Inconsistent effects of species diversity and N fertilization on soil microbes and carbon storage in perennial bioenergy cropping systems

Abstract Positive relationships between plant species diversity, soil microbial function and nutrient cycling have been well documented in natural systems, and these relationships have the potential to improve the production and sustainability of agroecosystems. Our objectives were to study the long-term effects of planted species composition and nitrogen (N) fertilization on soil microbial biomass C, extracellular enzyme activity, changes in total soil C, soil fertility and aboveground biomass yield in mixtures of native prairie species managed with and without N fertilizer for bioenergy production at four sites in Minnesota (MN), USA. Species were sown into mixture treatments and composition was not maintained (i.e., no weeding) throughout the duration of the study. Species mixture treatments at establishment included a switchgrass (Panicum virgatum L.) monoculture (SG), a four-species grass mixture (GM), an eight-species legume/grass mixture (LG) and a 24-species high diversity forb/legume/grass mixture (HD). Species diversity and aboveground productivity were similar for most mixture treatments at final sampling after 11 or 12 years of succession. Despite this homogenization of productivity and diversity throughout the study, the effects of planted species diversity and a decade of succession resulted in some differences in soil variables across species mixture treatments. On a peat soil in Roseau, MN, soil enzyme activities including β-glucosidase (BG), cellobiohydrolase (CBH) and phosphatase (PHOS) were highest in HD compared to GM treatments. On a sandy soil at Becker, MN, total soil C increased in all treatment combinations at the 0–15 and 15–30 cm depth intervals, with SG showing greater increases than HD at the 15–30 cm depth. Final soil pH also varied by species mixture at the Becker and Roseau sites, but differences in treatment comparisons varied by location. Nitrogen fertilization did not affect any response variable alone, but interacted with species mixture treatment to influence PHOS and total soil C at Becker. The inconsistent effects of species mixture and N fertilization on soil biological and chemical properties observed across sites highlight the importance of local soil and climate conditions on bioenergy and ecosystem service provisioning of perennial bioenergy cropping systems.

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Soil microbial communities in bioenergy cropping systems: unearthing relationships across a heterogeneous agroecosystem

10.31274/etd-180810-37 ◽

2014 ◽

Author(s):

Sarah Kate Hargreaves

Keyword(s):

Microbial Communities ◽

Cropping Systems ◽

Soil Microbial Communities ◽

Soil Microbial ◽

Bioenergy Cropping Systems

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Plant Diversity and Nitrogen Addition on Belowground Biodiversity and Soil Organic Carbon Storage in Biofuel Cropping Systems

10.18122/td/1701/boisestate ◽

2020 ◽

Author(s):

Jennifer Butt

Keyword(s):

Plant Community ◽

Plant Diversity ◽

Cropping Systems ◽

C Sequestration ◽

Community Diversity ◽

Big Bluestem ◽

Soil Biodiversity ◽

Soil C ◽

C Storage ◽

Bioenergy Cropping Systems

Bioenergy production may reduce the emission of CO2 which contributes to climate change, particularly when management strategies are adopted that promote soil carbon (C) sequestration in bioenergy cropping systems. Planting perennial native grasses, such as switchgrass (Panicum virgatum L.) and big bluestem (Andropogon gerardii Vitman) may be used as a strategy to enhance soil C accumulation owing to their extensive root systems. Fertilizer use may further promote soil C sequestration, because of its positive impacts on plant production and soil C input. However, the influence of fertilizer addition on soil C accumulation is variable across bioenergy cropping systems, and fertilizer can negatively impact the environment. Increasing plant diversity may be used as a strategy to enhance soil C accumulation while augmenting other ecosystem properties such as soil biodiversity. The present study evaluates how inter- and intra- specific plant community diversity and N addition influence soil C storage and soil biodiversity. Soil was collected from a long-term (9 growing seasons) field experiment located at the Fermilab National Environmental Research Park in Illinois, USA. Treatments included [1] three cultivars of big bluestem and three cultivars of switchgrass cultivars grown in monoculture, [2] plant community diversity manipulated at both the species- and cultivar level, and [3] nitrogen (N) applied annually at two levels (0 and 67 kg ha-1). The soil at the site was dominated by C3 grasses for 30 years before replacement with C4 bioenergy grasses, which enabled quantification of plant-derived C accumulation owing to the natural difference in isotopic signature between C3 and C4 grasses. Soil samples were analyzed for [1] soil C and its δ13C isotopic signature, and [2] nematode and soil bacterial diversity. Our results indicate that both plant diversity and N addition influence soil community structure but not soil C storage or soil nematode biodiversity. However, the addition of big bluestem to the plant species mixes enhanced plant-derived C storage. In summary, our findings suggest that plant species identity can control soil C accumulation in the years following land conversion, and that manipulating plant community structure in bioenergy cropping systems may have a greater positive impact on soil C accumulation than N fertilization.

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Effect of livestock manure on soil microbial and nutrient dynamics in Zaï cropping systems of the Sahel

Land Degradation and Development ◽

10.1002/ldr.3979 ◽

2021 ◽

Author(s):

Salifou Traoré ◽

Pauline Ouédraogo ◽

Philippe Bayen ◽

Babou André Bationo ◽

Nathan Lee ◽

...

Keyword(s):

Nutrient Dynamics ◽

Cropping Systems ◽

Livestock Manure ◽

Soil Microbial

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Measurement of soil microbial biomass provides an early indication of changes in total soil organic matter due to straw incorporation

Soil Biology and Biochemistry ◽

10.1016/0038-0717(87)90076-9 ◽

1987 ◽

Vol 19 (2) ◽

pp. 159-164 ◽

Cited By ~ 653

Author(s):

D.S. Powlson ◽

P.C. Prookes ◽

B.T. Christensen

Keyword(s):

Organic Matter ◽

Soil Organic Matter ◽

Microbial Biomass ◽

Soil Microbial Biomass ◽

Soil Microbial ◽

Total Soil ◽

Straw Incorporation ◽

Early Indication

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Deciphering Substrate-Specific Methane Yields of Perennial Herbaceous Wild Plant Species

Agronomy ◽

10.3390/agronomy11030451 ◽

2021 ◽

Vol 11 (3) ◽

pp. 451

Author(s):

Moritz von Cossel ◽

Lorena Agra Pereira ◽

Iris Lewandowski

Keyword(s):

Plant Species ◽

Dry Matter ◽

Plant Biomass ◽

Cropping Systems ◽

Wild Plant ◽

Small Scale ◽

Social Ecological ◽

Wild Plant Species ◽

Global Demand ◽

Bioenergy Cropping Systems

The global demand for plant biomass to provide bioenergy and heat is continuously increasing because of a growing interest among many industrialized and developing countries towards climate sound and renewable energy supply. The exacerbation of land-use conflicts proliferates social-ecological demands on future bioenergy cropping systems. Perennial herbaceous wild plant mixtures (WPMs) represent an approach to providing social-ecologically more sustainably produced biogas substrate that has gained increasing public and political interest only in recent years. The focus of this study lies on three perennial wild plant species (WPS) that usually dominate the biomass yield performance of WPM cultivation. These WPS were compared with established biogas crops in terms of their substrate-specific methane yield (SMY) and lignocellulosic composition. The plant samples were investigated in a small-scale mesophilic discontinuous biogas batch test for determining the SMY. All WPS were found to have significantly lower SMY (241.5–248.5 lN kgVS−1) than maize (337.5 lN kgVS−1). This was attributed to higher contents of lignin (9.7–12.8% of dry matter) as well as lower contents of hemicellulose (9.9–11.5% of dry matter) in the WPS. Only minor, non-significant differences to cup plant and Virginia mallow were observed. Thus, when planning WPS as a diversification measure in biogas cropping systems, their lower SMY should be considered.

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Comparison of Drivers of Soil Microbial Communities Developed in Karst Ecosystems with Shallow and Deep Soil Depths

Agronomy ◽

10.3390/agronomy11010173 ◽

2021 ◽

Vol 11 (1) ◽

pp. 173

Author(s):

Huiling Guan ◽

Jiangwen Fan ◽

Haiyan Zhang ◽

Warwick Harris

Keyword(s):

Microbial Community ◽

Microbial Communities ◽

Soil Depth ◽

Phospholipid Fatty Acid ◽

Soil Microbial Communities ◽

Deep Soil ◽

Soil System ◽

Soil Microbial ◽

Total Soil ◽

Karst Ecosystems

Soil erosion is prevalent in karst areas, but few studies have compared the differences in the drivers for soil microbial communities among karst ecosystems with different soil depths, and most studies have focused on the local scale. To fill this research gap, we investigated the upper 20 cm soil layers of 10 shallow–soil depth (shallow–SDC, total soil depth less than 100 cm) and 11 deep–soil depth communities (deep–SDC, total soil depth more than 100 cm), covering a broad range of vegetation types, soils, and climates. The microbial community characteristics of both the shallow–SDC and deep–SDC soils were tested by phospholipid fatty acid (PLFAs) analysis, and the key drivers of the microbial communities were illustrated by forward selection and variance partitioning analysis. Our findings demonstrated that more abundant soil nutrients supported higher fungal PLFA in shallow–SDC than in deep–SDC (p < 0.05). Furthermore, stronger correlation between the microbial community and the plant–soil system was found in shallow–SDC: the pure plant effect explained the 43.2% of variance in microbial biomass and 57.8% of the variance in the ratio of Gram–positive bacteria to Gram–negative bacteria (G+/G−), and the ratio of fungi to total bacteria (F/B); the pure soil effect accounted for 68.6% variance in the microbial diversity. The ratio of microbial PLFA cyclopropyl to precursors (Cy/Pr) and the ratio of saturated PLFA to monounsaturated PLFA (S/M) as indicators of microbial stress were controlled by pH, but high pH was not conducive to microorganisms in this area. Meanwhile, Cy/Pr in all communities was >0.1, indicating that microorganisms were under environmental stress. Therefore, the further ecological restoration of degraded karst communities is needed to improve their microbial communities.

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Soil microbial diversity–biomass relationships are driven by soil carbon content across global biomes

The ISME Journal ◽

10.1038/s41396-021-00906-0 ◽

2021 ◽

Author(s):

Felipe Bastida ◽

David J. Eldridge ◽

Carlos García ◽

G. Kenny Png ◽

Richard D. Bardgett ◽

...

Keyword(s):

Microbial Diversity ◽

Soil Carbon ◽

Soil Microbial Communities ◽

Ecosystem Functions ◽

Arid Environments ◽

Soil Microbial Diversity ◽

Soil Biodiversity ◽

Soil C ◽

Soil Microbial ◽

Biomass Ratio

AbstractThe relationship between biodiversity and biomass has been a long standing debate in ecology. Soil biodiversity and biomass are essential drivers of ecosystem functions. However, unlike plant communities, little is known about how the diversity and biomass of soil microbial communities are interlinked across globally distributed biomes, and how variations in this relationship influence ecosystem function. To fill this knowledge gap, we conducted a field survey across global biomes, with contrasting vegetation and climate types. We show that soil carbon (C) content is associated to the microbial diversity–biomass relationship and ratio in soils across global biomes. This ratio provides an integrative index to identify those locations on Earth wherein diversity is much higher compared with biomass and vice versa. The soil microbial diversity-to-biomass ratio peaks in arid environments with low C content, and is very low in C-rich cold environments. Our study further advances that the reductions in soil C content associated with land use intensification and climate change could cause dramatic shifts in the microbial diversity-biomass ratio, with potential consequences for broad soil processes.

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Changes in Bacterial and Fungal Soil Communities in Long-Term Organic Cropping Systems

Agriculture ◽

10.3390/agriculture11050445 ◽

2021 ◽

Vol 11 (5) ◽

pp. 445

Author(s):

Jessica Cuartero ◽

Onurcan Özbolat ◽

Virginia Sánchez-Navarro ◽

Marcos Egea-Cortines ◽

Raúl Zornoza ◽

...

Keyword(s):

Microbial Community ◽

Crop Yield ◽

Soil Microbial Community ◽

Cropping Systems ◽

Sequencing Analysis ◽

Soil Microbial Community Structure ◽

Soil Microbial ◽

Network Analyses ◽

Organic Cultivation

Long-term organic farming aims to reduce synthetic fertilizer and pesticide use in order to sustainably produce and improve soil quality. To do this, there is a need for more information about the soil microbial community, which plays a key role in a sustainable agriculture. In this paper, we assessed the long-term effects of two organic and one conventional cropping systems on the soil microbial community structure using high-throughput sequencing analysis, as well as the link between these communities and the changes in the soil properties and crop yield. The results showed that the crop yield was similar among the three cropping systems. The microbial community changed according to cropping system. Organic cultivation with manure compost and compost tea (Org_C) showed a change in the bacterial community associated with an improved soil carbon and nutrient content. A linear discriminant analysis effect size showed different bacteria and fungi as key microorganisms for each of the three different cropping systems, for conventional systems (Conv), different microorganisms such as Nesterenkonia, Galbibacter, Gramella, Limnobacter, Pseudoalteromonas, Pantoe, and Sporobolomyces were associated with pesticides, while for Org_C and organic cultivation with manure (Org_M), other types of microorganisms were associated with organic amendments with different functions, which, in some cases, reduce soil borne pathogens. However, further investigations such as functional approaches or network analyses are need to better understand the mechanisms behind this behavior.

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Environmental Impact of Rotationally Grazed Pastures at Different Management Intensities in South Africa

Animals ◽

10.3390/ani11051214 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1214

Author(s):

Hendrik P. J. Smit ◽

Thorsten Reinsch ◽

Pieter A. Swanepoel ◽

Ralf Loges ◽

Christof Kluß ◽

...

Keyword(s):

South Africa ◽

N Fertilization ◽

Yield Response ◽

N2o Emissions ◽

Pasture Management ◽

N Losses ◽

Enteric Fermentation ◽

Soil C ◽

Grazed Pastures ◽

Soil C And N

Nitrogen fertilization, irrigation and concentrate feeding are important factors in rotational pasture management for dairy farms in South Africa. The extent to which these factors affect environmental efficiency is subject to current and intense debate among scientists. A three-year field study was conducted to investigate the yield response of different N-fertilizer treatments (0 (N0), 220 (N20), 440 (N40), 660 (N60) and 880 (N80) kg N ha−1 year−1) on grazed pastures and to calculate the carbon footprint (CF) of milk produced. Excessive N-fertilization (N60 and N80) did not increase herbage dry matter and energy yields from pastures. However, N80 indicated the highest N-yield but at the same time also the highest N surpluses at field level. A maximum fertilizer rate of 220 kg ha−1 year−1 (in addition to excreted N from grazing animals) appears sufficient to ensure adequate herbage yields (~20 t DM ha−1 year−1) with a slightly positive field-N-balance. This amount will prevent the depletion of soil C and N, with low N losses to the environment, where adequate milk yields of ~17 t ECM ha−1 with a low CF (~1.3 kg CO2 kg ECM−1) are reached. Methane from enteric fermentation (~49% ± 3.3) and N2O (~16% ± 3.2) emissions from irrigated pastures were the main contributors to the CF. A further CF reduction can be achieved by improved N-fertilization planning, low emission irrigation techniques and strategies to limit N2O emissions from pasture soils in South Africa.

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