Proper plant nutrition that takes into consideration both the requirements of plants and ecological conditions is one of the most important precondition of successful plant production. An important element of the N-fertilization of wheat is that the optimum zone of nitrogen supply is significantly narrower than that of other plant species, ther...efore it can easily happen that we apply higher or lower nitrogen doses than the optimal one. A possible solution to this problem can be precision agriculture. Applying the methods of precision agriculture we can take into consideration the heterogeneity of fields. By applying precision methods either online or offline we can intervene faster than if we would rely only on regular soil and plant analysis procedures. The determination of the doses of nitrogen and the timing of application are influenced also environmental and
economic aspects. The chlorophyll content of the leaves indicates the nitrogen status of plants, since there is a relationship between the nitrogen content and the amount of chlorophyll in the leaves. According to plant analysis results there was a strong and significant relationship between the values of the NDVI (Normalized Difference Vegetation Index)and the total nitrogen content measured in the leaves.
The authors have been carrying out stand evaluation, crop estimation and yield analysis in winter wheat since 2012. The sampling areas were assigned at the fields of the Training Farm of the Faculty of Agricultural and Food Sciences of Széchenyi István University Mosonmagyaróvár according to the structure of the cropping system. According t...o their observations the value of field emergence is always lower than the laboratory germination. The weak emergence is important because the lower plant density cannot be compensated by the increased tillering in spite of having larger plant growth space. It is proven by the fact that they detected strong productive tillering even at 5 and 10 mm plant spacing while there were single-spiked plants at 40-50 mm plant spacing as well. The analysis revealed that the total ear mass and grain mass of wheat plants bearing two or more ears is almost the double than that of the single-spiked plants. It was a further basic experience that the largest ear of ”multiple-spiked” plants is always heavier than the single ear of one-spiked plants. Plants with intense tillering and more ears demonstrate the importance of proper seedbed preparation and drilling and the significance of sowing good quality seeds. These are the factors that determine field germination and emergence, influence the speed and intensity of initial development and by all these factors the sufficient productive tillering. The authors emphasize the use of exact and objective methods at crop estimation, e.g. the relationship between the ear mass and the yield which is in strong correlation whilst ear length and grain mass are not suitable for a precise estimation. The authors conclude that crop estimation and yield analysis must be inevitable tools of modern crop production and will be particularly important in precision agriculture. These tools also qualify the job done by farmers and helps to identify the areas that require special attention.