scholarly journals Nutrient Cycling and Soil Health in Organic Cropping Systems - Importance of Management Strategies and Soil Resilience

2015 ◽  
Vol 4 (3) ◽  
pp. 80 ◽  
Author(s):  
Derek H. Lynch
Keyword(s):  
Organic Matter ◽  
Microbial Community ◽  
Soil Organic Matter ◽  
Organic Agriculture ◽  
Soil Microbial Community ◽  
Cropping Systems ◽  
Management Strategies ◽  
Soil Health ◽  
Farming System ◽  
Soil Microbial

<p>Organic field crop systems are characterized by complex rotations with high spatial and temporal vegetative diversity, an enhanced use of legumes, and reduced external nutrient (nitrogen (N) and phosphorus (P)) use. At the same time, a core premise of certified organic agriculture is that this farming system provides benefits to soil health via enhanced microbial diversity. The following short review, drawing primarily upon selected studies from North America, examines the impact of farming systems, and various management strategies within these, on soil organic matter, N and P dynamics, and soil microbial and macrofaunal abundance and diversity. Organic cropping systems are shown to provide benefits with respect to reduced farm N and P surpluses, in combination with maintenance of soil organic matter and improved soil health. However, soil health benefits appear consistently achieved only for larger soil organisms partly due to the resilience of the soil microbial community. Recent research examining soil P dynamics and P uptake in relation to legume biological N<sub>2</sub> fixation and bacterial and mycorrhizal community diversity provide evidence of the resilience of the soil microbial community with respect to functionality, if not diversity of microbial community composition. These latter results may challenge organic agriculture core premises of consistent benefits to soil health via enhanced microbial diversity, but in its place may lead to an improved understanding of how specific cropping practices and production system intensity overall, rather than farming system per se, influences both nutrient cycling and soil ecosystem functioning.</p>

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

Agriculture ◽  
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.

Organic matter additions to soil and effects on microbially mediated carbon cycling

2020 ◽  
Author(s):  
Rachel hasler ◽  
Mark pawlett ◽  
Jim harris ◽  
Helen bostock ◽  
Marc redmile-gordon
Keyword(s):  
Organic Matter ◽  
Microbial Community ◽  
Carbon Cycling ◽  
Community Composition ◽  
Soil Microbial Community ◽  
Microbial Community Composition ◽  
Soil Microbial ◽  
Horse Manure ◽  
Soil Microbial Community Composition

&lt;p&gt;The type of soil organic amendment selected can have profound implications for carbon cycling processes in soils. Understanding the link between this choice and its effect on the soil microbiome will improve our understanding of the capacity of these materials to improve carbon sequestration and cycling dynamics. Understanding and facilitating the lifestyle strategies of microorganisms processing organic matter is essential to improving our understanding of the terrestrial carbon cycle. This research focuses on utilising organic amendments to alter the indigenous soil microbial community composition and function to improve the capacity of the soil to cycle and store carbon in horticultural soils. &amp;#160;The effects of annual application of various organic fertilisers (peat, bracken, bark, horse manure, garden compost) in a long-term (10year) field experiment were explored. Sampling was completed pre and post application of organic matter within one season (following 10 years of applications) to identify which organic amendment was more effective in producing benefits to plants through improved soil organic matter and which amendments provide the greatest legacy effect on carbon cycling. The response of the soil microbial community composition (phospholipid fatty acid analysis) and carbon functional cycling dynamics (respiration using MicroResp&amp;#8482;) were determined with a view to improving our understanding of the interaction between the materials applied and microbial processes. PCA of the MicroResp&amp;#8482; data identified that all treatments had a different functional profile compared to the control[PM1]&amp;#160; with peat being significantly different from all other treatments. Horse manure and bark differed significantly within a single growing season; prior and post organic matter addition in spring 2019. &amp;#160;Microbial biomass measurements for garden compost and horse manure were significantly higher following organic matter addition compared to all other treatments and the control[PM2]&amp;#160;.&amp;#160; All treatments had a significant effect [PM3]&amp;#160;on hot water extractable carbon and total carbon. Peat had a significantly different effect[PM4]&amp;#160;, when compared to other treatments, on the soil PLFA profile and bark application significantly increased [PM5]&amp;#160;the neutral lipid (NLFA) biomarker 16:1&amp;#969;5. &amp;#160;Bark and horse manure application both significantly increased PLFA fungal biomarker 18:2&amp;#969;6,9. No significant differences were found between the fungal/bacterial ratios of the organic matter additions prior to being added to the soil. These findings show that altering the resources available to the soil microbial community has a significant impact on soil microbial community composition and microbially mediated carbon cycling functionality. Increasing our understanding of how soil functions are altered by land management decisions will enable better informed predictions of the long-term benefits of organic matter applications on carbon sequestration and cycling dynamics.&lt;/p&gt;

Do diverse mixtures of cover crop residues alter the soil microbial community and increase soil function?

2020 ◽  
Author(s):  
Xin Shu ◽  
Yiran Zou ◽  
Liz Shaw ◽  
Lindsay Todman ◽  
Mark Tibbett ◽  
...  
Keyword(s):  
Microbial Community ◽  
Soil Respiration ◽  
Cover Crops ◽  
Soil Microbial Community ◽  
Cover Crop ◽  
Crop Residues ◽  
Soil Health ◽  
Soil Function ◽  
Soil Microbial ◽  
Quaternary Mixture

&lt;p&gt;Cover crops are a contemporary tool to sustainably manage agricultural soils by boosting fertility, suppressing weeds and disease, and benefiting cash crop yields, thus securing future food supply. Due to the different chemical composition of crop residues from different plant families, we hypothesised that a mixture of cover crop residues may have a greater potential to improve soil health than the sum of the parts. Our experiment focused on the impact of four cover crops (clover, sunflower, radish and buckwheat) and their quaternary mixture on soil respiration and the soil microbial community in an 84-day microcosm experiment. On average adding cover crop residues significantly (P &lt; 0.001) increased soil respiration from 29 to 343 &amp;#181;g C g&lt;sup&gt;-1&lt;/sup&gt; h&lt;sup&gt;-1&lt;/sup&gt; and microbial biomass from 18 to 60 &amp;#181;g C g&lt;sup&gt;-1&lt;/sup&gt;, compared to the unamended control during 84 days&amp;#8217; incubation. Cover crop addition resulted in a significant (P &lt; 0.001) alteration of the soil microbial community structure compared to that of the control. The quaternary mixture of cover crop residues significantly (P = 0.011) increased soil respiration rate by 23.79 &amp;#181;g C g&lt;sup&gt;-1&lt;/sup&gt; h&lt;sup&gt;-1&lt;/sup&gt; during the period 30 to 84 days after residue incorporation, compared to the average of the four individual residues. However, no significant difference in the size of the microbial biomass was found between the mixture and the average of the four individuals, indicating the mixture may invest resources which transit dormant microbial species into a metabolically active state and thus boost microbial respiration. Analysis of similarity of microbial community composition (ANOSIM) demonstrated the mixture significantly (P = 0.001) shifted microbial community structure away from buckwheat (R = 0.847), clover (R = 0.688), radish (R = 0.285) and sunflower (R = 0.785), respectively. This implies cover crop residues provide a niche specialization and differentiation on a selection of microbial communities that favour certain plant compounds. While applying cover crop residues has positive impacts on soil function, we found that applying a mixture of cover crop residues may provide greater potential to select for microorganisms or activate dormant microbial species which result in higher soil function. The outcome of this study will help seed suppliers to design, and farmers to select, novel cover crop mixtures which enhance soil function synergistically, leading to a greater potential to sustainably improve soil health.&lt;/p&gt;

scholarly journals Plant functional traits determined the latitudinal variations in soil microbial functions: evidence from a forest transect in China

2019 ◽  
Author(s):  
Zhiwei Xu ◽  
Guirui Yu ◽  
Xinyu Zhang ◽  
Ruili Wang ◽  
Ning Zhao ◽  
...  
Keyword(s):  
Organic Matter ◽  
Microbial Community ◽  
Soil Organic Matter ◽  
Microbial Biomass ◽  
Functional Traits ◽  
Plant Functional Traits ◽  
Decomposition Rates ◽  
Substrate Use ◽  
Soil Microbial ◽  
Carbon Concentrations

Abstract. Plant functional traits have increasingly been studied as determinants of ecosystem properties, especially for soil biogeochemical processes. While the relationships between biological community structures and ecological functions are a central issue in ecological theory, these relationships remain poorly understood at the large scale. We selected nine forests along the North–South Transect of Eastern China (NSTEC) to determine how plant functional traits influence the latitudinal pattern of soil microbial functions, and how soil microbial communities and functions are linked at the regional scale. We found that there was considerable variation in the profiles of different substrate use along the NSTEC. Soil microorganisms from temperate forests mainly metabolized high-energy substrates, while those from subtropical forests used all the substrates equally. The soil silt content and plant functional traits together shaped the biogeographical pattern of the soil microbial substrate use. Soil organic matter decomposition rates were significantly higher in temperate forests than in subtropical and tropical forests, which was consistent with the pattern of soil microbial biomass carbon concentrations. Soil organic matter decomposition rates were also significantly and negatively related to soil dissolved organic carbon concentrations, and carboxylic acid, polymer, and miscellaneous substrates. The soil microbial community structures and functions were significantly correlated along the NSTEC. Soil carbohydrate and polymer substrate use were mainly related to soil G+ bacterial and actinomycetes biomass, while the use of amine and miscellaneous substrates were related to soil G− bacteria, fungal biomass, and the F/B ratio. The contributions of different groups of microbial biomass to the production of soil enzyme activities differed. The relationship between soil microbial community structure and functions supported that there was functional dissimilarity.

Sign in / Sign up

Export Citation Format

Share Document