Nitrogen mineralization trends of applied Mucuna pruriens var. utilis

The effect of method of applying Mucuna pruriens var. utilis on the release of mineral nitrogen in an acid soil was investigated in the laboratory. The above-ground parts of M. pruriens were dried, milled and applied at a rate of 0.3 g 100 g-1 of field moist soil. Two methods of applying milled M. pruriens were used, namely surface application (T2) and incorporation (T3). The control treatment (T1), involving soil only, was also used. The treated soil samples were incubated at room temperature for periods ranging from 0 to 90 days while maintaining their contents at 60 per cent water holding capacity. At the end of the appropriate incubation period, the mineral N contents of the soil samples were measured by extracting soil with 2 M KCI, filtered and the filtrates were then steam-distilled. The mineral N released increased with increasing incubation period. The T1, T2 and T3 had cumulative NH4 +-N values of 5, 5 and 8 kg ha-1, respectively, after the 90 days\' incubation period. The incorporation treatment had the largest amount of NO3-N (66 kg ha-1), followed by the surface application treatment (54 kg ha-1). The control treatment had the least (10 kg ha-1). The soil into which M. pruriens was incorporated (T3) had larger cumulative amount of mineral N (74 kg ha-1) than either T2 (59 kg ha-1) or T1 (15 kg ha-1). The efficiency of mineral N released from M. pruriens was 45 per cent for T2 and 61 per cent for T3. The results indicated that M. pruriens var. utilis, when applied to the soil, could be a potential source of mineral N for crop production.L\'effet de la méthode d\'application de Mucuna pruriens var. utilis sur le dégagement d\'azote (A) minéral dans un sol acide était enquêté au laboratoire. Les parties au-dessus du sol de M. pruriens étaient séchées, moulues et appliquées á raison de 0.3 g 100 g-1 de sol humide du champ. Deux méthodes d\'application de M. pruriens moulue étaient employées: à savoir, application superficielle (T2) et incorporation (T3). Le traitement de contrôle (T1) consistant le sol seulement était utilisé. Les prélèvements de sol traités étaient incubés à une température ambiante pour des périodes variant entre 0 et 90 jours en gardant le contenu d\'eau à 60% de la capacité de rétention d\'eau. A la fin de la période d\'incubation appropriée, les contenus de minéral A de prélèvements de sol étaient mésurés par l\'exraction du sol avec 2 M KCl, filtrés et les filtrats étaient ensuite distillés à vapeur. Le minéral A dégagé augmentait avec la prolongation de la période de l\'incubation. Les T1, T2 et T3 avaient les valeurs cumulatives de NH4 + _ N de 5, 5 et 8 kg ha-1, respectivement, après la période de 90 jours d\'incubation. Le traitement d\'incorporation avait la quantité élevée de NO3-N (66 kg ha-¹) suivi par le traitement d\'application superficielle (54 kg ha-¹). Le traitement de contrôle avait la moindre (10 kg ha-¹). Le sol dans lequel M. pruriens était incorporé (T3) avait la quantité cumulative plus élevée du minéral A (74 kg ha-¹) que le T2 (59 kg ha-¹). L\'efficacité de dégagement de minéral A de M. pruriens était 45% pour T2 et 61% pour T3. Les résultats indiquent que M. pruriens var. utilis lorsque appliquée au sol, pourrait être une source potentielle de minéral A pour la production culturale. Ghana Journal of Agricultural Science Vol. 40 (2) 2008: pp. 223-22

Regenerative capacity and factors influencing the management of Mucuna pruriens var. utilis live-mulch

The regenerative capacity of Mucuna pruriens var. utilis live-mulch and factors affecting its management were investigated. Six plots of mucuna (each measuring 48 m2) were established at an intra-row spacing of 40 cm and inter-row spacing of 80 cm. The number of days to canopy closure after planting and after the first, second and third trimmings were recorded. The trimming frequency for early-maturing and late-maturing maize varieties and the biomass yield and number of active nodules per plant were determined. Mucuna pruriens attained complete canopy closure 55 days after planting (DAP). The number of days required for complete canopy closure after the first, second and third trimmings were 34, 32 and 26, respectively. The number of trimmings (60 to 90 DAP) varied from 0-1 (for earlymaturing maize) to 1-2 (for late-maturing maize). The fresh biomass yields at the first, second and third trimmings were 12364, 5941 and 7209 kg ha–1, respectively; while litter yield ranged from 469 to 914 kg ha–1. The effective nodule count per plant varied from 4 (45 DAP) to a maximum of 63 (120 DAP). The N yield (90 days after planting mucuna) was 179 kg ha-1 of which 60 kg ha-1 mineralizable N could be provided for an intercrop. Significant positive relationships were established between biomass yield, N content of mucuna plant, days after planting, and number of effective nodules per plant. The study showed that it would be appropriate to trim M. pruriens two times (at 60 DAP and 34 days after first trimming) during the intercropping of a latematuring maize crop to reduce competition between maize crop and live-mulch for water and plant nutrients in the soil. La capacité régénératrice de paillis vif Mucuna pruriens var. utilis et les facteurs influançant son aménagement étaient étudiés. Six lots de mucuna ( de 48 m² chacun) étaient cultivés avec un espacement 40 cm intra-rayons et un espacement de 80 cm inter-rayons. Les nombres de jours à la fermeture de la canopée après la plantation et après les tailles premières, deuxièmes et troisièmes étaient enregistrées . La fréquence de la taille pour les variétés de maïs de maturation tôt et de maturation tardive, le rendement de la biomasse et le nombre de nodule actif par plante étaient déterminés. Mucuna pruriens ont atteint une fermeture complete de la canopée 55 jours après la plantation. Le nombre de jours exigés pour la fermeture complète de la canopée après les tailles premières, deuxièmes et troisièmes étaient respectivement 34, 32 et 26. Les nombres de taille (60-90 jours après plantation ) variaient de 0-1 ( pour le maïs de maturation tôt ) à 1-2 (pour le maïs de la maturation tardive ) . Les rendements de biomasse fraîche aux tailles premières, deuxièmes et troisièmes étaient 12364, 5941 et 7209 kg ha-¹, respectivement, alors que le rendement de litière variait de 469 à 914 kg ha-¹ . Le compte effectif de nodule par plante variait 4 ( 45 jours après plantation) à un maximum de 63 (120 jours après plantation ). Le rendement d'azote (A) (90 jours après plantation de mucuna) était 179 kg ha-¹ dont 60 kg ha-¹ d'A minéralisable pourrait être disponible à une culture associée. Des rapports positives considérables étaient établis entre le rendement de biomasse, la teneur d'A de la plante mucuna, les jours après la plantation et le nombre de nodules effectifs par plante. L'étude montrait qu'il serait approprié de tailler légèrement M. pruriens deux fois (60 jours après plantation et 34 jours après la taille première ) pendant l'association culturale de la culture du maïs d'une maturation tardive afin de réduire la concurrence pour l'eau et les nutriments de plante dans le sol entre la culture maïs et le paillis vif. Ghana Journal of Agricultural Science Vol. 40 (1) 2007: pp. 51-5

Appraisal of some methods of weed control during initial establishment of cocoa in a semi-deciduous forest zone of Ghana

In appraising the effects of the quantum and quality of weed control required in establishment of young cocoa, six manual methods of controlling weeds were compared with chemical weed control at two stations of the Cocoa Research Institute of Ghana. Growth of cocoa seedlings after 2 years in the field was superior (P < 0.05) in plots which were clean-weeded two or four times per year or treated with paraquat four times per year than when plots were slashed two or four times per year. There was strong evidence to suggest that treatments which ensured a weed-free environment to the cocoa over a long period were favourable to girth increments in the seedlings. Death of seedlings during establishment was generally lower in plots which were either clean-weeded or treated with paraquat. Labour requirement for controlling weeds with paraquat was considerably lower than that required for the other treatments. Considering the equipment and chemical input, paraquat application was expensive compared to high slashing with or without clean-line weeding two times a year, or clean weeding two times a year; but by virtue of its efficacy, it is recommended for cocoa establishment. En évaluant les effets du quatum et de la qualité de désherbage exigé dans la culture de jeune cacao, six méthodes de désherbage manuel étaient comparées avec le désherbage chimique à deux stations de l'Institut de Recherche en cacao du Ghana. La croissance de semis de cacao, après deux années, dans le champ était supérieure (P £ 0.05 ) dans les lots qui étaient complètement désherbés 2 ou 4 fois/an ou traités avec le paraquat 4 fois/an que dans les lots qui étaient entaillés 2 ou 4 fois/an. Il y avait de nombreuses preuves qui laissent penser que les traitements qui assuraient un environnement sans mauvaise herbe pour le cacao sur une longue période étaient favorables aux augmentations de circonférence des semis. La mort de semis pendant la culture était dans l'ensemble plus faible dans les lots, qui étaient soit complètement désherbés soit traités avec le paraquat. L'exigence de main-d'oeuvre pour maîtriser les mauvaises herbes avec le paraquat était considérablement plus faible que celle exigée pour les autres traitements. En ce qui concerne les matériels et les intrants chimiques, l'application de paraquat était chère que les entailles élevées avec ou sans le désherbage complet en ligne deux fois par an ou le désherbage complet deux fois par an mais en vertu de son efficacité il est recommandé pour la culture de cacao. Ghana Journal of Agricultural Science Vol. 40 (1) 2007: pp. 67-7

Analysis of Foodstuff Price Volatility in Ghana: Implications for Food Security

In recent years, price volatility is becoming increasingly relevant to producers and consumers in the saturated food markets amidst stiff completion and globalisation. The analysis of price volatility is necessary to develop bidding strategies or negotiation skills in order to maximize profit. The generalised autoregressive conditional heteroscedasticity (GARCH) regression model is used to forecast foodstuff prices in Ghana over the period 1970 to 2006. The data used are monthly wholesale prices for maize, millet, and rice obtained from the Ghana Ministry of Food and Agriculture. The empirical results reveal that foodstuff prices exhibit high volatility with continual increasing prices over the study period. The results of the out-sample forecast reveal that maize, millet and rice prices would increase by 23%, 11% and 10% respectively in the next month. The study recommends the provision of adequate storage facilities, and farmers’ market centres in the districts to stabilize food prices. The increases in food prices have implications for food and nutrition situation of the poor in Ghana

On-Site Effects and Cost of Fertility Erosion from Five Small Reservoir Catchments in the Upper East Region of Ghana

A study was carried out in the Upper East Region of Ghana to assess the on-site effects and the cost of fertility erosion from five small reservoir catchments (Dua, Doba, Zebilla, Kumpalgogo and Bugri). The catchment soils and reservoir sediments were sampled and analyzed for their bulk density and nutrient content. The mean reduction in soil depth in the various catchments was 3.996&#177;3.806 mm y-1 in the order of Kumpalgogo&gt;Dua&gt;Bugri&gt;Zebilla&gt;Doba. The corresponding decrease in the water holding capacity of the top 20 cm depth of the catchment soils ranged from 0.563 to 4.698 % per year. The percentage loss in the total nutrient stocks in the top 20 cm of the catchments as eroded sediment-bound nutrients ranged from 9.63 to 64.71, 7.87 to 56.83, 6.12 to 54.82, 1.26 to 40.14, 49.86 to 12.65, 16.84 to 72.07 for OC, N, P, K, Ca and Mg, respectively. The total amount of nutrient loss in kg ha-1 among the reservoirs ranged from 2383 to 19672 for OC, 153 to 3048 for N, 3.15 to 42.59 for P, 41 to 290 for K, 432 to 2158 for Ca, and 63 to 483 for Mg. The cost of N, P and K removed by erosion was calculated by the Replacement Cost Method. The total cost per year (GH&#162; ha-1 y-1) of fertilizers (sulphate of ammonia, single superphosphate and muriate of potash) was 286.15 for Dua, 74.289 for Doba, 225.061 for Zebilla, 1119.997 for Kumpalgogo and 96.376 for Bugri. The study has amply shown that soil loss through erosion reduces top soil depth, nutrient stocks and the water holding capacity of catchment soils. This will adversely affect crop productivity if no control measures are implemented. This can also lead to land degradation

Scaling the saturated hydraulic conductivity of an Alfisol

Alfisols exhibit a high degree of spatial variability in their physical properties. As a result, it is difficult to use information on physical parameters measured at one location to model larger-scale hydrologic processes. In this study, the saturated hydraulic conductivity, Ks, of an Alfisol was determined on 109 undisturbed monoliths using the falling-head permeameter method. The model developed by Arya & Paris (Soil Science Society of America Journal 45, 1023-1030, 1981) was used to calculate the pore volume from sand and clay fractions. Scaling factors were calculated from the measured Ks, sand pore-volume, clay pore-volume, clay content and effective porosity, using the similar media concept. Prediction of Ks of gravelly Alfisol using clay pore-volume is confounded by high gravel content which, when discounted, improves the prediction remarkably. The scaled mean saturated hydraulic conductivity K* for all horizons of the alfisol was approximately 1.0 × 10-5 m s-

Photoexcitation of iodide ion-pyrimidine clusters above the electron detachment threshold : Intracluster electron transfer versus nucleobase-centred excitations

Laser photodissociation spectroscopy of the I-·thymine (I-·T) and I-·cytosine (I-·C) nucleobase clusters has been conducted for the first time across the regions above the electron detachment thresholds to explore the excited states and photodissociation channels. Although photodepletion is strong, only weak ionic photofragment signals are observed, indicating that the clusters decay predominantly by electron detachment. The photodepletion spectra of the I-·T and I-·C clusters display a prominent dipole-bound excited state (I) in the vicinity of the vertical detachment energy (∼4.0 eV). Like the previously studied I-·uracil (I-·U) cluster [W. L. Li et al., J. Chem. Phys. 145, 044319 (2016)], the I-·T cluster also displays a second excited state (II) centred at 4.8 eV, which we similarly assign to a π-π∗ nucleobase-localized transition. However, no distinct higher-energy absorption bands are evident in the spectra of the I-·C. Time-dependent density functional theory (TDDFT) calculations are presented, showing that while each of the I-·T and I-·U clusters displays a single dominant π-π∗ nucleobase-localized transition, the corresponding π-π∗ nucleobase transitions for I-·C are split across three separate weaker electronic excitations. I- and deprotonated nucleobase anion photofragments are observed upon photoexcitation of both I-·U and I-·T, with the action spectra showing bands (at 4.0 and 4.8 eV) for both the I- and deprotonated nucleobase anion production. The photofragmentation behaviour of the I-·C cluster is distinctive as its I- photofragment displays a relatively flat profile above the expected vertical detachment energy. We discuss the observed photofragmentation profiles of the I-·pyrimidine clusters, in the context of the previous time-resolved measurements, and conclude that the observed photoexcitations are primarily consistent with intracluster electron transfer dominating in the near-threshold region, while nucleobase-centred excitations dominate close to 4.8 eV. TDDFT calculations suggest that charge-transfer transitions [Iodide n (5p6) → Uracil σ∗] may contribute to the cluster absorption profile across the scanned spectral region, and the possible role of these states is also discussed

IMPACT OF CROP PRODUCTIVITY ON POVERTY AMONG FARM HOUSEHOLDS IN GHANA

Ghana Poverty Reduction Strategy I &amp; II sought to increase crop productivity to reduce high poverty incidence in farm sector, but the magnitude of impact of the productivity on poverty is not present in all agro-ecological zones in Ghana. The aim of the study is to estimate poverty headcount ratio, poverty gap and poverty severity, and link crop productivity to poverty according to agroecology subject to a two-step instrumental variable regression technique using Pseudo Panel data from the Ghana Living Standards Survey (GLSS rounds 5 &amp; 6). Farmers’ poverty headcount ratio, poverty gap, and poverty severity reduced from 57%, 25%, and 14% in 2005 to 37%, 14%, and 7% in 2013 respectively. The result further indicates that 1% growth in crop productivity reduces the probability of poverty headcount ratio, poverty gap and poverty severity by 0.28%, 0.38% and 0.75% respectively in all agro-ecological zones. Additionally, the paper shows that education, livestock and remittance income reduces poverty, while household size and great distance to access water increase poverty differently from agro-ecology. The study recommends rapid crop productivity growth by prioritizing technology adoption and institutional coordination to suit agro-ecological conditions among the poor, illiterate and non-partisan

Lip print enhancement: review

Published online: 05 May 2020.Lip print (LP) evidence can be an essential tool for human forensics. LPs have conventionally been developed using substances such as lysochrome dyes, fluorescent dyes, indigo dye, aluminium powder, and silver metallic powder. However, techniques for LP enhancement from various substrates are currently inconsistent and lack standardisation in practice. This review summarises current knowledge on the physical and chemical techniques of LP enhancement, identifies limitations, and provides suggestions for future research on practical applications of cheiloscopy as a forensic tool in criminal justice.Maxwell Abedi, Constance Afoakwah and Dan Nana Osei Mensah Bons