Wetland eco-engineering: measuring and modeling feedbacks of oxidation
processes between plants and clay-rich material

Abstract. Interest is growing in using soft sediment as a foundation in eco-engineering projects. Wetland construction in the Dutch lake Markermeer is an example: here, dredging some of the clay-rich lake-bed sediment and using it to construct wetland will soon begin. Natural processes will be utilized during and after construction to accelerate ecosystem development. Knowing that plants can eco-engineer their environment via positive or negative biogeochemical plant–soil feedbacks, we conducted a 6-month greenhouse experiment to identify the key biogeochemical processes in the mud when Phragmites australis is used as an eco-engineering species. We applied inverse biogeochemical modeling to link observed changes in pore water composition to biogeochemical processes. Two months after transplantation we observed reduced plant growth and shriveling and yellowing of foliage. The N : P ratios of the plant tissue were low, and these were affected not by hampered uptake of N but by enhanced uptake of P. Subsequent analyses revealed high Fe concentrations in the leaves and roots. Sulfate concentrations rose drastically in our experiment due to pyrite oxidation; as reduction of sulfate will decouple Fe-P in reducing conditions, we argue that plant-induced iron toxicity hampered plant growth, forming a negative feedback loop, while simultaneously there was a positive feedback loop, as iron toxicity promotes P mobilization as a result of reduced conditions through root death, thereby stimulating plant growth and regeneration. Given these two feedback mechanisms, we propose the use of Fe-tolerant species rather than species that thrive in N-limited conditions. The results presented in this study demonstrate the importance of studying the biogeochemical properties of the situated sediment and the feedback mechanisms between plant and soil prior to finalizing the design of the eco-engineering project.

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Wetland eco-engineering: measuring and modeling feedbacks of oxidation processes between plants and clay-rich material

10.5194/bg-2016-116 ◽

2016 ◽

Author(s):

Rémon Saaltink ◽

Stefan C. Dekker ◽

Jasper Griffioen ◽

Martin J. Wassen

Keyword(s):

Plant Growth ◽

Building Material ◽

Feedback Loop ◽

Pyrite Oxidation ◽

Iron Toxicity ◽

Biogeochemical Processes ◽

Engineering Project ◽

Feedback Mechanisms ◽

Plant Soil ◽

Water Composition

Abstract. Interest is growing in using soft sediment as a building material in eco-engineering projects. Wetland construction in the Dutch lake Markermeer is an example: here the option of dredging some of the clay-rich lake-bed sediment and using it to construct wetland will soon go under construction. Natural processes will be utilized during and after construction to accelerate ecosystem development. Knowing that plants can eco-engineer their environment via positive or negative biogeochemical plant–soil feedbacks, we conducted a six-month greenhouse experiment to identify the key biogeochemical processes in the mud when Phragmites australis is used as an eco-engineering species. We applied inverse biogeochemical modeling to link observed changes in pore water composition to biogeochemical processes. Two months after transplantation we observed reduced plant growth and shriveling and yellowing of foliage. The N:P ratios of plant tissue were low and were affected not by hampered uptake of N but by enhanced uptake of P. Subsequent analyses revealed high Fe concentrations in the leaves and roots. Sulfate concentrations rose drastically in our experiment due to pyrite oxidation; as reduction of sulfate will decouple Fe-P in reducing conditions, we argue that plant-induced iron toxicity hampered plant growth, forming a negative feedback loop, while simultaneously there was a positive feedback loop, as iron toxicity promotes P mobilization as a result of reduced conditions through root death, thereby stimulating plant growth and regeneration. Given these two feedback mechanisms, we propose that when building wetlands from these mud deposits Fe-tolerant species are used rather than species that thrive in N-limited conditions. The results presented in this study demonstrate the importance of studying the biogeochemical properties of the building material and the feedback mechanisms between plant and soil prior to finalizing the design of the eco-engineering project.

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Nitrogen availability modulates the host control of the barley rhizosphere microbiota

10.1101/605204 ◽

2019 ◽

Cited By ~ 1

Author(s):

Rodrigo Alegria Terrazas ◽

Senga Robertson-Albertyn ◽

Aileen Mary Corral ◽

Carmen Escudero-Martinez ◽

Katharin Balbirnie-Cumming ◽

...

Keyword(s):

Plant Growth ◽

Microbial Communities ◽

Biological Processes ◽

N Application ◽

Plant Soil ◽

Unplanted Soil ◽

Bacterial Microbiota ◽

Soil Feedback ◽

The Impact ◽

Barley Genotypes

AbstractBackgroundSince the dawn of agriculture, human selection on plants has progressively differentiated input-demanding productive crops from their wild progenitors thriving in marginal areas. Barley (Hordeum vulgare), the fourth most cultivated cereal globally, is a prime example of this process. We previously demonstrated that wild and domesticated barley genotypes host distinct microbial communities in their rhizosphere. Here, we tested the hypothesis that microbiota diversification is modulated by, and responds to, nitrogen (N) application in soil and assessed the impact of microbiota taxonomic and functional compositions on plant growth.MethodsWe grew two wild (H. vulgare ssp. spontaneum) and an ‘Elite’ domesticated (H. vulgare ssp. vulgare) barley genotypes in an agricultural soil treated with and without N inputs. By using a two-pronged 16S rRNA gene amplicon sequencing and comparative metagenomics approach, we determined the impact of N application on taxonomic composition and metabolic potential of the microbial communities exposed to limiting and replete N supplies. We then implemented a plant-soil feedback experiment to assess microbiotas’ recruitment cues and contribution to plant growth.ResultsN availability emerged as a modulator of the recruitment cues of the barley bacterial microbiota as evidenced by the increased number of bacterial genera differentially recruited between unplanted soil and rhizosphere communities under N-limiting conditions. This recruitment pattern mirrored the impact of the host genotype on rhizosphere bacteria. The characterisation of the assembled metagenomes of plants exposed to N-limiting conditions revealed a metabolic specialisation of the rhizosphere microbiota compared to unplanted soil controls. This specialisation is underpinned predominantly by bacteria and is manifested by the enrichment of a core set of biological processes sustaining the adaptation of polymicrobial communities such as N utilisation, quorum sensing and motility across genotypes. The quantitative variation in a group of these biological processes defined host signatures in the barley rhizosphere metagenome. Finally, a plant-soil feedback experiment revealed that the host-mediated taxonomic diversification of the bacterial microbiota is associated with barley growth under sub-optimal N supplies.ConclusionsOur results suggest that under N limiting conditions, a substrate-driven selection process underpins the assembly of barley rhizosphere microbiota. Host-microbe and microbe-microbe interactions fine-tune this process at the taxonomic and functional level across kingdoms. The disruption of these recruitment cues negatively impacts plant growth.

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The effects of replaced topsoil of different depths on the vegetation and soil properties of reclaimed coal mine spoils in an alpine mining area

Israel Journal of Ecology and Evolution ◽

10.1163/22244662-20191048 ◽

2019 ◽

Vol 65 (3-4) ◽

pp. 92-105

Author(s):

Xinguang Yang ◽

Xilai Li ◽

Mingming Shi ◽

Liqun Jin ◽

Huafang Sun

Keyword(s):

Plant Growth ◽

Soil Properties ◽

Coal Mine ◽

Growth Parameters ◽

Soil Depth ◽

Mining Area ◽

Vegetation Coverage ◽

Mine Spoils ◽

Plant Soil ◽

Different Depths

Replacement of topsoil to an appropriate depth is one of the key methods for ecological restoration. The objective of this study was to investigate the effects of topsoil replacement depth on vegetation and soil properties, and to identify the optimum soil depth for reclamation of coal mine spoils in a cold alpine mining area. We sowed 3 herbaceous species after coal mine spoil heaps were treated with topsoil to 3 depths (0, 20‒25, 40‒45 cm). The variations in vegetation community structure, plant growth, soil properties were measured at different replaced topsoil depths. The correlations between plant and soil properties were analyzed statistically. The results showed species richness, diversity and evenness were not significantly different among different depths of topsoil (P > 0.05). Vegetation coverage, density, height and aboveground biomass increased significantly (P < 0.05) with increasing topsoil depth. Soil properties did not change significantly with increasing topsoil depth (P > 0.05), but soil organic matter was significantly higher at 40‒45 cm topsoil depth than at other two depths (P < 0.05). All soil properties, with the exception of total potassium, were positively correlated with the plant growth parameters. The 40‒45 cm topsoil depth of replacement should be considered as effective method in reclaiming coal mine spoils. The use of both topsoil replacement to a depth of 40‒45 cm and sowing of suitable herbaceous seeds is found to be an effective restoration strategy. Additionally, fertilization might be used as a substitute for artificial topsoil replacement to improve soil quality and speed up revegetation process by the positive plant-soil interactions.

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Teaching Authentic Soil & Plant Science in Middle School Classrooms with a Biochar Case Study

The American Biology Teacher ◽

10.1525/abt.2019.81.4.256 ◽

2019 ◽

Vol 81 (4) ◽

pp. 256-268

Author(s):

Yamina Pressler ◽

Mary Hunter-Laszlo ◽

Sarah Bucko ◽

Beth A. Covitt ◽

Sarah Urban ◽

...

Keyword(s):

Climate Change ◽

Middle School ◽

Plant Growth ◽

Plant Interactions ◽

Ongoing Research ◽

Global Issues ◽

Promote Plant Growth ◽

Rich Material ◽

Mitigate Climate Change

We designed two NGSS-aligned middle school classroom experiments to investigate the effects of biochar on plant growth and soil respiration. Biochar is a carbon-rich material, produced by heating organic matter under limited oxygen, that is added to soils to improve fertility, to promote plant growth, and as one possible strategy to help mitigate climate change. The experiments offer an ideal case study for students learning fundamentals of soil and plant interactions. Soils and biochar are accessible, are connected to global issues such as agriculture and climate change, and are the focus of ongoing research in soil science. These classroom experiments promote authentic science because students design replicated experiments, collect and analyze data, discuss variability in the data, and interpret their results in the context of recent research.

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Biogeochemical Processes Governing Natural Pyrite Oxidation and Release of Acid Metalliferous Drainage

Environmental Science & Technology ◽

10.1021/es500154z ◽

2014 ◽

Vol 48 (10) ◽

pp. 5537-5545 ◽

Cited By ~ 54

Author(s):

Ya-ting Chen ◽

Jin-tian Li ◽

Lin-xing Chen ◽

Zheng-shuang Hua ◽

Li-nan Huang ◽

...

Keyword(s):

Pyrite Oxidation ◽

Biogeochemical Processes ◽

Natural Pyrite

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PEMODELAN FLUKTUASI MUKA AIR TANAH UNTUK MENDUKUNG PENGELOLAAN AIR PADA PERTANIAN LAHAN RAWA PASANG SURUT TIPE A/B

Jurnal Matematika Sains dan Teknologi ◽

10.33830/jmst.v10i2.582.2009 ◽

2009 ◽

Vol 10 (2) ◽

pp. 92-101 ◽

Cited By ~ 1

Author(s):

Ngudiantoro ◽

Hidayat Pawitan ◽

Muhammad Ardiansyah ◽

M Yanuar J. Purwanto ◽

Settings Robiyanto H. Susanto

Keyword(s):

Water Management ◽

Plant Growth ◽

Water Table ◽

Standard Error ◽

Agricultural Development ◽

Pyrite Oxidation ◽

High Sensitivity ◽

Water Table Fluctuation ◽

Lowland Area ◽

Reclamation Area

The objectives of this research are to develop a model of water table fluctuation on tidal lowland area of A/B type. The results of the research are expected to support of the agricultural development on tidal lowland area, especially on water management, because the water management play an important role in the agricultural on tidal lowland area. The water table on tidal lowland area fluctuates according to space and time. The water table controls at a certain depth can support the plant growth and the pyrite oxidation restraint. The model of water table fluctuation which is developed in this research based on the ellipse concept. The research was conducted on the reclamation area of tidal lowland at the fourth tertiary block in P8-12S Delta Telang I, Banyuasin district, South Sumatra province. The simulations of model show good result of estimating the depth of water table on tidal lowland area of A/B type. The proportion of variation the depth of water table which can be explained by model that is 89,6% up to 95,5% with standard error of the estimate is 0,021-0,035 meters. The parameter of the water level in the tertiary canals has high sensitivity to the model.

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Effects of shade stress on turfgrasses morphophysiology and rhizosphere soil bacterial communities

10.21203/rs.2.16025/v3 ◽

2020 ◽

Author(s):

Juanjuan Fu ◽

Yilan Luo ◽

Pengyue Sun ◽

Jinzhu Gao ◽

Donghao Zhao ◽

...

Keyword(s):

Bacterial Community ◽

Plant Growth ◽

Bacterial Communities ◽

Shade Tolerance ◽

Soil Microorganisms ◽

Rhizosphere Soil ◽

Photosynthetic Capacity ◽

Soil Bacterial Communities ◽

Plant Soil ◽

Soil Bacterial

Abstract Background: The shade represents one of the major environmental limitations for turfgrass growth. Shade influences plant growth and alters plant metabolism, yet little is known about how shade affects the structure of rhizosphere soil microbial communities and the role of soil microorganisms in plant shade responses. In this study, a glasshouse experiment was conducted to examine the impact of shade on the growth and photosynthetic capacity of two contrasting shade-tolerant turfgrasses, shade-tolerant dwarf lilyturf (Ophiopogon japonicus, OJ) and shade-intolerant perennial turf-type ryegrass (Lolium perenne, LP). We also examined soil-plant feedback effects on shade tolerance in the two turfgrass genotypes. The composition of the soil bacterial community was assayed using high-throughput sequencing. Results: OJ maintained higher photosynthetic capacity and root growth than LP under shade stress, thus OJ was found to be more shade-tolerant than LP. Shade-intolerant LP responded better to both shade and soil microbes than shade-tolerant OJ. The shade and live soil decreased LP growth, but increased biomass allocation to shoots in the live soil. The plant shade response index of LP is higher in live soil than sterile soil, driven by weakened soil-plant feedback under shade stress. In contrast, there was no difference in these values for OJ under similar shade and soil treatments. Shade stress had little impact on the diversity of the OJ and the LP bacterial communities, but instead impacted their composition. The OJ soil bacterial communities were mostly composed of Proteobacteria and Acidobacteria. Further pairwise fitting analysis showed that a positive correlation of shade-tolerance in two turfgrasses and their bacterial community compositions. Several soil properties (NO3--N, NH4+-N, AK) showed a tight coupling with several major bacterial communities under shade stress. Moreover, OJ shared core bacterial taxa known to promote plant growth and confer tolerance to shade stress, which suggests common principles underpinning OJ-microbe interactions. Conclusion: Soil microorganisms mediate plant responses to shade stress via plant-soil feedback and shade-induced change in the rhizosphere soil bacterial community structure for OJ and LP plants. These findings emphasize the importance of understanding plant-soil interactions and their role in the mechanisms underlying shade tolerance in shade-tolerant turfgrasses.

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The Role of Soil pH in Plant Nutrition and Soil Remediation

Applied and Environmental Soil Science ◽

10.1155/2019/5794869 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 26

Author(s):

Dora Neina

Keyword(s):

Plant Growth ◽

Soil Remediation ◽

Soil Ph ◽

Soil Acidification ◽

Plant Nutrition ◽

Biomass Yield ◽

Biological Processes ◽

Biogeochemical Processes ◽

Soil Environment

In the natural environment, soil pH has an enormous influence on soil biogeochemical processes. Soil pH is, therefore, described as the “master soil variable” that influences myriads of soil biological, chemical, and physical properties and processes that affect plant growth and biomass yield. This paper discusses how soil pH affects processes that are interlinked with the biological, geological, and chemical aspects of the soil environment as well as how these processes, through anthropogenic interventions, induce changes in soil pH. Unlike traditional discussions on the various causes of soil pH, particularly soil acidification, this paper focuses on relationships and effects as far as soil biogeochemistry is concerned. Firstly, the effects of soil pH on substance availability, mobility, and soil biological processes are discussed followed by the biogenic regulation of soil pH. It is concluded that soil pH can broadly be applied in two broad areas, i.e., nutrient cycling and plant nutrition and soil remediation (bioremediation and physicochemical remediation).

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