FIGURE 5.

Proposed pattern of phosphate release from mineral fertilizer and dried algae biomass. The initial P bars represent the amount initially added in Schreiber et al., 2018 with either dried algae biomass (A) or mineral fertilizer (B). The figure states our hypothesis on how algal biomass will release phosphate from different bound forms (A), including inorganic P, organically bound P and polyphosphates. The algae biomass will release its nutrients close to the roots or in abundance of microbial activity. The plants will take up inorganic portions first (upper left, DAS 30), then facilitate the release of phosphates from organic forms (upper right, DAS 55) and then the polyphosphates. The uptake from mineral fertilizer (B) will be less complicated, inorganic phosphate will be taken up, as soon as it is close to the root (upper left, DAS 30) and therefore completely taken up faster (upper right, DAS 55). The amounts of different P forms are estimated from literature Feng et al., 2016.