Fertilizzanti Certaldo, since 1931 it has been producing specialized organic-mineral fertilizers starting from a valuable organic matrix, enhancing the potential of the nutritional elements, protecting them from losses and guaranteeing a high agronomic yield
Engineer Luigi Petralli, please tell us about Fertilizzanti Certaldo and your involvement with the world of leather. Fertilizzanti Certaldo was founded in Certaldo, a town near Florence (Italy), around the 1920s as a bone superphosphate factory. It used to be an artisanal factory, as it still is in many ways, but today it has also become one of the most advanced European companies in our sector. Our raw material is leather processing scraps which are classified as waste: we must therefore make a careful selection of the hides in order to obtain a high-quality fertilizer. For this reason, we have been looking for leathers that are as natural as possible, that is, leathers that have not been tanned and finished with a high concentration of chemical products that modify the structure and make it different. Tanned leathers, of course, because we need a stable product over time; but real leather, not the so-called ecological and synthetic “leathers” based on plastic! True and natural, also because our finished product must then comply with the requirements imposed by the Italian Legislative Decree n. 75 of 2010 on fertilizers which ensures that the final product is not dangerous to humans or the environment.
How did the collaboration with Silvateam begin? We needed a waste material that could comply with the legal requirements, but that could also help transform our fertilizer into an excellent product: a quality, safe material. Ecotan leathers tanned with natural tannins fit the bill perfectly.
How does Ecotan leather help you to obtain an excellent fertilizer? We hydrolyse waste from leather processing, i.e. through sulfuric acid we degrade the hide collagen into polypeptide chains and amino acids. The result is a very dense liquid, to which micronutrients such as nitrogen and phosphorus must be added. Eventually, we get a substance, the fertilizer, which is easily digested by the microorganisms present in the soil, increasing the availability of the nutrients necessary for plant growth: this quality can easily be obtained from Ecotan leather scraps.