Soil microbiological properties during decomposition of crop residues under conventional and zero tillage

2004 ◽  
Vol 84 (4) ◽  
pp. 411-419 ◽  
Author(s):  
N. Z. Lupwayi ◽  
G. W. Clayton ◽  
J. T. O’Donovan ◽  
K. N. Harker ◽  
T. K. Turkington ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Microbial Diversity ◽  
Microbial Activity ◽  
Soil Quality ◽  
Functional Diversity ◽  
Crop Residue ◽  
Crop Residues ◽  
Zero Tillage ◽  
Microbial Functional Diversity ◽  
Soil Microbial

Field experiments were conducted to correlate decomposition of red clover (Trifolium pratense) green manure (GM), field pea (Pisum sativum), canola (Brassica rapa) and wheat (Triticum aestivum) residues, and soil organic C (SOC), under zero tillage and conventional tillage, with soil microbial biomass C (MBC), bacterial functional diversity and microbial activity (CO2 evolution). A greenhouse experiment was also conducted to relate crop residue quality to soil microbial characteristics. Zero tillage increas ed MBC only in the 0- to 5-cm soil layer. Soil MBC decreased more with soil depth than either microbial diversity or total SOC. Legume GM residues induced greater initial CO2 evolution than the other residues. This means that results that do not include the initial flush of microbial activity, e.g., by sampling only in the season(s) following residue placement, probably underestimate gas evolution from legume crop residues. Residue N, P and K contents were positively correlated with microbial functional diversity and activity, which were positively correlated with crop residue decomposition. Therefore, microbial functional diversity and activity were good indicators of microbial decomposition processes. Residue C/N and C/P ratios (i.e., high C content) were positively correlated with MBC, which was positively correlated with SOC. Therefore, soil MBC was a good indicator of soil quality (soil organic matter content). Key words: Biological soil quality, crop residues, crop rotation, microbial activity, microbial biomass, microbial diversity

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.

Soil microbial biomass and diversity respond to tillage and sulphur fertilizers

2001 ◽  
Vol 81 (5) ◽  
pp. 577-589 ◽  
Author(s):  
N. Z. Lupwayi ◽  
M. A. Monreal ◽  
G. W. Clayton ◽  
C. A. Grant ◽  
A. M. Johnston ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Microbial Diversity ◽  
Soil Microorganisms ◽  
Soil Microbial Biomass ◽  
Conventional Tillage ◽  
Bulk Soil ◽  
Zero Tillage ◽  
Negative Effects ◽  
Tillage Systems ◽  
Soil Microbial

There is little information on the effects of S management strategies on soil microorganisms under zero tillage systems o n the North American Prairies. Experiments were conducted to examine the effects of tillage and source and placement of S on soil microbial biomass (substrate induced respiration) and functional diversity (substrate utilization patterns) in a canola-wheat rotation under conventional and zero tillage systems at three sites in Gray Luvisolic and Black Chernozemic soils. Conventional tillage significantly reduced microbial biomass and diversity on an acidic and C-poor Luvisolic soil, but it had mostly no significant effects on the near-neutral, C-rich Luvisolic and Chernozemic soils, which underlines the importance of soil C in maintaining a healthy soil. Sulphur had no significant effects on soil microbial biomass, and its effects on microbial diversity were more frequent on the near-neutral Luvisol, which was more S-deficient, than on the acidic Luvisol or the Chernozem. Significant S effects on microbial diversity were observed both in the bulk soil (negative effects, compared with the control) and rhizosphere (positive effects) of the acidic Luvisol, but all significant effects (positive) were observed in root rhizospheres in the other soils. Sulphur by tillage interactions on acidic Luvisolic soil indicated that the negative effects of S in bulk soil occurred mostly under zero tillage, presumably because the fertilizer is concentrated in a smaller volume of soil than under conventional tillage. Sulphate S effects, either negative or positive, on microbial diversity were usually greater than elemental S effects. Therefore, S application can have direct, deleterious effects on soil microorganisms or indirect, beneficial effects through crop growth, the latter presumably due to increased root exudation in the rhizosphere of healthy crops. Key Words: Biolog, conservation tillage, microbial biodiversity, rhizosphere, soil biological quality, S fertilizer type and placement

scholarly journals SOIL QUALITY IN RELATION TO FOREST CONVERSION TO PERENNIAL OR ANNUAL CROPPING IN SOUTHERN BRAZIL

2015 ◽  
Vol 39 (4) ◽  
pp. 1003-1014 ◽  
Author(s):  
Elcio Liborio Balota ◽  
Ines Fumiko Ubukata Yada ◽  
Higo Furlan Amaral ◽  
Andre Shigueyoshi Nakatani ◽  
Mariangela Hungria ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Microbial Activity ◽  
Soil Quality ◽  
Conventional Tillage ◽  
Soil Disturbance ◽  
Forest Conversion ◽  
No Tillage ◽  
Southern Brazil ◽  
Soil Microbial ◽  
C And N

Many forested areas have been converted to intensive agricultural use to satisfy food, fiber, and forage production for a growing world population. There is great interest in evaluating forest conversion to cultivated land because this conversion adversely affects several soil properties. We examined soil microbial, physical, and chemical properties in an Oxisol (Latossolo Vermelho distrófico) of southern Brazil 24 years after forest conversion to a perennial crop with coffee or annual grain crops (maize and soybeans) in conventional tillage or no-tillage. One goal was to determine which soil quality parameters seemed most sensitive to change. A second goal was to test the hypothesis that no-tillage optimized preservation of soil quality indicators in annual cropping systems on converted land. Land use significantly affected microbial biomass and its activity, C and N mineralization, and aggregate stability by depth. Cultivated sites had lower microbial biomass and mineralizable C and N than a forest used as control. The forest and no-tillage sites had higher microbial biomass and mineralizable C and N than the conventional tillage site, and the metabolic quotient was 65 and 43 % lower, respectively. Multivariate analysis of soil microbial properties showed a clear separation among treatments, displaying a gradient from conventional tillage to forest. Although the soil at the coffee site was less disturbed and had a high organic C content, the microbial activity was low, probably due to greater soil acidity and Al toxicity. Under annual cropping, microbial activity in no-tillage was double that of the conventional tillage management. The greater microbial activity in forest and no-tillage sites may be attributed, at least partially, to lower soil disturbance. Reducing soil disturbance is important for soil C sequestration and microbial activity, although control of soil pH and Al toxicity are also essential to maintain the soil microbial activity high.

scholarly journals A framework for refining soil microbial indices as bioindicators during decomposition of various organic residues in a sandy loam soil

2015 ◽  
Vol 7 (2) ◽  
pp. 700-708 ◽  
Author(s):  
Sandeep Sharma ◽  
Jatinder Kaur ◽  
H. S. Thind ◽  
Yadvinder Singh ◽  
Neha Sharma ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Soil Quality ◽  
Biochemical Composition ◽  
Crop Residues ◽  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Soil Microbial ◽  
Loam Soil ◽  
Microbial Indices ◽  
Amended Soil

Assessment of soil quality is an invaluable tool in determining the sustainability and environmental impact of agricultural ecosystems. Soil microbial indices like microbial biomass and microbial activity are important criteria for the determination of soil quality. Laboratory incubation study was undertaken to examine the influence of eight crop residues widely varying in biochemical composition on the periodic changes in important soil microbial indices {(microbial (Cmic: Corg), metabolic (qCO2), carbon mineralization (qC) and microbial biomass change rate (qM) quotients)} at 28 days and 63 days after incubation (DAI) in a sandy loam soil. A. sativa amended soil showed maximum soil respiration rate (14.23 mg CO2-C g-1 soil day-1) whereas T. aestivum amended soil showed maximum microbial biomass C (790 µg/g). The metabolic quotient among different crop residues ranged from 11.1 to 19.8 μg CO2-C μg-biomass-C-1 h-1 at 63 DAI. The results indicate that incorporation of different crop residues has positive effect on microbial flora and their activity. Microbial quotient (Cmic:Corg) was significantly positively correlated with microbial biomass carbon (MBC), qC and qM. The study suggests that the biochemical composition of different crop residues seems to be of better option for long term sustainable crop production with maintenance of soil quality in a sandy loam soil.

scholarly journals Effects of Mixing Feldspathic Sandstone and Sand on Soil Microbial Biomass and Extracellular Enzyme Activities—A Case Study in Mu Us Sandy Land in China

2019 ◽  
Vol 9 (19) ◽  
pp. 3963
Author(s):  
Xiuxiu Feng ◽  
Lu Zhang ◽  
Fazhu Zhao ◽  
Hongying Bai ◽  
Russell Doughty
Keyword(s):  
Enzyme Activity ◽  
Microbial Biomass ◽  
Microbial Activity ◽  
Soil Quality ◽  
Enzyme Activities ◽  
Soil Microbial Biomass ◽  
Extracellular Enzyme ◽  
Soil Microbial Activity ◽  
Soil Microbial ◽  
Feldspathic Sandstone

Microbial biomass, extracellular enzyme activity, and their stoichiometry in soil play an important role in ecosystem dynamics and functioning. To better understand the improvement of sand soil quality and the limitation of soil nutrients after adding feldspathic sandstone, we investigated changes in soil microbial activity after 10 months of mixing feldspathic sandstone and sand, and compared the dynamics with soil properties. We used fumigation extraction to determine soil microbial biomass carbon (MBC), nitrogen (MBN), phosphorus (MBP), and microplate fluorometric techniques to measure soil β-1,4-glucosidase (BG), β-1,4-xylosidase (BX), β-D-cellobiohydrolase (CBH), N-acetyl-β-glucosaminidase (NAG), and Alkaline phosphatase (AKP). We also measured soil organic carbon (SOC), pH, electrical conductivity (EC), soil inorganic carbon (SIC), and soil water content (SWC). Our results showed that the soil microbial biomass C, N, P, and individual extracellular enzyme activities significantly increased in mixed soil. Similarly, the soil microbial biomass C:N, C:P, N:P, MBC:SOC, and BG:NAG significantly increased by 54.3%, 106.3%, 33.1%, 23.0%, and 65.4%, respectively. However, BG:AKP and NAG:AKP decreased by 19.0% and 50.3%, respectively. Additionally, redundancy analysis (RDA) and Pearson’s correlation analysis showed that SWC, SOC, porosity and field capacity were significantly associated with soil microbial biomass indices (i.e., C, N, P, C:N, C:P, N:P in microbial biomass, and MBC:SOC) and extracellular enzyme activity metrics (i.e., individual enzyme activity, ecoenzymatic stoichiometry, and vector characteristics of enzyme activity), while pH, EC, and SIC had no correlation with these indices and metrics. These results indicated that mixing feldspathic sandstone and sand is highly susceptible to changes in soil microbial activity, and the soil N limitation decreased while P became more limited. In summary, our research showed that adding feldspathic sandstone into sand can significantly improve soil quality and provide a theoretical basis for the development of desertified land resources.

Effects of Nitrogen Deposition on Soil Microbial Biomass, Microbial Functional Diversity and Enzyme Activities in Fir Plantations of Subtropical China

2012 ◽  
Vol 610-613 ◽  
pp. 323-330 ◽  
Author(s):  
Ying Hong Yuan
Keyword(s):  
Microbial Biomass ◽  
Functional Diversity ◽  
Polyphenol Oxidase ◽  
Enzyme Activities ◽  
Soil Microbial Biomass ◽  
Soil Depth ◽  
N Deposition ◽  
Soil Parameters ◽  
Microbial Functional Diversity ◽  
Soil Microbial

The effects of simulated nitrogen (N) deposition on soil microbial biomass, microbial functional diversity and enzyme activities involved in C cycling (sucrase, β-glucosidase, cellulose, amylase, polyphenol oxidase and peroxidase) were studied in southeast Chinese fir plantation (Cunninghamialanceolata (Lamb.)). All soil parameters measured decreased with increasing soil depth. The results indicated that low N (N1) deposition could accelerate soil microbial biomass and functional diversity, but moderate or high N deposition (N2, N3) restrain them. Nitrogen additions promoted soil sucrase, β-glucosidase and cellulase activities, while inhibited soil amylase, polyphenol oxidase and peroxidase activities to some extent, suggesting that decomposition of labile and recalcitrant organic matter were promoted and restricted by extra N deposition, respectively. Changes in microbial community biomass and function under extra N deposition indicated soil ecosystems experienced functional shifts under the current or future condition of human-accelerated N supply.

The mixture of cover crop residues induced a synergistic effect on microbial communities and an additive effect on soil organic matter priming

2021 ◽  
Author(s):  
Xin Shu ◽  
Yiran Zou ◽  
Liz Shaw ◽  
Lindsay Todman ◽  
Mark Tibbett ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Cover Crop ◽  
Crop Residue ◽  
Soil Microbial Biomass ◽  
Crop Residues ◽  
Soil Microbial ◽  
Quaternary Mixture ◽  
Individual Residue ◽  
The Individual ◽  
Som Decomposition

&lt;p&gt;Applying cover crop residues to increase soil organic matter (SOM) is a widely used strategy to sustainably intensify agricultural systems.&amp;#160; However, fresh residue inputs create &amp;#8220;hot spots&amp;#8221; of microbial activity during decomposition which could also &amp;#8220;prime&amp;#8221; the decomposition of native SOM, resulting in accelerated SOM depletion and greenhouse gas emissions. Microbes exert control over SOM decomposition and stabilisation as a consequence of their carbon use efficiency (CUE), the balance between microbial catabolism and anabolism. The CUE during residue decomposition and the extent to which native SOM decomposition is primed by residue addition may depend on residue biochemical quality.&amp;#160; Given that cover crops may be grown in monoculture, or in species mixes with the aim of providing multiple benefits to agricultural ecosystem services, it is important to understand whether applying cover crop residues as a mixture results in a different CUE and soil carbon stock, than would be expected by observations made on the application of individual residues. We used &lt;sup&gt;13&lt;/sup&gt;C labelled cover crop residues (buckwheat, clover, radish, and sunflower) to track the fate of cover crop residue-derived carbon and SOM derived carbon in treatments comprising a quaternary mixture of the residues and the average effect of the four individual residues (non-mixture) one day after residue incorporation in a laboratory microcosm experiment. The soil microbial community composition was measured by phospholipid-derived fatty acids (PLFA) fingerprint. Our results indicate that, despite all treatments receiving the same amount of plant-added carbon (1 mg C g&lt;sup&gt;-1&lt;/sup&gt; soil), the total microbial biomass (&lt;sup&gt;12&lt;/sup&gt;C + &lt;sup&gt;13&lt;/sup&gt;C) in the treatment receiving the residue mixture was significantly greater, by 3.69 &amp;#181;g C g&lt;sup&gt;-1&lt;/sup&gt;, than the average microbial biomass observed in the four treatments receiving individual components of the mixture. The microbial biomass in the quaternary mixture, compared to the average of the individual residue treatments, that can be attributed directly to the plant matter applied, was also significantly greater by 3.61 &amp;#181;g C g&lt;sup&gt;-1&lt;/sup&gt;. However, there was no evidence that the mixture resulted in any more priming of native SOM than average priming observed in the individual residue treatments. The soil microbial community structure measured by analysis of similarities (ANOSM) was significantly different in the soil receiving the residue mixture, compared to the average structure of the four communities in soils receiving individual residues. Differences in the biomass of fungi and Gram-positive bacteria were responsible for the observed synergistic effect of cover crop residue mixtures on total microbial biomass and plant-derived microbial biomass; especially biomarkers 16:0, 18:1&amp;#969;9, 18:2&amp;#969;6 and 18:3&amp;#969;3. Our study demonstrates that applying a mixture of cover crop residues initially increases soil microbial biomass to a greater extent than would be expected from applying individual components of the mixture and that this increase may occur either due to faster decomposition of the cover crop residues or greater CUE, but not due to greater priming of native SOM decomposition. Therefore, applying cover crop residue mixtures could be an effective method to increase soil microbial biomass, and ultimately soil carbon stocks in arable soils.&lt;/p&gt;

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