Aim/Objectives: In order to assess the fallow contribution on the carbon cycle and soil organic matter restoration, a study of the carbon dynamics was undertaken in fallow systems of 1, 2, 5 and 20 years old in the Ngaoundere savannahs of... more
Aim/Objectives: In order to assess the fallow contribution on the carbon cycle and soil organic matter restoration, a study of the carbon dynamics was undertaken in fallow systems of 1, 2, 5 and 20 years old in the Ngaoundere savannahs of Cameroon. Methodology: Carbon stock was estimated in 100 m2 plot for shrubs, in 1 m2 plot for understorey, litter and earthworm casts, and 0.0625m2 plot for fine roots and soil. The experimental design was randomised complete block with three replicates. The age of fallows was the mean treatment whereas the plots were the replicates. Results: The results showed that the phytomass increased with fallow age, except that of shrubs. Soils and earthworm casts were the mean carbon sinks in the four fallows, with more than 55.61% and 26.24% of the total carbon stock respectively in the soil and earthworm casts. The total carbon stock increased with fallow age, from 34.54 in the young fallows to 154.52 tC.ha-1 in the old fallows. In the same way, vegetatio...
Litter decomposition processes are poorly studied in the savannahs. Leaf litter decomposition of the twenty-four contrasting plant species including trees, shrubs and grass species, was studied in the sudano-guinea savannahs of... more
Litter decomposition processes are poorly studied in the savannahs. Leaf litter decomposition of the twenty-four contrasting plant species including trees, shrubs and grass species, was studied in the sudano-guinea savannahs of Ngaoundere, Cameroon. The litterbag technique was used to assess litter mass loss and single exponential model was adopted to estimate decay rate constants. Initial litter thickness varied from 0.02 to 1.11 mm, area from 4.27 to 245.89 mm2, sclerophyllous index from 0.01 to 1.75 mg.mm-2, density from 0.21 to 87.50 mg.mm-3, and specific mass area from 0.57 to 185.46 mm2.mg-1. Litter cellulose content varied from 3.79 to 11.84%; lignin from 2.84 to 8.12%, NDF from 21.35 to 80.41%, and total phenolic compounds from 0.47 to 17.76%. During the 52 weeks of the field experiment, mean dry mass remaining of litter samples was significantly between 8.05 and 75.22% of initial litter dry mass for C. papaya and C. regidus respectively. Litter decomposition rate constant (k...
The effect of microorganisms particularly those of bacteria on litter decomposition in the tropical savannahs of Adamawa Cameroon is poorly investigated. Litter decomposition was conducted in the field on the litter of Ficus sycomorus,... more
The effect of microorganisms particularly those of bacteria on litter decomposition in the tropical savannahs of Adamawa Cameroon is poorly investigated. Litter decomposition was conducted in the field on the litter of Ficus sycomorus, Terminalia glaucescens, Daniellia oliveri, and Hymenocardia acida, and the dynamic of bacterial populationas well as their enzymatic activity during degradation of leaf litters was studied. For this purpose, bacteria were isolated from the litterof these plants at the initial time (zero), 12 and 24 weeks of degradation by serial dilution method and spreading onto nutrient agar culture medium. Identification of bacteria was done under photonic microscope after Gram staining and the production of enzymes was carried out on specific media. Results indicate that: 25 bacteria were isolated from distinct phenotypic characteristics on nutrient agar. Based on morphological appearance as observed under light microscope, 24% of isolates were found to be single ...
Litter production which is important for understanding nutrient cycling and assessing productivity in forest ecosystems is poorly studied in the African savannahs, particularly in the savannahs of Cameroon. Thus, litter production and... more
Litter production which is important for understanding nutrient cycling and assessing productivity in forest ecosystems is poorly studied in the African savannahs, particularly in the savannahs of Cameroon. Thus, litter production and organic compounds of the thirty-six (36) contrasting plant species were studied in the Sudano-guinea savannahs of Ngaoundere, Cameroon. Litter collected in framework of 50 cm x 50 cm under the three tree of each plant species in three sites of the savannahs of Ngaoundere during the period of their maximum fall that from November and January. After two years of collection, mean annual litter production varied from 0.36 in S. longipedunculata to 10.06 t.ha-1.year-1 in F. polita at Dang, from 0.14 in G. aqualla to 9.39 t.ha-1.year-1 in V. paradoxa at Biskewal, and from 0.35 in G. aqualla to 3.64 t.ha-1.year-1 in S. guineense var. macrocarpum at Wakwa. Contribution of leaf litter, fruits and wood were respectively more than 50%, 1.40% and 32% to the total ...
Few studies on effects of termites on litter decomposition have been done in African savannahs, particularly in the Adamawa savannahs of Cameroon. In the framework of management of resource quality to restore or improve soil fertility of... more
Few studies on effects of termites on litter decomposition have been done in African savannahs, particularly in the Adamawa savannahs of Cameroon. In the framework of management of resource quality to restore or improve soil fertility of farming systems of Sudano-guinea savannahs of Ngaoundere, Cameroon, study on termites’ control of leaf litter decomposition of eight plant species was conducted on the field. The selected plant species are Bixa orellana, Erythrina sigmoïdea, Ficus polita, Maytenus senegalensis, Mucuna stans, Piliostigma thonningii, Vitex madiensis and Vitellaria paradoxa. Leaf litter samples were incubated in situ using litterbags of 2 mm mesh during 24 weeks in two plots out of canopy, corresponding to two treatments, with and without termites. Experimental design was split-plot with three replications. Collected data was carried out on litter dry mass remaining (LMR). Results showed total mass loss at the end of incubation time (24 weeks) and decomposition rate co...
The study, which covered "study the dynamics of the Minawao vegetation cover and its surroundings (Far North, Cameroon), took place in five villages: Minawao, Gawar, Sabongari, Windé and Zamay. The main objective was to help manage... more
The study, which covered "study the dynamics of the Minawao vegetation cover and its surroundings (Far North, Cameroon), took place in five villages: Minawao, Gawar, Sabongari, Windé and Zamay. The main objective was to help manage the impacts of populations on the Minawao vegetation cover and its surroundings in order to improve the living conditions of refugees and local populations. In each village, floristic surveys were carried out in 5 plants formations (shrub savannah, forest gallery, tree savannah, field and dwellings). For satellite images, the 14-year interval (2006 to 2020) was retained. Analysis of the data identified 23 species, 21 gender and 14 families over the 120 hectares of study area. The annual rate of regression indicates that the village of Minawao and the river side villages are experiencing more degradation after the settlement of refugees than before, with their respective regression rates of -10.81 ha/year and -8.93 ha/year. The maximum carbon is store...
Impact of organic matter management on the mineral status of soils and harvests in the sudano-guinean savannas of Ngaoundere, Cameroon. In sub-Saharan Africa, we know little about the relationship between management methods for Organic... more
Impact of organic matter management on the mineral status of soils and harvests in the sudano-guinean savannas of Ngaoundere, Cameroon. In sub-Saharan Africa, we know little about the relationship between management methods for Organic Matter (OM), soil quality and the resulting food produced. The current study demonstrates the influence of OM management methods on the bioavailability of nutrients and mineral quality of harvests. Thus, in the Dang locality (Ngaoundere, Cameroon), the soils and tomato fruits sampled in plots of 1 m for tomatoes and 0.0625 m for soil were analyzed according to three OM management methods (household waste, chemical fertilizers, chemical fertilizers + animal waste), fallows (fallows of 1, 2, 5 and 20 years) and burnt 20 year-old fallow. The results show that the practice of fallow for more than 2 years and applications of organic manure effectively restore soil OM (SOM) and pH, as well as N, P, Ca and Mg in soil and tomatoes. However, the practice of bu...
