Quality in practice

These management strategies are key to ensure high returns by optimizing quality. 

What needs to be checked?

Optimum N-efficiency

Nitrogen uptake

Yield expectations reach a ceiling at the agronomic optimum and increasing nitrogen supply further will not improve yield, as shown by the nitrogen response curves. Nitrogen absorption and protein content, however, continue to increase linearly even beyond the agronomic optimum. This relation is shown in the graph. Limiting nitrogen supply therefore has a strong effect on protein, but less so on yielf. The question therefore arises how to manage quality and thus protein content under the increasing economical and environmental pressure that limits nitrogen use.

Split application

Split application has been established as best agricultural practice since the early 90s. It enables improved matching of nitrogen supply with actual plant needs and absorption capacities and therefore enhances nitrogen use efficiency. Splitting nitrogen fertilization into 3 or 4 applications increases protein levels and yield as compared to single or dual application. For the same reason it reduces residual nitrogen in the soil after harvest and thus reduces the risk of leaching.

Late application

Special attention needs to be paid to the last (3rd or 4th) application. this shall be timed when absorption is highest. The nitrogen is then stocked in the organs involved in active growth, close to the ear. It therefore contributes to an efficient nitrogen transfer into the grains. the graph compares impact of application timing on yield and protein content.

Sulfur fertilization

Sulfur increases quality

Sulfur is key when it comes to fertilization strategies that target highest quality. Without sulfur, crops can't reach their full potential in terms of yield, quality or protein content. The graph shows the result of field trials in Germany for different scenarios. Yield and protein content were compared for mean and high nitrogen intensity strategies. The results show the potential of sulfur in high value cropping strategies.

Checklist for protein content 

• Select appropriate wheat variety 
• Use high efficiency nitrogen form 
• Measure and address sulfur needs 
• Account for in-field variations 
• Plan for late application

Adequate timing

Precision farming

Increasing protein by late application of nitrogen requires a fine adjustment of the last application. Precision farming tools such as the N-Tester or the N-Sensor® reliably detect the nitrogen status of plants. They enable a tailored application and compensation for in-field variations of nitrogen needs. Accounting for such in-field vasriations significantly increases overall nitrogen use efficiency and thus protein content while maintaining the same nitrogen balance for the entire field.

Proven results

Field trials have demonstrated the capacity of the N-Tester and N-Sensor® to enhance protein content and yield as compared to standard nitrogen balances. Using the N-tester in a field trial conducted by Arvalis in France increased protein content by 0.3% and yield by 1.2 dt/ha while the overall nitrogen application rate remains the same.

Adequate N-source

Avoiding losses 

Urea and UAN are known to produce higher volatization losses than nitrate fertilizers. To reach the same protein content and yield, significantly higher amounts of nitrogen need to be spread as Urea or UAN than as ammonium nitrate. This, however, is in contradiction with high protein strategies that try to maximize nitrogen use efficiency. In addition, losses with Urea and UAN are hard to predict. It is therefore particularly difficult to fine-tune the critical last application with Urea or UAN. Many studies have demonstrated the superior performance of nitrate-based fertilizers as compared to ureic fertilizers with regard to both yield and quality of produced crops.