Leaching of nitrogen, phosphorus and potassium and EC changes in soil under the conditions of zucchini fertigation

Assen Nikolov, Vesselin Koutev

Резюме: Knowledge of nutrient movement in the soil is essential to offer fertilizer management that allows them to locate at the depth of maximum root densities of plants. In this way, the efficiency of the fertigation is improved, reducing the possibility of groundwater contamination by leaching the nutrients.
In this study nitrogen fertilizer was applied as ammonium nitrate. Phosphorus is applied in the form of orthophosphates and polyphosphates. Potassium is applied as part of complex fertilizers containing phosphorus and potassium sulfate.
In all treatments, the nitrogen leaching is due to the movement of water from irrigation and to the wetting front (side and down) with increased concentration of nitrogen. The granules of the polyphosphate fertilizer have a special coating that protects the phosphorus from them from rapidly dissolving and fixing it in the soil. This is a prerequisite for the higher phosphorus concentration at the end of the growing season. Its delayed dissolution continues and its absorption by plants is negligible. The effect of this coating is similar to that of potassium imported with polyphosphate fertilizer. The use of the EС as an indicator gives us a good idea of the movement of nutrients in the soil and can be used in practice.

Ключови думи: fertigation; nitrogen; nutrients leaching; phosphorus; potassium; soil; soil electro conductivity

Дата на публикуване: 2020-06-01