Evaluating hydrogels for agriforestry applications

Hydrogels synthesised by inverse suspension polymerisation (ISP) technique consisting of acrylamide and potassium acrylate interlinked with N, N’ methylene-bis-acrylamide and presenting different behavior in terms of rooting ability and speed, elastic module and release properties were studied. Markedly clayey soil properties were modified by drawing up moisture-retention curves using ceramic plate pressure waves and developing montages for evaluating modifications made to their retention, regarding prolonged and instantaneous irrigation-water dosage conditions. Acacia and radish crops were grown in nursery phase in soil conditioned with different hydrogels. Delayed specie withering was simultaneously evaluated in the first crop and difference in growth in the second one. Follow-up of in situ soil moisture content was also evaluated over a fixed period of time. A method was achieved for measuring elastic module and release properties and model was established for predicting hydrogel behavior in soil having known basic properties in free state. The results revealed the usefulness of hydrogels in such applications: greater facility in usable water release and retention by soil, notable delay in withering in hostile conditions and greater growth of species. Guidelines were also established for defining the characteristics of hydrogel more adequately, depending on the desired application and a projection was made concerning reducing water consumption for maintaining a particular crop.