Coating of fertilizers by degradable polymers

The conventional agriculture leads to some important pollution of ground water (particularly, by nitrates). The solution is the coating of fertilizers by degradable polymers. In this work, we have studied the water vapour and liquid diffusion through polymer films detached from their support. Therefore, we may classify polymers as a function of their properties like water vapour and liquid barrier. We may choose the best polymer(s) for coating. coated fertilizers by chosen polymer(s) with mechanical techniques such as fluidised bed and pan coating. Moreover, the electron microscopy used to see the quality of the wall has showed the presence of pores due to the rapid evaporation of solvent. A drying in air current and an annealing could be done to avoid this problem. followed the ions release of fertilizers immersed in distilled water by conductimetry. The more interesting result was obtained with fertilizers coated by polylactic acid. In effect, the total release reached three weeks. (C) 2002 Elsevier Science B.V. All rights reserved.