Rainforest Agro-ecological Zone Research Articles

Investigating smallholder farmers’ practical experiences, perceptions and response to climate change: An empirical analysis in Cameroon

Climate change is constraining rural wellbeing, agriculture and food security. This necessitates adaptive strategies to overcome negative effects especially at the level of low-income tropical farming households. Using survey data from farming households in the Western Highland and the Bimodal Rainfall Humid Forest agro-ecological zones in Cameroon, this study evaluates the socio-economic and institutional factors associated with farmers’ perception and adaptive response to climate variability and change. We employed a logistic regression model to estimate the drivers of farmers’ perception. Our results show that farmers’ experience and land status (ownership) are positively associated with farmers’ ability to perceive climate change in the Western highlands agro-ecological zone. Access to credit, membership in a farmers’ organisation and gender are significant drivers in the Rainforest agro-ecological zone. Our findings show that different socio-economic and institutional factors drive perception and these factors differ between zones. The findings have important implications for short-term adoption of coping strategies and medium-term adaptation planning. We suggest that farmers’ capacity is improved through early-warning climate information and the creation of farmer field school to vulgarise climate smart farming techniques and supplemented with timely technical support from the governmental extension services.

Agricultural land use policies and landscape dynamics: Evidence from rainforest agroecological zone

Agricultural-land use policies play a crucial role in shaping agroecological landscapes globally. The evidence suggests that some of these policies tend to have undesired feedback/trade-offs, particularly about coastal resource use and conservation planning. The present study explores how agricultural policies influence land use/land cover (LULC) transition patterns in Ghana's Rain Forest Agroecological Zone (RFAZ). Landsat satellite images for 1991, 2008, and 2022 were acquired for the LULC mapping. Change detection and Intensity analysis were used to assess the pattern of land change. Also, documentary research processes were used to review and assess agricultural land use policies. The results showed that before rubber-related policy implementation, oil palm plantation was the dominant LULC type in the 1990 s. In the 1990 s and early 2000 s, there was a conscious government drive to leverage oil palm plantation development. This led to the growth in the size of oil palm plantations within the RFAZ landscape, considering the zone’s conducive natural environment. However, between 2008 and 2022, corresponding to the period of the increased promotion of rubber cultivation through the Outgrower project in the RFAZ, rubber plantations became the predominant land use, with an area of 11,763.81 ha in 2008 and 21,611.61 ha in 2022. The results from the LULC mapping and the intensity analysis showed that the Rubber Outgrowers Plantation Project (ROPP) and Norpalm Smallholder Scheme Project (NSSP) have degraded the natural cover through rubber and oil palm cultivation. The authors conclude that landscape dynamics, particularly in rainforest agroecological zones, represent a nexus challenge transforming policy adaptation's discursive context. The study recommends that agriculture and landscape policy/projects must have/take intermediary steps to address the feedback/trade-offs from well-intended initiatives. The study further suggests that management plans and strategies in the RFAZ should be consistent with the strict protection of forest reserves and water bodies.

Improving the yield and nutritional quality of cassava (Manihot esculenta Crantz) in the rainforest agro-ecological zone of southeast Nigeria through agronomic biofortification with micronutrients

Cassava (Manihot esculenta Crantz) is an important staple crop, especially for resource-poor populations. Cassava-based diets are rich in calories but grossly deficient in essential mineral elements. A field study in southeastern Nigeria aimed at increasing yields and concentrations of bioavailable mineral elements in a β-carotene cassava variety, UMUCASS 38 (TMS 01/1371), through agronomic biofortification. A randomized complete block design experiment in triplicate, with foliar application of Zn (3.0 kg ha−1 Zn as ZnSO4), I (4.0 kg ha−1 I as KI), Se (0.25 kg ha−1 Se as Na2SeO3) and Zn + Se + I in combination at vegetative, tuber initiation and bulking stages of cassava. Results indicated neither phytotoxicity nor altered physical and chemical soil properties. Application of Zn or Zn + Se + I at the vegetative stage significantly increased cassava tuber yields. More Zn, Se, and I accumulated in fresh and processed cassava tuber products (gari, lafun), especially when Zn + Se + I was applied at tuber initiation stage. The combined application of Zn + Se + I consistently outperformed sole applications indicating a synergistic interaction effect between the three elements. It is concluded that in the Zn-deficient soils of southeast Nigeria, yield of cassava root tubers can be significantly increased by foliar application of Zn-containing fertilizer at the vegetative stage, but for optimal accumulation of elemental Zn, Se, and I, a combined Zn + Se + I fertilizer be applied at the tuber initiation stage.

Allometric equations and carbon stocks assessment for Bambusa vulgaris Schrad. ex J.C.Wendl. in the bimodal rainfall forest of Cameroon

Over the last two decades, bamboo has received increasing attention owing to its socio-economic and environmental importance. Environmentally, bamboo plays an important role in carbon sequestration, thus enhancing climate change mitigation. In Cameroon, knowledge about the importance of Bambusa vulgaris Schrad. ex J.C.Wendl. to climate change mitigation is deficient, despite the fact that it is the most abundant bamboo species in Cameroon's Bimodal rainforest agroecological zone (Agroecological zone 5 - AEZ5). This study was initiated to develop allometric equations and estimate carbon stocks of B. vulgaris in Cameroon's AEZ5. The destructive, clump-based method was used for bamboo biomass data collection on 40 clumps and 86 culms. Regression analyses were performed to obtain allometric models for B. vulgaris biomass prediction which were used for B. vulgaris carbon stocks estimation in AEZ5. The best allometric model for culms was obtained when all predictive variables including age, diameter and height were considered into the model. For clump, the best model was obtained when the number of culms per clump, girth and average diameter were considered in the model. Model quality adjustment was better for clump aboveground biomass (AGB) compared to those of culm AGB. The model of B. vulgaris of the evergreen rainfall forest was validated with a bias of 45.5 %. Bamboo aboveground biomass proportions were 77 %, 15 % and 8 %, respectively for culms, branches and leaves. The mean density and carbon stocks of B. vulgaris were estimated at 2,0679 culms.ha−1, 257 clumps.ha−1, and 61.65 tC ha−1. B. vulgaris has a veritable carbon sequestration capacity which policymakers should consider in climate change mitigation strategies like those linked to payments for ecosystem services, voluntary carbon stocks market, Bonn Challenge, AFR100 initiative, and the Paris agreement ratified by the government of Cameroon.

Effect of Different Staking Methods on the Growth and yield of Tomato (Solanum Lycopersicum) in the Rainforest Agro-ecological Zone

Effect of Different Staking Methods on the Growth and yield of Tomato (Solanum Lycopersicum) in the Rainforest Agro-ecological Zone

Soil properties affecting soil organic carbon stock of different land use types in two agro-ecological zones of Nigeria

Soil organic carbon (SOC) stock is the carbon proportion that is of biological origin stored with respect to soil depth. It is more prone to loss than soil inorganic carbon. High sequestration of SOC in soil is germane to the improvement of soil quality and mitigating impact of climate change. Thus, this study was carried out to evaluate soil properties affecting SOC stock in the two agro-ecological zones, namely Upland Rainforest (Ado-Ekiti) and southern Guinea Savanna (Kabba) agro-ecological zones of Nigeria, with respect to three selected land use types; arable, oil palm and wetland. Random collection of soil samples was carried out at four varying depths (0-15, 15-30, 30-45, and 45-60 cm) for evaluation of soil properties. The SOC stock regression models for the two agro-ecological zones showed that land use, SOC, pH, SOM (soil organic matter), Ex-K, Ex-Ca, Ex-Mg (exchangeable potassium, calcium, magnesium, respectively), BD (bulk density), and gravel content would predict variation in SOC stock in the two agro-ecological zones with coefficient of determination (R2) values of 0.952 and 0.996 for Kabba and Ado-Ekiti respectively. Principal component analysis identified that in the soil of the southern Guinea Savanna agro-ecological zone, SOC, CEC, EA, Ex-Na, land use, clay content, and soil depth with Eigenvalues > 1 explained 80.58% of sample variance while in the soil of the Upland Rainforest agro-ecological zone, Ex-Ca, SOC, Ex-Na, EA, sand and silt contents with Eigenvalues > 1 explained 78.81% of sample variance as potential determinants of SOC stock.

Fizičko-hemijske osobine zemljišta nastalih iz različitih geoloških formacija u tipičnoj kišinoj agro-ekološkoj zoni

Climatic conditions and geologic formations have been found to influence the nature of soils formed. Therefore, this study seeks to study the physical and chemical properties of the soils derived from the different geologic formations of a typical West African rainforest agroecological zone. 90 soil samples were generated from the field using standard field procedures. Standard laboratory method was used in carrying out the physico-chemical analysis of the collected soil samples. The results obtained showed the range of some selected soil properties coarse sand (32.25 to 61.62), fine sand (18.17 to 29.87%), total sand (62.22 to 85.93), silt (2.88 to 19.86%), Clay (10.3 to 18.46%), the structural code (1.77 to 3.77), porosity (50.55 to 61.20%), permeability (2.98 to 9.27 cm/hr), bulk density (1.35 to 1.57g/cm3 ) and a permeability class (1.77 to 2.87 cm/hr), pH (5.22 to 5.62), organic matter (5.17 to 6.60%), available phosphorus (19.43 to 28.37%), calcium (4.98 to 19.11%), magnesium (1.39 to 3.34%), sodium (0.06 to 2.8%), potassium (0.04 to 0.29%) and ECEC (8.96 to 17.14 Cmolc/kg). The results indicate the different physico-chemical properties of the formed from the different geologic formation of the study area. There is no statistical difference on the soils across the depth of the each geologic formation. The results obtained show that geologic formation have impact on the physicochemical properties of the soils. The results obtained in this research can served as a guide in soil management, utilization and conservation.

Differential Availability of Different Weed Species for Cattle Production in the Selected Derived Savannah and Rainforest Agro-ecological Zones of Nigeria

Among the major factors that determine the success of cattle production in Nigeria is the availability of palatable weed species. Hence the need to conduct research on the availability of palatable, edible and non-edible weed species for cattle production in the selected two agro-ecological zones (Derived savannah and rainforest) of North center and Southwest in Nigeria becomes imperative. The study involved three parallel transects, each of 12.5 m x 12.5 m and ten evenly spaced different weed species sampled quadrats (1 m x1 m) were taken and replicated three times. The results showed that non-edible Hyptis suaveolens (94.2%) dominated the derived savannah and palatable Pennisetum species (36.8%) dominated the rainforest. The analysis of variance and New Duncan Multiple Range Tests (p = 0.05) revealed that there was a statistically significant (p \(\le\) 0.01) difference within the agro-ecological zones and availability of palatable, edible and non-edible weed species. However, in the derived savannah agro-ecological zone, the non-edible weed species had pronounced significant (p \(\le\) 0.01) availability, while in the rainforest agro-ecological zone, the palatable weeds had pronounced significant (p \(\le\) 0.01) availability. It could be concluded therefore, that if urgent steps are not taken, cattle will continue to move from the derived savannah (more non-edible weeds) to rainforest (more palatable weeds) and this will cause farmers-herders’ conflict. In addition, there would be more propagation of these non-edible weeds especially H. suaveolens as a result of cattle movement to the rainforest, an act that could cause more weeds imbalance in the rainforest.

Phenotypic diversity and path analysis of seed yield in Bambara groundnut grown in rain forest agroecological zone

Abstract Bambara groundnut is a reliable source of carbohydrates and protein in rainforest agroecology, but limited research had been done and few varieties commercialised. The magnitude of phenotypic variability, character association, and contribution of characters to seed yield were investigated among 50 accessions received from IITA, Nigeria. Field evaluation took place during the 2017 – 18 cropping seasons. The accessions were allocated to experimental plots using a Randomised Complete Block Design with three replicates. Data were collected on phenological, agronomic, and seed yield characters. The main effect showed significant (p ≤ 0.05) differences for phenological, vegetative, and reproductive characters. The year effect influenced agronomic and seed yield characters while accessions by year interaction were insignificant for all characters. The stepwise discriminant analysis identified three redundant characters. The leaflet length and width, canopy spread, leaf/plant, seeds/plant, and seed weight showed high discriminatory ability and are efficient for morphological characterisation and conservation. Hybridisation between accessions dispersed in quadrants 1, 2, and 4 may evolve early and medium maturity types with improved seed yield and biomass. The number of seeds/plant and pods/plant are indices for seed yield. The contribution of pods/plant to seed yield was masked by canopy spread, peduncle length, and pod width indicating competition for photo-assimilates. TVSu 17, TVSu 277, TVSu 271, and TVSu 278 are donor parents for earliness. TVSu 261 performed best for seed yield and yield component characters. Hybridisation among TVSu 261, TVSu 587, TVSu 275, and TVSu 17 will evolve medium maturing and high seed-yielding varieties for further evaluation.

Soil properties and tree growth performance along a slope of a reclaimed land in the rain forest agroecological zone of Ghana

Reforestation of degraded forest lands has always involved the use of multipurpose tree species. However, understanding the relations between tree growth and soil fertility attributes along slopes of degraded mine sites by reforestation is limited, especially in Ghana. Therefore, a study was carried out at a rehabilitated degraded land to determine the influence of slope on soil fertility attributes and growth performance of trees. Plots were laid in the upslope, midslope and downslope, with an adjacent undisturbed forest as a control for sampling purposes. Soil samples were collected (0–15 and 15–30 cm depth) from the various sampling locations to determine soil properties, as well as tree growth parameters (e.g., height, basal area, and biomass). Slope positions impacted on tree growth (above and below ground biomass, and basal area) and soil properties. Highest soil organic carbon (1.80%), total N (0.22%), available P (6.92 mg kg−1), exchangeable K (0.20 cmolckg−1), and NO3−-N (19.03 mg N kg−1) were observed at the midslope position, whilst the upslope recorded the least values. The results also revealed that the midslope position recorded the highest tree growth characteristics. Aboveground biomass ranged from 17.67 to 21.73 mg ha−1, indicating the trees’ potential as carbon sinks. Furthermore, principal component analysis revealed that 3 components had their eigenvalues > 1, and accounted for 79.50% of the total variance. These results clearly demonstrate that spatial variations in soil properties are influenced by slope, and gives reference for future rehabilitation processes by reforestation.

Growth performance, genetic parameters and selection index of pure and crossbred populations of Red Sokoto and West African Dwarf goats

In 2008, a breeding programme was designed to develop hybrid goat suitable for the rainforest agro-ecological zone of South-Eastern, Nigeria. Two indigenous goat breeds namely, Red Sokoto (RS) and West African Dwarf (WAD) goats were utilized and mated in a main (RS x WAD), reciprocal (WAD x RS) and pure line (RS x RS and WAD x WAD) fashion. A total of 74 progenies were generated from the matings and were evaluated for 12week growth performance. As part of the ranking procedure, a selection index was constructed based on two major body components namely body weight (BWT) and heart girth (HGT) to objectively determine the genetic worth of the growing pure and crossbred progenies of Red Sokoto and West African Dwarf kids. The results showed that average body weight (BWT) of RS x RS (5.29±0.13kg) and RS x WAD (5.14±0.21kg) buck kids were similar but significantly (P< 0.05) heavier than that of their WAD x RS (4.84 + 0.17kg) and WAD x WAD (4.79 + 0.17kg) counterparts. The performance of crossbred RS x WAD compared to WAD x RS and WAD x WAD buck kids indicate that the main crossbred kids sired by Red Sokoto bucks but nursed by WAD dams received superior sets of genes from their large-sized sire. The RS x WAD buck kids in particular, had significantly longer body length (BLT), height-at-withers (HWT) and HGT than WAD x RS and WAD x WAD kids. The phenotypic and genetic correlations of BWT and HGT in both sexes for the different genotypes were high and positive which were indicative of the nature of association between these conformation traits in goats. Heritability estimates (h2) for BWT and HGT in males and females kids ranged from 0.31 – 0.36 versus 0.28 – 0.30, respectively in most of the growing kids. The relative economic values (REV) of chosen traits were generally higher for male kids compared to their female counterparts. Phenotypic variances for BWT and HGT in male and female kids ranged from 0.65 – 0.80. The selection index values were highest in male and female kids of RS x RS, followed by RS x WAD, while WAD x RS kids ranked low and WAD x WAD kids ranked the least. Thus, indicating that selection and improvement of growth traits in these pure and crossbred kids would be in favour of the RS x RS and RS x WAD individuals.

Growth assessment of juvenile oil palm (Elaeis guineensis Jacq.) intercropped with fruit vegetables in a rainforest zone of Nigeria

Improper intercropping of Elaeis guineensis with other crops has impaired the growth and development of the oil palm due to competition for environmental resources. The study was conducted to investigate the impact of intercropping on the growth of juvenile oil palm for 2 years. The research commenced during the rainy season of 2016 at an established juvenile oil palm plantation in Ala, Akure-North Local Government of Ondo State. Four fruit vegetables were intercropped separately within the alley of the plantation at 1, 2 or 3 m away from the oil palms in a randomized complete block design. Growth parameters of the juvenile oils were assessed. Results revealed that at 16 weeks after intercropping (WAI), the intercropped oil palm recorded better growth performance with higher canopy spread, number of frond, number of leaflets and trunk height (218.20, 37.00, 87.48 and 38.17 cm) respectively, than the sole oil palms (214.67, 32.83, 72.89 and 31.67 cm) respectively. There were no significant difference in all the growth parameters examined except canopy height (p < 0.05). Juvenile oil palm cultivated in rainforest agroecological zone of Nigeria can be intercropped with fruit vegetables without any deleterious effect when intercropped at minimum of 1 m away from the oil palms.

Physico-Chemical and Microbiological Constituents of Honey Obtained from Tropical Rainforest Agro-Ecological Zone of Nigeria

Physico-Chemical and Microbiological Constituents of Honey Obtained from Tropical Rainforest Agro-Ecological Zone of Nigeria

The role of shade trees in influencing farmers’ adoption of cocoa agroforestry systems: Insight from semi-deciduous rain forest agroecological zone of Ghana

Farmers growing desire for no shade cocoa system has reiterated the scepticism about the impact of research on farmers’ adoption of cocoa Agroforestry. In this study, we assess farmers’ perception about shade trees and how that influences their adoption of cocoa Agroforestry. Five cocoa growing communities in the Eastern Region of Ghana and 91 cocoa farmers were purposively sampled and interviewed. The result showed that the most desirable shade trees among the farmers were Spathodea campanulata, Terminalia superba, and Terminalia ivorensis while Alstonei boonei was the least desirable. About 87 % of farmers introduced shade trees at different stages of cocoa farm establishment while 13 % of farmers had existing trees at establishment. Farmers with less than 11 years farming experience and those with Senior High education kept the recommended number (15–18) of shade trees ha−1. Most farmers related the importance of shade trees to the good growth of cocoa associated crops (37 %) and as source of fodder (31 %), while higher cocoa yield and low education on the importance of shade trees were major reasons farmers removed shade trees. In conclusion, collaboration between farmers and other stakeholders in the cocoa sector is essential in reversing the growing hunger for no shaded cocoa system. This collaboration must focus on educating farmers on the importance of shade trees, and by providing money and agro-inputs support to farmers as impetus for the adoption of cocoa Agroforestry in Ghana.

Factors Influencing Cassava Farmers' Choices of Climate Adaptation Strategies in Rainforest Agro-Ecological Zone of Southwest, Nigeria

Factors Influencing Cassava Farmers' Choices of Climate Adaptation Strategies in Rainforest Agro-Ecological Zone of Southwest, Nigeria

Evaluation of Bambara Groundnut (Vigna Subterranea (L) Verdc.) Varieties for Adaptation to Rainforest Agroecological Zone of Delta State, Nigeria

Evaluation of Bambara Groundnut (Vigna Subterranea (L) Verdc.) Varieties for Adaptation to Rainforest Agroecological Zone of Delta State, Nigeria

Assessment of Bambara Groundnut (Vigna Subterranea (L) Verdc) Varieties for Adaptation to Rainforest Agro-Ecological Zone of Anambra State of Nigeria

Field experiments were carried out to evaluate the adaptability of Bambara groundnut (Vigna subterranea (L) Verdc) varieties to rainforest agro-ecological zone of Anambra State using selected varieties. The varieties used were: EXMF1, EXMF2, EXMF3, EXMF4, IITA355, IITA182, IITA165, IITA1480, IITA1132, ENZK1 and ENZK2. The aim of this experiment was to identify the varieties of Bambara groundnut that will be most suitable in this agro-ecological zone. The design used in this experiment was a Randomized Complete Block Design (RCBD) replicated three times. The parameters collected were: days to seed germination (seed emergence), percentage seed germination, number of leaves, total leaf area, number of pods per plant, pod and seed weight per plant(g), and seed yield (kg/ha). The result showed that varieties EXMF1, EXMF4, IITA165 and ENZK2 performed better than others both in growth and yield parameters collected and analyzed. Variety EXMF4 was outstanding in yield with the mean value of 5267kg/ha followed by ENZK2 with the mean value of 5000kg/ha. The least in yield was IITA182 followed by ENZK1 with the values of 2445 and 2600kg/ha respectively. The outstanding variety EXMF4 was recommended to farmers in the area for cultivation.

Evaluation of hybrids Sorghum (Sorghum bicolor L. Moench.) for growth and yield in a rainforest agro-ecological zone

Evaluation of hybrids Sorghum (Sorghum bicolor L. Moench.) for growth and yield in a rainforest agro-ecological zone

Response of maize (Zea mays L.) growth and yield to different fertilizer application in rainforest agro-ecological zone of Nigeria: Evaluation of CERES-maize crop model

Field trials were carried out in the Rainforest agroecological zone of Nigeria to assess the usefulness of the CERES – maize model as a decision support tool for optimizing growth and yield production of maize crop through varying application of organic manure as well as recommended NPK 20:10:10 fertilizer rate. The experiment was laid in a Randomized Complete Block Design (RCBD) in three (3) replications. The trial was conducted in the 2016 growing season at the Teaching and Research Farm, Federal University of Technology, Akure (FUTA) to calibrate and evaluate the performance of three (3) maize cultivars (Suwan-1-SR-Y, ART/98/SW1, ART/98/SW6 respectively) using sunshine organic manure (SOM) applied at the rate of 0, 60, 90, and 120 kg ha-1 and NPK 20:10:10 applied at a recommended rate of 70 kg N ha-1. Model performance across fertilizer management was evaluated using some statistical indicators such as Mean Square error (RMSE), Mean bias error (MBE), and R2 to measure its efficacy. Results showed that the model predictions captured the agronomic response of all the maize cultivars used across the fertilizer application rates. However, the model predicts accurately maize grain yield and total biomass with NPK 20:10:10 at 70kgNha-1 better than different rates of sunshine organic manure (SOM) application for all the maize cultivars. The result further showed good agreement between the model predicted and observed data with low RMSE of ≤ 1day for anthesis and ≤ 5 days for physiological maturity while the total leaf number ranged from 1.9 – 2.7. Model accuracy for predicting grain yield and total biomass was also good, for both the calibration and validation with lowest RMSE and NRMSE of the observed mean values.

Contributions of Charcoal Production to Socio-Economic Activities of Rural Dwellers in the Rain Forest Agro-Ecological Zone of Nigeria

Contributions of Charcoal Production to Socio-Economic Activities of Rural Dwellers in the Rain Forest Agro-Ecological Zone of Nigeria