Survey of properties and constraints of some soils of Cross River State, Nigeria, for higher yields of rubber (Hevea brasiliensis Muel Agro) trees.

摘要

The physical and chemical properties of some soils in Cross-River State, Nigeria grown to rubber (Hevea brasiliensis) and their constraints to higher productivity examined using seventy two soil samples taken from twenty-four randomly distributed profile across the state. Results indicated that the soils are generally deep, sandy at the surface and clayey at the sub-surface layers, well-drained, friable when moist and slightly susceptible to water erosion. The soils were generally acid in reaction and moderate in their levels of organic carbon and available phosphorus on the surface soils but rather low in total nitrogen. Except for sodium, the levels of all exchangeable bases were low to very low particularly in the subsurface horizons of these soils. Consequently, the effective cation exchange capacity values obtained were generally low being dominated by hydrogen and aluminium. Constraints associated with the poor physical and chemical constitution of the present soils and measures aimed at correcting these problems are discussed in relation to optimal growth and performance of rubber trees.