Adaptation of phosphate fertilization strategies

Contents and goals

The goal of this trial is to investigate the long-term effects of different phosphate fertilization strategies in combination with minimum tillage on agricultural crops. The focus is on yield, quality, soil fertility and sustainability, which raises the following questions:

• Is the common fertilization strategy of "fertilizing from A/B to C" still justified?

• Can the efficiency of phosphate fertilization on phosphate-poor soils be increased by specifically placing the fertilizer in depositories?

• What effects does fertilizer placement have on the development of plant health and yield-forming parameters?

To investigate these questions, seven fertilization variants, each with four repetitions, were compared in the farm's crop rotation.

These include fertilization according to the guide value with TSP, fertilization according to calculated P removal with TSP and the unfertilised control variant. All three fertiliser variants are used at two tillage depths. In addition, fertilisation after calculated P removal with DAP, as contact fertilisation with the seed for crops without nitrogenous fertilisation in autumn, is also being investigated.  

Task of the DLG

The DLG organises this trial with experts from DLG committees such as the Committee for Plant Nutrition and is responsible for the planning, implementation and evaluation of the phosphate fertilisation trial in the field. This includes the complete inventory management of the individual crops, including assessments and soil analyses, as well as economic analyses.