MINERAL FERTILIZATION BY APPLYING OPTIMUM NITROGEN DOSES AT FARM LEVEL

An important measure included in the Code of Agricultural Practices is related to the standards on maximum quantities of nitrogen fertilizers which may be applied on agricultural lands in order to prevent or reduce nitrates pollution of water bodies. For this, fertilizer plans at farm level are reccomended to be carried out. The case study is accomplished within a farm located in Ialomita watershed. This paper shows a fertilization plan obtained by using best practices for efficiently nitrogen use at farm level. Different indicators were needed: expected crop yield at farm level, soil indicators and coefficients of nitrogen use. As much the difference between applied applied nitrogen and exported nitrogen is lower within the farm, as much the nitrogen use efficiency is higher. In case of wheat, the optimum economic nitrogen dose recommended for obtaining 8000 kg/ha is 138 kg/ha of nitrogen. This dose is correlated with the optimum soil nitrogen supply, plant nitrogen need and the lower risk of nitrogen losses in water bodies