Sign inSubmit
Tips: “quotes” for a phrase · author:Lee · a DOI goes straight to its article

20 articles for “humic acids”
Set a search alert
Research ArticleOpen accessPhrase in the titleEffects of Extractants on the Yields and Selected Chemical Characteristics of Humic Acids Isolated from Tropical Saprists PeatLee Jia Huey, Osumanu Haruna Ahmed, Nik Muhamad Ab. MajidProblem statement: Humic acids are beneficial to soil aggregation, binding of heavy metal, plant growth and many more. However, the isolation of Humic Acids (HA) from its origin is not only time-consuming, but the isolation is also affected by factors such as temperature and the types of extractants and their concentrations. Different concentrations of extractant are said to alter the … …American Journal of Applied Sciences, Vol. 7, Issue 7 · 31 Jul 2010 · 7,503 accessesView PDFCite
Research ArticleOpen accessPhrase in the titleReduction of Isolation Period of Coal Humic AcidsClaudia Hui Hui Chen, Osumanu Haruna Ahmed, Nik Muhamad Ab. Majid, Mohamadu Boyie JallohProblem statement: The isolation of Humic Acids (HA) from coal is laborious, costly and time consuming. The extraction and fractionation periods of HA vary from 4 h to 7 days. Fractionation period ranges from 12-24 h. However, most studies use 24 h as extraction period and also 24 h as fractionation period. This study was conducted to investigate whether the … …American Journal of Applied Sciences, Vol. 6, Issue 7 · 31 Jul 2009 · 7,234 accessesView PDFCite
Research ArticleOpen accessPhrase in the titleReduction of Ammonia Loss from Urea through Mixing with Humic Acids Isolated from Peat Soil (Saprists)Regis Bernard, Osumanu Haruna Ahmed, Nik Muhamad Ab. Majid, Mohamadu Boyie JallohProblem 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 … …American Journal of Environmental Sciences, Vol. 5, Issue 3 · 30 Jun 2009 · 7,846 accessesView PDFCite
Research ArticleOpen accessPhrase in the titleOrganic Matter, Carbon and Humic Acids in Rehabilitated and Secondary Forest SoilsLee Yit Leng, Osumanu Haruna Ahmed, Nik Muhamad Ab. Majid, Mohamadu Boyie JallohProblem Statement: Tropical rainforests cover about 19.37 million ha (60%) of Malaysia’s total area and about 8.71 million ha can be found in Sarawak, Malaysia. Excessive logging, mining and shifting cultivation contribute to deforestation in Sarawak. The objectives of this study were to: (i) Quantify soil Organic Matter (SOM), Soil Organic Carbon (SOC) and Humic Acids (HA) in rehabilitated and … …American Journal of Applied Sciences, Vol. 6, Issue 5 · 31 May 2009 · 7,761 accessesView PDFCite
Research ArticleOpen accessPhrase in the titleSimple and Rapid Method of Isolating Humic Acids from Tropical Peat Soils (Saprists)Shamsuddin Rosliza, Osumanu Haruna Ahmed, Kasim Susilawati et al.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 … …American Journal of Applied Sciences, Vol. 6, Issue 5 · 31 May 2009 · 8,552 accessesView PDFCite
Research ArticleOpen accessPhrase in the titleSimple Method of Purifying Humic Acids Isolated from Tropical Hemists (Peat Soil)Susilawati Kasim, Osumanu Haruna Ahmed, Nik Muhamad Ab. Majid, Mohd Khanif YusopThe objectives of this study were: To investigate whether a purification period of HA isolated from Hemists peat soils could be reduced and to investigate whether distilled water could be used to purify HA isolated from Hemists peat soils. Standard procedures were used to extract and fractionate HA in a Hemists peat soil. The isolated HA was purified by suspending … …American Journal of Applied Sciences, Vol. 5, Issue 12 · 31 Dec 2008 · 7,151 accessesView PDFCite
Research ArticleOpen accessPhrase in the titleDetermination of Minimal Duration Essential for Isolation of Humic Acids From Soils in Forest Restoration ProgrammesMohd Ramzan Nur Hanisah, Osumanu Haruna Ahmed, Kasim Susilawati et al.This study was conducted to investigate whether a simple and rapid method could be developed for extracting, fractionating and purifying soil HA in forest rehabilitation programmes. Humic acids from 10 g of soil were extracted with 100 mL of 0.10 M NaOH. Different extraction periods (4, 8, 12, 16, 20 and 24 h) were tested. Samples were centrifuged (16,211 G … …American Journal of Agricultural and Biological Sciences, Vol. 3, Issue 3 · 30 Sep 2008 · 8,173 accessesView PDFCite
Research ArticleOpen accessPhrase in the titleEffects of Extraction and Fractionation Period on the Yield of a Tropical Peat Soil (Hemists) Humic AcidsSusilawati Kasim, Osumanu Haruna Ahmed, Nik Muhamad Ab. Majid, Khanif YusopThe isolation of humic acids from soils is laborious and time consuming. Factors that affect the yield of humic acids isolated from soils include extraction, fractionation and purification periods. This study was conducted to investigate whether a relationship could be separately established between extraction time, fractionation time, and the yield of humic acids of a tropical peat soil (Hemists), as … …American Journal of Agricultural and Biological Sciences, Vol. 2, Issue 3 · 30 Sep 2007 · 8,099 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleReducing Ammonia Loss from Urea by Mixing with Humic and Fulvic Acids Isolated from CoalAmeera Abdul Reeza, Osumanu Haruna Ahmed, Nik Muhamad Nik Ab. Majid, Mohamadu Boyie JallohProblem statement: Ammonia volatilization is a major pathway for nitrogen loss from surface applied urea. While all top-dressed ammonia and ammonium based N fertilizers can volatilize, the potential loss is greatest with urea and fluids containing urea. As much as 20-50% of N applied to soils is lost through volatilization alone. Thus, the objective of this laboratory study was to … …American Journal of Environmental Sciences, Vol. 5, Issue 3 · 30 Jun 2009 · 10,897 accessesView PDFCite
Research ArticleOpen accessEvery word in the titleReduction of Ammonia Volatilization through Mixing Urea with Humic and Fulvic Acids isolated from Palm Oil Mill Effluent SludgeShamsuddin Rosliza, Osumanu Haruna Ahmed, Nik Muhamad Ab. Majid, Mohamadu Boyie JallohProblem statement: Ammonia volatilization from surface-applied urea may be substantial but it is possible to control it by mixing urea with acidic substances such as Humic Acids (HA) and Fulvic Acids (FA). The objective of this study was to compare the effects of urea-HA, urea-FA, urea-acidified (HA+FA) mixtures on ammonia loss, soil pH, soil exchangeable ammonium and available nitrate accumulation … …American Journal of Environmental Sciences, Vol. 5, Issue 3 · 30 Jun 2009 · 7,350 accessesView PDFCite