Do you expect the same yield in every part of your field? No?

Then it would also make sense to take this into account in the fertilization!

Hardly any field is homogeneous. Usually, there are areas within the plots that have different growth potentials due to variations in the emergence conditions, for example due to other soil properties. A classic example is variations in the water-holding capacity of the soil. Sandy or gravelly areas within the field come under drought stress much earlier in warm summer days than the loamy areas in the immediate vicinity. Where the grain stand was still wonderfully even and strong in May, there are often clear differences during the maturity stage. In some places, the plants cannot develop their full potential because the growing conditions do not allow it. Every kilogram of nitrogen that is not absorbed by the plants burden the groundwater and the environment. But also the farmer’s wallet! This is all the more problematic when the amount of fertilizer that can be applied is limited by legal requirements anyway. If fertilizer is applied evenly to a heterogeneous area and the amount is based on the average expected yield, poor areas in the field will inevitably be overfertilized, while good areas with above-average yield potential will be under fertilized. This not only means a loss of efficiency in the respective crop year and a burden on the environment, but actually lowers the expected yields in the long term. High-yield areas are regularly undersupplied, but the low-yield areas cannot compensate for this by applying too much fertilizer.

The TalkingFields® NManager products for site-specific fertilization provide you with information on how to optimally distribute the available fertilizer quantity in the area for each fertilization application. There are products adapted for different crops, which take into account the respective special features. For each of these products, we supply you with the N requirement in 10x10m on time for the planned fertilizer application. You can then offset this N requirement against the fertilizer of your choice and apply it with suitable technology on a site-specific basis.

The TalkingFields® NManager product range

The basic product for site-specific N fertilization is the TalkingFields® NManager. This provides a once-a-year N distribution map based on satellite data from previous years. This product is suitable for crops that are fertilized only once during the growing season, such as corn and sugar beets. The natural variation of growth potentials within the area is used to distribute the fertilizer application in an optimized way in the area. The maximum permissible amount of fertilizer according to DÜV (Düngeverordnung; fertilization ordinance)  is taken into account when creating the product.

Cereal crops are usually fertilized several times within a growing season. TalkingFields® NManager Pro was developed for these significantly more complex crops. For each upcoming fertilizer application, an up-to-date distribution map is delivered a few days before the planned fertilizer application, which precisely maps the current N requirement of the crop. The product takes into account both the current emergence in the field and the expected development of the crop, derived from analyses of satellite data from previous years. This so-called map overlay procedure combines all available information about the crop stand to make the best decision (see also: Maidl et al., Teilflächenspezifische Stickstoffdüngung, Getreidemagazin 3/2012). In this way, site characteristics that influence maturity, and thus yield formation, can be factored in. In addition to the optimized spatial distribution of the fertilizer in the area, an assessment is made as to whether the target yield assumed during fertilizer planning will be achieved in the respective year. If the analysis of the current data shows that the crop will develop significantly better or worse in the respective year, the total fertilizer quantity is adjusted if necessary. The maximum permissible fertilizer quantity according to DÜV is carried along during the entire growing season and, of course, taken into account in every fertilizer requirement calculation.

For the special case of canola, the TalkingFields® product portfolio includes the TalkingFields® NManager Pro Canola solution. As with cereals, both the current development of the crop at the time of fertilizer application and the expected development are taken into account for canola. Satellite data also provide information in winter, so that the current N uptake is taken into account for canola fertilization in spring. A recommendation for the division of the fertilizer application into 2 applications, as well as their weighting, is also provided.

With the TalkingFields NManager products you can therefore for the most diverse cultures:

• plan an optimal nutrient supply for your crops
• optimize the use of fertilizers and thereby
• maximize yields on fertile subplots in an environmentally compatible manner
• while at all times observing the legal requirements according to DÜV.

Prescription Maps using the Map-Overlay Approach

Various scientific studies and practical trials have shown that a combination of long-term yield potential and the current development and supply status of the crop leads to the best results in site-specific nitrogen fertilization. This is called the map overlay approach. By extracting long-term biomass patterns from archive data (TalkingFields Base Map / TalkingFields Yield Potential Map) and calculating the current biomass status with current satellite data and a growth model (TalkingFields Biomass Map), TalkingFields’ methods make it possible to build the map overlay approach on one uniform, comprehensive data source.