Papers by Mohamadu jalloh
Arid Land Research and Management, 1988
Loss of NH3 from urea fertilizer in a cultivated sandy desert soil was evaluated by using various... more Loss of NH3 from urea fertilizer in a cultivated sandy desert soil was evaluated by using various fertilizer treatment regimes. The nitrification of added urea increased with the pretreatment of (NH4)2SO4. The increase in nitrification rate was directly related to the amount of (NH4)2SO4 added. These results suggested that when urea was applied after sufficient increase in nitrification rate, i.e.,
American Journal of Agricultural and Biological Sciences, 2009
Problem statement: Fertilizer N use efficiency is reduced by ammonia volatilization. Under low so... more Problem statement: Fertilizer N use efficiency is reduced by ammonia volatilization. Under low soil CEC and high pH, N from soil solution is released to the atmosphere. Ammonia loss due to low worldwide N use efficiency (33%) has been implicated in global warming. Thus, the objectives of this laboratory study were to evaluate the effectiveness of liquid humic and fulvic acids, isolated from tropical peat soils in reducing N loss from urea fertilizer as well as to investigate the ability of these acids to retain NH 4 + and NO 3¯ or reduce soil pH. Approach: Formulated liquid N fertilizers consisting of urea and different types of humic molecules (HA or FA or mixture of both), solid and liquid urea were surface applied to 250 g of soil. A closed dynamic air flow system was used to trap NH 3 loss in boric acid after which samples were titrated with 0.01 M HCl to estimate NH 3 loss. After 30 days of incubation, the soil was air dried and analysed for pH, exchangeable NH 4 + , available NO 3¯ and exchangeable cations. The results were analysed using SAS and treatments means were compared using Duncan's New Multiple Range Test (DNMRT). Results: The use of humic molecules reduced NH 3 loss and increased exchangeable NH 4 +. The high CEC of Humic Acids (HA) made the LHA treatment the best in reducing N loss after surface application. The presence of HA and Fulvic Acids (FA) increased NH 4 + recovery. Even though, the soil pH of all the treatments were high, significant reduction of N loss was observed for humic molecules treatments. Conclusion: The use of liquid organic N fertilizer has the ability to reduce NH 3 volatilization in acid soil. The use of both humic and fulvic acids could be effective in promoting NH 4 + retention. Thus, it can be concluding that, humic substances, in general, have great ability in controlling NH 3 loss and retaining NH 4 + in acid soils. It could be a cheapest, practical and easiest way to control N loss.
Land
Intensified cultivation of rice has accelerated weathering of most tropical acid soils leading to... more Intensified cultivation of rice has accelerated weathering of most tropical acid soils leading to significant loss of base cations. In most developing countries, rice yield is low and this results in its production being costly because productivity versus labor is low. The objectives of this study were to (i) enhance soil chemical properties, nutrient uptake, and grain yield of rice grown on a mineral tropical acid soil using agro-wastes; (ii) determine the agro-waste (chicken manure, cow dung, forest litter, and Leucaena) that has the potential to significantly increase rice yield; and (iii) determine the residual effects of the organic soil amendments produced from the agro-wastes on soil and rice productivity. The treatments used in this three-cycle field study were (i) soil without amendments (S0); (ii) prevailing recommended rates for fertilizers (NPK-Mg); (iii) biochar–forest litter compost (OSA1); (iv) biochar–chicken litter compost (OSA2); (v) biochar–cow dung compost (OSA3)...
Sustainability
Efficient management of N fertilizers enhances crop yields and contributes to sustainable food se... more Efficient management of N fertilizers enhances crop yields and contributes to sustainable food security. Tropical acidic soils with high Al and Fe are prone to easy loss of basic cations, such as NH4+, via leaching and erosion. Appropriate soil amendments and agronomic practices minimize the loss of fertilizer nutrients, improve soil nutrient retention, and maximize their uptake by plants. This study aimed to evaluate the effects of co-applying charcoal and sago bark ash with inorganic fertilizers on N availability, uptake, use efficiency, and dry matter production of sorghum in a tropical acid soil. The results revealed that the co-application of inorganic fertilizers with charcoal and sago bark ash increased sorghum plant height, dry matter production, N uptake and N use efficiency. The soil treated with a combination of 100% of the recommended rate of charcoal and sago bark ash (C1A1) resulted in significantly higher sorghum dry matter production, N uptake, and use efficiency com...
Agronomy
The highly weathered, acidic tropical soils are generally less fertile because of their low pH, h... more The highly weathered, acidic tropical soils are generally less fertile because of their low pH, high exchangeable acidity, and Al, Fe, and Mn saturations. Using soil amendments to solve the aforementioned problems is essential. To this end, Calciprill and sodium silicate are worth considering because of their high neutralizing value and dissolution to suppress exchangeable acidity and Al, Fe, and Mn hydrolysis, while at the same time increasing soil pH to improve the availability of inorganic N, available P, exchangeable base cations, and Effective Cation Exchange Capacity (ECEC). An incubation study was conducted to determine the right combination of Calciprill and sodium silicate to reduce exchangeable acidity and Al and Fe hydrolysis to improve inorganic N, available P, exchangeable base cations availability, and ECEC. Bekenu series (Typic Paleudults) was incubated with a combined use of Calciprill at 80%, 90%, and 100% Ca saturations and sodium silicate at 90, 105, 120, 135, and...
Agronomy
In the tropics, warm temperatures and high rainfall contribute to acidic soil formation because o... more In the tropics, warm temperatures and high rainfall contribute to acidic soil formation because of the significant leaching of base cations (K+, Ca2+, Mg2+, and Na+), followed by the replacement of the base cations with Al3+, Fe2+, and H+ ions at the soil adsorption sites. The pH buffering capacity of highly weathered acid soils is generally low because of their low pH which negatively impacts soil and crop productivity. Thus, there is a need to amend these soils with the right amount of inorganic liming materials which have relatively high neutralizing values and reactivity to overcome the aforementioned problems. Soil leaching and the pH buffering capacity studies were conducted to determine whether the co-application or co-amendment of a calcium carbonate product (Calciprill) and sodium silicate can improve soil nutrient retention and pH buffering capacity of the Bekenu series (Typic Paleudults). A 30 day soil leaching experiment was carried out using a completely randomized desi...
Agronomy, 2021
Inappropriate drainage and agricultural development on tropical peatland may lead to an increase ... more Inappropriate drainage and agricultural development on tropical peatland may lead to an increase in methane (CH4) emission, thus expediting the rate of global warming and climate change. It was hypothesized that water table fluctuation affects CH4 emission in pineapple cultivation on tropical peat soils. The objectives of this study were to: (i) quantify CH4 emission from a tropical peat soil cultivated with pineapple and (ii) determine the effects of water table depth on CH4 emission from a peat soil under simulated water table fluctuation. Soil CH4 emissions from an open field pineapple cultivation system and field lysimeters were determined using the closed chamber method. High-density polyethylene field lysimeters were set up to simulate the natural condition of cultivated drained peat soils under different water table fluctuations. The soil CH4 flux was measured at five time intervals to obtain a 24 h CH4 emission in the dry and wet seasons during low- and high-water tables. So...
Sustainability, 2021
Soil acidity compromises agricultural output in tropical acid soils. Highly weathered tropical ac... more Soil acidity compromises agricultural output in tropical acid soils. Highly weathered tropical acidic soils are characterized by low pH, organic matter, nutrient availability, but high aluminium and iron concentration. Hence, N availability becomes a limiting factor in such soils. To this end, these leaching and pH buffering capacity studies were conducted to determine the effects of co-application of charcoal and sago bark ash on the N leaching or retention and pH buffering capacity of acid soils. The soil leaching experiment was conducted for 30 days by spraying distilled water to each container with soil such that the leachates were collected for analysis. The rate of urea used was fixed at 100% of the recommended rate. The rates of charcoal and sago bark ash were varied by 25%, 50%, 75%, and 100%, respectively, of the recommended rates. The pH buffering capacity was calculated as the negative reciprocal of the slope of the linear regression. The leaching study revealed that the ...
Microorganisms, 2020
Plant growth-promoting rhizobacteria (PGPR), which include isolates from genera Paraburkholderia,... more Plant growth-promoting rhizobacteria (PGPR), which include isolates from genera Paraburkholderia, Burkholderia and Serratia, have received attention due to their numerous plant growth-promoting mechanisms such as their ability to solubilize insoluble phosphates and nitrogen-fixation. However, there is a dearth of information on the potential plant growth-promoting effects of these three groups of bacteria on non-legumes such as maize. This study determined the influences of the aforementioned strains on soil properties, maize growth, nutrient uptake and nutrient use efficiency. A pot trial using maize as a test crop was done using a randomized complete block design with 7 treatments each replicated 7 times. The treatments used in this study were: Control (no fertilizer), chemical fertilizer (CF), organic-chemical fertilizers combination without inoculum (OCF) and with inocula consisting of single strains [cellulolytic bacteria (TC), organic fertilizer and chemical fertilizer with N-...
Sustainability, 2021
Sustaining soil health cannot be divorced from sustainable crop production. Organic, or natural, ... more Sustaining soil health cannot be divorced from sustainable crop production. Organic, or natural, farming is being promoted as a good sustainable agriculture practice. One aspect of organic farming that could significantly enhance and sustain soil health, soil quality, and crop productivity is the use of high-quality soil conditioners or organic amendments produced from agro-wastes. Thus, the objective of this study was to characterize the chemical and biological properties of selected agro-wastes with potential for use as organic amendments in sustaining soil health. Standard procedures were used to produce and characterize the soil conditioners, namely fermented plant juice (FPJ), fermented fruit juice (FFJ), palm kernel shell (PKS) biochar, and kitchen waste (KW) compost. The fermented juices (FPJ and FFJ), PKS biochar, and KW compost exhibited chemical and biological properties with good potential as soil conditioners or organic amendments to sustain soil health. The fermented ju...
Applied Sciences, 2020
High nitrogen use efficiency (NUE) is important for improving crop yield. There are many nitrogen... more High nitrogen use efficiency (NUE) is important for improving crop yield. There are many nitrogen (N) fractions in soil and their uptake by crops varies. Most of the N that is taken up by plants is not native to the soil but usually from fertilizer added to the soil. However, the unbalanced use of fertilizers is currently an important issue that needs to be addressed. The objectives of this work were to determine the effects of using the recommended chemical fertilizers together with inorganic and organic amendments on (i) soil organic and inorganic N fractions, (ii) N uptake and use efficiency, and (iii) maize (Zea mays L.) dry matter production and ear yield. A randomized complete block design field trial, using maize as a test crop, was done with seven fertilizer treatments, each replicated thrice for two crop cycles. The treatments included different combinations of urea N, clinoptilolite zeolite (CZ), rice straw compost, and paddy husk compost. The variables of the study were s...
In the midst of major soil degradation and erosion faced by tropical ecosystems, rehabilitated fo... more In the midst of major soil degradation and erosion faced by tropical ecosystems, rehabilitated forests are established to avoid further deterioration of forest land. In this context, cellulolytic, nitrogen-fixing (N-fixing), and phosphate-solubilizing bacteria are very important functional groups in regulating the elemental cycle and plant nutrition, hence replenishing the nutrient content in forest soil. As other potential plant growth-promoting (PGP) rhizobacteria, these functional bacteria could have cross-functional abilities or beneficial traits that are essential for plants and improve their growths. This study was conducted to isolate, identify, and characterize selected PGP properties of these 3 functional groups of bacteria from tropical rehabilitated forest soils at Universiti Putra Malaysia Bintulu Sarawak Campus, Malaysia. Isolated cellulolytic, N-fixing and phosphate-solubilizing bacteria were characterized for respective functional activities, biochemical properties, m...
Italian Journal of Agronomy, 2019
Tropical soils such as Ultisols fix phosphorus (P) because of their characteristically high conte... more Tropical soils such as Ultisols fix phosphorus (P) because of their characteristically high contents of aluminium and iron. Organic amendments could be used to mitigate P fixation. This study aimed to: i) improve soil P availability, nutrients uptake, and yield of Zea mays L. using biochar and pineapple leaf residues compost; and ii) determine if the use of biochar and pineapple leaf residues compost could exert a residual effect on P. Two cycles of field trials were carried out and the test crop used was Zea mays L. hybrid F1. At harvest, the plants were harvested, partitioned into leaves and stems, and analysed. Soil samples were also collected and analysed. The results suggest that the soil total P, available P, inorganic P, and organic P recovered from the treatments with the organic amendments were higher compared with the nonorganic amendments. The availability of soil macro-nutrients in the soils and Zea mays L. yield were higher in the treatments with the organic amendments ...
Journal of Phytopathology, 2017
Nutrients are essential for normal physiological processes in plants, and they play important rol... more Nutrients are essential for normal physiological processes in plants, and they play important roles in defence mechanisms against pathogens. Oil palms cultivated on peat are more prone to nutrient deficiency, especially micronutrients, and this may affect their susceptibility to Ganoderma species, the major threat to the sustainability of oil palm throughout SouthEast Asia. This study was conducted to investigate the association of copper (Cu) and zinc (Zn) in mature oil palm to the spatial distribution of Ganoderma species in the plantations on peat. Foliar samples (frond 17) of oil palm from two plantations (Betong and Miri) on peat in Sarawak, Malaysia, were collected based on the spatial distribution pattern of Ganoderma, and total Cu and Zn were quantified spectrometrically. The experiment was conducted twice at a 1-year interval. The concentrations of Cu and Zn were significantly lower in oil palms from infected areas in contrast to those from uninfected areas. In addition, oil palms in infected areas in Miri suffered Cu and Zn deficiencies. Furthermore, Cu and Zn were significantly lower in the oil palms in Miri that had higher Ganoderma occurrence, as compared to those in Betong, which had significantly higher Cu and Zn but lower Ganoderma occurrence.
The Scientific World Journal, 2015
High cation exchange capacity and organic matter content of crude humic substances from compost c... more High cation exchange capacity and organic matter content of crude humic substances from compost could be exploited to reduce ammonia loss from urea and to as well improve rice growth and soil chemical properties for efficient nutrients utilization in lowland rice cultivation. Close-dynamic air flow system was used to determine the effects of crude humic substances on ammonia volatilization. A pot experiment was conducted to determine the effects of crude humic substances on rice plant growth, nutrients uptake, nutrients recovery, and soil chemical properties using an acid soil mixed with three rates of crude humic substances (20, 40, and 60 g pot−1). Standard procedures were used to evaluate rice plant dry matter production, nutrients uptake, nutrients recovery, and soil chemical properties. Application of crude humic substances increased ammonia volatilization. However, the lowest rate of crude humic substances (20 g pot−1) significantly improved total dry matter, nutrients uptake,...
American Journal of Environmental Sciences, 2009
Problem statement: Application of urea as a source of nitrogen fertilizer has an adverse effect o... more Problem statement: Application of urea as a source of nitrogen fertilizer has an adverse effect on ammoniacal loss to the environment. This study was conducted to reduce ammonia loss from urea by mixing with Humic Acids (HA) isolated from Saprists peat. Approach: The effects of urea amended with four different amounts of humic acids, 0.25, 0.50, 0.75 and 1.00 g were evaluated in laboratory conditions using a closed dynamic air flow system. The mineral soil that was used as medium for the study was Bekenu series (typic paleudults). Amnonia loss, soil pH, exchangeable ammonium, available nitrate, exchangeable K, Ca, Mg and Na were determined using standard procedures. Results: All the treatments with HA significantly reduced ammoinia loss compared to urea alone. Increasing the amount of HA also significantly retained soil exchangeable ammonium and available nitrate. Treatments with HA had no significant effect on the concentrations of Mg, K and Ca, except for Na. The effect of HA in the mixtures on ammonia loss was related to their effect on the formation of ammonium over ammonia. Conclusion: Surface-applied urea fertilizer efficiency could be increased when coated with 1.00 g of HA.
American Journal of Applied Sciences, 2009
Problem Statement: The isolation (extraction, fractionation and purification) of humic acids (HA)... more Problem Statement: The isolation (extraction, fractionation and purification) of humic acids (HA) from soils is laborious, time consuming and expensive. The extraction, fractionation and purification periods of these substances vary from 12 h-7 days. In order to facilitate production of HA at competitive cost, this study was conducted to investigate whether a simple and rapid procedure could be developed for isolation of HA from well decomposed tropical peat soils (Saprists).
American Journal of Agricultural and Biological Sciences, 2009
Problem statement: Peat has been identified as one of the major groups of soils found in Malaysia... more Problem statement: Peat has been identified as one of the major groups of soils found in Malaysia. Sarawak as the largest state in Malaysia has the biggest reserve of peat-land. There are about 1.5 million ha of peat-land in Sarawak, which are relatively under developed. As is the case with any plant, oil palm trees do sequester carbon as they grow. Nevertheless, the process of clearing forest in order to establish a plantation may release carbon. Little studies have been done on the comparison of soil organic matter, soil organic carbon and yield of humic acids when secondary forest on peat soil is converted to oil palm plantation. The objective of this study was to compare carbon storage of secondary forest and early stages of oil palm plantations on a tropical peat soil. Approach: Soil samples were collected from the secondary forest, 1, 3, 4 and 5 year old oil palm plantations in Tatau district, Sarawak. Ten samples were taken at random with a peat auger at 0-25 and 25-50 cm depths. The bulk densities at these depths were determined by the coring method. The bulk density method was used to quantify the total carbon, total organic matter, total nitrogen, humic acids and stable carbon at the stated sampling depths on per hectare basis. Results: There were no significant differences in the amounts of stable C of both secondary forest and different ages of the oil palm plantations at 0-25 and 25-50 cm soil depth. The amounts of stable C in the secondary forest, 1, 3, 4 and 5 year old oil palm plantations at 0-25 cm depth were generally higher than those in the 25-50 cm depth. This was attributed to higher yield of HA in the secondary forest, 1, 3, 4 and 5 year old oil palm plantations soil partly due to better humification at the 0-25 cm soil depth.Conclusion: Conversion of secondary forest on peat to initial stages of oil palm plantation seems to not exert any significant difference on carbon storage in tropical peat soil.
This study aims to assess the biochemical changes of maize during water stress condition. Methodo... more This study aims to assess the biochemical changes of maize during water stress condition. Methodologically, Yellow Super Sweet Corn (YSC) and Thai Super Sweet Corn (TSC) were conducted with water stress condition in different days of interval for watering. The leaves sample were collected and determined for biochemical parameters responses to drought stress. The finding shows that increasing water stress siginificantly reduced the biochemical parameters as compared to control treatment which is watering everyday. The experiment show that proline accumulated highest in YSC treated with T4 (3.8 x 10-3 mg mL-1 in 200 mg of leaves) at day 65 and TSC which treated with T5 (0.08 mg mL-1 in 200 mg of leaves) at day 40. Protein content in YSC treated with T2 (5.6 x10-4mg mL-1) was no significant differences with control treatment but showed differences in TSC which treated with same treatment (3.3 x 10-4 mg mL-1) at day 65. There was no significant differences in chlorophyll content between...
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Papers by Mohamadu jalloh