Since 2018, there has been much focus on monitoring and improving nutrient uptake in the Fossil Free Cultivation Tomato Cultivation project in the Netherlands. In the winter, much potassium was offered in the drip water to prevent the plants from wobbling.
That also lets the fruits ripen quickly. Kas als Energiebron (Greenhouse as an Energy Source) reports that the feed needs more potassium when there is less crop evaporation due to lower energy consumption.
In the first four years, when the project growers switched to unlit summer cultivation, they switched to a feeding schedule with less potassium and much more calcium. Magnesium deficiency then sometimes occurred in the leaves, and the calcium content in the young fruits was too low. That led to blossom end rot toward the end of the growing season.
To prevent that, initially, the EC was increased to stimulate nutrient uptake. That slightly increased the young fruits' calcium content, but the harvested fruits had far higher dry matter content. That resulted in lost production.
Nutrient uptake
Based on the winter experience, a different feeding strategy was chosen this year. It was also decided to give more potassium in the summer than in previous years. Potassium is key to nutrient and mineral distribution in the plant. If there is too little potassium, the young leaves and fruit have more dry matter. Mineral levels, including calcium, decrease in the process.
You can read the full article here at Kas als Energiebron.
