Agroforestry practices and food security in the mount Bamboutos landscape, Western Highlands of Cameroon

This study presents agroforestry practices by farmers in Mount Bamboutos, why they adopt agroforestry practices and main constraints towards adoption as well as the relationship between agroforestry practices and household food security. A purposive sampling technique was used to administer 195 questionnaires. Data collected were analyzed using both descriptive and inferential statistics. The demographic information analyzed showed that the majority of respondents were males (76%) and all were literate with a majority using fuel wood as their main source of energy. The major agroforestry practices were, planting of fodder, fertilizer, fruit and timber trees, compost manure and farm yard manure preparation. The highest year of adoption of agroforestry practices was in 2019. Most (50%) of the respondents adopted agroforestry practices for better crop yields. However, the main constraints to agroforestry adoption were lack of training, lack of seeds and much labour involved. Lack of training was the greatest constraint cited by respondents. 39% of the respondents were food secure and apart from compost manure practice that was negatively associated with food security, all the other agroforestry practices were positively associated with food security. Based on findings of this study, it is recommended that extension agents and other stakeholders should intensify efforts to educate and train more farmers on the practice and advantages of agroforestry. This will go a long way to increase adoption rate while ensuring food security.

The Influence of Soil Fertilization on the Distribution and Diversity of Phosphorus Cycling Genes and Microbes Community of Maize Rhizosphere Using Shotgun Metagenomics

Biogeochemical cycling of phosphorus in the agro-ecosystem is mediated by soil microbes. These microbes regulate the availability of phosphorus in the soil. Little is known about the response of functional traits of phosphorus cycling microbes in soil fertilized with compost manure (derived from domestic waste and plant materials) or inorganic nitrogen fertilizers at high and low doses. We used a metagenomics investigation study to understand the changes in the abundance and distribution of microbial phosphorus cycling genes in agricultural farmlands receiving inorganic fertilizers (120 kg N/ha, 60 kg N/ha) or compost manure (8 tons/ha, 4 tons/ha), and in comparison with the control. Soil fertilization with high level of compost (Cp8) or low level of inorganic nitrogen (N1) fertilizer have nearly similar effects on the rhizosphere of maize plants in promoting the abundance of genes involved in phosphorus cycle. Genes such as ppk involved in polyphosphate formation and pstSABC (for phosphate transportation) are highly enriched in these treatments. These genes facilitate phosphorus immobilization. At a high dose of inorganic fertilizer application or low compost manure treatment, the phosphorus cycling genes were repressed and the abundance decreased. The bacterial families Bacillaceae and Carnobacteriaceae were very abundant in the high inorganic fertilizer (N2) treated soil, while Pseudonocardiaceae, Clostridiaceae, Cytophagaceae, Micromonosporaceae, Thermomonosporaceae, Nocardiopsaceae, Sphaerobacteraceae, Thermoactinomycetaceae, Planococcaceae, Intrasporangiaceae, Opitutaceae, Acidimicrobiaceae, Frankiaceae were most abundant in Cp8. Pyrenophora, Talaromyces, and Trichophyton fungi were observed to be dominant in Cp8 and Methanosarcina, Methanobrevibacter, Methanoculleus, and Methanosphaera archaea have the highest percentage occurrence in Cp8. Moreover, N2 treatment, Cenarchaeum, Candidatus Nitrososphaera, and Nitrosopumilus were most abundant among fertilized soils. Our findings have brought to light the basis for the manipulation of rhizosphere microbial communities and their genes to improve availability of phosphorus as well as phosphorus cycle regulation in agro-ecosystems.

Microbial Community Structure Drives Predatory Myxobacteria Distribution Under Different Compost Manures

Myxobacteria are unique predatory microorganisms with a distinct social lifestyle. The associated taxa play key roles in the microbial food webs in different ecosystems and regulate the community structures of soil microbial communities. Compared with conditions under conventional management, under organic conditions, myxobacteria abundance increases in the soil, which could be related to the presence of abundant myxobacteria in the applied compost manure. In the present study, high-throughput sequencing technologies were used to investigate the distribution patterns and drivers of predatory myxobacteria community distribution patterns in four common compost manures. According to the results, there was a significant difference in predatory myxobacteria community structure among different compost manure treatments (P < 0.05). The alpha-diversity indices of myxobacteria community under swine manure compost were the lowest (Observed OTU richness = 13.25, Chao1 = 14.83, Shannon = 0.61), and those under wormcast were the highest (Observed OTU richness = 30.25, Chao1 = 31.65, Shannon = 2.62). Bacterial community diversity and Mg2+ and Ca2+ concentrations were the major factors influencing myxobacteria distribution patterns under different compost manure treatments. In addition, pH, total nitrogen, and organic carbon influenced myxobacteria distribution in compost manure. The predator–prey relationship between prey bacteria and myxobacteria and the interaction between myxobacteria and specific bacterial taxa (Micrococcales) in compost manure could explain the influence of bacteria on myxobacteria community structure. Further investigations on the in-situ distribution patterns of predatory myxobacteria and the key bacteria influencing their distribution are would advance our understanding of the ecological distribution patterns and functions of predatory microorganisms in the microbial world.

Metagenomics Assessment of Soil Fertilization on the Chemotaxis and Disease Suppressive Genes Abundance in the Maize Rhizosphere

Soil fertility is a function of the level of organic and inorganic substances present in the soil, and it influences the activities of soil-borne microbes, plant growth performance and a host of other beneficial ecological functions. In this metagenomics study, we evaluated the response of maize microbial functional gene diversity involved in chemotaxis, antibiotics, siderophores, and antifungals producing genes within the rhizosphere of maize plants under compost, inorganic fertilizer, and unfertilized conditions. The results show that fertilization treatments at higher compost manure and lower inorganic fertilizer doses as well as maize plants itself in the unfertilized soil through rhizosphere effects share similar influences on the abundance of chemotaxis, siderophores, antifungal, and antibiotics synthesizing genes present in the samples, while higher doses of inorganic fertilizer and lower compost manure treatments significantly repress these genes. The implication is for a disease suppressive soil to be achieved, soil fertilization with high doses of compost manure fertilizer treatments as well as lower inorganic fertilizer should be used to enrich soil fertility and boost the abundance of chemotaxis and disease suppressive genes. Maize crops also should be planted sole or intercropped with other crops to enhance the rhizosphere effect of these plants in promoting the expression and abundance of these beneficial genes in the soil.

Effects of False yam (Icacina oliviformis) tuber compost manure on the growth performance of garden eggs (Solanum aethiopicum l)

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Control of Root-Knot Nematode (Meloidogyne incognita) in Tomato (Solanum lycopersicum) Crop Using Siam Weed (Chromolaena odorata) Compost Manure

A field experiment was conducted at Landmark University Omu-Aran, Nigeria from June to November 2017 and repeated at the same time in the year 2018 on a nematode infested soil to evaluate the effects of different amounts of Siam weed compost on the performance of root-knot nematode (RKN) infested tomato. The compost was applied a week before planting as soil amendment at the amount of 0.0, 0.5, 1.5, and 2.0 t·ha−1, while carbofuran was applied at the rate of 3.0 kg·ha−1. Four weeks old tomato seedlings cultivar ‘Roma VF’, which is susceptible to RKN, was transplanted to already prepared soil. Results of the experiment showed that the compost, especially in the amount 2 t·ha−1 and carbofuran at 3 kg·ha−1, brought about significant reduction of the population of RKN in soil and roots, and a significant increase in the growth and yield of tomato. The result of the experiment showed that Siam compost can be used for the managing root-knot nematodes in tomato cultivation, as an environmentally safe factor.

Improving Maize Productivity under Rain-Fed Conditions through the Combined Use of Inorganic and Organic Fertilizer in Malawi

Integrated soil fertility management was promoted on-farm during the 2018/2019 cropping season in Thyolo, Phalombe, Mulanje and Zomba districts of southern Malawi, in purposively selected extension planning areas (EPAs). Sixty farmers, fifteen from each district were involved. Trials were established in farmers’ fields with smallholder farms as replicates and extension EPAs as blocks. The following were the treatments; Maize + 92 kg N ha-1 + 46 kg of P ha-1; Maize + 3 tons of compost manure ha-1; and Maize + 46 kg N ha-1 + 23 kg P ha-1 + 1.5 tons of compost manure. Grain yield data were collected at harvest. The data were analyzed in Genstat Discovery Edition 4 and were subjected to ANOVA at 95% level of confidence. Means were separated by the least significant difference (LSD0.05). No significant differences (>0.05) in Maize grain yields were observed between the treatment with Maize + 46 kg N ha-1 + 23 kg P ha-1 + 1.5 tons of compost manure and the treatment with Maize + 92 kg N ha-1 + 46 kg of P ha-1 in all the districts. Maize grain yields were significantly lower in plots treated with the full rate of manure (3 tons of compost manure ha-1) in Thyolo, Mulanje and Zomba district. Higher maize grain yields were registered in Phalombe (3,867-4,838 kg ha-1), followed by Thyolo (1,764-2,374 kg ha-1) and Zomba (740-1,120 kg ha-1). The trials confirmed that applying a combination of organic and inorganic fertilizer to maize, increase grain yields.

Soil fertilization affects the abundance and distribution of carbon and nitrogen cycling genes in the maize rhizosphere

Soil microbes performs important functions in nitrogen and carbon cycling in the biosphere. Microbial communities in the rhizosphere enhance plants’ health and promote nutrient turnover and cycling in the soil. In this experimental study, we evaluated the fundamental effects of soil fertilization with organic (compost manure) and inorganic fertilizer on the abundances and distribution of carbon and nitrogen cycling genes within the rhizospheric regions of maize plants. Our result showed that maize plants through rhizosphere effects selected and enriched the same functional genes glnA, gltB, gudB involved in nitrogen cycle as do higher compost and lower inorganic fertilizer treatments. This observation was significantly different from those of higher doses of inorganic fertilizer and lower compost manure treated soil. Only alpha amylase encoding genes were selectively enriched by lower compost and higher inorganic fertilized soil. The other treatments only selected peculiar carbon cycling genes in the rhizosphere of maize. Also Actinomycetales are selected by high compost, low inorganic fertilizer and control while Bacillales are promoted by low compost and higher inorganic fertilizer and this indicated that only microbes capable of tolerating the stress of higher dose of inorganic fertilizer will thrive under such condition. Therefore, soil fertilization lower nitrogen gas emission but increases carbon dioxide evolution in the agricultural soil.

Bioremediation of Hydrocarbon Contaminated Soil: Assessment of Compost Manure and Organic Soap

This study was carried out to investigate the effect of compost manure and organic soap on hydrocarbon degradation in petroleum products contaminated soil. 10 kg of top soil collected at a depth of 0-20 cm, air dried and sieved, were poured into plastic containers. The soil samples were was pounded with 1 L of spent engine oil, 1 L of kerosene, 1 L of petrol and 1 L of diesel daily for five days. The containers were placed under natural environmental conditions for three weeks to enable full acclimatization of the petroleum products with the soil. A completely randomized design comprising T1 (Polluted soil without treatment ‘control’); T2 (10 kg contaminated soil + 500 g organic soap); T3 (10 kg contaminated soil + 500 g compost manure); and T4 (10 kg contaminated soil + 500 g compost manure + 500 g organic soap) was used for this study. Some physical characteristics (soil porosity and specific gravity) and Total Hydrocarbon Content (THC) of the soil samples were tested for, after the full acclimatization of the soil samples, and at the end of the 10 week experimental period, in accordance with standard methods. Results of the study showed that addition of the compost manure and organic soap the contaminated soil samples significantly (p ≤0.05) degraded the THC, and improved the soil physical characteristics. The result showed that the combination of compost manure and organic soap gave the best remediation result (from 957.21 mg/kg to 154.36 mg/kg), followed by organic soap (from 957.21mg/kg to 203.61 mg/kg), and then compost manure (from 957.21 mg/kg to 262.03 mg/kg). At the end of the experimental period, vegetative growth was observed in the treated soil samples; whereas, in the control soil samples vegetative growth was absent. Results obtained from this study have shown that amending petroleum products contaminated soils with compost manure and organic soap will enhance remediation of petroleum products contaminated sites.