Biochar as biofertilizer

Biochar application as biofertilizer in agriculture provides multiple advantages, such as enhancing soil quality, boosting crop productivity, and mitigating climate change. Biochar is rich in stable carbon and essential nutrients, and improves soil features as water retention, aeration, and nutrients’ availability. This reduces the need for chemical fertilizers and helps sequester carbon in the soil. When made from agricultural waste, biochar reduces waste and supports the circular economy by transforming waste materials into valuable resources, promoting a more sustainable agriculture. In this study, the effect of biochar on the growth and development of strawberry plants was evaluated. Strawberry plants sprouts were rooted in commercial garden soil supplemented with biochar produced via pyrolysis of soft wood at 550°C. Biochar was dosed according to literature (2-12 tons/ha) involving 12 pots supplemented with biochar and 3 control (i.e. no biochar) pots placed in a lab-scale greenhouse. Biochar was applied unaltered and after physical activation with CO2 at 900°C. The growth and productivity of the plants was monitored for 3 months, recording plant height, number of flowers, and number of ripe fruits twice per week, and through continuous remote sensing. Specifically, a low-cost automated proximal sensor system was installed in the greenhouse to monitor the micro-climate and plant development. The system includes a MAPIR Survey 3W multispectral camera, a DHT22 temperature and humidity sensor, and five capacitive soil moisture sensors. The sensors were integrated using a Raspberry Pi 4 for data collection and storage. The 12 MP camera captured three spectral bands (550nm, 660nm, 850nm) with an 87° field of view and was positioned to capture all plants in one nadir image. Images were taken hourly, recording red, green, and near-infrared (RGN) spectral data, which allows for the calculation of vegetation indices (VIs) like the Normalized Difference Vegetation Index (NDVI) to estimate plant health. The correlation between NDVI and the biochar dose was investigated. The average height of the plants supplemented with biochar was 16.35 ± 2.05 cm, with activated biochar was 16.3 ± 1.75 cm, and for the control group was 11.1 ± 1.30 cm. During the first month +17% net plant height was observed in the pots supplemented with biochar, but no significant difference was noticed between activated biochar and unaltered biochar (Figure 1). In terms of number of flowers and ripe fruits, the plants treated with biochar were 15 days beforehand when compared to control plants. Again, no evident difference was visible between activated and unaltered biochar. This study was carried out within the Agritech National Research Center and received funding from the European Union Next-GenerationEU (PIANO NAZIONALE DI RIPRESA E RESILIENZA (PNRR) – MISSIONE 4 COMPONENTE 2, INVESTIMENTO 1.4 – D.D. 1032 17/06/2022, CN00000022).