African Journal of Agronomy

African Journal of Agronomy ISSN 2375-1177 Vol. 6 (3), pp. 362-369, March, 2018. © International Scholars Journals

Full Length Research Paper

A study of dairy sewage sludge as the source of soil quality improvement or its degradation

*Jurgiel Artur¹, Zuba Opiola² and Marek Goss²

¹Department of Food Technology, Agricultural University of Kraków, Kraków, Poland.

²Department of Biotechnology, Agricultural University of Kraków, Kraków, Poland.

*Corresponding author. E-mail: [email protected]

Accepted 12 April, 2017

Abstract

Biochemical indices related with the transformations of C, N and P are frequently used in the diagnosis of soil quality. Such an assessment usually includes analysis of the following enzymes – the activity of dehydrogenases and of hydrolytic enzymes such as phosphatases, urease and protease. The objective of the study presented here was evaluation of dairy sewage sludge as an agent causing an improvement of soil quality or its degradation. Estimation of soil quality was performed on the basis of a comprehensive study comprising analyses of microbiological and biochemical parameters. The results of the study indicate a stimulating effect of dairy sewage sludge on the soil microorganisms, which was apparent also as an increase in the activity of the enzymes studied. That effect should be attributed to soil enrichment in organic matter, total nitrogen and minerals.

Key words: Dairy sewage sludge, enzymatic activity, microorganisms, soil.

African Journal of Agronomy ISSN 2375-1177 Vol. 6 (4), pp. 370-382, April, 2018. © International Scholars Journals

Review

Transformations, stages and microorganisms that participate in methane fermentation process

*Edvard O. Fredriksen, Fridtjof Amundsen and Ragnar Haavelmo

¹Department of Biotechnology and Food Microbiology, The Faculty of Food Science, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.

²Agriculture and Biology, Warsaw University of Life Sciences, Warsaw, Poland.

*Corresponding author. E-mail: [email protected]

Accepted 26 April, 2016

Abstract

Anaerobic decomposition of organic compounds is conducted in close cooperation of specialized bacteria of different types, including mostly hydrolyzing, digestive, acetogenic, homoacetogenic, sulfate-reducing (VI) and methanogenic bacteria. A great interest in the anaerobic digestion process results mainly from its advantages, as compared to aerobic methods. The main advantages of the methane digestion process are: Production of an insignificant amount of biomass and lower energy input, as compared to degradation conducted under aerobic conditions. This paper reviews the transformations, stages and microorganisms that participate in methane fermentation process.

Key words: Biogas, methane fermentation, methanogens, microorganisms, anaerobic digestion.

African Journal of Agronomy ISSN 2375-1177 Vol. 6 (5), pp. 383-392, May, 2018. © International Scholars Journals

Full Length Research Paper

Effect of electric treatment on germination, seedling growth and water uptake in chickpea seed

*Kovind Nisar¹, Kumar Sangma¹ and Singh Rani²

¹Department of Agrophysics, Faculty of Life Science, Rajiv Gandhi University, Arunachal Pradesh, India.

²Department of Agronomy, Faculty of Agriculture, Assam University, Assam, India.

Corresponding author E-mail: [email protected]

Accepted 02 July, 2016

Abstract

The chickpea (Cicer arietinum) seeds were exposed to the electric field at 270, 470, 670, 870 and 1070 V/cm for 15 min duration at a constant temperature (13°C). The effect of electric treatment on germination, seedling growth and water uptake was investigated. Electrically treated seeds have shown a delay in water absorption as compared to the control (unexposed); hence, there was an increase in mean germination time and transition time. Maximum delay was observed at 470 V/cm with 15 min exposure. Rate of water uptake was calculated experimentally. It increased at all field values. A new water uptake model was used to find water content absorbed by the seed at any instant as a function of the electric field at a constant temperature (13°C). Among the various treatments, 470 V/cm for 15 min yielded the peak performance (for root and shoot lengths).

Key words: Germination time, electric-treatment, water-uptake model, ferroelectric effect.

African Journal of Agronomy ISSN 2375-1177 Vol. 6 (5), pp. 393-400, May, 2018. © International Scholars Journals

Full Length Research Paper

A study of the impact of crude oil pollution on soil microbial community

*Okidia B. George¹, Orhonigbe G. H¹ and Idedia Henry²

¹Department of Soil Science, Faculty of Agriculture, Chukwuemeka Odumegwu Ojukwu University, Uturu, Nigeria.

²Department of Agronomy, Faculty of Agricultural Sciences, Chukwuemeka Odumegwu Ojukwu University, Uli, Nigeria.

Corresponding author. E-mail: [email protected]

Received 27 November, 2017

Abstract

Impact of petroleum pollution in a vulnerable Niger Delta ecosystem was investigated to assess interactions in a first-generation phytoremediation site of a crude oil freshly-spilled agricultural soil. Community-level approach for assessing patterns of sole carbon-source utilization by mixed microbial samples was employed to differentiate spatial and temporal changes in the soil microbial communities. Genetic diversity and phenotypic expressions were measured for a more holistic perspective. The 5’-terminal restriction fragments generated after Csp digestion of 16S rRNA gene correlated with observed DNA concentrations in the community profile and revealed loss of diversity with pollution. Crude oil pollution significantly reduced phosphomonoesterases and respiratory activities and values were pH dependent. There were no expressed dehydrogenases activity in initial spill site but were enhanced with phytoremediation. Factor analysis of predictors and independent variables indicates that respiratory, alkaline phosphatase and â-glucosidase activities could be used to explain underlying factors. Positive soil – microbes - plant interactions were observed.

Key words: Species diversity, impact of crude oil pollution, soil – biota interactions, ecosystem monitoring, genetic diversity.

African Journal of Agronomy ISSN 2375-1177 Vol. 6 (2), pp. 356-361, February, 2018. © International Scholars Journals

Full Length Research Paper

Effect of salinity and drought stresses on growth parameters, essential oil constituents and yield in peppermint

*Lech G. Polanski¹, Andrew Khanifar¹ and Witold Tadeusz²

¹Department of Horticulture, Faculty of Agriculture,  Ferdowsi University of Mashhad, Mashhad, Iran.

²Department of Agronomy, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Golestan Province, Iran.

*Corresponding author. E-mail: [email protected]

Accepted 6 August, 2016

Abstract

Peppermint (Mentha piperita L.) is one of the most important plants producing essential oil. Two experiments were conducted to determine the effect of drought stress on growth parameters, essential oil constituents and yield of peppermint. 5 levels of water deficit stress including D1 (100% field capacity-control), D2 (85% field capacity), D3 (70% field capacity), D4 (60% field capacity) and D5 (45% field capacity) were investigated during 4 months. Results indicated that drought stress motivated a significant reduction in all of the growth parameters and essential oil yield and percent. The highest values of growth parameters and essential oil percent and yield were observed under 100% field capacity (control). Also, the highest values of Mentone and menthofuran were obtained under 100% field capacity (control) and the highest values of menthol were obtained under 70% field capacity by using gas chromatography-mass spectroscopy (GC-MS).

Key words: Peppermint, essential oil, drought, gas chromatography-mass spectroscopy (GC-MS).

African Journal of Agronomy ISSN 2375-1177 Vol. 5 (4), pp. 333-345, November, 2017. © International Scholars Journals

Full Length Research Paper

Sweetpotato slip planting density and slip length optimization for mass production of quality planting material in smallholder farm settings

Rogers Kakuhenzire¹, Meshack Mwenda¹, Fredrick Grant¹ and John Kalaye²

¹International Potato Centre, P.O. Box 2473, Morogoro, ²Tanzania. ARI Uyole, Box 400 Mbeya, Tanzania.

Corresponding author. E-mail: [email protected]

Accepted 11 October, 2017

Abstract

Sweetpotato production in unimodal rainfall farming systems in sub-Saharan Africa is constrained by inadequate quality planting material. Technologies for efficient production of sweetpotato planting material are imperative to improve this sub-sector. Consequently, two separate field experiments, using five orange-fleshed sweetpotato varieties were conducted to determine the optimum slip spacing and slip length for optimal vine growth and vine-cutting production as planting material. Slip spacing levels were (15x15), (20x20), (25x25) and (30x30) cm. The slip length treatments were; 15, 20, 25 and 30 cm all planted at 20x20 cm spacing. The experimental sites were ARI Uyole, Mbeya in 2016 and 2017 and SUA, Morogoro only in 2017. Both experiments were set in split-split plots in randomized complete blocks with three replications. The vine growth rate (cm day^-1) and vine-cutting yield m^-2 were significantly (P≤0.05) higher at Morogoro than at Uyole. Cultivars; Kakamega and Ejumula, respectively had significantly (P≤0.05) higher vine-cutting yield than Kiegea and Mataya while cultivar Kabode had intermediate yield. Vine-cutting yield was significantly (P≤0.05) higher at (15x15) cm than at (30x30) and increased with repeated vine harvesting. The effect of slip length though significant (P≤0.05) over varieties, years and locations was inconsistent except for fresh foliage yield (t ha^-1).

Keywords: Orange-fleshed sweetpotato, repeated harvesting, vine-cutting length, vine yield.