The Soil Heroes Foundation set up a field experiment in the south-western Netherlands to study if and how regenerative practices impact soil health, plant nutrient content, and crop nutritional value. The study investigates the effect of various practices including compost tea and biofertilizer, mulching, companion crops, and lasagne (alternating layers of rock dust, compost, and manure). These regenerative practices are tested on a till and no-till field, and they are compared with a conventional agricultural practise.
The year 2024 was the first full experimental year. In January, chemical and physical soil properties were determined to study the starting position. In summer, plant and crop nutrient content was analysed, and in autumn, soil chemical characteristics were analysed. In this report, we investigate the starting position of the experiment, and the soil, plant, and crop nutrient content after the first experimental year.
The soil analyses of January 2024 indicate that the regenerative field and conventional fields are different in their chemical and physical properties. These differences were expected, because the two fields have a very different management history, but they are relevant to consider for future analyses.
The analyses after the first experimental year show that, for phosphorus (P) and potassium (K), a high supply (with the mulch) increased soil P and K content, while soil P and K content decreased for a treatment with low supply (compost tea + biofertilizer). Soil organic matter content increased, also for the conventional treatment without the supply of organic matter. For most macro- and micronutrients, there were no or minor changes in soil nutrient densities, but no big change was expected after only one year.
The treatments did partly, but not always, impact the leaf nutrient content. With did find a high leaf K content for the mulch treatment with a high supply of K and high soil K content. The yield was lowest for the conventional plots, followed by the regenerative till, and regenerative no-till plots. There was a ten-fold difference in the lowest yield (conventional) and highest yield (no-till, lasagne + compost tea + biofertilizer). The crop nutritional values for macronutrients and vitamins were highest for the conventional treatment. The conventional treatment had the lowest yield, and this might explain the overall high nutrient density.
The results mark the end of the first full experimental year of the regenerative experiment of the Soil Heroes Foundation. The coming years of data and analyses will be very interesting and relevant, to confirm, and further explain, the preliminary results that were presented here.