Bacterial and fungal community structure and diversity in a mining region under long-term metal exposure revealed by metagenomics sequencing

Aims 
To assess the effects of dolomitic limestone applications on soil microbial communities’ dynamics and bacterial and fungal biomass, relative abundance, and diversity in metal reclaimed regions.


Methods and Results 
The study was conducted in reclaimed mining sites and metal uncontaminated areas. The limestone applications were performed over 35 years ago. Total microbial biomass was determined by Phospholipid fatty acids. Bacterial and fungal relative abundance and diversity were assessed using 454 pyrosequencing. There was a significant increase of total microbial biomass in limed sites (342 ng/g) compared to unlimed areas (149 ng/g). Chao1 estimates followed the same trend. But the total number of OTUs (Operational Taxonomic Units) in limed (463 OTUs) and unlimed (473 OTUs) soil samples for bacteria were similar. For fungi, OTUs were 96 and 81 for limed and unlimed soil samples, respectively. Likewise, Simpson and Shannon diversity indices revealed no significant differences between limed and unlimed sites. Bacterial and fungal groups specific to either limed or unlimed sites were identified. Five major bacterial phyla including Actinobacteria, Acidobacteria, Chloroflexi, Firmicutes, and Proteobacteria were found. The latter was the most prevalent phylum in all the samples with a relative abundance of 50%. Bradyrhizobiaceae family with 12 genera including the nitrogen fixing Bradirhizobium genus was more abundant in limed sites compared to unlimed areas. For fungi, Ascomycota was the most predominant phylum in unlimed soils (46%) while Basidiomycota phylum represented 86% of all fungi in the limed areas.


Conclusion 
Detailed analysis of the data revealed that although soil liming increases significantly the amount of microbial biomass, the level of species diversity remain statistically unchanged even though the microbial compositions of the damaged and restored sites are different.


Significance and Impact of the study 
Soil liming still have a significant beneficial effects on soil microbial abundance and composition > 35 years after dolomitic limestone applications.

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Microbial Response to Soil Liming of Damaged Ecosystems Revealed by Pyrosequencing and Phospholipid Fatty Acid Analyses.

Selection of pig manure management strategies: Case study of Polish farms

This experiment was conducted to find the influence of organic manure sources and chemical fertilizers alone or in combination on the quality and yield of sunflower and also on the macro nutrients content of seeds under water stress. Three levels of water stress (S1: full irrigation, S2: withholding irrigation at flowering stage, and S3: withholding irrigation at seed filling stage) were randomized to the main plot units and 8 fertilizer treatments (F1: control, F2: cattle manure, F3: sheep manure, F4: poultry manure, F5: chemical fertilizer, F6: 50% cattle manure+50% chemical fertilizer, F7: 50% sheep manure+50% chemical fertilizer, and F8: 50% poultry manure+50% chemical fertilizer) were randomized to the subplot units. Obtained results revealed that seed yield decreased significantly due to water stress when imposed at either of the growth stages. Assessment of the qualitative parameters of sunflower seeds showed that water stress caused a marked decrease in oil content and unsaturated fatty acids of oil, however this negative effect was greater in water stress at seed filling stage with respect to water stress at flowering stage. While, protein content increased due to water stress at flowering stage. Results also indicated that drought stress at seed filling stage significantly decreased nutrient content of the seeds, whereas drought stress at flowering stage caused to increase of nutrient uptake. Sunflower plants significantly responded to fertilizer treatments. The seed yield was highest in case of application of manure alone or in combination with chemical fertilizer than in control. Protein and oil percentage were significantly higher in F3 (sheep manure) and F6 (50% cattle manure+50% chemical fertilizer), respectively. Compared to control, all fertilization methods generally increased nutrient concentration of sunflower. The highest N content was observed in F4 and F6 treatment. Combination of poultry manure and chemical fertilizer (F8) led to the highest P content and sheep manure application (F3) resulted to the highest K content than control.

/pdf/comparison-of-sole-and-combined-nutrient-application-on-4hbudsjdj7.pdf

Comparison of Sole and Combined Nutrient Application on Yield and Biochemical Composition of Sunflower under Water Stress

Soybean (Glycine max (L.) Merrill) is one of the most important legume crops being introduced into the smallholder farming systems of the Central Highlands of Kenya (CHK) to improve income and household nutrition of farmers. However, phosphorus fixation, depletion of soil nutrients and soil acidity are major causes of low yields. The objective of this study is to evaluate effects of manure application, liming and phosphorus application on soil properties and soybean performance. The study consisted of 8 treatments: manure (0, 5 and 10 t ha -1 ), lime (0 and 2 tha -1 ) and P fertilizer (0, 30 and 60 kg P ha -1 ). The experiment was laid out in a randomized complete block design (RCBD) with 4 replicates in plots of 4 m × 4.5 m. Manure and lime significantly reduced exchangeable acidity and increased soil pH. Application of manure alone or combined with lime or P fertilizer also increased Mg and K. Treatments that had sole lime, lime combined with manure and manure combined with P applied gave a significant increase in exchangeable Ca. Soybean responded well and significantly to application of manure either alone or combined with lime, P or both. These results showed the potential role of lime, manure and P fertilizer in improving soil fertility and soybean yields.

/pdf/effects-of-manure-lime-and-mineral-p-fertilizer-on-soybean-18ggfcsb0o.pdf

Effects of manure, lime and mineral P fertilizer on soybean yields and soil fertility in a humic nitisol in the Central Highlands of Kenya

A pot experiment was conducted to compare different organic manures with NPK fertilizer for improvement of chemical properties of acid soil from farmer’s field in coastal area of Epe and nutrient depleted soil from research field of Institute of Agricultural Research and Training, Moor Plantation, Ibadan. Maize was planted for 12 weeks and dry matter yield was determined. Results showed that application of 5 ton/ha of each of the evaluated organic manures and 100 kg/ha NPK 15-15-15 fertilizer improved chemical properties of both acid and nutrient depleted soils compared with unfertilized soil. Application of different types of organic manures reduced the acidic levels of both the soils. Cow dung application resulted in the highest pH levels of 6.37 and 6.50 in acid soil and nutrient depleted soil respectively while NPK fertilizer gave lowest pH levels of 5.28 and 5.74 for both soils. Also, application of different types of organic manures enhanced soil organic C, total N, available P, exchangeable K and CEC better than NPK fertilizer in both soils. The study indicated that among the organic manures evaluated, cane rat droppings improved soil chemical properties best. Plant dry matter yield increased with application of NPK fertilizer compared with compost, poultry manure and cane rat droppings in both soils. In acid soil, application of NPK fertilizer gave the highest dry matter yield of 4.77 g/plant while in nutrient depleted soil; application of NPK fertilizer gave the highest dry matter yield of 5.58 g/plant.  

	 

	Key words: Manure, fertilizer, dry matter, pH levels.

https://www.academicjournals.org/article/article1380031998_Adeniyan et al.pdf

Comparative study of different organic manures and NPK fertilizer for improvement of soil chemical properties and dry matter yield of maize in two different soils

Akinbode

Papers

Comparative study of different organic manures and NPK fertilizer for improvement of soil chemical properties and dry matter yield of maize in two different soils

Pathobiology for Investigators, Students, and Academicians 2022 Young Investigators Virtual Meeting – Author Index