Characteristics of Major Lowland Rice-growing Soils in the Guinea Savanna Voltaian Basin of Ghana

Le papier revue les sols principaux pour la cultivation du riz dans la Savanne guinéenne de la cuvette voltaïque du Ghana et évaluer leur potentialité pour la production du riz. Les sols principaux pour la cultivation du riz dans la Savanne guinéenne sont les séries Lima et Volta. Les autresincluent les séries Laplik, Siare, Pani, Kupela, Brenyase et Pale. Les propriétés physiques du sol étaient utilisées comme les paramètres principaux et l'estimation adaptée du Sys et al. (1993) étaient utilisées pour évaluer leur potentialité pour la cultivation du riz. La série volta(Gleysol dystrique ou entrique) était evaluée comme modérément convenable avec sa limitation principale étant le couche arable limoneux. Les séries Lima (Endogleyi-ferric planosol et Lapliki (Abrupti-stagnique Lixisol) étaient évaluées comme marginalement convénable grâce à un couche arable sableux-limoneux. Ces sols sont très vastes et sont lessols principaux pour la cultivation du riz dans cette zone. La gestion éfficace y compris l'irrigation et l'incorporation de la matière organique augmenteront significativement leurs évaluations puisque leur sous-sol est basiquement arigile. L'utilisation judiciense de l'engrais et le chaulage modéré où le pH est moins que 5.0 augmenteront significativementleur productivité.The paper reviews the major soils for growing rice in the Guinea savanna Voltaian basin of Ghana and evaluates their potential for rice production. The major soils for growing rice in the Guinea Savanna are Lima and Volta series. The others include Lapliki, Siare, Pani, Kupela, Brenyase and Pale series. Soil physical properties were used as the main parameters and ratings adapted from Sys et al. (1993) were used in evaluating their potential for growing rice. Volta series (Dystric or Eutric Gleysol) was assessed as moderately suitable, with its major limitation being loamy or silty topsoil. Lima (Endogleyi Ferric Planosol) and Lapliki series (Abrupti-Stagnic Lixisol), were assessed as marginally suitable on account of a sandy loam topsoil. These soils are very extensive and are the major soils for rice production in this area. Proper management, including puddling and the incorporation of organic matter, will significantly improve their ratings since their subsoil is basically clay. Judicious use of fertilizer and moderate liming where the soil pH is below 5.0 will significantly improve their productivity

Evaluation of growth of young coconut and nut yield of old coconut and their nutrient status under coconut-cassava intercropping systems

Two on-farm experiments were carried out in the coconut belt of Southern Ghana from 2006 to 2009 to evaluate growth of young coconut plantings and nut yield of old coconut fields and their nutrient status under coconut-cassava intercropping systems. Experiment I was carried out inyoung MYD x VTT coconut plantings. Experiment II was conducted in old West African Tall coconut plantings. The same cropping systems were evaluated under the two experiments in randomized complete block design with two replications each. The cropping systems were: 1. Solecoconut 2. Coconut + non-fertilized cassava 3. Coconut + cassava-fertilizer-I (Fertilizer I= 30- 45-45 kg/ha N-P2O5-K2O) and 4. Coconut + cassava-fertilizer-II (Fertilizer II = 60-45-90 kg/ha N-P2O5-K2O). Young coconut planted as sole crop had significantly (

Assessment of Fertility Status of Soils Supporting Coconut (Cocus nucifera) Cultivation in Western and Central Regions of Ghana

Coconut cultivation is mostly practiced in the Western and Central regions of Ghana. Information on the fertility status of the soils on which coconuts are grown and possible fertilizer recommendation is not common. Sincecoconut yield is generally related to the fertility status of the soil, a study was conducted to evaluate the fertility status of soils supporting coconut in the Western and Central regions. The soils were sampled at three depths, 0–20 cm, 20–40 cm and 40–60 cm at 21 different sites. The soil physical properties do not constitute any major limitation to good coconut growth and yield. Evaluation of the top soil showed that the mean top soil pH was very strongly acidic (4.1 + 0.12) and far below the acceptable limits for good coconut yield. Mean exchangeable acidity [0.57 0.06 cmol(+)kg-1] was relatively high while exchangeable basic cations (Ca, Mg and K) were generally very low. Mean effective cation exchange capacity (ECEC) of 3.1 0.48 cmol (+) kg-1was very low. Mean organic matter status 22.1 1.9 gkg-1 was moderate. Mean available phosphorus of 2.8 0.56 mgkg-1 was very low and one of the major nutrients that will affect coconut yield. Except for soil pH, nutrient levels generally showed a decreasing trend in the order top soil > subsoil > sub-subsoil. The evaluation showed that the soils  suffer from multi-nutrient deficiency. Nutrient levels of the soils are low to very low, and will not support good coconut growth and yield. Liming to improve the exchangeable basic cations and pH of the soils is  recommended. Use of rock phosphate is also recommended for raising the levels of both phosphorus and some basic cations. Amendments and fertilizers with high K content must also be considered

Different methodological approaches to the assessment of in vivo efficacy of three artemisinin-based combination antimalarial treatments for the treatment of uncomplicated falciparum malaria in African children.

BACKGROUND: Use of different methods for assessing the efficacy of artemisinin-based combination antimalarial treatments (ACTs) will result in different estimates being reported, with implications for changes in treatment policy. METHODS: Data from different in vivo studies of ACT treatment of uncomplicated falciparum malaria were combined in a single database. Efficacy at day 28 corrected by PCR genotyping was estimated using four methods. In the first two methods, failure rates were calculated as proportions with either (1a) reinfections excluded from the analysis (standard WHO per-protocol analysis) or (1b) reinfections considered as treatment successes. In the second two methods, failure rates were estimated using the Kaplan-Meier product limit formula using either (2a) WHO (2001) definitions of failure, or (2b) failure defined using parasitological criteria only. RESULTS: Data analysed represented 2926 patients from 17 studies in nine African countries. Three ACTs were studied: artesunate-amodiaquine (AS+AQ, N = 1702), artesunate-sulphadoxine-pyrimethamine (AS+SP, N = 706) and artemether-lumefantrine (AL, N = 518).Using method (1a), the day 28 failure rates ranged from 0% to 39.3% for AS+AQ treatment, from 1.0% to 33.3% for AS+SP treatment and from 0% to 3.3% for AL treatment. The median [range] difference in point estimates between method 1a (reference) and the others were: (i) method 1b = 1.3% [0 to 24.8], (ii) method 2a = 1.1% [0 to 21.5], and (iii) method 2b = 0% [-38 to 19.3].The standard per-protocol method (1a) tended to overestimate the risk of failure when compared to alternative methods using the same endpoint definitions (methods 1b and 2a). It either overestimated or underestimated the risk when endpoints based on parasitological rather than clinical criteria were applied. The standard method was also associated with a 34% reduction in the number of patients evaluated compared to the number of patients enrolled. Only 2% of the sample size was lost when failures were classified on the first day of parasite recurrence and survival analytical methods were used. CONCLUSION: The primary purpose of an in vivo study should be to provide a precise estimate of the risk of antimalarial treatment failure due to drug resistance. Use of survival analysis is the most appropriate way to estimate failure rates with parasitological recurrence classified as treatment failure on the day it occurs

Community screening and treatment of asymptomatic carriers of Plasmodium falciparum with artemether-lumefantrine to reduce malaria disease burden: a modelling and simulation analysis

<p>Abstract</p> <p>Background</p> <p>Asymptomatic carriers of <it>Plasmodium falciparum </it>serve as a reservoir of parasites for malaria transmission. Identification and treatment of asymptomatic carriers within a region may reduce the parasite reservoir and influence malaria transmission in that area.</p> <p>Methods</p> <p>Using computer simulation, this analysis explored the impact of community screening campaigns (CSC) followed by systematic treatment of <it>P. falciparum </it>asymptomatic carriers (AC) with artemether-lumefantrine (AL) on disease transmission. The model created by Okell <it>et al </it>(originally designed to explore the impact of the introduction of treatment with artemisinin-based combination therapy on malaria endemicity) was modified to represent CSC and treatment of AC with AL, with the addition of malaria vector seasonality. The age grouping, relative distribution of age in a region, and degree of heterogeneity in disease transmission were maintained. The number and frequency of CSC and their relative timing were explored in terms of their effect on malaria incidence. A sensitivity analysis was conducted to determine the factors with the greatest impact on the model predictions.</p> <p>Results</p> <p>The simulation showed that the intervention that had the largest effect was performed in an area with high endemicity (entomological inoculation rate, EIR > 200); however, the rate of infection returned to its normal level in the subsequent year, unless the intervention was repeated. In areas with low disease burden (EIR < 10), the reduction was sustained for over three years after a single intervention. Three CSC scheduled in close succession (monthly intervals) at the start of the dry season had the greatest impact on the success of the intervention.</p> <p>Conclusions</p> <p>Community screening and treatment of asymptomatic carriers with AL may reduce malaria transmission significantly. The initial level of disease intensity has the greatest impact on the potential magnitude and duration of malaria reduction. When combined with other interventions (e.g. long-lasting insecticide-treated nets, rapid diagnostic tests, prompt diagnosis and treatment, and, where appropriate, indoor residual spraying) the effect of this intervention can be sustained for many years, and it could become a tool to accelerate the reduction in transmission intensity to pre-elimination levels. Repeated interventions at least every other year may help to prolong the effect. The use of an effective diagnostic tool and a highly effective ACT, such as AL, is also vital. The modelling supports the evaluation of this approach in a prospective clinical trial to reduce the pool of infective vectors for malaria transmission in an area with marked seasonality.</p

Efficacy of artesunate-amodiaquine for treating uncomplicated falciparum malaria in sub-Saharan Africa: a multi-centre analysis

BACKGROUND: Artesunate and amodiaquine (AS&AQ) is at present the world's second most widely used artemisinin-based combination therapy (ACT). It was necessary to evaluate the efficacy of ACT, recently adopted by the World Health Organization (WHO) and deployed over 80 countries, in order to make an evidence-based drug policy. METHODS: An individual patient data (IPD) analysis was conducted on efficacy outcomes in 26 clinical studies in sub-Saharan Africa using the WHO protocol with similar primary and secondary endpoints. RESULTS: A total of 11,700 patients (75% under 5 years old), from 33 different sites in 16 countries were followed for 28 days. Loss to follow-up was 4.9% (575/11,700). AS&AQ was given to 5,897 patients. Of these, 82% (4,826/5,897) were included in randomized comparative trials with polymerase chain reaction (PCR) genotyping results and compared to 5,413 patients (half receiving an ACT). AS&AQ and other ACT comparators resulted in rapid clearance of fever and parasitaemia, superior to non-ACT. Using survival analysis on a modified intent-to-treat population, the Day 28 PCR-adjusted efficacy of AS&AQ was greater than 90% (the WHO cut-off) in 11/16 countries. In randomized comparative trials (n = 22), the crude efficacy of AS&AQ was 75.9% (95% CI 74.6-77.1) and the PCR-adjusted efficacy was 93.9% (95% CI 93.2-94.5). The risk (weighted by site) of failure PCR-adjusted of AS&AQ was significantly inferior to non-ACT, superior to dihydroartemisinin-piperaquine (DP, in one Ugandan site), and not different from AS+SP or AL (artemether-lumefantrine). The risk of gametocyte appearance and the carriage rate of AS&AQ was only greater in one Ugandan site compared to AL and DP, and lower compared to non-ACT (p = 0.001, for all comparisons). Anaemia recovery was not different than comparator groups, except in one site in Rwanda where the patients in the DP group had a slower recovery. CONCLUSION: AS&AQ compares well to other treatments and meets the WHO efficacy criteria for use against falciparum malaria in many, but not all, the sub-Saharan African countries where it was studied. Efficacy varies between and within countries. An IPD analysis can inform general and local treatment policies. Ongoing monitoring evaluation is required

Soil organic amendments and mineral fertilizers: options for sustainable lowland rice production in the forest agro-ecology of Ghana Rectification organique des sols et engrais chimiques: options pour la production durable du riz dans les terrains bas dans l'agro-ecologie des forets du Ghana

The “sawah” technology (bunded and leveled irrigated rice field) was introduced to some farmers within the forest agro-ecology of Ghana. To improve the productivity of their soils and also to minimize expenditure on mineral fertilizers, the effect of three organic amendments on rice yield was evaluated. Poultry manure, cattle manure and rice husk were used either solely or in combination with mineral fertilizer on rice at three different locations within the forest agro-ecological zone at Potrikrom, Biemso No. 1 and Biemso No. 2. Sole organic amendments were applied at a rate of 7.0 t ha-1 and sole mineral fertilizer was applied as N-P-K at 90-60-60 kg ha-1. The N source was either urea or sulphate of ammonia, P source was triple super phosphate and K source was muriate of potash. Combinations were half rate (organic amendments + mineral fertilizer). Results showed that organic amendments, mineral fertilizer and their combinations significantly contributed to the growth and grain yield of rice. A combination of poultry manure (half rate) and mineral fertilizer (half rate) gave significantly greater grain yield than all the treatments except mineral fertilizer (full rate) at two out of the three locations. Rice grain yields were 6.2, 7.3 and 3.7 t ha-1 for half rate poultry manure + half rate mineral fertilizer at Potrikrom, Biemso No. 1 and Biemso No. 2 respectively, while full rate mineral fertilizer gave 6.6, 7.3 and 3.9 t ha-1 at the three sites respectively. In addition, a combination of organic amendments with mineral fertilizer out-yielded sole organic amendments at all the three sites. Organic amendments applied solely performed in the order: poultry manure > cattle manure > rice husk. Keywords: agro-ecology, forest, organic amendments, “sawah”, sustainability Agricultural and Food Science Journal of Ghana Vol. 3 2004: 237-24

Soil resources of Saboba-Chereponi district: An assessment for Agricultural Production

No Abstract

Effect of Cropping System and Mineral Fertilizer on Root Yield of Cassava

The objective of this study was to evaluate the effect of cropping system and fertilizer on the root yield of three introduced high yielding cassava varieties (Afisiafi, Abasafitaa and Tekbankye) and two local varieties (Tuakentenma and Akosuatumtum). Two cropping systems (sole cassava and cassava-maize intercrop and five fertilizer regimes (0-0-0, 30-30-30, 60-60-60, 90-90-90 and 120-120-120 kg ha-1 N-P2O5-K2O) were studied in 2000 and 2001. A split-split plot design with four replications was used in the first study and a split-plot design for the second. Cassava-maize intercrop significantly reduced root yield at Mampong (2000) and Asuansi (2001) but not at Wenchi (2001). Afisiafi and Abasafitaa performed better than the local varieties or Tekbankye. At Asuansi and Kpeve, Afisiafi gave significantly greater root yield than Abasafitaa. Root yields of Afisiafi and Abasafita were, however, similar at Mampong and Wenchi in 2000. At Wenchi (2001), Abasafitaa gave significantly greater root yield than Afisiafi. At Mampong (2000) and Wenchi (2001), Afisiafi produced significantly more roots per stand than the local varieties and Abasafitaa gave significantly greater root yield per stand than the local variety. At all the four sites mineral fertilizer resulted in significantly greater root yield over control. At Asuansi (2001), Kpeve (2001) and Mampong (2000), 60-60-60 kg ha-1 N-P2O5-K2O gave significantly greater root yield than the 30-30-30 kg N-P2O5-K2O ha-1 but similar to the 90-90-90 and 120-120-120 kg ha-1 N-P2O5-K2O. At Wenchi (2001) all the rates gave similar root yield. Across locations, Afisiafi and Abasafitaa produced greater root yield than the local varieties and Tekbankye. Mineral fertilizer at 60-60-60 kg ha-1 N-P2O5-K2O was the optimum level for root yields. L\'objeclif de cette étude était pour évaluer l\'effet du système de la culture et l\'engrais sur le rendement racinaire de trios nouvelles variétés du manioc qui possèdent le rendement élevé. Les variétés sont (Afisiafi, Abasafitaa et Tekbankye) et deux variétés locales (Tuakentenma et Akosua tumtum). Deux systèmes de la culture (manioc unique, l\'intercalaire du manioc maïs et cinq régimes d\'engrais (0 - 0 - 0, 30 - 30 - 30, 60 - 60 - 60, 90 - 90 - 90 et 120 - 120 - 120 kg ha-1 N-P2O5-K2O) étaient étudiés en 2000 et 2001. Un déssein de deux parcelles avec quatre réplications était utilisé lors de la première étude et un déssein d\'une parcelle lors de la deuxième étude. L\'intercalaire du manioc - maïs a réduit considérablement le rendement racinaire à Mampong (2000) et Asuansi (2001) mais pas à Wenchi (2001). Afisiafi et Abasafitaa ont fonctionné mieux que les variétés locales ou Tekbankye. À Asuansi et Kpeve, Afisiafi a fait mieux que Abasafitaa en ce qui concerne le rendement racinaire. Le rendement racinaire était pourtant similaire à Mampong et Wenchi en 2000. À Wenchi (2001) Abasafitaa a fait mieux que Afisiafi. À Mampong (2000) et Wenchi (2001) Afisiafi a produit plus de racines par parcelle que les variétés locales. De la même manière, Abasafitaa a produit plus de racines que les variétés locales. À tous les quatre sites, l\'engrais minéral a résulté en plus élevé sur contrôle. À Asuansi (2001) Kpeve (2001) et Mampong (2000) 60 - 60 - 60 kg ha-1 N-P2O5K2O a donné un rendement plus grand que le 30 - 30 - 30 kg N-P2O5K2O ha-1 mais similaire au 90 - 90 - 90 et 120 - 120 - 120 kg ha-1 -P2O5K2O. À Wenchi (2001) tous les niveaux ont donné un similaire rendement. À travers les localisations, Afisiafi et Abasafitaa ont produit des rendements plus élevés que les variétés locales et Tekbankye. L\'engrais minéral à 60 - 60 - 60 kg ha-1 N-P2O5K2O était le niveau optimum pour les rendements racinaires. Keywords: keyCassava varieties, cropping system, fertilization, root yield. Agricultural and Food Science Journal of Ghana Vol. 6 2007 pp. 445-45