Abstract
This study explores the potential use of frass, the larval excrement residue obtained from mealworm rearing, as organic fertilizer for crops. Its high organic matter content means that its joint application with a biostimulant based on efficient microorganisms, favoring its mineralization, is of interest. An experiment with lettuce plants (Lactuca sativa L.) was conducted with two factors and six replicates under greenhouse conditions. The first factor was frass amendment at 0%, 1%, 2.5%, and 5% of the peat substrate, and the second factor was a Bacillus-based BS at two levels, with and without efficient microorganism application. The results reveal that frass shows great potential as an organic fertilizer, providing macronutrients and increasing lettuce aerial biomass, although its effect is mediated by the application rate. Rates of 2.5% or higher proved negative for lettuce plant growth, especially root development, probably due to an increased incidence of potentially pathogenic fungi. The negative effect of medium–high frass rates was counteracted by the addition of a PGP-based biostimulant, enhancing lettuce plant nutrient uptake, aerial biomass, and quality in terms of succulence, but also favoring microbial diversity in the rhizosphere, increasing the incidence of beneficial microorganisms, and decreasing potentially pathogenic fungi. This positive synergy observed between frass and the PGP-based biostimulant is of interest for the design of new organic fertilization strategies.
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Claims 6
Claim · model-written summary
Frass supplied macronutrients and increased lettuce aerial biomass, depending on rate.
- Taxon
- lettuce
Lactuca sativae0 - Treatment
- frasse0
- Outcome
- aerial biomasse0
- Direction
- increasinge0
- Qualifier
- mediated by the application ratee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“frass shows great potential as an organic fertilizer, providing macronutrients and increasing lettuce aerial biomass, although its effect is mediated by the application rate.”
Claim · model-written summary
Frass rates of 2.5% or higher impaired lettuce growth, especially root development.
- Taxon
- lettuceLactuca sativae0
- Treatment
- Rates of 2.5% or highere0
- Interactor
- potentially pathogenic fungie0pathogen
- Outcome
- plant growth, especially root developmente0
- Direction
- negativee0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Rates of 2.5% or higher proved negative for lettuce plant growth, especially root development, probably due to an increased incidence of potentially pathogenic fungi.”
Claim · model-written summary
Adding a PGP-based biostimulant counteracted the adverse effect of medium to high frass rates.
- Taxon
- LettuceLactuca sativat0
- Treatment
- addition of a PGP-based biostimulante0
- Outcome
- negative effecte0
- Direction
- counteractede0
- Comparator
- medium–high frass ratese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The negative effect of medium–high frass rates was counteracted by the addition of a PGP-based biostimulant”
t0“Lettuce Plants”
Claim · model-written summary
The biostimulant enhanced lettuce nutrient uptake, aerial biomass, and succulence.
- Taxon
- lettuceLactuca sativae0
- Treatment
- PGP-based biostimulante1
- Outcome
- nutrient uptake, aerial biomass, and quality in terms of succulencee0
- Direction
- enhancinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“enhancing lettuce plant nutrient uptake, aerial biomass, and quality in terms of succulence”
e1“addition of a PGP-based biostimulant”
Claim · model-written summary
The biostimulant increased rhizosphere microbial diversity and beneficial microorganisms.
- Taxon
- LettuceLactuca sativat0
- Treatment
- PGP-based biostimulante1
- Interactor
- beneficial microorganismse0symbiont
- Outcome
- microbial diversity in the rhizosphere, increasing the incidence of beneficial microorganismse0
- Direction
- increasinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“favoring microbial diversity in the rhizosphere, increasing the incidence of beneficial microorganisms”
e1“addition of a PGP-based biostimulant”
t0“Lettuce Plants”
Claim · model-written summary
The biostimulant decreased potentially pathogenic fungi.
- Taxon
- LettuceLactuca sativat0
- Treatment
- PGP-based biostimulante1
- Interactor
- potentially pathogenic fungie0pathogen
- Outcome
- potentially pathogenic fungie0
- Direction
- decreasinge0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“decreasing potentially pathogenic fungi”
e1“addition of a PGP-based biostimulant”
t0“Lettuce Plants”
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See all 9 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.