Dataset Information

Linking rhizosphere bacterial diversity and soil fertility in tobacco plants under different soil types and cropping pattern in Tanzania: A pilot study.

ABSTRACT: Tobacco (Nicotiana tabacum L.), one of the major crop plants in Tanzania, cropping affects the level of soil fertility, but the reason has not been known. Plant rhizosphere plays an important role in affecting soil fertility through changing microbial composition. We planned a pilot study to understand the changes in microbial composition and soil nutrients in the rhizosphere soils of tobacco in three agro-ecological zone, namely Sikonge, Tabora and Urambo in Tanzania. This study assessed bacteriota composition using 16S rRNA sequencing and soil fertility in the rhizosphere of tobacco plants. The results showed that bacterial diversity in tobacco rhizosphere soils belonged to Proteobacteria phyla, associated significantly (p < 0.05) with solubilization of insoluble P, K and S. The solubilization of P, K and S in soils facilitates the availability of these nutrients to the tobacco plants (a heavy feeder crop) allows low levels of these nutrients in the soils for the subsequent crop. The Proteobacteria phyla also associated with an increase in soil N content through fixation. Therefore, bacteria diversity in tobacco rhizosphere influence solubilities of macronutrients (P, K, S) and quickly up taken by the tobacco plant and reduces their levels in soils, some bacteria involved in fixing N and increases total N in the soil.

SUBMITTER: Lisuma JB

PROVIDER: S-EPMC7347649 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature

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Linking rhizosphere bacterial diversity and soil fertility in tobacco plants under different soil types and cropping pattern in Tanzania: A pilot study.

Lisuma Jacob Bulenga JB Zuberi Zavuga Z Ndakidemi Patrick Alois PA Mbega Ernest Rashid ER

Heliyon 20200708 7

Tobacco (<i>Nicotiana tabacum</i> L.), one of the major crop plants in Tanzania, cropping affects the level of soil fertility, but the reason has not been known. Plant rhizosphere plays an important role in affecting soil fertility through changing microbial composition. We planned a pilot study to understand the changes in microbial composition and soil nutrients in the rhizosphere soils of tobacco in three agro-ecological zone, namely Sikonge, Tabora and Urambo in Tanzania. This study assessed ...[more]

PMID: 32671244

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Project description:The widespread and continuous cultivation of tobacco has led to soil degradation and reduced crop yields and quality. Green manure is an essential organic fertilizer that alleviates obstacles to continuous cultivation. However, the plant-soil microecological effects of green manure on flue-cured tobacco cultivation remain unclear. Thus, a positioning trail including two treatments, chemical fertilizer application only (treatment NPK) and chemical fertilizer application with turning ryegrass (treatment NPKG) was conducted, and the effect of ryegrass returning on the soil physicochemical properties, soil microbiome, crop yield, and quality of flue-cured tobacco in continuous cropping soil were investigated. Results showed that returning ryegrass to the field increased the thickness of soil humus layer from 13 cm to 15 cm, reduced the humus layer soil bulk density to 1.29 cm3/g. Ryegrass tilled and returned to the field increased soil organic matter content by 6.89-7.92%, increased rhizosphere soil available phosphorus content by 2.22-17.96%, and converted the soil non-exchangeable potassium into potassium that was available for plant absorption and utilization. Ryegrass tilling and returning to the field increased the potassium content of middle leaves of flue-cured tobacco by 7.69-10.07%, the increased potassium content in flue-cured tobacco was accompanied by increased total sugar, reducing sugar, and the ratio of reducing sugar to nicotine, which facilitated the harmonization of the chemical composition of cured tobacco leaves. Moreover, the increased number of markedly improved operational taxonomic units enhanced the complexity of the soil bacterial community and its compactness after ryegrass tillage and their return to the field. The available potassium, available phosphorus, total potassium content, pH, and sampling period of the rhizosphere soil had considerable effects on the rhizosphere microbial. Ryegrass tilling and returning to the field changed the soil microbiome, which increased the abundance of bulk soil Proteobacteria, rhizosphere soil Fibrobacterota, and microbes with anti-pathogen activity (Lysobacteria, Sphingomonas, Chaetomium, and Minimedusa); and reduced the abundance of pathogenic fungi Neocosmospore genus in the soil. In brief, ryegrass returned to the field, improved soil microecology and restored soil nutrients, and established a new dynamic balance of soil ecology, thereby improving the quality of cultivated land and the quality of flue-cured tobacco.

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Dataset Information

Linking rhizosphere bacterial diversity and soil fertility in tobacco plants under different soil types and cropping pattern in Tanzania: A pilot study.

Publications

Linking rhizosphere bacterial diversity and soil fertility in tobacco plants under different soil types and cropping pattern in Tanzania: A pilot study.

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