Balance of a PK-fertilisation trial in a clay soil (Changins 1971 to 2000)

• Published in: Revue suisse d'agriculture Vol. 35; no. 2
• Main Authors: Ryser, J.-P, Vullioud, P. (Station federale de recherches en production vegetale de Changins (RAC), Nyon (Switzerland))
• Format: Journal Article
• Language: French
• Published: 01.03.2003
• Subjects: APLICACION DE ABONOS; CLAY SOILS; CROP YIELD; CULTIVATION; CULTIVO; EXPERIMENTACION EN CAMPO; EXPERIMENTATION AU CHAMP; FERTILISATION; FERTILIZER APPLICATION; FIELD EXPERIMENTATION; FOSFORO; PHOSPHORE; PHOSPHORUS; POTASIO; POTASSIUM; PRATIQUE CULTURALE; RENDEMENT DES CULTURES; RENDIMIENTO DE CULTIVOS; SOL ARGILEUX; SUELO ARCILLOSO
• ISSN: 0375-1325

P and K fertilization has been tested over 30 years on a heavy clay soil which was considered by the analysis as low by P and very low by K. Following conclusions have been derived from the trial results: - The interpretation of soil analysis results has to be adapted to this particular soil type which obviously delivers its fertilisers very slowly to the plants. - A PK-fertilisation counterbalancing the exportations by crop harvest - input/output balance - is generally considered as suitable in order to maintain the yield level of crops and the fertility level in the soil as weIl. - The P and K contained in crop residues left on the field can be fully accounted as restored to the soil. - It doesn't seem to be useful, for that type of clay soil, to enhance fertility level by reinforced PK fertilisation. This could even be noxious to the environment and without any signification on yield. - In this particular heavy clay soil, soil tillage requires a great attention. Soil structure is highly important for crop establishment. The low delivery of fertilisers in the soil makes any disturbance in plant growth worse. A more as 30 years old soil tillage trial on a same neighbouring soil has shown that tine tillage (15 cm depth) leads mostly to the best results in these conditions.