Variations in soil seed banks of abandoned farmlands of various ages in Umukabia Umuagbom, Abia State, Nigeria

A 3 x 5 Factorial Experiment in Randomized Complete Block design Experiment was used to study seeds stocked in soils of four abandoned farmlands and a secondary forest regrowth at Umukabia, Nigeria. Soil monoliths 25.0 x 25.0 x 10.0 cm were collected from the depths 0-10 cm and 10.0-20.0 cm from four abandoned farmlands and a secondary forest regrowth in the months of August, September and October, 2008. The experiment was replicated twice at each site for each month. Sieving- floatation method was adopted and two sieves of 1.85 mm and 0.80 mm mesh opening were used to sieve each soil monolith. The left over after sieving were air dried under the room temperature. The dried soil materials for each sample were viewed with a 10 magnifying hand lens to sort and enumerate the number of seeds contained in each sample. The seeds found at both depth of 0 - 10 cm and 10 - 20 cm were identified. After collection of the seeds, the data obtained were analyzed and the differences between the treatment means were separated using Fisher’s - Least Significant differences (F-LSD) at P<0.05. The total number of seeds counted from soil monoliths collected from the depths of 0.0 – 10.0 cm and 10.0-20.0 cm were 344 and 99, respectively. For months, September with a mean of 12.90 seeds had the highest number of seeds while seven year old abandoned farmland with a mean of 14.67 seeds had the highest number of seeds amongst the various abandoned farmlands. Except seeds of Canariums chweinfurthii and Dialium guineense no other tree seeds were recorded. It was concluded that man should help in tree seeds dispersal and seedlings maintenance within abandoned farmland of the tropical rainforest to minimize the danger of most tree species being classified as being rare or endangered. © 2013 International Formulae Group. All rights reserved.Keywords: seed stocked, soil, sieving-floatation, secondary forest, regrowth