Soybean is one of the most important sources of vegetable protein, having a great agronomic importance by fixing atmospheric nitrogen following symbiosis with bacteria of the genus Rhizobium. Bifactorial experience, of the AxB model A - phosphorus doses: P0; P40; P80; P120; P16 and B - nitrogen doses:N0; N25; N50; N75; N100, aims to identify the influence of these doses on the development of soybean cultivation. Although soybeans are a heavy consumer of nitrogen and phosphorus in the early stages of development, however, they do not react well to large amounts of nitrogen as they prevent the development of the number of nodules on soybean roots and inhibits the growth of bacteria, and the increases obtained production do not justify the higher amount of nitrogen applied to soybeans. The number of pods and the mass of 1000 grains are also influenced more by the application of phosphorus doses than  nitrogen. Phosphorus applied in higher amounts leads to an increase of over 60% of the number of nodules but also at significant production increases of 5-7%, compared to the non-fertilized variant. On nutrient-rich soils, soybeans do not require fertilization with large amounts of nitrogen, but they react very well to the application of phosphorus fertilizers.

Fertilization is a basic technological element of modern agriculture. The complex process of absorption of nutrients is dependent on a number of biotic and abiotic factors and the interaction between them. The research aimed to establish a rational system of fertilization, with low impact on the environment and identifying the optimal fertilization variant, to obtained satisfactory maize yield. The experiment was conducted between 2018-2021 at Agricultural Research and Development Station Turda (ARDS Turda). The experimental factors: factor A - climatic conditions in the experimental years (2018; 2019; 2020; 2021); factor B - nitrogen doses, with five graduations (N<sub<0</sub<; N<sub<50</sub<; N<sub<100</sub<; N<sub<150</sub<; N<sub<200</sub< kg/ha a.s.); factor C - phosphorus doses, with five graduations (P<sub<0</sub<; P<sub<40</sub<; P<sub<80</sub<; P<sub<120</sub<; P<sub<60</sub< kg/ha a.s.). The biological material was represented by Turda 332 hybrid. In addition to the climatic factor, a significant contribution to the increase in maize yield was made by the doses of fertilizers, especially those with nitrogen, the highest yields being recorded in the variants where was applying more than 150 kg/ha a.s. N respectively 120 kg/ha a.s.

Wheat is an essential crop for global food security, and for good development and to achieve satisfactory yields wheat needs favorable climatic conditions and adequate nutritional support. Was executed a bifactorial experience, of the AxB model A - phosphorus doses: P0; P40; P80; P120; P160 and B - nitrogen doses: N0; N30; N60; N90; N120. The research carried out during the period 2020-2022 aimed to determine the optimal doses of the two nutrients for the autumn wheat crop in achieving the most efficient yields. Nitrogen is the factor with the greatest contribution to the formation of yield, an amount of 30 kg/ha s.a. can bring an increase in yield of 22%, growth that decreases with the additional application of others 30 kg/ha s.a. N. Phosphorus has a lower contribution to yield, as a unilateral factor, but it is important in plant nutrition, especially as a support for nitrogen.

The study was conducted in the experiments with long-term fertilizers in non-irrigation conditions in 2016 and 2021. The experiments were based on the two-factor subdivision method. Factor A doses of Nitrogen and Phosphorus N0P0, N60P40, N60P80 and N120P80 respectively factor B Potassium doses K0, K40, K80 and K120. Fertilizers were applied in the fall under the plow and in the spring. The average monthly temperature was higher in April, June and July for 2016 and June and July in 2021, compared to the 65-year average. The average values ​​of monthly precipitation were higher in 2016 during the vegetation period, and in 2021 they were higher in May and July, reduced in April and June compared to the average for 65 years. Following the obtained results, the production indicators were analyzed under the action of applying nitrogen, phosphorus and potassium fertilizers, respectively the obtained crop increase.

Climate change has become the biggest global challenge to agriculture and food production. In the context of current environmental changes, the aim of this study is to identify the optimal sowing season that leads to obtaining high and constant yields. The study followed the reaction of 7 native maize hybrids to cultivation in 3 different sowing seasons, over a period of 3 years. The data obtained show us that the best yield results are obtained on mid-early hybrids (9327- 9843 kg/ha). Sowing maize too early, are obtained lower yields than for maize sown at 10ºC in the soil, with a very significant difference of 1337 kg/ha. Favorable climatic conditions in 2020 and 2021 emerge from the average yields obtained in the two years, 10343 kg/ha (2020) respectively 9424 kg/ha (2021). The climatic conditions of 2022 were less favorable, summer drought having a negative effect on average maize yield, which was 6924 kg/ha.