Prove preliminari di gesso di defecazione su colture agrarie: effetti su alcuni parametri del suolo

[Autom. eng. transl.] The aim of the work was to evaluate the possible fertilizing actions, with a view to a sustainable management of agricultural soil, of a defecation gypsum (commercial name biosulfate) produced starting from sewage sludge tomato processing plant on two lands, one clay loam of medium-good fertility, hosting the wheat cultivation in the Piacenza plains and the other Franco-sandy area poor in organic matter located in the lodigiano hosting maize. In the clay-loamy soil the plasters have contrasted a natural tendency to acidification due to the use of traditional fertilizers; have maintained and increased the organic substance content, keeping discrete C / N ratio values. From an environmental point of view the use of gypsum has allowed to reduce the values of nitrate concentrations in the soil, showing that all the nitrogen they have added has been completely absorbed by the crop. In the sand-free soil the use of gypsum has contrasted a natural tendency of this soil to alkalinization under cultivation of corn and tomato; has allowed a lower reduction of the content of Ntot and Ctot occurred for the traditional thesis and has produced a significant drop in the share of nitrate concentrations, resulting in being environmentally sustainable.