The use of composts promotes plant growth and physiology as a promising sustainable strategy. The main objective of this study is to evaluate the impact of phosphate flotation waste (PFW) and phosphogypsum (PPG) composts on the growth and physiology of tomato plants under two water regimes (40% field capacity (FC) and 80% FC). The experiment was conducted under controlled conditions using eight treatments: Control80%, Control40%, PFW80%, PFW40%, PPG80%, PPG40%, PFW + PPG80%, PFW + PPG40%. The results showed that the application of PFW and PPG composts alone and/or combined improved growth parameters as well as fresh and dry matter and physiology of tomato plants under 80 and 40% FC. When PFW and PPG were applied together in addition to the cactus, the growth parameters favour a significant increase due to the regular supply of mineral nutrients, the modification of the soil texture and most importantly their water-holding abilities, due to the clay composition of PFW. The results demonstrate the potential of PFW and PPG composts for improving and optimizing of soil fertility and crop productivity under water stress conditions. These organic amendments could be an efficient practice to improve growth and biological agriculture of tomato production.
