scholarly journals Effects of biochar on waterlogging and the associated change in micro-ecological environment of maize rhizosphere soil in saline-alkali land

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9303-9323
Author(s):  
Zhihui Wang ◽  
Dawei Yin ◽  
Hongyi Wang ◽  
Changjiang Zhao ◽  
Zuotong Li

Saline-alkali soils of northern China are prone to waterlogging after degradation caused by overuse. The effects of biochar (40 t/ha) were tested relative to the physico-chemical properties of maize rhizosphere soil, the composition and function of the soil bacterial community, and its response to sudden waterlogging. Biochar treatment decreased the pH and bulk density of the soil and increased soil organic carbon (SOC), available nitrogen (AN), and available phosphorus (AP). The relative abundance of bacteria (Proteobacteria, Actinobacteria, Bacteroidetes, and Nitrospirae) also increased, along with the activities of soil enzymes, such as dehydrogenase, β-glucosidase, and alkaline phosphomonoester. The response of soil microbial enzymes to biochar addition was induced by changes in the soil physical properties (pH, soil moisture content, and soil respiration (BR)). Changes in the bacterial community structure were driven by soil nutrients and physical characteristics (AN, AP, SOC, pH, moisture, water-stable aggregate stability rate, BR, and bulk density). After waterlogging, soil with biochar demonstrated high water permeability and improved soil respiration. The relative abundance of soil bacteria and enzyme activities remained higher in the biochar plot than in the no-biochar plot. Biochar maintained the growth and vitality of maize roots in unfavorable environmental conditions, thus ensuring high yields.

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249834
Author(s):  
Junhong Wang ◽  
Lei Liu ◽  
Xiaoyin Gao ◽  
Jianxia Hao ◽  
Mengliang Wang

This study was conducted to investigate the effect of biofertilizers on the structure and diversity of the rhizosphere bacterial community of maize. Different biofertilizers were applied to maize. The physical and chemical properties of rhizosphere soil samples were analyzed and the rhizosphere bacteria were analyzed by 16S amplicon sequencing. The results showed that treatment with Bacillus licheniformis and B. amyloliquefaciens as biofertilizers increased the soil organic matter (SOM), total nitrogen, total phosphorus (TP), available phosphorus (AP), and available potassium (AK) contents, indicating that the plant growth-promoting rhizobacteria in the biofertilizers might help the host plant to produce root exudates that, in return, recruit beneficial communities due to available sugars, amino acids, organic acids, vitamins, and polymers. The rhizosphere of maize treated with B. subtilis biofertilizer had the highest diversity and richness. However, the rhizosphere treated with the combined bacterial strains had the lowest diversity and richness, which might be due to the directional increase of the abundance of some bacteria with special functions, but the decrease of the overall bacterial community diversity in the soil. The dominant bacterial phyla were Proteobacteria (32.2%–34.6%), Acidobacteria (15.0%–21.0%), Actinobacteria (13.1%–17.2%), and Gemmatimonadetes (9.0%–10.8%), and the dominant bacterial species were Aciditerrimonas ferrireducens JCM 15389 (4.3%–5.2%), Gemmatimonas aurantiaca (3.2%–4.1%), and Pyrinomonas methylaliphatogenes (2.1%–4.8%). The significantly enriched bacterial functions were associated with amino acid metabolism, sugar metabolism, and energy metabolism pathways. The results of a redundancy analysis showed that SOM, TP, and AK were the main factors affecting the microbial community structure in the maize rhizosphere. In conclusion, the application of biofertilizers increased the diversity and richness of the bacterial community in the maize rhizosphere soil. However, combined strain treatment was failed and not an ideal strategy due to the lowest abundance and diversity.


Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 118
Author(s):  
Saheed Akinola ◽  
Ayansina Ayangbenro ◽  
Olubukola Babalola

The northwest (NW) province of South Africa is a semi-arid area, often disturbed by soil extremes such as drought and intense temperature. However, many functions possessed by the rhizosphere microbiome are still required, especially those inhabiting arid and semi-arid soils. This study involves a metagenomic comparison of the major metabolic attributes of two maize rhizosphere soils and their surrounding soils. Here, we hypothesized that there is a considerable difference between the functional diversity of maize rhizosphere and bulk soils and that the rhizosphere soil has distinct functional traits of agricultural importance. A high-throughput sequencing approach was used to assess the metabolic profile of rhizosphere soil microbiota of maize collected from the Gauteng and NW provinces of South Africa. The relative abundance of 13 functional hit categories was significantly different between the sampling sites. The diversity indices showed a considerable difference between the rhizosphere and surrounding soils. The difference in the chemical properties of the sampling sites was responsible for the variation in the microbial functional composition. Nevertheless, the presence of a high relative abundance of functional categories with unknown functions in SEED subsystem-2 coupled with the large number of functional hits conferring a response to soil stressors viz. oxidative stress, heat shock, osmotic stress, and cold shock noticed in the rhizosphere samples may indicate the presence of novel genes at the sampling sites. Exploring the plant growth-promoting traits of microorganisms present at these sites could eliminate the constraint posed by soil stressors on sustainable agriculture.


2021 ◽  
Author(s):  
Wenchun He ◽  
Yang Wang ◽  
Xiaochen Wen ◽  
Yu Wang ◽  
Baoru Xiao ◽  
...  

Abstract The growth of fine roots of trees is affected by environmental changes and biological factors. At present, there have been many researches on the physiological plasticity of fine roots caused by environmental changes, but there are still few studies on the influence of biological factors on fine roots. This paper focused on the contents of carbon (C), nitrogen (N), and phosphorus (P), and their ecological stoichiometric ratios in different root orders of Cupressus funebris fine roots in 11 mixed stands with Koelreuteria paniculate or Toona sinensis at different ratios, and the effects of soil physical and chemical properties on the root chemical properties. It aimed to provide new insights into the fine-root nutrient distribution pattern and the transformation or reconstruction of low-efficiency pure forests from the standpoint of forest types. The results showed that: soil pH, and the content of available nitrogen (SAN), available phosphorus (SAP) and available potassium (SAK) differed significantly in the tested mixed forest stands. No significant differences in carbon content of fine roots were observed in different mixed stands. The content of nitrogen and phosphorus in fine roots in mixed forests showed heterogeneity. Species mixing changed the C/N, C/P and N/P of the C. funebris compared the pure stands. The "T. sinensis + C. funebris" forest alleviated the limitation of the lack of phosphorus on fine roots of C. funebris on. The principal component analysis showed that mixed stands of "T. sinensis + C. funebris" had the highest comprehensive score at ratio of "3:1". Thus, our results recommended the adoption of T. sinensis, especially at 75%, to reconstruct the low-efficiency pure C. funebris forest.


Author(s):  
H. Haruna

Land use changes from forest into cultivated ecosystems result in negative impact on soil structure and quality. The purpose of this study was to determine effect of land use on soil quality in Afaka forest northern guinea savannah of Nigeria. Land use systems, including natural forest and cultivated land were identified. Eighteen (18) composite disturbed and undisturbed samples were collected from depth of 0-5 and 5-10 cm for analysis of pertinent soil properties in the laboratory using grid procedure. Most physical and chemical properties show relative variations in response to land use types and geomorphic positions. Results  indicate  that the soils had  high degree of weathering potentials, low  to moderate  bulk density at 0-5cm depth values between 1.42 to 1.49 Mg m-3 in  forest and  cultivated land, bulk density of  1.34 and 1.46 1.Mg m-3at 5 -1ocm depth   for forest and  cultivated land respectively. The soil water at 0-5cm depth is from 4.20 to 2.63 cm3/cm3, while at 5-10 cm depth these values vary from 4.32 to 2.13 cm3/cm3 under forest and cultivation land use. The pH (H2O) is 6.9 to 7.16 with low electrical conductivity of 0.13 dS/m(forest) and 0.12 dS/m (cultivation). The CEC of soils is recorded as 8.60 cmol kg-1 (forest) to 8.54 cmol kg-1 (cultivated)whereas  total nitrogen content of 1.21 g kg-1 and 1.11 g kg-1 and available phosphorus of 8.78 mg kg-1 (cultivated) and 5.47 mg kg-1 (forest).. Results indicate that soil fertility parameters were moderate to low for cultivated land and at all slope positions, suggesting that soil fertility management is required in order to make agriculture sustainable on Afaka area.


2018 ◽  
Vol 7 (2) ◽  
pp. 30 ◽  
Author(s):  
Theobald Bizuhoraho ◽  
Alexis Kayiranga ◽  
Noel Manirakiza ◽  
Khaldoon A. Mourad

Land use change has a significant impact on the ecosystem. In this paper the effects of land use change on the physicochemical properties of the soil in Rulindo District, Rwanda have been studied. Three different land use types were selected; forestland, cattle farmland and cultivated land. A randomised complete block research design was used to carry out this research. Nine soil samples were collected and then analysed. The distributed samples were analysed in the Soil Laboratory of University of Rwanda-Busogo campus, while the undisturbed samples were analysed in-situ. Eight physicochemical properties were measured: pH, Organic Matter (OM), available nitrogen, available phosphorus, exchangeable potassium, soil bulk density, moisture content and porosity. The results showed that changing land use from forest or farm to cultivated land reduced the organic matter, available nitrogen, soil moisture and porosity while bulk density and pH were significantly increasing. On the other hand, the exchangeable potassium and exchangeable phosphorus did not change significantly for the both land use changes. Hence, the reduction of forestland and farmland are highly sensible to erosion and will decline soil fertility. The paper proposed few steps and recommendations to be the base for a new sustainable land use management in Rwanda.


2014 ◽  
Vol 955-959 ◽  
pp. 3505-3508 ◽  
Author(s):  
Tian Ming Gao ◽  
Rui Qiang Zhang ◽  
Jian Ying Guo

In northern China, grassland has degraded severely and wind erosion occurs remarkably due to irrational land use in recent years. By employing sand sampler and mobile wind tunnel, an observation for 6 years was made to analyze the mechanisms of wind erosion in Xilamuren grassland, the central of Yinshan Mountains, Inner Mongolia. Results show that: (1) vegetation is the decisive factor for controlling wind erosion and the inhibiting effect of vegetation height on wind erosion is greater than that of vegetation coverage. (2) Wind erosion modulus in the initial period of enclosure reaches 1313.7 t km-2a-1 and with the improvement of the grassland vegetation, wind erosion decreases year by year. (3) For every 1000 kg soil eroded by wind, 15 kg organic matter, 227g available nitrogen, 262g available phosphorus and 120g available potassium lose in the region at the same time, being a tremendous fertility loss. Therefore, the protection of base grassland and restoration of degraded grassland are two fundamental approaches to control wind erosion on the grassland.


2016 ◽  
Author(s):  
Mavinakoppa S. Nagaraja ◽  
Ajay Kumar Bhardwaj ◽  
G.V. Prabhakara Reddy ◽  
Chilakunda A. Srinivasamurthy ◽  
Sandeep Kumar

Abstract. Soil fertility and organic carbon (C) stock estimations are crucial to soil management especially that of degraded soils, for productive agricultural use and in soil C sequestration studies. Currently, estimations based on generalized soil mass (hectare-furrow basis) or bulk density (BD) basis are used which may be suitable for normal agricultural soils but not for degraded soils. We measured soil organic C, available nitrogen (N), available phosphorus (P) and available potassium (K), and estimated stocks using three methods: (i) generalized soil mass (GSM, 2 million kg ha−1 furrow soil), ii) bulk density based soil mass (BDSM) and (iii) the proportion of fine earth volume (FEV) method, for soils sampled from physically degraded lands in Eastern Dry Zone of Karnataka State in India. Comparative analyses using these methods revealed that the soil organic C, and N, P and K stocks determined by using BDSM were higher than those by GSM method. The soil organic C values were the lowest in the FEV method compared to the other two methods. The GSM method overestimated soil organic C, N, P and K by 9.3–72.1 %, 9.5–72.3 %, 7.1–66.6 % and 9.2–72.3 %, respectively, compared to FEV based estimations for physically degraded soils. The differences among the three methods of determinations were lower in soils with low gravel content and increased with increase in gravel volume. There was overestimation of soil organic C and soil fertility with GSM and BDSM methods. A reassessment of methods of estimation was, therefore, attempted to provide fair estimates for land development projects in degraded lands.


Author(s):  
V. Manasa ◽  
N. S. Hebsur ◽  
P. L. Patil ◽  
M. Hebbara ◽  
B. N. Aravind Kumar ◽  
...  

A soil survey was carried out in different groundnut growing calcareous Vertisols of Dharwad district, Karnataka, India. One hundred surface composite soil samples were collected from five talukas (mandal) of Dharwad district and analyzed for soil chemical properties and nutrient status. The results showed that soil pH, electrical conductivity, organic carbon, free CaCO3 content ranged from 6.9-8.9, 0.15-1.79 dS m-1, 2.40-9.10 g kg-1, 5.8 -22.2 respectively across the regions. Available nitrogen, phosphorus (P2O5), potassium (K2O) and sulphur contents widely varied from 107-268, 18.5 - 56.0 and 386- 876, 14.8- 41.0 kg ha-1, respectively. On the basis of nutrient index values, groundnut growing calcareous soils of Dharwad were categorized as deficient in available nitrogen, medium in available phosphorus and high in available potassium. Most of the samples were deficient in available Fe and Zn whereas DTPA-extractable Cu and Mn were above the critical limits. A significant and positive correlation was found between organic carbon and available nitrogen (r=0.730**). However, a negative correlation was observed between Soil pH and micro nutrients while CaCO3 was negatively correlated with available iron (r=-0.31**).


2007 ◽  
pp. 137-147 ◽  
Author(s):  
Tanumi Kumar ◽  
Monoranian Ghose

Soil samples from twenty seven sites of Indian Sundarbans were analysed for some chemical parameters, These sites were divided into three inundation types namely, diurnal, usual springtide and summer springtide. The study demonstrated that most of the soil properties significantly varied with inundation type. Sites inundated by usual springtides exhibited lowest concentrations of pH, salinity (Sal), available phosphorus (I)), and exchangeable potassium (K), sodium (Na) and magnesium (Mg), whereas summer springtide inundated sites had the highest concentrations of Sal, organic carbon (OC), available nitrogen (N), Na, K and Mg. Highest level of P and lowest N in the diurnally inundated sites could be attributed to increased mobility of phosphates and denitrification or volatilization losses of inorganic nitrogen in the soils respectively, Highest concentration of in summer springtide inundated sites could be attributed to increased ammonium ion mobility in the soils.


AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xu Jiang ◽  
Hui Ma ◽  
Qing-lei Zhao ◽  
Jun Yang ◽  
Cai-yun Xin ◽  
...  

AbstractAs an important form of sustainable agriculture, rice-crab (Eriocheir sinensis) co-culture is rapid developing worldwide. However, the knowledge on the bacterial communities of the different components of the system is limited. In this study, we investigated the bacterial community structure in paddy soil and ditch sediment by using high-throughput sequencing technology. The results showed that compared with the ditch sediment, the content of NH4+-N in paddy soil decreased by 62.31%, and the content of AP (available phosphorus) increased by 172.02% (P < 0.05). The most abundant phyla in paddy soil and ditch sediment were Proteobacteria, Bacteroidetes and Chloroflexi, whose relative abundance was above 65%. Among the dominant genera, the relative abundance of an uncultured bacterium genus of Saprospiraceae and an uncultured bacterium genus of Lentimicrobiaceae in paddy soil was significantly lower than ditch sediment (P < 0.05). Alpha diversity indicated that the bacterial diversity of paddy soil and ditch sediment was similar. The bacterial community structure was affected by the relative abundance of bacteria, not the species of bacteria. Redundancy analysis (RDA) showed that the bacterial communities in paddy soil and ditch sediment were correlated with physicochemical properties. Our findings showed that the bacterial community structure was distinct in paddy soil and ditch sediment under rice-crab co-culture probably due to their different management patterns. These results can provide theoretical support for improving rice-crab co-culture technology.


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