Soil microbial, fungal, and nematode responses to soil fumigation and cover crops under potato production

2005 ◽  
Vol 42 (3) ◽  
pp. 247-257 ◽  
Author(s):  
H. P. Collins ◽  
A. Alva ◽  
R. A. Boydston ◽  
R. L. Cochran ◽  
P. B. Hamm ◽  
...  
2019 ◽  
pp. 1578-1585
Author(s):  
Catia Aparecida Simon ◽  
Sebastião Ferreira de Lima ◽  
Meire Silvestrini Cordeiro ◽  
Vinícius Andrade Secco ◽  
Guilherme Nacata ◽  
...  

Carbon sources are exuded and deposited by different soil cover plants. They promote growth, diversity and enhancement of soil microbial community functionality, due to organic matter degradation by participating in major biochemical cycles and the availability of inorganic nutrients to plants. In this way, it is necessary to evaluate the microbiological attributes of the soil after cover cropping, which allows for surveying and monitoring the soil quality, thereby enabling rapid responses in relation to managing changes in the soil. Thus, the objective of this study was to evaluate soil microbiological attributes and soybean grain yield under the influence of different cover crops. The experiment was installed in the year 2015. The treatments were constituted by the following vegetation coverages: sorghum, millet, Urochloa ruziziensis, forage turnip, Urochloa brizantha, crambe and fallow area, with cover crops sown in succession to the soybean crop for three years prior to the date of installation of the experiment .The evaluated parameters were soil microbial biomass carbon, soil basal respiration, metabolic quotient, enzymatic activity of acid phosphatase and soil β-glucosidase, plant phytomass produced by the different cover crops and soybean yield in each area. The use of cover crops promotes higher soybean yield. The microbial activity and its efficiency were modulated according to the type of cover crop used. Soil under sorghum mulch provided lower microbial efficiency. The U. ruziziensis plant residues remain for less time on the soil. The results show that U. brizantha may be the most suitable for its use as a soil cover plant, providing improvements in its attributes.


2006 ◽  
Vol 21 (4) ◽  
pp. 245-252 ◽  
Author(s):  
Jason L. De Bruin ◽  
Nicholas R. Jordan ◽  
Paul M. Porter ◽  
Sheri C. Huerd

AbstractIntegration of rye (Secale cereale L.) cover crops into the corn (Zea mays L.) soybean [(Glycine max (L.) Merr.] rotation of the upper Midwest USA can provide many agronomic and agroecological benefits. Integration is made difficult by short growing seasons, but may be facilitated by management of key agroecological interactions such as those between rye and soil microbiota. Rye growth was measured and colonization by arbuscular-mycorrhizal fungi (AMF) was determined in greenhouse experiments using soils from seven different management systems from a long-term cropping-systems experiment in southwest Minnesota. Microbial effects on rye growth were not evident before vernalization, but at final harvest (4 weeks after vernalization) soil microbial populations reduced rye shoot and root growth, relative to a pasteurized control inoculum. At final harvest, shoot biomass in 2-year rotations was 17% greater than 4-year rotations, indicating that microbial populations selected for by 4-year rotations may be more deleterious or pathogenic than those selected for by 2-year rotations. Growth of three rye cultivars was examined in all inocula; cultivars differed in their mean response to soil microbiota and their ability to host AMF. These findings suggest that management factors affect interactions between rye and soil microbiota resulting in altered rye growth.


2020 ◽  
Author(s):  
Xin Shu ◽  
Yiran Zou ◽  
Liz Shaw ◽  
Lindsay Todman ◽  
Mark Tibbett ◽  
...  

<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>


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