Effects of organic amendment on some soil physicochemical characteristics and vegetative properties of Zea mays in wetland soils of the Niger Delta impacted with crude oil

Purpose This study sought to investigate the effects of organic amendments on the degradation of hydrocarbons and vegetative properties of Zea mays grown in crude oil-contaminated wetland soils of the Niger Delta, Nigeria. Methods Two soil types were investigated, namely, fadama soil (oxisol) and swamp forest soil (utisol). For each soil type, 48 treatment cells and 1 control containing 1 kg of soil each were spiked with crude oil at concentrations ranging from 50 to 200 g kg−1, representing 5–20% (m/m) contamination levels, respectively. Then, 5 days after the contamination, the soils were amended with cow dung (CD), poultry waste (PW), and palm oil waste (POW). The ratios of soil to organic amendments used were 1:1 and 2:1. The soils were tilled and irrigated regularly, and monitored for a total period of 112 days. The same conditions were used to investigate the vegetative properties of Z. mays in these oil-contaminated soils with organic amendments. Results The total organic carbon (TOC) and pH increased significantly within the first 2 weeks after crude oil contamination; thereafter, the pH of the soil decreased significantly over incubation time, while there was steady increase in TOC with incubation time. The percentage nitrogen and total petroleum hydrocarbons (TPH) decreased significantly. The utisol soil showed better plant performance, despite the lower hydrocarbon degradation rate. Conclusion The organic amendments showed a TPH degradation trend that followed the order: PW > CD > POW. They also improved the seed emergence of Zea mays.

Correction to: Effects of organic amendment on some soil physicochemical characteristics and vegetative properties of Zea mays in wetland soils of the Niger Delta impacted with crude oil

In the original publication of the article, the author’s name Reuben N. Okparanma was misspelled.

Physico-chemical and microbiological quality of M’Zar wastewater treatment plant effluents and their impact on the green irrigation of the Golf course

Purpose Reuse of treated wastewater (TWW) for irrigation can be an effective strategy in Morocco to overcome the pressure on freshwater resources. The M’zar wastewater plant is based on percolation infiltration treatment, allowing the purification of the wastewater of Agadir, and with its UV disinfection system, it is now possible to reuse this water for irrigation. In this sense, the aim of our study is to evaluate the microbiological and physicochemical quality of the treated wastewater of this station, used for irrigation of a Golf course as well as to determine its impact on grass and soil. Methods A monitoring of TWW quality was carried out monthly on the level of the Ocean’s Golf on water samples, grass and soil. This monitoring is related to the physicochemical (pH, temperature, conductivity, STD, COD, and BOD5) and bacteriological characteristics by counting the indicators of faecal contamination, faecal coliforms (FC), faecal streptococci (FS), Salmonella and Vibrios as well as sulphito-reducers spores (SRS). Results The results of microbiological analysis in the three compartments confirm the presence of various organisms such as FC, FS, and SRS in a very significant number with no load in Salmonella and Vibrios during our study period. For physicochemical analyses, we observed that only the conductivity showed fairly a high value of 6.38 dS/m. Conclusion The obtained physicochemical and bacteriological results revealed that the treated wastewater with the M’zar plant complies with national and international standards.

Upcycling of food industry side streams by basidiomycetes for production of a vegan protein source

Purpose Novel protein sources are urgently needed to meet the increasing protein demand of a continuously growing world population. This study is focused on the production of protein rich mushroom mycelia on industrial side streams. Methods Submerged propagation of mushrooms was carried out in shake flasks which contained agro-industrial side streams as the sole carbon source. The biomass obtained was analyzed for its crude protein, ash and fat content as well as for its fatty acid and amino acid profiles. Vitamin D2 production from ergosterol in the biomass was induced by UV-B irradiation and determined by HPLC–DAD. The share of fungal mycelium in the total biomass was determined by extraction and quantitation of ergosterol. Additionally, water and oil binding capacity (WBC and OBC) were evaluated. Results A screening of basidiomycetes grown on agro-industrial side streams indicated a fast growth of Pleurotus sapidus on apple pomace. After 4 days of cultivation, the biomass obtained from this mushroom–substrate combination contained 21% true protein in dry matter. In addition to proteins, the amounts of lipids (4%), ash (2%) and carbohydrates (74%) were quantitated. The dominating fatty and amino acids of Pleurotus sapidus grown on apple pomace were linoleic acid and glutamic acid/glutamine, respectively. Concentrations of up to 115 µg (g dry matter)−1 vitamin D2 were formed from ergosterol by UV-B irradiation. Ergosterol was used as a biomarker to monitor the amount of fungal content. Conclusion The nutritional value of agro-industrial side streams such as apple pomace can be upcycled by biotransformation with basidiomycetes.

Effect of incremental levels of apple pomace and multi enzyme on performance, immune response, gut development and blood biochemical parameters of broiler chickens

Purpose During the apple processing procedures, a large amount of apple pomace is generated which is contains peel, core, seed, calyx, stem, and soft issue. The polyphenolic compounds in apple pomace are strong antioxidants that are able to counterbalance the free radicals; also, it is a rich source of many nutrients such as carbohydrates, minerals, fiber except protein. The experiment was conducted to investigate the effect of different levels of dried apple pomace in broilers diet. Methods The incremental levels of dried apple pomace (4, 8, 12, 16 and 20%) with and without enzyme were used in broilers diet (8 dietary treatments). The growth performance, immune response, gut development, antioxidant capacity (TAC) and blood biochemical parameters were evaluated. Results The lowest daily weight gain, body weight and poorest feed conversion ratio was obtained by F treatment (P < 0.05), enzyme inclusion along with dried apple pomace had positive effect on growth performance. The antibody titter against Newcastle, Influenza and SRBC was increased by C, H, G and H treatments, respectively (P < 0.05). Antibody titer against NDV, IDV, and SRBC by 4, 8, 12 and TAC by 12, 16 and 20% of dried apple pomace significantly increased. The villous height by 4, 8, 12 and crypt depth by 12, 16 and 20% dried apple pomace significantly and insignificantly decreased, respectively. Conclusion The results suggested that the incremental levels of dried apple pomace deteriorate growth performance, modified antibody titer production, total antioxidant capacity and blood parameters of broilers.

Effects of termites growth on litter decomposition: a modeling approach

Purpose Litter decomposition is a biological process resulting from enzymatic activities of microorganisms and influenced in a variety of ways by activities of termites in semi-arid regions. We presented a general model of the decomposition process from litter to carbon sequestration and nitrogen. We aimed at building a termite population growth model which could deal with one substrate. Methods Our model divides the decomposition/growth process at the population level. We put these changes into equations using an analogy with chemical reactions at equilibrium. Results Our findings provide evidence that activities of termites can promote the significant activity of microbial decomposers and increase degradation rates of soil organic matter (SOM). Also, termite activity was probably an additional contributor to the difference between fungus-comb chamber and soil environment, in which the fungus-comb compartment was positively related to carbon and nutrients release. According to the developed, observed differences in decomposition rate, changes were strongly affected by the termite communities’ activities in the two types of compartment. Conclusion This functional distinction highlights the importance of termites’ activities on microbial activities stimulation through their development featuring their impacts on soil nutrient cycling.

Banana peel biochar as alternative source of potassium for plant productivity and sustainable agriculture

Purpose Biochar addition to soil is immensely beneficial for increasing plant productivity and C sequestration, attenuating nutrient leaching loss, counteracting heavy metal contamination and organic waste triggered environmental pollution. To understand the sustainable benefits of biochar, two pot experiments were conducted under net house condition in Khulna University, Bangladesh. Methods Biochar was prepared from banana peel waste through slow pyrolysis process under limited oxygen condition. Three lower rates (1, 2 and 3%) of banana peel biochar (BPB) were added with agricultural soil along with control with three replications for each. After incorporation of BPB into soil, pots were kept under field condition for 7 days and then the seeds of Ipomoea aquatica were sown. Plants were harvested after 42 days from seeds sowing and plant height, leaf number, fresh weight, and dry weight were measured. Another pot experiment was also conducted under sand medium to test the BPB as K-rich soil amendment where K was applied from two different sources (KCl and BPB) along with control. Seeds of Cucurbita moschata were sown and 40 days after seed sowing, K deficiency was observed in control treatments. Results Banana peel biochar was found to be rich in K content. Plant productivity and above-ground biomass were reduced in 1% BPB treatments, but increased in 2 and 3% BPB treatments as compared to control but statistically insignificant (p < 0.05). In case of second experiment, K deficiency symptoms were observed in 40 days aged Cucurbita moschata seedlings under control treatments, whereas no K deficiency symptom was noticed in plants grown under K supplied from both KCl and BPB. Moreover, the plant grown with BPB was found healthy, stronger and greener in appearance. Conclusion This positive influence of BPB on plant growth suggests the alternative way to overcome the use of chemical fertilizer and effective way of utilization of agricultural wastes through recycling.

Maximizing rice husk waste for Daucus carota production

Purpose Rice husk is one of the most widely available agricultural wastes in many rice producing countries of the world. Here, we evaluated carrot production under different rice husk-amended media aimed at providing alternative use for rice husk. Methods The experimental design was 2 × 5 × 4 factorial in completely randomized design with six replications. Factor A consist of two production environments—high tunnel and open field while factor B was five growth media—5:0:0, 4:0:1, 3:1:1, 2:2:1 and 1:3:1 (topsoil:rice husk:poultry manure). Factor C was four carrot varieties; ‘Touchon’, ‘Amazonia’, ‘Carrot New Kuroda’ and ‘Touchon Mega’. Data were collected on seedling emergence and yield parameters. The analysed means were separated using FLSD(0.05). Results The biomass yield from plants grown in high tunnel was significantly higher than plants in the open field. Highest root weight, wet and dry biomass yield were obtained from medium 4:0:1 followed by 3:1:1. Harvest index ranged from 32.3% in medium 1:3:1 to 62% in 3:1:1. Days to seedling emergence among varieties ranged from 8.5 to 11.3. ‘Amazonia’ variety produced the highest root weight, wet and dry biomass yield and was followed by ‘Touchon Mega’. Conclusion Carrot seedling emergence and yield differed in rice husk-amended media under high tunnel and open field environments. ‘Amazonia’ variety grown in media 4:0:1 or 3:1:1 gave the best yield. Inclusion of rice husk in media formulation beyond an optimum rate resulted in yield reduction in carrot. Carrot is sensitive to the physio-chemical properties of its growth medium.

Effect of active and passive aeration on composting of household biodegradable wastes: a decentralized approach

Purpose Present work aims at studying the influence of active (using external aerator) and passive (natural) aeration on composting of household biodegradable wastes. Methods To study the suitability of these reactors to household conditions, continuous loading was carried out for a period of 60 days. Both the reactors were loaded with cooked as well as raw vegetable and fruit waste. Physico-chemical parameters such as temperature, pH, C/N ratio, moisture content, total organic content, Total Kjeldahl Nitrogen and seed-germination parameters such as Germination Index (GI) and Root Length Index (RLI) of the mulch were analyzed at different stages of the composting process. Results Results confirmed that, although both types of aeration seem to have performed well under continuous loading, the maturation period required for actively aerated reactor was 37.30% lesser than that of naturally aerated reactor. Conclusion Active aeration found to be more suitable to household conditions as odor and fly nuisance was relatively less.

Assessing the quality of sewage sludge as an agricultural soil amendment in Mediterranean habitats

Purpose Municipal sewage sludge generated from three operational wastewater treatment plants, located in the Bekaa valley of Lebanon, was assessed for its potential use as agricultural soil amendment. Methods Sludge samples were taken from three treatment plants located in the villages of Iaat, Ablah and Joub Jannine during the summer season of 2018, from June to September, on a monthly basis. The evaluation was based on characterizing the physicochemical parameters such as the metal content, the pathogenic microorganisms (Salmonella, E.Coli, Staphylococcus aureus, Helminth eggs, Ascaris, Acinetobacter) and the phytotoxicity–stability indicators of the sludge samples. Results The obtained results were compared to the Lebanese guidelines for sludge reuse in agriculture. For the physicochemical analysis, all the samples showed a possibility to be used in agriculture due to the high content of minerals and organic matter. Considering the metal content of sludge, Iaat and Ablah sludge were classified as Class A according to the Lebanese guidelines; however, sludge from Joub Janine was classified as B due to its high content of zinc that exceeded the limit of 700 ppm. Helminth eggs and Salmonella were absent in the sludge samples. Pathogenic organisms, mainly E. coli, were detected in Iaat dry sludge, Staphylococcus aureus was present in Joub Jannine sludge and Acinetobacter in Ablah station (> 100 CFU/100 g). Conclusion It is recommended to submit the sludge which did not meet the required criteria, for further treatments, particularly the composting process to reduce the metal content and pathogenic microorganisms for a safer reuse in agriculture.