Valentina Constanta Tudor, Paula Stoicea, Irina-Adriana Chiurciu, Elena Soare, Adina Magdalena Iorga, Toma Adrian Dinu, Livia David, Marius Mihai Micu, Dragos Ion Smedescu, and Eduard Alexandru Dumitru
The aspects highlighted in this paper refer to the application of fertilizers and plant protection products to the wheat crop, and their impact on total production, competitiveness in export markets, price optimization as a result of increased harvest quality, and not least row, ensuring farmers’ incomes. The present analysis concerned the areas cultivated with wheat, and the productions achieved in relation to the quantities of fertilizers and protection products used in wheat cultivation, in Romania, Germany, Spain, France, Italy, Hungary, Poland and the UK. The analysis highlighted that, the average productions are influenced both by the technology used, by the fertilization and treatments applied, as well as by other synergistic factors that intervene in wheat crops. In countries such as Spain and Italy, the correlation between the amounts of N (nitrogen), P2O5 (phosphorus), K2O (potassium) and the average production of wheat is insignificant, but in Romania and Hungary, there is a strong, direct connection between the number of fertilizers used and the average wheat crop yield. In Romania and Hungary, there is a very significant connection, but the production link average with pesticides is negative, while in Germany, the correlation is direct and quite intense for all types of fertilizers used, while the use of pesticides has a lower influence on average wheat production. In this study, we also applied a multiple regression model; in which the dependent variable was the average yield of wheat per ha and the independent variables were the average quantity of pesticides and fertilizers used. We used the “t Stat” values for each coefficient to determine whether the coefficient is equal to zero; where a high value of “t Stat”, greater than 2; indicates the fact that the coefficient is significantly different from the value zero. The “p-value” for each coefficient indicates the probability that the coefficient has the value zero. A value below the significance level of 5% results in a coefficient significantly different from zero and with an impact on the dependent variable. The use of fertilizers on wheat crops has a synergistic effect as shown by the multiple linear regression analysis which demonstrated a strong direct relationship, particularly with the amount of N, K2O and P2O5 applied.