Liquid organic amendments and drought: a new study on tomato and lettuce
Regenerative News · Research published on 3 October 2026
A liquid preparation made from organic residues improved tomato and lettuce growth under restricted irrigation in a greenhouse experiment.
What was tested
The researchers grew plants in pots, comparing normal and restricted irrigation, with and without the SEFEL preparation.
The material contained pig slurry, whey, compost, and molasses or sugar. Two formulations were used, enriched respectively with sources of calcium and zinc, or iron and potassium.
How the plants responded
Under restricted irrigation, compared with equivalent plants that received no preparation:
- Tomato leaf dry mass increased by 32.6%.
- Tomato root biomass increased by 53.3%.
- Lettuce leaf dry mass increased by 23%.
Improved nutrient uptake and changes in soil microbial communities were also recorded. These results concern the combined effects of this particular formulation, which brings together organic materials, microorganisms and additional nutrients.
Connection with our field work
At our Center, we produce compost extracts and aerated compost tea, with continuous microscopic monitoring. We are interested in examining how restoring soil microbiology relates to root development and plant responses under limited moisture, following our training at the Soil Food Web School.
Source
Hernández-González and colleagues, Journal of Soil Science and Plant Nutrition, 2026