TWO FORMS OF PHOSPHORUS IN PLANT NUTRITION
The use of phosphorus-containing fertilizers in agriculture is a long-proven fact and raises no doubts. This includes the use of phosphorus fertilizers in foliar nutrition, which is effective for all crops.
The question of using phosphorus in the form of phosphite as a plant fertilizer remains topical. Phosphites have different properties compared with phosphates. Fertilizers of this type contain the phosphite ion, which has one oxygen atom fewer than the phosphate ion, which makes it mobile, and it moves easily in plants and soil. Most researchers have concluded that phosphites show a fungicidal effect, act as growth stimulators for plants and reduce signs of phosphorus shortage (Tambascio et al. (2014).
Main differences between phosphates and phosphites
| PHOSPHATE | PHOSPHITE |
| Main purpose | |
| Source of phosphorus | Fungicide |
| Biostimulant | |
| Anti-stress agent | |
| After conversion in cells becomes a source of phosphorus | |
| Uptake temperature | |
| ≥+15 °C | ≥+5 °C |
| Speed of uptake through the leaf surface | |
| From several days to several weeks | Up to 24 hours |
| Interaction with other nutrients | |
| Interacts with Ca+3, Fe+3, Al+3, forming poorly available forms of these elements | No formation of poorly available forms has been established in interaction with Ca+3, Fe+3, Al+3 |
| Effect on plants | |
| Stimulates root system growth | Stimulates root system growth |
| Raises yield and harvest quality | Chlorophyll formation |
| Brings plants out of stress | |
| Raises yield and harvest quality | |
| Promotes nitrogen uptake at low temperatures (≥+5 °C) | |