Phosphorus (P) and potassium (K) inputs on grassland aim to maintain an appropriate botanical composition and to produce sufficient quantities of forage without harming the environment. Over a 13-year period, eight different levels of P and K fertilisation were applied on a low-intensive permanent grassland in the Swiss Jura. Rising inputs of P (between 0 and 26 kg P/ha/year) and K (between 0 and 116 kg K/ha/year) improved the availability of these elements in the soil. PK fertilisation had little influence on the botanical composition, but a significant and positive effect on the quantity of forage from the tenth year onwards. P and K content of the forage increased substantially with increasing inputs of these two elements. Based on the soil P content, the botanical composition, the quantity of forage and its P content, the annual P balance (inputs-removal) and the P nutrition index (PNI), an annual input between 9 and 17 kg P/ha/year can be considered as optimal for this type of grassland producing around 45 dt DM/ ha/year. The optimal dose of K is more difficult to determine, since it varies significantly depending on the indicator considered.
Stucky T., Hochstrasser M., Meyer S., Segessemann T., Ruthes A. C., Ahrens C. H., Dahlin P., Pelludat C.
The root knot nematode (RKN) Meloidogyne incognita causes damage in field and greenhouse crops. Agroscope researchers have developed a new screening test to identify bacteria that antagonise this agricultural pest.
With CULTAN fertilisation, nitrogen is injected into the soil as an ammonium solution. Multi-year trials conducted by Agroscope show that this method reduces nitrogen leaching by an average 38% without negatively affecting yields.
Tuta absoluta is one of the most destructive pests of solanaceous crops. Agroscope has developed a statistical model to study the population dynamics of the pest and its parasitoids and allows interventions to be optimally planned.