Hydrogel film developed for medical use is utilized in agriculture for the first time in the world. This ImecTM film allows only water and nutrients to pass through to the plants while eliminating bacteria and viruses, thus reducing the use of pesticides. Since water in hydrogel is difficult for plants to absorb, plants produce more sugar and amino acids as they try to absorb water in this hydrogel by increasing osmotic pressure. As a result, for example, sweet and tasty tomatoes can be produced.