Long Term Experiment Platform (LTEP) to establish the effectiveness of biochar applications: a case study in vineyards at Tebano, Ravenna, Italy.

In the recent years many papers explored the potentiality of biochar as soil improver as for water retention capacity and chemical and biological fertility. Many of these studies are 1-2 years lab-scale to study the biochar short term effects.

Although is well known that the behavior of biochar in soil changes with the progress of time, few are the open-field 5 years longer experiments which we propose to consider as Long Term Experiments (LTE). Furthermore the few current LTE experiments repeat the same experimental design, changing every time biochar (feedstocks and pyrolysis parameters), soil type and crop.

In this context, there is an evident need for a common platform where assembling information e where new experiments can be designed to progress and demonstrate biochar effectiveness.

The ICHAR (the Italian Biochar Association) and the University of Bologna - CIRSA Department are launching a Long-Term Experiment Platform (LTEP) aiming to be the house for all the Italian LTE for agronomic applications of the biochar. The LTEP is currently based on data from more than 15 experiments in Italy, looking for include also other European trials and it is preparing an identity card with a) a description of the project and its objectives, b) site description, c) tested biochar and substrates, d) published results, e) a working group description.

As an example of application and identity card, we present the experiment started in Tebano during 2019. Differently from the other operating LTEs, it brought biochar in a new vineyard field, amending soil before the shoot transplanting and just in proximity of the rows, exactly at root depth. The applied biochar has been produced by local the vineyard pruning residues with the purpose to establish a closed circular pattern in grape cultivation. Biochar was applied to soil as such and blended with a fertilizing sludge-based compost, produced by a company owned by a winery cooperative.  The compost, labelled as ACFa in accordance to the Italian legislation, is obtained mixing ligno-cellulosic biomass and centrifuged-sludge from digestate from anaerobic digestion plants, in a ratio 6:4, respectively. Biochar as such and 3 blends were distributed, four replica each one, in a randomized design experiment. Each of the 20 treated parcels includes 15 grape plants. Soil characterization, before the amending and yearly at the end of the growing season is planned. Plant biomass, leaf nutrient content, quantity and quality of the production of grape and wine will be monitored. Weathering of the amending matrices, especially biochar will be investigated every year. From last summer, 4 stations for continuous monitoring of water content, electrical conductivity and temperature are operating for all the matrices.

The working group involved in the project is multidisciplinary including environmental scientist, chemists, soil experts, agronomic experts, grape and winery expert, as well as personnel of a regional research center for agronomic studies and personnel from the industry and winery cooperative of compost suppliers.