Browsing by Author "Nartey, E.K."

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Acidity and Aluminum Speciation in Biochar Amended Tropical Soils
(Taylor & Francis Group, 2022) Eduah, J.O.; Nartey, E.K.; Abekoe, M.K.; Asomaning, S.K.; Essibu, J.K.; Henriksen, S.W.
Soil acidification in the tropics has become a more pressing issue due to its associated aluminum (Al) phytotoxicity. The chemical reactive nature of biochar can alter Al speciation in soils. The study assessed the chemical properties and Al speciation in a Ultisol and an Oxisol amended with corn cob (CC) and rice husk (RH) biochars charred at 300, 450 and 650°C in an incubation study for 120 d. pH was determined periodically while organic carbon (OC), cation exchange capacity (CEC), exchangeable base cations, exchangeable acidity, and exchangeable Al3+ were measured at the end of the incubation period. Dissolved organic carbon (DOC) and pH were also determined in soil solution from each treatment. Throughout the incubation period CC and RH biochars significantly increased soil pH, with CC biochar showing a greater effect. Similar effects were also observed for OC, CEC, and exchangeable base cations (Ca2+, Mg2+ and K+). Soil exchangeable Al3+ and exchangeable acidity, soluble Al and Al3+ activity in soil solution decreased significantly upon biochar application; it was more significant at the 650°C. Biochars at 300–450°C exhibited a more notable increase in soil DOC. At pH ≤ 5.8, Al-DOC and free Al3+ dominated in soil solution while at pH > 5.8, Al species was mainly Al-OH ions (i.e. Al(OH)2+, Al(OH)2 +, Al(OH)3, and Al(OH)4−). Biochars at 300–450°C promoted the large formation of Al-DOC while Al-OH ions dominated in 650°C-biochar treatments. Biochar can be used to ameliorate Al phytotoxicity in tropical acid soils, particularly at 300–450°C.
Biofertilizer Activity of Azospirillum sp. B510 on the Rice Productivity in Ghana
(Microorganisms, 2021) Sarkodee-Addo, E.; Tokiwa, C.; Bonney, P.; Aboagye, D.A.; Yeboah, A.; Abebrese, S.O.; Bam, R; Nartey, E.K.; Okazaki, S.; Yasuda, M.
Rice production in Ghana has become unsustainable due to the extremely nutrient-poor soils. It is caused by inadequate soil fertility management, including the inefficient application of fertilizers. A practical solution could be the biofertilizers, Azospirillum sp. B510. We performed field trials in Ghana and Japan to compare the effects of B510 colonization on selected Ghanaian rice varieties grown. The B510 inoculation significantly enhanced the rice cultivars’ growth and yield. The phenotypic characteristics observed in rice varieties Exbaika, Ex-Boako, AgraRice, and Amankwatia were mainly short length and high tillering capacity. These features are attributed to the host plant (cv. Nipponbare), from which the strain B510 was isolated. Furthermore, Azospirillum species has been identified as the dominant colonizing bacterium of rice rhizosphere across a diverse range of agroecologies in all major rice-growing regions in Ghana. Our results suggest that the utilization of B510 as a bio-fertilizer presents a promising way to improve rice growth, enhance soil fertility, and sustain rice productivity in Ghana.
Characterization of Biochar Prepared from Three Different Feed Stocks
(University of Ghana, 2013-07) Zolue, G.M.; Dowuona, G.N.N.; Nartey, E.K.
Biochar-based soil management strategies in Ghana are new and are now being evaluated in the context of the country’s agricultural system. Biochar produced from organic materials such as saw dust, rice husk and saw dust are being used in Ghana. These different feedstocks may have different physico-chemical properties which will influence the quality of the biochar produced when the feedstocks are carbonized and in turn govern their suitability for use in agriculture. A detailed characterization of biochar produced from rice straw, rice husk and saw dust was carried out in a bid to document the basic features of the products to ensure their safety and suitability for use as soil amendments. Rice husk and straw from the same plant material and saw dust from a saw mill were pyrolysed at 350 o C in a kiln at the Soil Research Institute of the Council of Science and Industrial Research, Kwadaso, Kumasi. These samples were air dried and parameters such as particle size distribution, bulk density, available water, electrical conductivity, pH in water and KCl, total oxidizable organic carbon, total nitrogen, total phosphorus, available phosphorus, and exchangeable basic cations and total elemental analysis were carried out. Over 70% of the rice straw and the rice husk biochar types were in the very small size fraction of between 63 μm and 250 μm. The saw dust biochar, however, had 63.7% of its size fraction in the coarse size regime of between 500 μm and 2500 μm. The bulk density values of the three biochar types were very low ranging between 0.19 Mg/m 3 and 0.23 Mg/m 3 . Moisture content at field capacity was in the order of saw dust (9.55%) > rice straw (8.92%) > rice husk (7.70%). The rice straw biochar had the highest available moisture content of 3.39% which was almost 1.7 times higher than that of the saw dust biochar type. The rice straw had the highest pH of 10.5 as a result of its very high contents total Ca (10.44 mg/kg) and exchangeable Ca (7.63 cmol/kg) in addition to a high Si concentration of 170.8 mg/kg. The rice straw biochar also had the highest EC of 3.57 dS/m due to its high exchangeable Na concentration. The total oxidisable organic carbon of 191.97 g/kg was highest in the rice straw biochar with the rice husk sequestering 136.23 g/kg and saw dust 115.8 g/kg. The saw dust biochar type was the lowest in N content. On account of the C:N ratios of 166.9 for the rice straw, 142 for the rice husk biochar and 156 for the saw dust biochar, the rice straw biochar type would be the most stable and hence sequester more carbon. Available P was very high in the rice straw as a result of the high Si content of the material and was found to be 2.5 and almost 3.8 times more than the total P in the rice husk and saw dust biochar types, respectively. The concentration of heavy metals Cu, Zn and more importantly Co and Pb were very low in all the three samples with concentrations below 0.5 mg/kg due to the near neutral to strongly alkaline pH regime of all the three biochar types. These very low levels of the heavy metals make the three biochar materials very safe for use as soil amendments without any toxicity hazards. The study has identified at a charring temperature of 350 o C, the rice straw biochar has high concentrations of Ca (10.44 mg/kg,) Mg (1.61mg/kg) and Si (170.8 mg/kg) and a high pH of 10.5 in both water and KCl and therefore has the potential of being used as an agricultural liming material.
Characterizing market crop waste as feedstock for composting to reduce environmental pollution in developing countries
(Islamic Azad University, 2023) Nartey, E.K.; Akumah, A.M.; Ofosu-Budu, G.K.; et al.
Abstract Purpose Market crop waste (MCW) contributes significantly to the quantity of municipal solid waste generated in sub-Saharan Africa. These wastes, however, contain high levels of plant nutrients which can be harnessed through composting to improve soil organic matter and nutrient status of impoverished tropical soils. Method In this work, annual MCWs from two urban markets in Accra, Ghana were characterized by quantifying their seasonal availabilities, primary nutrients, heavy metals concentrations and level of microbial contamination to ascertain their suitability or otherwise for composting. Results Waste generated in the rainy seasons was higher than in the dry seasons. Primary nutrients sequestered in the MCW collected were 211.1 kg N, 1.84 kg P and 89.66 kg K for both markets. Feedstock quality analysis showed heavy metal levels in the MCW were far below the contaminant levels. Moisture content of vegetable and fruit waste was 74.34 - 90.46% and far above the desired level of aerobic composting. Pathogen levels of 5.92 CFU/g E. coli and 5.41 CFU/g Salmonella in cocoyam leaves; 6.27 CFU/g total coliform and 4.74 CFU/g Enterococcus in cabbage were detected and found to be above the maximum contaminant level as per USEPA standard. Conclusion Use of cassava, plantain peduncle and corn husk as bulking agents with vegetable and fruit waste as N, P and K sources should serve as feedstock for good quality compost production.
Distribution Of Heavy Metals In Cocoa Farm Soils In The Western Region Of Ghana
(University of Ghana, 2012-10) Ackah, J.E.; Carboo, D.; Nartey, E.K.; University of Ghana, College of Basic and Applied Sciences, School of Physical and Mathematical Sciences, Department of Chemistry
Western Region is the largest cocoa producer in Ghana. Cocoa farmlands have over the past decades received heavy doses of agrochemical application to boost cocoa production. These agrochemicals, however, may contain heavy metals and it is therefore likely that the metals may have accumulated in the soils. Evaluating the total concentrations and understanding the distribution characteristics of heavy metals in cocoa growing soils can aid environmental managers and even help regulate the rate of agrochemical application. A study was therefore, carried out on some selected soils of major cocoa growing areas in Western Region of Ghana to determine the levels of cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) in the soils and also to determine some of the soil factors that control the distribution of the heavy metals in the soil. Eight soils (two Haplic Luvisols, three Ferric Acrisols, one Haplic Ferrasol and two Dystric Fluvisols) and their accompanying pristine soils as control were taken from adjacent natural forests sampled at depths of 0 – 10 cm, 10 – 30 cm, 30 – 50 cm, 50 – 80 cm and 80 – 100 cm. These soils were analysed for their particle size distribution, pH, organic carbon, cation exchange capacity, exchangeable bases, and total and bio-available Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn. The study indicated that the ΔpH which is pHKCl – pHH2O were all negative indicating that the soils generally had net negative charges on their colloidal surface. For all soils, clay content and pH increased with depth indicating co-migration of the two soil parameters whilst total organic carbon content decreased with depth. Cation exchange capacity, however, did not show any clear pattern with depth in the soils. The average abundance of heavy metals determined in these soils decreased as follows: Fe > Mn > Cr > Zn > Cu > Cd > Pb > Ni. The soils had low metal contents, less than or within the range of concentration for non-polluted soils and for European norms. However, total concentrations of Cd, Cu, Cr and Pb in the surface soils (0 – 10 cm) exceeded the thresholds for atmospheric fallout concentrations in top soil to 20 cm depth indicative of anthropogenic contamination. The lowest heavy metal contents were observed in the Haplic Luvisols while the highest metal loadings were in the Haplic Ferrasols and the Dystric Fluvisols. Depth function plots, ANOVA and correlation analyses indicated that clay influenced the distribution of Cr, Cu, Fe, Ni and Zn in the soils. Clay and total organic carbon controlled Cd distribution while pH and clay were associated with the distribution of Mn. Thus, clay had the most pronounce effect on the distribution of the metals in the soils. Accumulation-depletion ratios, enrichment factors and principal component analysis indicated that the distribution of Cd, Cu, Mn and Pb in the soils highlighted an anthropogenic pollution, most probably, from agrochemical inputs and/or from atmospheric deposition. Iron and Ni distributions were associated with lithogenic origin whereas Zn and Cr distribution were related to both anthropogenic and lithogenic contributions.
Efficacy of Organic N-Fertilizer on Maize Growth in a Vertisol and an Acrisol in the Accra Plains
(University of Ghana, 2012-07) Mutala, E.B.; Dowuona, G.N.N.; Nartey, E.K.; Adjadeh, T.A.
The use of inorganic fertilizers in crop production in Sub Saharan Africa is very low due to exorbitant cost. Coincidentally nitrogen which is a limiting nutrient in sub Saharan African soils is locked up in organic waste with the waste breeding flies and having become an environmental nuisance in most towns in the sub region. Composting these organic wastes to be used as organic amendment has been proposed as one of the ways of improving on the low fertility status in soils and ridding the towns of filth in sub Saharan Africa. Ecological fertilizer is an organic N fertilizer formulated by the Department of Soil Science, University of Ghana from agricultural waste for Eco Products Limited. Though the nutrient composition of the fertilizer is known, its efficacy in relation to crop production is yet to be investigated to ascertain its effectiveness and competitiveness with the traditional inorganic N fertilizer sources. A greenhouse study was, therefore, conducted to test the efficacy of Eco-fertilizer on the growth of maize on Akuse Series, Vertisol and Toje Series, an Acrisol. Exactly 8.0 and 9.7 kg respective weights of fine earth fraction of the Vertisol and the Acrisol were weighed into plastic buckets with perforated bottoms to a predetermined height of 6.2m to attain the field bulk density of the two soils. The packed soils were left undisturbed for three weeks prior to the application of treatments to allow for stabilization of microbial activity. Each soil was kept at two moisture contents of field capacity (FC) and 75% field capacity. Maize of variety Obatampa was sown at three seeds per pot and one week after sowing, two N fertilizers; one organic (Eco-fertilizer) and an inorganic fertilizer , (NH 4 ) 2 SO 4 were surface applied at three rates of 0, 20 and 40 kg/ha. Each treatment was replicated three times and the pots were arranged in a randomized complete block design pattern, giving a 2×2×2×1×3x3 factorial experiment. Sampling of soils was done at 28 and 65 days after sowing, after which the soils were tested for NH 4+ and NO 3- . Agronomic parameters such as chlorophyll content, leaf area index, plant height at 28 and 65 days after sowing at the two moisture levels were also measured. Net assimilation rate was estimated and dry matter yield measured after 65 days of sowing. Results of the study showed that leaf area index, dry matter yield, total nitrogen content of the maize plant, net assimilation rate, plant height and chlorophyll content increased with fertilization of the two soils for both fertilizers. When the two soils were amended with the fertilizers, LAI at 28 days after sowing (LAI-1) was higher in the Akuse series than the Toje series at the two moisture contents due to the superior inherent fertility of the former soil. The higher LAI-1 in the Akuse soils is also supported by the higher available N in the soil at 28 days after sowing which also tied in very well with higher chlorophyll content at 28 days after sowing. At 20 kg/ha for the Akuse series, the nitrogen content in the plant was higher in the inorganic amended soil than that of the organic amended one. However at 40 kg/ha the nitrogen contents of the plants were statistically the same. In the Toje series, the nitrogen content of the plants at the two rates of application, irrespective of fertilizer type were similar just as dry matter yield (DMY).Similar growth parameters such as LAI, height and DMY at both 28 days and 65 days of sowing in the organically and inorganically amended Toje soil and the fact that there was generally no difference in DMY in the two soils at the two application rates indicated that the organic fertilizer competes favourably with the inorganic one in maize growth. There was generally no difference in moisture content at FC and 75% FC on N accumulation and hence DMY of maize plants after 65 days of sowing. At 28 days after sowing which is the vegetative stage of the maize plant, the NH 4+ contents in the soils was higher at 75%FC than at FC suggestive of the fact that more NH 4+ had been absorbed at FC due to the prevailing optimum condition for N absorption
Influence of method of residue application and moisture content on water soluble nitrogen in a rhodickandiustalf amended with different fallow plant materials
(West African Journal of Applied Ecology, 2019-10-05) Darko, D.A.; Nartey, E.K.; Adiku, S.; Laryea, K.B.
Use of plant residues as nutrient sources presents a viable option to resource poor farmers who sparsely use mineral fertilizer in crop production. A study was conducted to gain an insight into how different application methods of residues from different fallow management systems under two moisture regimes would affect soluble N release in a Rhodic Kandiustalf. Three residue types viz, elephant grass from a natural fallow (T1) and another as a fallow following a previously fertilized maize (T2) and a fallow legume (T3) were surface applied and incorporated in a Rhodic Kandiustalf at both field capacity (FC) and 60% field capacity over a sixteen-week period. Incorporation of mucuna residues and elephant grass from previously fertilized maize fallow released similar soluble N levels which were higher than levels from the natural elephant grass amendments. At 60% FC, both mucuna and elephant grass from the fertilized maize fields that were surface applied had slower N releases than the grass from the natural fallow, suggesting the elephant grass from the natural fallow field could be used as an N source amidst light watering to avoid leaching in the dry season.
Mechanism of orthophosphate (PO4-P) adsorption onto different biochars
(Environmental Technology & Innovation, 2019-12-04) Eduah, J.O.; Nartey, E.K.; Abekoe, M.K.; Henriksen, S.W.; Andersen, M.N.
The adsorption mechanisms of phosphate (PO4-P) onto cocoa pod husk (CP), corn cob (CC), rice husk (RH) and palm kernel shell (PK) biochar pyrolyzed at 300 ◦C and 650 ◦C were investigated. A series of batch experiments were undertaken to assess the effects of contact time and pH. Results show that PO4-P adsorption equilibria for the biochar types was within 6–15 h, being rapid in the 300 ◦C-biochar types. The equilibrium pH for maximum PO4-P adsorption varied among biochar types, ranging from of 2.6 to 4.8 and increasing with decreasing PO4-P adsorption. Pseudo-secondorder and Elovich models explained the adsorption data well indicating a chemisorption process on heterogeneous biochar surface. PO4-P adsorption was controlled initially by intraparticle diffusion and subsequently by chemisorption. Per the properties of the biochars (FTIR and elemental composition) and pH (equilibrium pH and ΔpH), PO4–P was adsorbed through electrostatic attraction, surface precipitation and ligand exchange, and the relative importance of these processes differed among the biochar types. Biochar types (PK300, PK650, CP300, CP650, RH650 and CC650) that adsorbed PO4-P through surface precipitation and ligand exchange reactions can be used to remove PO4-P from wastewater since PO4-P is strongly adsorbed, controlling PO4-P enrichment of water bodies.
Microbial activity and metabolic quotient of microbes in soils amended with biochar and contaminated with atrazine and paraquat
(Acta Agriculturae Scandinavica Section B: Soil and Plant Science, 2017) Sam, A.T.; Asuming-Brempong, S.; Nartey, E.K.
The study was conducted to determine how biochar as a soil amendment maintained the microbial community in pesticide contaminated soils. Alfisol (Adenta series–Typic Kandiustalf) and Vertisol (Akuse series–Typic Calciustert) were amended with biochar (0 t/ha biochar, 10 t/ha cocoa husk biochar (CHB), 10 t/ha rice husk biochar (RHB)) and pesticides (atrazine and paraquat at two rates each namely 0 kg/ha pesticide and 10 times the normal recommended rate of pesticide) were applied. The CHB-amended soils stimulated microbial activities such as ammonia and nitrate release more than the RHB-amended soils. Basal respiration was significantly higher in the atrazine polluted soils than in paraquat polluted soil. Significant interaction occurred between soil type and biochar and high microbial biomass carbon was recorded for vertisol amended with CHB. Metabolic quotient was lower in soils amended with biochar and polluted with atrazine than in the un-amended soil. The use of CHB in soil of high clay content (47.5%, i.e. the vertisol) was a more effective management tool in maintaining the microbial community in a pesticide-polluted environment than in soil of lower clay content (22.5%). Soils of high clay content amended with biochar can sustain the soil microbial community even in a disturbed environment. © 2017 Informa UK Limited, trading as Taylor & Francis Group.
Nonlinear sorption of phosphorus onto plant biomass-derived biochars at different pyrolysis temperatures
(Environmental Technology & Innovation, 2020-04-18) Eduah, J.O.; Henriksen, S.W.; Nartey, E.K.; Abekoe, M.K.; Andersen, M.N.
Aside the characterization of feedstocks and biochars (BCs), the nonlinear sorption of phosphorus (P) onto corn cob (CC), rice husk (RH), cocoa pod husk (CP) and palm kernel shell (PK) BCs charred at 300, 450 and 650 ◦ C were investigated using series of batch experiments. Conversion of feedstock to BC resulted in a higher pH, C content, ash, fixed C, surface area (SA) and lower volatile matter, moisture, H, N, O and S contents. Increasing pyrolysis temperature proportionally decreased the polarity (O/C, O+N/C, and O+ N+ S/C), volatile matter, moisture content, readily labile organic C and potentially unstable C vis-à-vis an increased in C content, fixed C, stable C and aromaticity (H/C). The nonlinearity index (n) as well as P sorption capacity (KF ) increased with temperature and were highly dependent on BC properties. Significant linear relationships were observed between P sorption parameters (n and KF ) and O content, polarity, aromaticity, fixed C, stable C, readily labile organic C and SA. The low polarity and high aromaticity and SA resulted in the high nonlinear sorption of P at 650 ◦ C. Findings of this study provides insight into P sorption behaviour, thereby serving as a theoretical basis for biochar application either agronomically or environmentally.
Phosphorus retention and availability in three contrasting soils amended with rice husk and corn cob biochar at varying pyrolysis temperatures
(Geoderma, 2019-05) Eduah, J.O.; Nartey, E.K.; Abekoe, M.K.; Breuning-Madsen, H.; Andersen, M.N.
The reactive nature of phosphorus (P) leads to the formation of insoluble Fe, Al and Ca phosphates in highly weathered tropical soils, thus reducing P availability for plant uptake. Biochar with its heterogeneous surface properties as influenced by feedstock and pyrolysis temperature can affect P retention and availability in tropical soils. In the present study, incubation studies were conducted for 90 days to investigate the effect of corn cob and rice husk biochar on P sorption and desorption in two acid (Typic Plinthustult-A & Plinthic Acrudox-B) and one neutral soil (Quartzipsamment-C). The biochars were pyrolyzed at varying temperatures (300 °C, 450 °C and 650 °C) and applied at a rate of 1% (w/w) to the soils. Phosphorus sorption data were fitted to Langmuir and Freundlich models. Phosphorus desorption was done on the residual samples that received initial P concentrations of 21.5 mg L−1, 43.0 mg L−1 and 86.0 mg L−1 solution using 10 mM KCl. The P sorption capacity of the two acid soils i.e. A (395 mg kg−1) and B (296 mg kg−1) were more than two fold that of the neutral soil (C) (105 mg kg−1). Addition of the biochar types to soil A raised the equilibrium P concentration in solution at decreasing pyrolysis temperature. Similar trend was observed in soil B with the exception of corn cob and rice husk biochar at 650 °C which increased the soil's (B) P sorption capacity. In soil C, both biochar types increased P sorption capacity with increasing pyrolysis temperatures. Phosphorus desorbability increased with increasing initial P concentrations in the three soils. Generally, P desorbability increased in the acid soils but decreased in the neutral soil upon biochar amendment. Decreases in P adsorption and consequently increases in P desorption were more pronounced when the 300 °C biochar types were amended with the soils. The study thus showed that biochar pyrolyzed at 300–450 °C could be used to reduce P sorption and increase P bioavailability especially in acid soils. The addition of biochar to neutral or alkaline soils might increase P retention possibly in the short-term, reducing P bioavailability.
Poultry litter and cow dung biochar as P sources for cowpea cultivation in two Ghanaian soils
(Frontiers in Agronomy, 2023) Nartey, E.K.; Sulemana, N.; Razak, A.; Adjadeh, T.A.; Akumah, A.M.; Amoatey, C.; Abekoe, M.K.
Introduction: The main constraint to cowpea, Vigna unguiculata, production in West Africa is unavailability of applied phosphorus due to ligand exchange with clay minerals and precipitation reactions facilitated by low pH and low organic matter. Materials and methods: To overcome this challenge, cow dung biochar (CB) and poultry litter biochar (PB) were applied as P sources for cowpea cultivation in Plinthustult and Kandiustalf soil in Ghana. The biochar types and triple super phosphate (TSP) were applied to meet the standard phosphorus requirement (SPR) and ½ SPR of the soils. Basal K from KCl was added to the TSP treatment. In addition to a non-amended soil, the treatments were triplicated and arranged in a completely randomized design in a screen house for an efficacy trial using cowpea as the test crop. Moisture content was maintained at 80% field capacity. Results and discussion: Hundred cowpea seed weight was 20.3 g and 19.6 g for the TSP-amended Plinthustult at SPR and ½ SPR, respectively. This increased to 25.1 g and approximately 27 g at SPR and ½ SPR in the CB- and PB-amended Plinthustult, respectively. Hundred seed weight for TSP at both rates was similar in the two soils. The PB-amended Kandiustalf at SPR had seed with a weight of 27.02 g, 1.1 g heavier than the ½ SPR. The CB-amended Kandiustalf at both rates had 100 seeds weighing 25 g. Residual available P was 334.2 mg/kg and 213.2 mg/kg at SPR and ½ SPR, respectively, in the Plinthustult as opposed to a paltry 2.5 mg/kg at SPR in the TSP counterpart. The study recommends for the two biochar types to be applied at ½ SPR.
Poultry litter and cow dung biochar as P sources for cowpea cultivation in two Ghanaian soils
(Frontiers in Agronomy, 2023) Nartey, E.K.; Sulemana, N.; Razak, A.; et al
Introduction: The main constraint to cowpea, Vigna unguiculata, production in West Africa is unavailability of applied phosphorus due to ligand exchange with clay minerals and precipitation reactions facilitated by low pH and low organic matter. Materials and methods: To overcome this challenge, cow dung biochar (CB) and poultry litter biochar (PB) were applied as P sources for cowpea cultivation in Plinthustult and Kandiustalf soil in Ghana. The biochar types and triple super phosphate (TSP) were applied to meet the standard phosphorus requirement (SPR) and½SPR of the soils. Basal K from KCl was added to the TSP treatment. In addition to a non-amended soil, the treatments were triplicated and arranged in a completely randomized design in a screen house for an efficacy trial using cowpea as the test crop. Moisture content was maintained at 80% field capacity. Results and discussion: Hundred cowpea seed weight was 20.3 g and 19.6 g for the TSP-amended Plinthustult at SPR and ½ SPR, respectively. This increased to 25.1 g and approximately 27 g at SPR and ½ SPR in the CB- and PB-amended Plinthustult, respectively. Hundred seed weight for TSP at both rates was similar in the two soils. The PB-amended Kandiustalf at SPR had seed with a weight of 27.02 g, 1.1 g heavier than the ½ SPR. The CB-amended Kandiustalf at both rates had 100 seeds weighing 25 g. Residual available P was 334.2 mg/kg and 213.2 mg/kg at SPR and ½ SPR, respectively, in the Plinthustult as opposed to a paltry 2.5 mg/kg at SPR in the TSP counterpart. The study recommends for the two biochar types to be applied at ½ SPR.
Simple formulation of the soil water effect on residue decomposition
(Communications in Soil Science and Plant Analysis, 2010-02) Adiku, S.G.K.; Amon, N.K.; Jones, J.W.; Adjadeh, T.A.; Kumaga, F.K.; Dowuona, G.N.; Nartey, E.K.
Soil water content, θ, is a major factor affecting residue decomposition, but simple formulation of this factor is often lacking. We observed that θ significantly (P < 0.001) affected the residue decomposition constant, kd· When θ varied from 0.09gg-1 to 0.23gg-1, kd ranged from 0.009 to 0.013d-1 and from 0.009 to 0.022d-1 for residues with carbon to nitrogen ratio (C/N) > 30 and C/N < 25, respectively. A θ factor was formulated in terms of the field capacity θFC and the air-dry θ d in the form fw = (θ - θd) / (θFC - θd), and this was used to modify the potential kd as θ varied. Coupling fw with a first-order residue decomposition equation resulted in the prediction of the decomposition of four residue types in the greenhouse (R2 = 0.94; relative root mean square error, RRMSE, = 0.06) and in the field (R2 = 0.93; RRMSE = 0.11). © Taylor & Francis Group, LLC.
Sustainable P-enriched biochar-compost production: harnessing the prospects of maize stover and groundnut husk in Ghana’s Guinea Savanna
(Frontier in Environment Science, 2023) Fianko, D.A.; Nartey, E.K.; Abekoe, M.K.; et al.
Farmers in resource-poor areas of the Guinea Savanna zone of Ghana often face declining soil fertility due to the continuous removal of nutrient-rich harvested produce from their fields. This study focuses on the Lawra Municipality in the Guinea Savanna zone of Ghana, where low soil fertility, specifically, limits phosphorus (P) bioavailability and hinders crop production. The objective of this research is to formulate P-enhanced biochar-compost from maize stover (MS) and groundnut husk, which abound in the area, to close the nutrient loop. MS was co-composted with groundnut husk biochar at varying rates of 0, 10, 20, 30, and 40% by volume. To facilitate decomposition using the windrow system, the composting heaps were inoculated with decomposing cow dung, and the moisture content was kept at 60% throughout the monitoring period. The addition of biochar shortened the lag phase of composting. However, rates above 20% resulted in reduced degradation of MS. Biochar incorporation enriched the available phosphorus content in the final compost from 286.7 mg kg−1 in the non-biochar-compost to 320, 370, 546, and 840.0 mg kg−1 in the 10, 20, 30, and 40% biochar-compost, respectively
The Use of Biochar to Remediate two Coastal Savannah Soils Contaminated with Atrazine nd Paraquat
(University of Ghana, 2014-12) Sam, A. T.; Asuming-Brempong, S.; Nartey, E.K.; University of Ghana, College of Basic and Applied Sciences, School of Agriculture, Department of Soil Science
The use of atrazine (1-Chloro-3-ethylamino-5-isopropylamino-2, 4, 6-triazine) and paraquat (1, 1’-Dimethyl-4, 4’-bipyridinium dichloride) as alternatives to manual or mechanical weeding in the developing world is becoming inevitable. The frequent application of these two pesticides has led to contamination of soils with dire attendant environmental consequences.A study was therefore, conducted to evaluaate the ability of cocoa and rice husk-derived biochar types to enhance the remediation of atrazine and paraquat contaminated Acrisol (Adenta series) and Vertisol (Akuse series) and to ascertain the effectiveness of the two biochar types in actively supporting the growth of beneficial soil microorganisms to enhance the degradability of the pesticide in contaminated soils. The two soils were amended with each of the two biochar types at 10 t/ha and thereafter contaminated with the each of the two pesticides at three rates of zero, normal application and ten times normal application rates and replicated three times in a completely randomized design. The moisture contentwas kept at 80% field capacity and the samples incubated for 90 days.. Total heterotroph count, microbial biomass C and N and C and N mineralized were determined at 10 day intervals for the entire duration of the experiment. Results showed that biochar amendment stimulated growth of heterotroph counts in both the Akuse and Adenta series with the highest mean counts of 66 x 105cfu/g soil being obtained from the Akuse series amended with cocoa husk biochar and contaminated with atrazine at ten times the normal rate of application. Microbial biomass carbon was also high for the biochar amended soils especially for the cocoa husk biochar amended soil. The use of paraquat had a depressive effect on the total heterotroph counts. Application of paraquat did not significantly depress the microbial biomass carbon especially in the cocoa husk biochar amended soils contaminated with ten times the normal rate of atrazine. Microbial activity was also high in the biochar amended soils compared to the un-amended soils and contaminated with pesticide. Degradation of atrazine at normal rate of application was faster in both soil series amended with rice husk biochar as compared to the soils amended with cocoa husk biochar and the un-amended. At ten times the normal application rate of atrazine, degradation was fast in the cocoa husk biohar amended Akuse and Adenta series. There was less degradation of paraquat in both soils; however, at normal application rate of paraquat, degradation was faster in the rice husk biohar amended soils i.e. for both Adenta and Akuse series. The high composition of the nutrients in the cocoa husk biohar biochar especially the available P materials make it a suitable material to be used as soil amendment in the highly acid soils in Ghana.