Climate-smart agriculture: microbiological impacts of plant diversity to soil carbon (C) sequestration.

2021 ◽  
Author(s):  
Rashmi Shrestha ◽  
Karoliina Huusko ◽  
Anna-Reetta Salonen ◽  
Jussi Heinonsalo
Keyword(s):  
Microbial Activity ◽  
Plant Diversity ◽  
Cover Crops ◽  
Cover Crop ◽  
Am Fungi ◽  
C Sequestration ◽  
Fungal Colonization ◽  
Soil C ◽  
Soil Microbial ◽  
Diversity Effect

<p>Soil organic matter (SOM) is any material produced by living organisms at various stages of decomposition. SOM enhances soil fertility and quality and influences soil’s ability to fight against soil-borne diseases. Atmospheric CO<sub>2</sub> sequestration into SOM through improved agricultural management practices has been suggested to be a cost effective way to mitigate climate change.</p><p>The build-up of SOM is largely regulated by soil microbial activity. Soil microbes use most plant-derived C and either produce CO<sub>2</sub> or incorporate C into their biomass and after death microbial necromass may contribute to stable SOM. Arbuscular mycorrhizal (AM) fungi are one of the root colonizing soil microbes important in nutrient cycling, plant nutrition, growth and composition and maybe soil aggregation. The benefits of microbes including AM fungi should be thus utilized for climate friendly agriculture by magnifying their benefits via better agricultural management.</p><p>Cover crops use is one of the climate friendly agricultural practices. Cover crops if managed right, can provide several benefits e.g. enhanced soil C sequestration, reduced emissions from fertilizer production, weed suppression, better soil moisture retention and microbial activity. Moreover, use of diverse cover crops may favor higher soil biodiversity leading to high SOM content. In this project, plant diversity impacts on soil and root fungal community composition and microbial activity related to soil C sequestration were studied in a field experiment. In addition, special attention was given to AM fungi.</p><p>The field experiment was started in May, 2019 in Viikki Research farm, University of Helsinki. The experiment consists of seven treatments comparing four different levels of biodiversity to conventional monoculture treatments and bare fallow. Eight different species of cover crops representing four functional traits were sown under barley: 1) nitrogen (N<sub>2</sub>)-fixing + shallow rooting , 2) deep rooting, 3) N<sub>2</sub>-fixing +deep rooting and 4) no N<sub>2</sub>-fixing and shallow rooting. Barley and cover crop root samples and soil samples were collected from two growing seasons 2019 and 2020. Root samples were analyzed for AM fungal colonization %. Soil samples were analyzed for soil microbial biomass and microbial respiration in different seasons. Preliminary results showed no significant cover crop diversity effect on AM fungal colonization % in barley root in 2019. Soil microbial biomass and soil microbial respiration showed seasonal variations but not significant cover crop diversity effect. Therefore, fungal communities in soil and root will be examined using Illumina (MiSeq) sequencing targeting the fungal internal transcribed spacer (ITS) region. Soil enzyme activities and carbon use efficiency will be performed to gain insight into microbial activity. Obtained results will show if microbial community and activity is affected by either plant family composition or plant diversity.</p>

Microbial activity and soil C sequestration for reduced and conventional tillage cotton

2008 ◽  
Vol 38 (2) ◽  
pp. 168-173 ◽  
Author(s):  
Alan L. Wright ◽  
Frank M. Hons ◽  
Robert G. Lemon ◽  
Mark L. McFarland ◽  
Robert L. Nichols
Keyword(s):  
Microbial Activity ◽  
C Sequestration ◽  
Conventional Tillage ◽  
Soil C ◽  
Soil C Sequestration

scholarly journals Use of Crop Rotations, Cover Crops and Green Manures for Disease Suppression in Potato Cropping Systems

2021 ◽  
Vol 8 ◽  
pp. 153-168
Author(s):  
Robert P. Larkin
Keyword(s):  
Disease Control ◽  
Microbial Activity ◽  
Cover Crops ◽  
Cover Crop ◽  
Green Manure ◽  
Cropping Systems ◽  
Crop Rotations ◽  
Disease Suppression ◽  
Green Manures ◽  
Rotation Crops

Crop rotations and the inclusion of cover crops and green manures are primary tools in the sustainable management of soil-borne diseases in crop production systems. Crop rotations can reduce soil-borne disease through three general mechanisms: (1) serving as a break in the host-pathogen cycle; (2) by altering the soil physical, chemical, or biological characteristics to stimulate microbial activity and diversity; or (3) directly inhibiting pathogens through the release of suppressive or toxic compounds or the enhancement of specific antagonists. Brassicas, sudangrass, and related plant types are disease-suppressive crops well-known for their biofumigation potential but also have other effects on soil microbiology that are important in disease suppression. The efficacy of rotations for reducing soil-borne diseases is dependent on several factors, including crop type, rotation length, rotation sequence, and use of the crop (as full-season rotation, cover crop, or green manure). Years of field research with Brassica and non-Brassica rotation crops in potato cropping systems in Maine have documented the efficacy of Brassica green manures for the reduction of multiple soil-borne diseases. However, they have also indicated that these crops can provide disease control even when not incorporated as green manures and that other non-biofumigant crops (such as barley, ryegrass, and buckwheat) can also be effective in disease suppression. In general, all crops provided better disease control when used as green manure vs. as a cover crop, but the addition of a cover crop can improve control provided by most rotation crops. In long-term cropping system trials, rotations incorporating multiple soil health management practices, such as longer rotations, disease-suppressive rotation crops, cover crops, and green manures, and/or organic amendments have resulted in greater yield and microbial activity and fewer disease problems than standard rotations. These results indicate that improved cropping systems may enhance productivity, sustainability, and economic viability.

Organic soil amendments as a tool to increase biological activity and C sequestration in clay soil

2021 ◽  
Author(s):  
Jussi Heinonsalo ◽  
Anna-Reetta Salonen ◽  
Rashmi Shrestha ◽  
Subin Kalu ◽  
Outi-Maaria Sietiö ◽  
...  
Keyword(s):  
Soil Structure ◽  
Soil Amendments ◽  
C Sequestration ◽  
Organic Soil ◽  
Plant Production ◽  
Soil C ◽  
Soil Microbial ◽  
Organic Soil Amendments ◽  
C Stocks ◽  
Soil C Sequestration

<p>Soil C sequestration through improved agricultural management practices has been suggested to be a cost-efficient tool to mitigate climate change as increased soil C storage removes CO<sub>2</sub> from the atmosphere. In addition, improved soil organic carbon (SOC) content has positive impacts on farming though better soil structure and resilience against climate extremes through e.g. better water holding capacity. In some parts of the world, low SOC content is highly critical problem for overall cultivability of soils because under certain threshold levels of SOC, soil loses its ability to maintain essential ecosystem services for plant production. Soil organic amendments may increase soil C stocks, improve soil structure and boost soil microbial activities with potential benefits in plant growth and soil C sequestration. Additional organic substrates may stimulate microbial diversity that has been connected to higher SOC content and healthy soils.</p><p>We performed a two-year field experiment where the aim was to investigate whether different organic soil amendments have an impact on soil microbial parameters, soil structure and C sequestration.</p><p>The experiment was performed in Parainen in southern Finland on a clay field where oat (Avena sativa) was the cultivated crop. Four different organic soil amendments were used (two wood-based fiber products that were leftover side streams of pulp and paper industry; and two different wood-based biochars). Soil amendments were applied in 2016. Soil C/N analysis was performed in the autumns 2016-2018 and soil aggregate in the summer and autumn 2018, as well as measures to estimate soil microbial activity: microbial biomass, soil respiration, enzymatic assays, microbial community analysis with Biolog ®  EcoPlates and litter bag decomposition experiment. The relative share of bacteria and fungi was determined using qPCR from soil samples taken in the autumns 2016, 2017 and 2018.</p><p>Data on how the studied organic soil amendments influence soil structure and C content, as well as soil microbial parameters will be presented and discussed.</p>

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

<p>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 < 0.001) increased soil respiration from 29 to 343 µg C g<sup>-1</sup> h<sup>-1</sup> and microbial biomass from 18 to 60 µg C g<sup>-1</sup>, compared to the unamended control during 84 days’ incubation. Cover crop addition resulted in a significant (P < 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 µg C g<sup>-1</sup> h<sup>-1</sup> 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.</p>

Effect of Drought and Recovery on Grazing Animal, Microbial, and Fungal Response in a Diverse Multi-Crop Rotation

2020 ◽  
Author(s):  
Douglas Landblom ◽  
Songul Senturklu
Keyword(s):  
Nutrient Cycling ◽  
Beef Cattle ◽  
Microbial Activity ◽  
Crop Rotation ◽  
Cover Crop ◽  
Crop Production ◽  
Microbial Respiration ◽  
Soil Nutrient ◽  
Soil Microbial ◽  
Animal Grazing

<p>Beef cattle grazing, soil microbial respiration, and Rhizobia spp. populations serve important roles in soil nutrient cycling and during periods of drought, when abnormal precipitation declines, forage production for animal grazing and performance are negatively impacted. Soil nutrient availability is essential for adequate crop production and extended drought reduces soil microbial activity and therefore nutrient cycling. During the 2017 growing season between April and October in the northern Great Plains region of the USA, effective precipitation for crop production and animal grazing was severely reduced due an exceptional drought as classified by the US Drought Monitor. At the NDSU – Dickinson Research Extension Center, Dickinson, North Dakota, USA, a long-term integrated system that includes yearling steer grazing within a diverse multi-crop rotation (spring wheat, cover crop, corn, pea-barley intercrop, and sunflower). Within the rotation of cash and forage crops, beef cattle graze the pea-barley, corn, and cover crop (13-specie) within the rotation and is being utilized to monitor the effects of animal, microbial and fungal activity over time and space in the crop and animal production system. Nitrogen fertilizer has been replaced in the system by soil microbial and fungal activity (Potential Mineralizable Nitrogen: 8.4 mg N/kg) such that for each 1% increase in SOM there is a corresponding increase of 18.8 kg of potential nitrogen mineralized per ha. Animal grazing days are severely reduced when precipitation is inadequate for soil microbial respiration to occur. What is even more concerning, when relying on microbial activity to supply plant nutrients, is recovery time for microbial activity to fully recover from exceptional drought as was the case in this research project. Compared to the 2016 crop production year that preceded the 2017 drought, cover crop (13-specie), pea-barley, and corn yields were reduced 86, 33, and 64% during the 2017 drought. This decline in crop production reduced the number of days of grazing by an average 50% and average daily gains were also reduced. Steer average daily gains were 1.05 0.95, and 0.83 kg/steer/day in 2017 when grazing pea-barley, corn, and cover crop, respectively. For this research that relies on soil derived plant nutrients soil analysis for microbial and Rhizobia spp. biomass began recovery in 2018 and continued into 2019 as evidenced by large percentage increases in organism biomass; however, complete production recovery did not occur by the end of the 2019 grazing season in which days of grazing were reduced compared to the 2016 grazing season. Biological animal, crop, microbial, fungal, and nutrient replacement recovery will be presented in the poster.</p>

Effects of probiotics on soil microbial activity, biomass and enzymatic activity under cover crops in field and greenhouse studies

2016 ◽  
Vol 90 (5) ◽  
pp. 811-827 ◽  
Author(s):  
Ahsan M. Rajper ◽  
Ranjith P. Udawatta ◽  
Robert J. Kremer ◽  
Chung-ho Lin ◽  
Shibu Jose
Keyword(s):  
Enzymatic Activity ◽  
Microbial Activity ◽  
Cover Crops ◽  
Soil Microbial Activity ◽  
Soil Microbial

The influence of a long-term black medic (Medicago lupulina cv. George) cover crop on arbuscular mycorrhizal fungal colonization and nutrient uptake in flax (Linum usitatissimum) under zero-tillage management

2011 ◽  
Vol 91 (6) ◽  
pp. 1071-1076 ◽  
Author(s):  
M. S. Turmel ◽  
M. H. Entz ◽  
M. Tenuta ◽  
W. E. May ◽  
G. P. LaFond
Keyword(s):  
Nutrient Uptake ◽  
Cover Crops ◽  
Linum Usitatissimum ◽  
Cover Crop ◽  
Arbuscular Mycorrhizal ◽  
Fungal Colonization ◽  
Zero Tillage ◽  
Medicago Lupulina ◽  
Micronutrient Uptake

Turmel, M. S., Entz, M. H., Tenuta, H., May, W. E. and LaFond, G. P. 2011. The influence of a long-term black medic ( Medicago lupulina cv. George) cover crop on arbuscular mycorrhizal fungal colonization and nutrient uptake in flax ( Linum usitatissimum ) under zero-tillage management. Can. J. Plant Sci. 91: 1071–1076. Leguminous cover crops are becoming a popular way to increase the sustainability of agricultural systems. Previously, cover crops have been found to increase colonization by arbuscular mycorrhizal fungi (AMF) and phosphorus and micronutrient uptake. Long-term field studies were conducted to test the hypothesis that self-regenerating black medic (Medicago lupulina cv. George) cover crops increase AMF colonization and early nutrient uptake in flax (Linum usitatissimum). Field experiments were established in 2000 (Manitoba) and 2002 (Saskatchewan) using a flax–wheat (Triticum aestivum)–oat (Avena sativa) rotation. In a second experiment, intact soil cores were harvested from the plots in spring and tested for soil disturbance and cover crop effects under controlled environment conditions (CEC). Both seedling flax crops sampled from the field in 2005 and 2006 and flax growth in CEC showed high levels of AMF root colonization, but no significant influence of the cover crop on AMF colonization by arbuscules or hyphal structures was detected. The AMF enhancing practices used in the experiments (i.e., zero-tillage and inclusion of mycorrhizal crops) may have contributed to the lack of cover crop effect on AMF colonization. The cover crop had no effect on macro- or micronutrient uptake by flax except during drought conditions (Winnipeg 2006), where flax biomass was reduced by 38% and the total uptake of N, P, Zn and Cu was decreased by 34, 30, 31 and 35%, respectively, in the medic treatment.

Comparative study of soil properties under various cultivation regimes of different crops

Soil Research ◽  
2011 ◽  
Vol 49 (7) ◽  
pp. 595 ◽  
Author(s):  
Binh Thanh Nguyen ◽  
Hai Thien Hoa ◽  
Van Thi Hong Ngo ◽  
Tra Thanh Duong ◽  
Brian R. Wilson
Keyword(s):  
Soil Fertility ◽  
Soil Properties ◽  
Cover Crops ◽  
Cover Crop ◽  
Aggregate Stability ◽  
Principal Component ◽  
The Other ◽  
P Availability ◽  
Soil C ◽  
Brachiaria Ruziziensis

Establishment of cover crops is an effective way to reverse the soil fertility decline, which can be caused by a range of inappropriate traditional agriculture practices, particularly tillage and inorganic fertiliser application. In this study, soil properties were assessed under various cultivation regimes of different crops, including legumes, grass, and nursery natural rubber (NR) trees (Hevea brasiliensis Muell. Arg.), in southern Vietnam. The crops studied had all been growing for 7 years commencing in 1999, on light-textured Acrisols. Soils under the cultivation regime of creeping legumes including Calopogonium caeruleum, Pueraria phaseoloides, and Stylosanthes gracilis had significantly higher carbon (C) and nitrogen (N) concentrations and porosity than soils under the other management types studied. Soils under Brachiaria ruziziensis and P. phaseoloides had the highest aggregate stability. Cultivation regimes with tillage, field traffic, and inorganic fertilisers applied to nursery NR trees increased phosphorus (P) availability, but this was accompanied by increased soil compaction and reductions in most of the other soil properties analysed. Relative to the nursery NR cultivation, creeping-legume cultivation increased soil C concentration (by 95%), soil pHH2O (by 19%), macro-aggregates (by 29%), and porosity (by 8%). From principal component analysis, three soil properties—soil organic carbon (SOC), porosity, and P availability—were selected as key indicators suitable for the evaluation of the effects of cultivation on soils. Establishment of C. caeruleum and B. ruziziensis was most effective in improving soil C content, and soil porosity was significantly higher under C. caeruleum and P. phaseoloides. These findings suggest that each cover crop had its own dominant agro-characteristics and that selection of a cover crop to either improve soil fertility or reduce compaction should be considered by farmers in this region.

scholarly journals Soil carbon content and its stratification at the medium-term (5 and 8 years) in a semi-arid vineyard with cover crops

2019 ◽  
Vol 9 ◽  
Author(s):  
Fernando Peregrina
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Soil Depth ◽  
Soil Surface ◽  
Conventional Tillage ◽  
Medium Term ◽  
Annual Increment ◽  
Maximum Increase ◽  
Soil C ◽  
Crop Establishment

There is little information available on the evolution and stratification of soil C content (SCC) at the medium- to long-term in semiarid vineyards with cover crops. The objective was to determine SCC at different depths in the medium term (5 and 8 years) in a semiarid vineyard with different cover crops. The field experiment was conducted on Typic Haploxerept soil with a loam texture, pH 8.2, situated in a vineyard (cv. Tempranillo) located in the La Rioja region (northeast Spain) on Miocene sandstones, siltstones, clays and marlstones. Two different soil managements were evaluated: conventional tillage (CT) and continuous cover crop of resident vegetation (RV). Soil samples were collected from four soil layers (at depths of 0-2.5, 2.5-5, 5-15, and 15-25 cm) in June 2009 and June 2012, 5 and 8 years respectively after cover crop establishment. The SCC was determined and the SCC variation with respect to tillage treatment was determined considering the percentage of soil &lt; 2 mm and soil bulk density. The results showed that the greatest increase in SCC occurred at 0-2.5 cm soil depth, increasing less with depth. The SCC annual increment in the whole soil sampled (0-25 cm) was 2.78 Mg C ha<sup>-1</sup> year<sup>-1 </sup>after 5 years and decreased to 1.98 Mg C ha<sup>-1</sup> year<sup>-1</sup> after 8 years of cover crop establishment. The lower SCC annual increase was not due to the maximum increase being reached in the whole of the sampled soil (0-25 cm). From 2009 to 2012, the SCC did not increase at the soil surface (0-2.5 cm), but did so in the subsurface zone (2.5-5 cm), although with an annual increment lower than that found at soil surface (0-2.5 cm). In conclusion, the steady state in SCC would not have been reached in the medium term (8 years) under cover crop, since there is still a increment of SCC in the subsurface layers.

scholarly journals Cover crop residue diversity enhances microbial activity and biomass with additive effects on microbial structure

2021 ◽  
Author(s):  
Xin Shu ◽  
Yiran Zou ◽  
Liz J. Shaw ◽  
Lindsay Todman ◽  
Mark Tibbett ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Biomass ◽  
Soil Respiration ◽  
Microbial Activity ◽  
Cover Crop ◽  
Crop Residue ◽  
Soil Microbial Biomass ◽  
Crop Residues ◽  
Soil Functions ◽  
Soil Microbial

AbstractCover crops have been widely used in agroecosystems to improve soil fertility and environmental sustainability. The decomposition of cover crop residues can have further effects on belowground communities and their activity, which is important for a series of soil functions (e.g., nutrient cycling and organic matter decomposition). We tested the effect of plant residues from a range of cover crop species on soil microbial activity and community assemblage. We predicted that cover crop residues would alter the soil microbial community and that a greater diversity of residues would enhance microbial decomposition. In an incubation study, we assessed the effect of crop residue diversity on microbial activity (soil respiration) and its consequent effects on microbial community composition (PLFA). We used either a biodiverse mixture of four cover crop residues (buckwheat, clover, sunflower and radish) or an equal mass of the residues of each of the individual species. The diverse mixture of cover crop residues had a significantly (P < 0.05) greater soil respiration rate, by 57.61 µg C g−1 h−1, than the average of the four individual residues, but did not have a significantly different soil microbial biomass or microbial community structure. This finding could be attributed to a greater diversity of organic resources increasing the number biochemical niches, and hence activating dormant microbial communities to increase microbial activity without affecting microbial biomass or community composition. Greater respiration from similar microbial biomasses suggests that microbial activity might be more efficient after a more diverse substrate input. This study confirms the positive impact of cover crop residues on soil microbial biomass and activity and highlights that mixtures of cover crop residues may deliver enhanced soil functions beyond the sum of individual cover crop residues.

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