbon, nitrogen, available P, and exchangeable cation
contents. Aerial plant production was quantified and analyzed for N, P, and K content
to estimate the uptake of these nutrients. Root biomass, depth, and distribution were
also measured. Data were analyzed through ANOVA. After 3 years of cultivation, soil
pH under plants did not vary but C and N concentrations declined from the initial
levels. Owing to their deep rooting systems, two ecotypes can recycle nutrients
apparently from deeper soil layers. While these ecotypes could be used for ley pastures
in savannah regions of West Africa, maintenance fertiliser applications would be
required to prevent nutrient depletion under a cut-and-carry regime. Further studies
to test the efficacy of farmyard manure in providing these nutrients seem warranted. |