University of Tehran Press Iranian Journal of Soil and Water Research 2008-479X 56 2 2025 04 21 The effect of phosphate solubilizing fungi, humic acid and phosphorus sources on growth and phosphorus uptake of tomato plant The effect of phosphate solubilizing fungi, humic acid and phosphorus sources on growth and phosphorus uptake of tomato plant 433 444 101778 10.22059/ijswr.2024.384683.669837 FA Safoora Nahidan Department of Soil Sciences and Engineering, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran 0000-0003-0683-9811 Sara Movahed Department of Soil Sciences and Engineering, Faculty of Agriculture, Bu-Ali Sina University, Hamedan, Iran 0009-0004-6077-3344 Journal Article 2024 11 14 The effect of <em>Trichoderma</em> fungus, humic acid and phosphorus sources on soil phosphorus availability and its effect on growth characteristics and phosphorus uptake of tomato plant was investigated in a greenhouse experiment. The experimental factors were 1) fungus (with and without <em>Trichoderma koningii</em>), 2) humic acid (0, 2 and 4 g kg^-1 soil) and 3) phosphorus treatment (without phosphorus, use of three calcium phosphate and simple superphosphate. The highest values of fresh and dry weight of shoots and roots and chlorophyll index of the plant were observed in the treatment of fungus, 4 g kg^-1 of humic acid and the application of simple superphosphate. Fungi inoculation led to increase the amount of root phosphorus uptake in soil treatment of without phosphorus, treated with three calcium phosphate and simple superphosphate by 33.7, 85.9 and 68.8%, respectively. The highest amount of soil available phosphorus and shoot phosphorus uptake was observed in soil treated with fungi, simple superphosphate and 4 g kg^-1 of humic acid, which was 58 and 153% higher than the treatment without fungi, phosphorus and humic acid. In general, the combined use of humic acid, <em>Trichoderma</em> and chemical phosphorus fertilizer can be a suitable solution to increase the availability of soil phosphorus and improve the phosphorus uptake and growth of tomato plant.  The effect of <em>Trichoderma</em> fungus, humic acid and phosphorus sources on soil phosphorus availability and its effect on growth characteristics and phosphorus uptake of tomato plant was investigated in a greenhouse experiment. The experimental factors were 1) fungus (with and without <em>Trichoderma koningii</em>), 2) humic acid (0, 2 and 4 g kg^-1 soil) and 3) phosphorus treatment (without phosphorus, use of three calcium phosphate and simple superphosphate. The highest values of fresh and dry weight of shoots and roots and chlorophyll index of the plant were observed in the treatment of fungus, 4 g kg^-1 of humic acid and the application of simple superphosphate. Fungi inoculation led to increase the amount of root phosphorus uptake in soil treatment of without phosphorus, treated with three calcium phosphate and simple superphosphate by 33.7, 85.9 and 68.8%, respectively. The highest amount of soil available phosphorus and shoot phosphorus uptake was observed in soil treated with fungi, simple superphosphate and 4 g kg^-1 of humic acid, which was 58 and 153% higher than the treatment without fungi, phosphorus and humic acid. In general, the combined use of humic acid, <em>Trichoderma</em> and chemical phosphorus fertilizer can be a suitable solution to increase the availability of soil phosphorus and improve the phosphorus uptake and growth of tomato plant.  https://ijswr.ut.ac.ir/article_101778_4fd26646b79d70faf53251905d2f81e0.pdf