Floating cultivation can be used to plant aquatic or hygrophytic plants on water surfaces such as reservoirs and lakes (because these plants are resistant to rhizosphere hypoxia). Floating culture is generally used in eutrophic or polluted ponds and lakes, which can repair polluted water bodies and beautify the water surface. Aquatic vegetables such as water spinach and watercress can also be cultivated in this way. The problem is that the nutrient content in natural water is not enough to meet the demand of rapid growth of vegetables, so the vegetables planted in this way are estimated to grow slowly and have low yield, and it is very likely that the normal growth will be affected because of insufficient nutrients. You can dig several grooves in the flat wasteland, spread a film, and add nutrient solution to it. This relatively simple method can be used to hydroponic vegetables. At the same time, rain protection is also a problem (preventing rainwater from flowing into the culture tank dilutes the concentration of nutrient solution). I recommend you to go to the learning website of Soilless Culture Technology Laboratory of South China Agricultural University-Principles and Techniques of Soilless Culture, where there is a column "Step-by-Step Tutorial" to have a systematic understanding of related technologies. Website: jpkc/ soilless/index.asp.