scholarly journals The Effects of Organic and Mineral Fertilization on Soil Enzyme Activities and Bacterial Community in the Below- and Above-Ground Parts of Wheat

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1452
Author(s):  
Abdoulaye Amadou ◽  
Alin Song ◽  
Zhi-Xi Tang ◽  
Yanling Li ◽  
En-Zhao Wang ◽  
...  

Bacterial community and soil enzymatic activity depend on soil and management conditions. Fertilization is an important approach to maintain and enhance enzyme activities and microbial community diversity. Although the effects of fertilizer application on soil microbial community and related parameters are explored, the effects on the soil microbiome associated with those of wheat plant organs, including those associated with roots and spikelets, are not well-known. Therefore, in this study, by using a sequencing approach, we assessed the effects of inorganic fertilizers, manure, and biochar on soil enzyme activities, bacterial community diversity and structure in the bulk soil, rhizosphere, roots, and spikelet of wheat (Triticumaestivum L.). For this, different treatment biochar (BC), manure (OM), low mineral fertilizer (HL), high mineral fertilizer (HF), and no fertilizer (FO) were used for the enzyme activities and bacterial community structure diversity tested. The result showed that organic amendment application increased total nitrogen, soil available phosphorus, and potassium compared to inorganic fertilizer and control, especially in the rhizosphere. Enzyme activities were generally higher in the rhizosphere than in the bulk soil and organic amendments increased activities of acid phosphatase (AcP), β-1,4-N-acetyl-glucosaminidase (NAG), and phenol oxydase (PhOx). Compared with soil and rhizosphere, bacterial diversity was lower in wheat roots and evenlower in the spikelet. From the bulk soil, rhizosphere to roots, the fertilization regimes maintained bacterial diversity, while organic amendment increased bacterial diversity in the spikelet. Fertilization regimes significantly influenced the relative abundances of 74 genera across 12 phyla in the four compartments. Interestingly, the relative abundance of Proteobacteria (Citrobacter, Pantoea, Pseudomonas, and unclassified Enterobacteriaceae) in the spikelet was decreased by increasing inorganic fertilizer and further by manure and biochar, whereas those of Actinobacteria (Microbacterium and an unclassified Microbacteriaceae) and Bacteroidetes (Hymenobacter and Chitinophagaceae) were increased. The results suggest that potential bacterial functions of both roots and above-ground parts of wheat would be changed by different organic amendment regimes (manure and biochar).

2021 ◽  
Vol 12 ◽  
Author(s):  
Quanqing Deng ◽  
Taobing Yu ◽  
Zhen Zeng ◽  
Umair Ashraf ◽  
Qihan Shi ◽  
...  

Silicon (Si) deficiency, caused by acidic soil and rainy climate, is a major constraint for sugarcane production in southern China. Si application generally improves sugarcane growth; however, there are few studies on the relationships between enhanced plant growth, changes in rhizosphere soil, and bacterial communities. A field experiment was conducted to measure sugarcane agronomic traits, plant nutrient contents, rhizosphere soil enzyme activities and chemical properties, and the rhizosphere bacterial community diversity and structure of three predominant sugarcane varieties under two Si treatments, i.e., 0 and 200 kg of silicon dioxide (SiO2) ha−1 regarded as Si0 and Si200, respectively. Results showed that Si application substantially improved the sugarcane stalk fresh weight and Si, phosphorus (P), and potassium (K) contents comparing to Si0, and had an obvious impact on rhizosphere soil pH, available Si (ASi), available P (AP), available K (AK), total phosphorus (TP), and the activity of acid phosphatase. Furthermore, the relative abundances of Proteobacteria showed a remarkable increase in Si200, which may be the dominant group in sugarcane growth under Si application. Interestingly, the AP was noticed as a major factor that caused bacterial community structure differences between the two Si treatments according to canonical correspondence analysis (CCA). In addition, the association network analysis indicated that Si application enriched the rhizosphere bacterial network, which could be beneficial to sugarcane growth. Overall, appropriate Si application, i.e., 200 kg SiO2 ha−1 promoted sugarcane growth, changed rhizosphere soil enzyme activities and chemical properties, and bacterial community structures.


2022 ◽  
Vol 12 ◽  
Author(s):  
Yang Li ◽  
Wenjing Li ◽  
Lei Ji ◽  
Fanyong Song ◽  
Tianyuan Li ◽  
...  

The biodegradation of organic pollutants is the main pathway for the natural dissipation and anthropogenic remediation of polycyclic aromatic hydrocarbons (PAHs) in the environment. However, in the saline soils, the PAH biodegradation could be influenced by soil salts through altering the structures of microbial communities and physiological metabolism of degradation bacteria. In the worldwide, soils from oilfields are commonly threated by both soil salinity and PAH contamination, while the influence mechanism of soil salinity on PAH biodegradation were still unclear, especially the shifts of degradation genes and soil enzyme activities. In order to explain the responses of soils and bacterial communities, analysis was conducted including soil properties, structures of bacterial community, PAH degradation genes and soil enzyme activities during a biodegradation process of PAHs in oilfield soils. The results showed that, though low soil salinity (1% NaCl, w/w) could slightly increase PAH degradation rate, the biodegradation in high salt condition (3% NaCl, w/w) were restrained significantly. The higher the soil salinity, the lower the bacterial community diversity, copy number of degradation gene and soil enzyme activity, which could be the reason for reductions of degradation rates in saline soils. Analysis of bacterial community structure showed that, the additions of NaCl increase the abundance of salt-tolerant and halophilic genera, especially in high salt treatments where the halophilic genera dominant, such as Acinetobacter and Halomonas. Picrust2 and redundancy analysis (RDA) both revealed suppression of PAH degradation genes by soil salts, which meant the decrease of degradation microbes and should be the primary cause of reduction of PAH removal. The soil enzyme activities could be indicators for microorganisms when they are facing adverse environmental conditions.


HortScience ◽  
2017 ◽  
Vol 52 (1) ◽  
pp. 78-84 ◽  
Author(s):  
Lantian Du ◽  
Baojian Huang ◽  
Nanshan Du ◽  
Shirong Guo ◽  
Sheng Shu ◽  
...  

Soil sickness from the continuous cropping of cucumbers has become a major limiting factor for protected cucumber cultivation. The use of reasonable cropping systems and the employment of allelopathy between different crops are considered to be the major safe and effective measures for alleviating soil sickness. The objective of this study assessed the effects of garlic (Allium sativum L. cv. Yusuan No. 1)/cucumber (Cucumis sativus L. cv. Jinchun No. 4) relay intercropping on soil enzyme activities and the microbial environment in a continuous cropping regime. Cucumbers and garlic were selected and planted in plastic barrels. The following four treatments were included in the experiment: continuous cropping without crops (Cont), monoculture cucumbers (C), monoculture garlic (G), and the relay intercropping of garlic with cucumbers (CG). The results showed that relay intercropping with garlic promoted cucumber plant growth and attenuated damage caused by soil sickness. In comparison with the Cont treatment, the C treatment decreased soil urease, catalase, invertase, and phosphatase activities; by contrast, the CG treatment enhanced all soil enzyme activities. The C treatment resulted in lower numbers of soil bacteria and actinomycetes and a lower bacteria/fungi ratio, but there were a higher number of soil fungi than there were in the Cont treatment. However, the CG treatment increased the numbers of soil bacteria and actinomycetes as well as the bacteria/fungi ratio, and it decreased the number of soil fungi. In comparison with the Cont treatment, the C treatment reduced the microbial biomass carbon (MBC) and soil basal respiration (BSR) without affecting the metabolic quotient (qCO2), whereas the CG treatment increased all three variables. A polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) analysis revealed decreased bacterial community diversity and increased fungal community diversity in soil with the C treatment; the opposite trend was observed in the CG treatment. The results indicated that the relay intercropping of garlic with cucumbers improved soil enzyme activities and promoted the conversion of continuous cropping soil from a “fungal” type to a “bacterial” type. Additionally, relay intercropping altered the soil bacterial community structure, increased the bacterial diversity indices, and enriched the dominant bacterial populations in the soil. These mechanisms improved the soil microbial environment and effectively alleviated damage caused by soil sickness, thus promoting cucumber plant growth.


2015 ◽  
Vol 536 ◽  
pp. 59-67 ◽  
Author(s):  
Xinyu Zhang ◽  
Wenyi Dong ◽  
Xiaoqin Dai ◽  
Sean Schaeffer ◽  
Fengting Yang ◽  
...  

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