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Fertilization is a worldwide agricultural practice used in agronomy to increase crop yields. Fertilizer application influences overall soil characteristics, including soil microbial community composition and metabolic processes mediated by microbial enzymatic activity. Changes in the structure of microbial communities and their metabolic activity after long-term fertilization were studied in this research. We hypothesized that the different types of fertilization regimes affect nutrient levels in the soil which subsequently influence the metabolic processes and microbial diversity and community structure. Manure (MF; 330 kg N/ha), sewage sludge at two application doses (SF; 330 kg N/ha and SF3x; 990 kg N/ha) and chemical (NPK; N-P-K nutrients in concentrations of 330-90-300 kg/ha) fertilizers have been applied regularly to an experimental field since 1996. The microbial diversity increased in all soils amended with both organic (MF, SF, SF3x) and chemical (NPK) fertilizers. The shifts in microbial communities were observed, which were mainly caused by less abundant genera that were mostly associated with one or more fertilization treatment(s). Fertilization also influenced soil chemistry and the activity of β-xylosidase, β-N-acetylglucosaminidase (NAG), acid phosphatase and FDA-hydrolases. Specifically, all fertilization treatments were associated with a higher activity of β xylosidase and lower NAG activity.

Inoculation with beneficial microbes has been proposed as an effective practice for the improvement of plant growth and soil health. Since soil acts as a physicochemical background for soil microbial communities, we hypothesized that its management will mediate the effects of microbial inoculants on the indigenous soil microbes. We examined the effects of bacterial inoculants [Bacillus subtilis (Ba), Pseudomonas fluorescens (Ps), and both (BaPs)] on the growth of Lactuca sativa cultivated in soils that originated from an organic maize (OS) and a conventional barley (CS) management system. Moreover, the biomass and the community structure of the rhizosphere microbial communities and the soil enzyme activities were recorded. The root weight was higher in CS than OS, while the foliage length was greater in OS than CS treatments. Only in OS pots, inoculants resulted in higher biomasses of bacteria, fungi, and actinomycetes compared to the control with the highest values being recorded in Ps and BaPs treated soils. Furthermore, different inoculants resulted in different communities in terms of structure mainly in OS soils. For soil enzymes, the effect of the management system was more important due to the high organic matter existing in OS soils. We suggest that for microbial inoculation to be effective it should be considered together with the management history of the soil.

Managing plant fertilization is a major concern of greenhouse growers to achieve sustainable production with growing media. Organic fertilization is popular but is more difficult to control, since organic compounds need first to be mineralized by microbes. After 7, 14, 28, and 56 days of incubation, we investigated the response of microbial activities and nutrient releases from three frequently used organic fertilizers (horn and two plant-based fertilizers) in three frequently employed growing media (GM) types (peat, coir, and bark). We measured pH, electrical conductivity, nutrient contents (NH4+-N, NO3−-N, PO43−-P, SO42−-S), and enzyme activities (β-1.4-glucosidase, urease, acid phosphatase, arylsulfatase). After fertilization, microbes in coir expressed all the C, N, P, and S functions studied, making related nutrients available. In peat and bark, some C, N, P, and S-related pathways were locked. Peat presented high NH4+-N and PO43−-P releases linked to high acid phosphatase and β-glucosidase activities, while bark showed high nitrification rates but weak enzyme activities. Fertilizer types modulated these responses with lower activities and nutrient releases with horn. Our results contributed to better understanding mineralization processes in GM, showing different microbial responses to fertilization.

500Foods shared this story from Agronomy.

Agronomy, Vol. 10, Pages 1752: Effects of Elevated CO2 on Tomato (Lycopersicon esculentum Mill.) Growth and Rhizosphere Soil Microbial Community Structure and Functionality

Agronomy doi: 10.3390/agronomy10111752

Authors: Hehua Wang Haoxin Fan Huaiying Yao

NUS researchers have reconstructed nearly a thousand microbial genomes from green leafy vegetables commonly consumed in Singapore to improve the quality of urban farmed crops. This study is a first step towards uncovering the microbiomes associated with urban farmed vegetables. It also marks progress in…

There is a need for plant growing media that can support a beneficial microbial root environment to ensure that optimal plant growth properties can be achieved. We investigated the effect of five rhizosphere bacterial community inocula (BCI S1–5) that were collected at three open field organic farms and two soilless farms on the performance of lettuce (Lactuca sativa L.). The lettuce plants were grown in ten different plant growing media (M1–10) composed of 60% v/v peat (black peat or white peat), 20% v/v other organics (coir pith or wood fiber), 10% v/v composted materials (composted bark or green waste compost) and 10% v/v inorganic materials (perlite or sand), and one commercial plant growing medium inside a plant factory with artificial lighting. Fractional factorial design of experiments analysis revealed that the bacterial community inoculum, plant growing medium composition, and their interaction determine plant performance. The impact of bacterial amendments on the plant phenotype relied on the bacterial source. For example, S3 treatment significantly increased lettuce shoot fresh weight (+57%), lettuce head area (+29%), root fresh weight (+53%), and NO3-content (+53%), while S1 treatment significantly increased lettuce shoot dry weight (+15%), total phenolic content (+65%), and decreased NO3-content (−67%). However, the effectiveness of S3 and S1 treatment depended on plant growing medium composition.

Scientists have revealed that plants have a ‘sealing’ mechanism supported by microbes in the root that are vital for the intake of nutrients for survival and growth. Plant Scientists from the Future Food Beacon at the University of Nottingham have demonstrated that the mechanism controlling the root…

Supplier claims its bags and boxes inhibit the growth of microbes by 99.99%

Legume plants know their friends from their enemies, and now, researchers found how they do it at the molecular level. Plants recognize beneficial microbes and keep harmful ones out, which is important for healthy plants production and global food security. Scientists have now discovered how legumes use…

The biological suppression of common plant diseases increasingly becomes the preferred alternative to chemical plant protection. Adding biostimulants to a growing medium can induce the required suppressing effects. Based on long-term research, Klasmann-Deilmann has developed TerrAktiv PLUS, a unique constituent consisting of…

Modern agriculture increasingly demands an alternative to synthetic chemicals (fertilizers and pesticides) in order to respond to the changes in international law and regulations, but also consumers’ needs for food without potentially toxic residues. Microbial (arbuscular mycorrhizal and plant growth promoting rhizobacteria: Azotobacter, Azospirillum and Rizhobium spp.) and non-microbial (humic substances, silicon, animal- and vegetal-based protein hydrolysate and macro- and micro-algal extracts) biostimulants represent a sustainable and effective alternative or complement for their synthetic counterparts, bringing benefits to the environment, biodiversity, human health and economy. The Special Issue “Toward a sustainable agriculture through plant biostimulants: from experimental data to practical applications” compiles 34 original research articles, 4 review papers and 1 brief report covering the implications of microbial and non-microbial biostimulants for improving seedling growth and crop performance, nutrient use efficiency and quality of the produce as well as enhancing the tolerance/resistance to a wide range of abiotic stresses in particular salinity, drought, nutrient deficiency and high temperature.

BioConsortia, Inc. was started in 2014 and has been working on the development of microbial solutions for natural plant trait enhancement and yield improvement since then. “It is our goal to develop a new generation of better products,” says Marcus Meadows-Smith, CEO with the company. “Our microbial…

As the climate crisis intensifies, a growing number of consumers have begun to see healthy soils as a potential solution. As a result, soil-building techniques like cover crops and diverse crop rotations are increasingly in the limelight. But for many dyed-in-the-wool organic farmers, they’re old hat.

“These are practices that have been part of organic certification for decades now,” said Laura Batcha, CEO of the Organic Trade Association (OTA), during a September media briefing to kick off a campaign positioning organic farming as a climate solution.

The aim was to determine the suitability of various substrates for application in a closed system of soilless tomato cultivation, based on the potential fitness of drainage waters from these substrates for recirculation. Four substrates were used: rockwool, coir substrate, lignite substrate (Carbomat) and biodegradable organic substrate (Biopot). Tomato plants grown in these substrates were fertilized with the same amount of nutrient solution, containing the same concentration of nutrients. The characteristics of drainage water from these substrates were analyzed during cultivation. The highest amount of drainage water was collected from the lignite substrate Carbomat. However, these leachates showed good properties for further recirculation: low electro conductivity and turbidity, high nutrient content, moderate microbial load with high population of Trichoderma fungi, and being beneficial for plant growth. Moreover, Carbomat produced the highest tomato yield compared to other substrates. This indicates that this organic substrate is an efficient alternative to rockwool and its drainage water may be reused in a recirculation system. On the contrary, the drainage water from the Biopot substrate showed the worst qualities: high pH and low EC, low concentration of nitrate nitrogen and phosphorus, very high turbidity and a high number of microorganisms. These parameters do not qualify Biopot drainage waters for reuse.

The integration of sanitation is a critical part of the food manufacturing process. This week’s episode of the 2020 Food Safety Consortium Virtual Conference Series will focus on effective approaches, best practices and lessons learned. The following are some highlights:

Sanitation Methods, Day-to-Day Operations and Applying It to a Pandemic (Now and Future Outbreaks), with Elise Forward, Forward Food Solutions; David Shelep, Paramount Sciences; and Bill Leverich, Microbiologics, Inc. The Critical Nature of a Good Environmental Program: The Story Behind Sabra’s Recall, Experience with the FDA, and Environmental Monitoring Journey, with Rob Mommsen, Sabra Dipping Company Surrogates & Emerging Applications: Their Role in Validation, Verification and Compliance, with Laure Pujol, Ph.D. and Vidya Ananth, Novolyze Tech Talks from Sterilex and Romer Labs.

In the webinar 'Food Safety in CEA Systems', presented by GLASE on September 24, 2020, Dr. Gioia Massa, plant scientist at NASA, will highlight some of the unique aspects of space crop production and the microbial food safety considerations of space-grown produce. Data will be presented on space-grown leafy green vegetables, as…

Veg-Fresh Farms, Corona, Calif., is using packaging to fight pathogens — and not just as a barrier during transport and on retail shelves.

The company is using Smart Plastic Technologies to add anti-microbial properties to the film packaging itself. The film is being used for conventional and organic Brussels sprouts packages, with plans to use Smart Plastic with clamshells, lidding film and more, according to a news release.

Smart Plastic Technologies have an array of plastic additives that are designed to address a number of specific issues, including food safety. They are added in the production of the films in “very small percentages,” along with other standard ingredients, according to the release, and are effective against salmonella, listeria, E. coli and numerous other organisms, promising a 99.9% reduction in bacteria.

Bob Wright, chief operations officer at Veg-Fresh Farms, said the company has been in contact with Smart Plastic Technologies for a few years.

“We have been closely following their independent testing trials and have been thoroughly impressed with the technology they provide,” Wright said in the release. “It is a natural fit to incorporate this technology into our packaging. Foodborne illness is one of the top threats to this industry, and we are committed to taking advantage of new technology to keep our customer’s food as fresh, safe and healthy as possible.”

Smart Plastic additives include:

In the wake of a voluntary 50-state recall of red, white, yellow and sweet onions originating from Thomson International Inc. in Bakersfield, CA, an increase in pathogen testing requests is anticipated by Certified Onions Inc. in Nyssa, OR.

Each of COI’s members undergoes sampling for off-label pesticide use and for maximum residue levels, and the pathogen testing is available on request.

Kay Riley, founding member and president of COI, said the pesticide residue testing service is utilized on approximately 80 percent of the onion fields in Idaho-E. Oregon’s Treasure Valley and can be made available to other onion-growing regions as well. And he said some of the area’s sheds routinely use the pathogen testing.

“I’m certain we’ll see more pathogen testing this year,” Riley said on Aug. 3, adding that E. coli 157 and Salmonella are the two microbials involved.

The principles of good agricultural and horticultural practice, which consider both giving environmental protection and high yielding of plants, require modern cultivation methods. Modern cultivation of horticultural plants uses, for example, cover crops, living mulches, plant growth-promoting microorganisms (PGPMs), plant growth regulators (PGRs) and other biostimulants protecting the soil against degradation and plants against phytopathogens and stress. The purpose of field and laboratory studies was to determine the effect of Trianum P (containing Trichoderma harzianum Rifai T-22 spores), Beta-Chikol (a.s.—chitosan), Timorex Gold 24 EC (based on tea tree oil) and fungicide Zaprawa Nasienna T 75 DS/WS (a.s.—tiuram 75%) on the health of carrot (Daucus carota L.) plants and the microorganism population in the rhizosphere of this plant. Moreover, the antagonistic effect of rhizosphere fungi on selected carrot fungal pathogens was determined. Laboratory mycological analysis allowed one to determine the qualitative and quantitative composition of fungi colonizing the underground parts of carrot plants. In addition, the total population of fungi and bacteria was determined (including Bacillus sp. and Pseudomonas sp.) based on the microbiological analysis of the rhizosphere soil.

Mary Beth Kirkham hadn’t studied microplastics when she was invited to co-edit a new book about microplastics in the environment—but something stood out to her about the existing research.

“I had read in the literature that . . . cadmium and other toxic trace elements [are] increased when we have these particulate plastics in the soil. So, that was of concern to me,” said Kirkham, a plant physiologist and distinguished professor of agronomy at Kansas State University.

Kirkham’s expertise is in water and plant relations and heavy metal uptake, so she decided to conduct her own research in which she cultivated wheat plants exposed to microplastics, cadmium, and both microplastics and cadmium. Then she compared these plants to those grown without either additive. She chose cadmium because it’s poisonous, carcinogenic, and ubiquitous in the environment due to human activity—it’s shed from batteries and car tires, and is naturally found in the phosphate rock used to make agricultural fertilizers.

The use of microorganisms for biological pest control as biological control agents (BCAs) and biopesticides was developed worldwide in the 1960s. Despite the abundance of reviews published on this topic, no meta-analysis using bibliometric tools has been published. The objective of a new study was to…

A research project developed by Ideagro to reduce the application of fertilizers in agriculture through the contribution of microorganisms is obtaining important results in melon, tomato, broccoli, apricot, and citrus crops in an experimental farm located in the Murcian district of Yechar. The Minister…

When looking at possible sources of contamination, far less attention has been put on produce distribution centers (DCs). “I think the DCs are a little out of sight, out of mind,” said Laurel Dunn, Ph.D., assistant professor in the department of food science & technology at the University of Georgia in a release from the Center for Produce Safety (CPS). “We have been so focused on foodborne outbreaks and what’s happening at the field level or packinghouse wash water and employees and hand hygiene.” As such, in an announcement from CPS, Dunn discusses a project that seeks to understand the contamination issues happening at the DC level, namely vented produce in breathable containers or stored in coolers. Examples of the items being examined are berries, tomatoes, and onions in mesh bags.