Abdul Conteh - Academia.edu (original) (raw)

Papers by Abdul Conteh

Zenodo (CERN European Organization for Nuclear Research), Jun 28, 2023

The study evaluated the viability of improved cassava Bonthe districts of southern Sierra Leone. ... more The study evaluated the viability of improved cassava Bonthe districts of southern Sierra Leone. mandated crops of Njala Agricultural Research center Sierra Leone Agricultural Research Institute (SLARI), charged with the mandate of developing and disseminating improved crop varieties within Sierra Leone. them, c Atregular reachability and level of performance of the crop commodity will to a larger extent shape the researchers focus. To ascertain that, four hundred and fifty (450) cassava growers Moyamba and Bonthe districts of southern Sierra Leone, using purposive and random sampling methods. Data were analyzed qua statistic. Resultsrevealed that there was weak farmers. However, information through farmer high knowledge and access to technology regarding the other released varieties was scarce, farmers to the technology based on trialability and income generated (profit accrued) through sales of its products.

$Research paper thumbnail of Dynamics of organic matter in soil as determined by variations in 13C/12C isotopic ratios and fractionation by ease of oxidation$

Dynamics of organic matter in soil as determined by variations in 13C/12C isotopic ratios and fractionation by ease of oxidation

Soil Research, 1997

Management of organic matter in soils requires techniques that accurately monitor changes in soil... more Management of organic matter in soils requires techniques that accurately monitor changes in soil organic matter over the short term and long term. This study was carried out in a glasshouse pot experiment to examine changes in soil carbon under the influence of long-term cropping, plant residue, and fertiliser application, using variations in 13C/12C isotopic ratios of organic materials and fractionation by ease of oxidation. The study examines the changes in carbon contents of adjacent soil samples with different cropping histories as affected by application of fertiliser and crop residue and the growth of wheat. Significant increases in soil carbon values were observed with residue application. The effects of the applied fertiliser on soil carbon levels depend on the presence or absence of wheat. A higher amount of labile carbon was found in the native soil than in cultivated soil.

Cassava Groundnut Intercropping: A Sustainable Land Management Practice for Increasing Crop Productivity and Organic Carbon Stock on Smallholder Farms

Agricultural Sciences

Cassava-groundnut intercropping is not a common practice among smallholder farmers in Sierra Leon... more Cassava-groundnut intercropping is not a common practice among smallholder farmers in Sierra Leone even though both crops are well suited for intercropping. On-farm trials were conducted in three locations (Bai Largor, Bassah, and Njala Kanima) in the Moyamba district during the 2021 cropping season to investigate the efficacy of cassava-groundnut intercropping for increasing crop productivity and soil organic carbon stock on smallholder farms in the Moyamba district, Southern Sierra Leone. The experimental design was a randomized complete block design in three replications with treatments of sole groundnut, sole cassava and cassava-groundnut intercropping. Data on the yield and yield components of cassava and groundnut were analysed using the PROC MIXED procedure of SAS 9.4 and means were compared using the standard error of difference (SED). The above-ground biomass, number of roots per plant, and fresh root yield of cassava were not significantly (p > 0.05) affected by the cassava-based cropping system. Averaged across locations, intercropping cassava with groundnut decreased the above-ground biomass, the number of roots per plant, and fresh root yield of cassava by 17%, 11%, and 17%, respectively. The above-ground biomass, number of pods per plant and fresh pod yield of groundnut were significantly (p < 0.05) affected by the groundnut-based cropping system. Averaged across locations, intercropping groundnut with cassava decreased the aboveground biomass, the number of pods per plant, and fresh pod yield of groundnut by 33%, 15%, and 31%, respectively. The cassava-groundnut intercropping treatment had favourable

Current Research in Agricultural Sciences

Competition among component crops in an intercropping system is an important factor that influenc... more Competition among component crops in an intercropping system is an important factor that influences productivity. To realize the benefit of intercropping in terms of higher productivity per unit area, the competitive behaviour of component crops needs to be quantified. As such, an experiment was conducted to determine the competitive behaviour of component crops in cassava-legume-based intercropping systems. The experiment was a factorial randomized complete design with three replications. The treatments consisted of seven cropping associations and two spatial arrangements. The result shows that both land equivalent ratio and area time equivalent ratio was greater than one and was higher for the cassava-soybean system compared to the other cropping systems. In general, the land equivalent ratio was higher than the area time equivalent ratio across the three agro-climatic zones. In the case for the competitive ratio and the relative crowding coefficient, both indices were higher for ...

World Journal of Advanced Research and Reviews, 2022

Competition is one of the most important factors that influence productivity of component crops i... more Competition is one of the most important factors that influence productivity of component crops in intercropping systems. Thus, an experiment was conducted in order to evaluate the competitive interactions between the component crops in a cassava-legume based intercropping system. The experiment was a factorial randomized complete block design with three replications. The treatments consisted of seven cropping associations and two spatial arrangements. The results show that the root yield for cassava was higher for the cassava-soybean system with Segbwema recording the highest root yield. For the grain legumes, yields were higher for the sole legumes compared to the intercropped. In addition, both root and grain yields were on average higher when the grain legumes were intercropped with cassava using the 2 m x 0.5 m spatial arrangement for cassava. The result further shows that land equivalent ratio was greater than one and was higher for the cassava-soybean system compared to the o...

EFFECT OF SPATIAL ARRANGEMENT, PLANT ARCHITECTURE AND CROPPING SYSTEM ON THE GROWTH, YIELD AND YIELD-RELATED COMPONENTS OF CASSAVA (Manihot esculenta L)

Field trials were conducted in 2015/2016 and 2016/2017 cropping seasons in three agro-ecological ... more Field trials were conducted in 2015/2016 and 2016/2017 cropping seasons in three agro-ecological zones of the country to evaluate the growth and yield parameters of cassava as a response to spatial arrangement, plant architecture and cropping systems. The treatments consisted of seven different cropping associations (sole cassava, sole groundnut, sole cowpea, sole soybean, cassava + cowpea, cassava + groundnut and cassava + soybean), two cassava architectures (branched and erect) and two spatial arrangements (1 m x 1 m and 2 m x 0.5 m). The experiment was laid out in a randomized complete block design with three replications. The results show that spatial arrangement, pant architecture and cropping systems were highly significant concerning plant height, stem girth and canopy width. The erect cassava variety intercropped with soybean at a spatial orientation of 1 m x 1 m recorded the highest values across the times of observation. The results further reveal significant differences i...

Survey on the Occurrence and Distribution of Major Cassava Arthropod Pests in Sierra Leone

Insect pests constitute the greatest constraint to cassava production in Sierra Leone and Africa ... more Insect pests constitute the greatest constraint to cassava production in Sierra Leone and Africa as a whole. The aim of the study was to generate up to date information on the status of cassava insect pests in the country. The objectives were to identify, map and determine the prevalence, incidence, severity and distribution in the major geo-political districts of the country. A total of 171 cassava farms were visited countrywide during the rainy season survey whilst a total of 193 farms were visited during the dry season survey with an average of 15 farms per district. The result of the survey reveals significant differences in percentage incidence, severity score and prevalence of the major cassava pests with respect to district, cassava variety and season. Percentage incidences and severity scores of the major insect pests were higher on local cassava varieties in most of the districts compared to improved varieties. The Population of the assessed insect pests were generally high...

Journal of Bioscience and Agriculture Research, 2018

Field experiments were conducted at SLARI's on-station sites located at Rogbasha, Sumbuya and Ser... more Field experiments were conducted at SLARI's on-station sites located at Rogbasha, Sumbuya and Serabu during the year 2013 cropping season to evaluate the influence of planting date on the phenology and yield of soybean genotypes in Sierra Leone. The experiment was arranged in a split plot design with 3 replications in each location. Five planting dates (June 7, June 28, July 14, August 15 and September 5) were assigned to the main plots and five soybean genotypes (TGx 1448-2E, TGx 1904-6F, TGx 1951-3F, TGx 1951-4F and TGx 1955-4F) to the subplots using a randomized complete block design. Planting date had a significant influence on the phenology and yield of the soybean genotypes evaluated. The number of days from emergence (VE) to full flower (R2), full pod (R4) and physiological maturity (R7), thenumber of pods plant-1 , 100-seed mass and grain yield for each soybean genotype decreased significantly in each location when planted late i.e. August 15 and beyond.The grain yield, number of pods plant-1 and 100-seed mass of soybean depend directly on the influence of the days to full fower, full pod and physiological maturity. The significant decrease in the days to full fower, full pod and physiological maturity in soybean when planted after July 14 altered the optimum yield potential in the soybean genotypes. For optimum grain yields, farmers in

International Journal of Plant & Soil Science, 2015

Aims: The main aim of the study was to assess the effects of organic manure on nitrogen mineraliz... more Aims: The main aim of the study was to assess the effects of organic manure on nitrogen mineralization, uptake, use and recovery of cauliflower. Methodology: Nitrogen is one of the major yield limiting nutrients in cauliflower production. However, organic manure is applied to supplement soil nitrogen supply to maximize dry-matter yield. A field experiment was conducted at the Droevendaal Certified Organic Research and Demonstration Site of Wageningen University, Netherlands during 2012. The experiment was laid out in a randomized complete block design with four replications. The treatments comprised of four Original Research Article

$Research paper thumbnail of The distribution and relative losses of soil organic carbon fractions in aggregate size fractions from cracking clay soils (Vertisols) under cotton production$

The distribution and relative losses of soil organic carbon fractions in aggregate size fractions from cracking clay soils (Vertisols) under cotton production

Australian Journal of Soil Research, 1998

The distribution and losses of organic carbon fractions in various aggregate sizes from cracking ... more The distribution and losses of organic carbon fractions in various aggregate sizes from cracking clay soils were studied to understand some factors associated with losses of soil organic carbon under cultivation. Five pairs of samples from cropped and adjacent uncropped (reference) soils were collected from 5 of the main cotton-growing regions of Australia. Five aggregate sizes were separated from each of these soils (<50 µm, 50-150 µm, 150-250 µm, 250-450 µm, and 450-500 µm). On each of these aggregate fractions, measurements were made for total carbon (CT), labile carbon by ease of oxidation (CL), d 13 C, total light fraction (LF), carbon content of light fraction (C%-LF), and the proportion of soil carbon in the light fraction (LF-C) calculated. CT and CL were found to increase with a decrease in aggregate size, whereas LF was found to decrease with a decrease in aggregate size. Losses of both CT and CL as a result of cultivation were higher in larger aggregates than in smalle...

$Research paper thumbnail of Soil organic carbon changes in cracking clay soils under cotton production as studied by carbon fractionation$

Australian Journal of Agricultural Research, 1997

This study examined soil carbon levels across a wide range of cracking clay soils used for growin... more This study examined soil carbon levels across a wide range of cracking clay soils used for growing cotton in Australia by using a simple carbon fractionation procedure. The soils studied included reference and cropped sites. The procedure employed determines soil carbon fractions based on their ease of oxidation to obtain the labile (CL) and non-labile (CNL) carbon components. Based on the total carbon (CT), labile carbon (CL), and non-labile carbon (CNL) of a cropped soil relative to a reference soil, various monitoring indices were developed. It was found that cultivation has generally led to a decrease in the organic carbon status of the soils. The effect of cultivation was found to be more pronounced in the CL and the carbon management index (CMI) than in the CT and CNL. The changes in the ratio of CL to CNL as a result of cultivation have been variable. The CMI has generally declined during cultivation, and since the CMI has incorporated the changes taking place in CT, CL, and ...

Rainfall erosivity for the Njala Area in Southern Sierra Leone dataset

Rainfall erosivity is an important characteristic of rainfall that gives an indication of its agg... more Rainfall erosivity is an important characteristic of rainfall that gives an indication of its aggressiveness and potential to cause soil erosion. There are models (such the USLE/RUSLE EI30) for estimating rainfall erosivity but they require pluviographic records which are limited or not available in developing countries like Sierra Leone. To address this challenge, methods have been developed to estimate rainfall erosivity from the relationship between rainfall erosivity (derived from pluviographic records) and the more readily available daily and monthly rainfall records. Furthermore despite the global application of the EI30 index, there are questions about its suitability at the local level. These datasets show how rainfall erosivity indices, EI30, EIavg and ETI were calculated from available 30-minute rainfall records in the Njala Area of Southern Sierra Leone. These indices were then used to derive relationships between rainfall erosivity and daily/monthly rainfall records which are readily available in the study area. These datasets have been generated to determining a suitable erosivity model for estimating rainfall erosivity from daily and monthly rainfall records for the Njala area.

Asian Journal of Advances in Agricultural Research

Background and Objective: The time of sowing component crops is an important management variable ... more Background and Objective: The time of sowing component crops is an important management variable that can improve productivity and increase land equivalent ratio in intercropping systems. The study aimed to evaluate the effect of the time of introduction of legumes into cassava on cassava productivity. Study Design: The experiment was a factorial randomized complete block design with three replications. Place and Duration of Study: Field trials were conducted in 2015/2016 and 2016/2017 cropping seasons in three agro-climatic zones. Methodology: The treatments consisted of seven cropping associations, two cassava architectures, two spatial arrangements of cassava, and two introduction times of the legume. The cassava was grown on flat land and the legumes were inserted in between the rows of the cassava. The introduction of the legumes were done in two stages, namely: simultaneous introduction in which the cassava and the legumes were planted at the same time and late introduction in...

Field trials were conducted in 2015/2016 and 2016/2017 cropping seasons in three agro-climatic zo... more Field trials were conducted in 2015/2016 and 2016/2017 cropping seasons in three agro-climatic zones of the country to evaluate the productivity and insect pests population dynamics of cassava as a response to spatial arrangement, plant architecture and cropping systems. The treatments consisted of seven cropping associations, two cassava architectures and two spatial arrangements. The study reveals that yield parameters of cassava were higher in cassava-soybean system at all locations. The number of marketable roots and forage yield were on average higher when the erect cassava variety was intercropped with the legumes using the 1 m x 1m spatial arrangement. On the other hand, root yield and canopy width were higher when the 2 m x 0.5 m spatial arrangement and the branched cassava architecture was used respectively. In general, yield parameters were higher at Segbwema expect for forage yield that was higher at Makeni. With respect to cassava insect pests, higher percentage incidences and severity scores were recorded on sole cassava and when the branched cassava variety was intercropped with legumes using the 2 m x 0.5 m spatial arrangement of cassava. In addition, cassava insect pests incidences were only observed at 6 MAP and 9MAP and were higher in Segbwema compared to the other locations. Thus, in order to improve productivity of cassava with low insect pest infestation, the erect cassava variety should be intercropped with soybean at a spatial arrangement of 1 m x 1 m.

Cowpea (Vigna unguiulata) is attacked by a wide spectrum of insect pests that ravages the crop in... more Cowpea (Vigna unguiulata) is attacked by a wide spectrum of insect pests that ravages the crop in the field at different growing stages sometimes resulting in complete crop failure. In order to reduce insect pest damage, increase cowpea seed yield and reduce the indiscriminate use of insecticide, it was necessary to conduct an experiment geared towards integrating cowpea cultivar with date of planting alongside minimal application of insecticide in the management of cowpea insect pests across two major agro-ecological zones. The experiment was laid out in a randomized complete block design with three replications at three locations; Sumbuya, Serabu and Nguala. Five improved cowpea cultivars with varying maturity dates and one local check, two planting dates and two spraying regimes were compared. The study reveals that flower thrips (Megalurothrips sjostedti) and legume pod borers (Maruca vitrata) were the major insect pests limiting cowpea production in the country. Planting improv...

The organic matter content of a soil is a key indicator of a sustainable soil management system b... more The organic matter content of a soil is a key indicator of a sustainable soil management system because of its influence on the physical, chemical and biological health of a soil. Management of soil organic matter requires appropriate methods to characterize and quantify the status of organic matter under different management practices. A wide range of approaches has been adopted for the determination of organic matter in soils. Some of these approaches include los-on-ignition, dry combustion, wet oxidation, spectroscopic methods and isotopic methods. This article examines each of these methods highlighting their shortcomings. -------------------------------------------------------------------------------------------------------------------------------------Date of Submission: 02-08-2020 Date of Acceptance: 17-08-2020 -------------------------------------------------------------------------------------------------------------------------------------

Cotton production in Australia is predominantly carried out on grey, red and brown cracking clays... more Cotton production in Australia is predominantly carried out on grey, red and brown cracking clays with self-mulching surfaces, and red-brown earths, which are hard alkaline duplex soils. A common management system for these soils for growing cotton in Australia has been outlined by Constable et al. (1992). This usually involves intensive cultivation which generally has involved some exploitation of accumulated soil organic matter (SOM) reserves. Under such intensive cropping systems, nutrient losses may be compensated for by fertiliser additions. The decline in SOM can lead to a deterioration in the physical condition of the soil. In addition, the economic and environmental impact of a heavily fertiliser-dependent cropping system may threaten longterm sustainability.

Evaluation of Improved Cassava Genotypes for Storage Root Yield and Post Harvest Traits in the Njala Soil Series

Yield and Yield Related Components of Cowpea as Influenced by Planting Date, Cultivar and Spraying Regime

Cowpea is attacked by a wide spectrum of insect pests that ravages the crop in the field at diffe... more Cowpea is attacked by a wide spectrum of insect pests that ravages the crop in the field at different growing stages sometimes resulting into complete crop failure. In order to reduce insect pest damage, increase cowpea grain yield and other yield related components, an experiment was conducted using five improved cowpea cultivars and one local check, two planting dates and two spraying regimes across two major agro-climatic zones during 2012 and 2013 cropping seasons. The experiment was laid out in a randomized complete block design with three replications at three locations Sumbuya, Serabu and Nguala. Result showed that the effect of cultivar, planting date and spraying regime on the measured parameters were highly significant. Also interaction effect of cultivar, planting date and spraying regime on the measured parameters were all significant. Grain yield, pod load and biomass were higher in sprayed plots compared to unsprayed plots. Also, grain yield and pod load were higher wh...