Phosphorus, soil and climate change in a feed production

Grass forage production is in many ways the most important factor behind the sustainable cattle farming. Efficient use of phosphorus plays a large role in improving the profitability of farming and reducing the environmental impacts. The new results of the grass phosphorus fertilization experiments differ significantly from the previous ones: no yield responses were obtained although they were expected based on previous studies. Due to climate warming, the growing season has lengthened, the thermal winter has shortened and the soil temperature has risen. This raises the question of whether the availability of phosphorus has changed, at least for perennial plants. And if so, what causes the phenomenon? Grass breeding has advanced and new grasses are more responsive to nitrogen fertilization. Do they also use phosphorus more efficiently? On the other hand, farmers' concerns about strict limits on phosphorus fertilization and the depletion of the soil's phosphorus resources and animal health have increased. Could plant diagnostics be used to predict phosphorus deficiency in plants? The core idea of the project is to investigate the changes in soil phosphorus availability and dynamics in terms of plant nutrition and water pollution on the most important crops in Finland (grass, barley) in the cattle production area. The research is based on empirical experiments, including long-term field experiments as well as new, novel experimental setups and results synthesis. Based on the results, it is possible to identify under which conditions and what cultivation practices the effects are most pronounced. The results can be utilized in refining fertilization recommendations and developing cultivation techniques, as well as in P-runoff load models, research collaboration, policy decisions and communicating the environmental impacts of livestock farming