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Research article2022Peer reviewed

Interactive long-term effects of liming and P application on clay soil: crop yield increases up to pH 7.5((aq))

Borjesson, Gunnar; Kirchmann, Holger

Abstract

Aims This study assessed the impact of combined lime and phosphorus application on soil pH, plant availability of added phosphorus and crop yield over time. Methods In a series of long-term field trials started in 1936 on a clayey soil in south-west Sweden, acidic superphosphate and basic Thomas phosphate were tested in combination, with and without an initial high dose of lime. Results Liming did not lower phosphorus availability in soil. Crop yield was increased throughout by addition of phosphorus together with lime. A single dose of lime, equivalent to 6 Mg CaO ha(-1), increased yield over decades and crop yield was positively correlated with pH((aq)) increases up to 7.5. In plots receiving no phosphorus for 80 years, the clay soil was able to supply phosphorus to crops, resulting in up to 80% of the phosphorus-fertilised yield. Vanadium in the basic slag product (Thomas phosphate) elevated levels in soil. Conclusions In the present study, we found that, even above pH 7, interactions between P and lime were positive and not negative. No differences in phosphorus availability were found on applying phosphorus fertiliser at the normal dose on a regular basis, or as a bulk dose at longer intervals. The data support a new target pH value up to 7.5 for optimal crop production.

Keywords

Long-term field trial; Liming; Phosphorus; Thomas phosphate; winter wheat

Published in

Plant and Soil
2022, Volume: 473, number: 1, pages: 407-421
Publisher: SPRINGER

      SLU Authors

      • UKÄ Subject classification

      Soil Science

      Publication identifier

      DOI: https://doi.org/10.1007/s11104-021-05293-1

      Permanent link to this page (URI)

      https://res.slu.se/id/publ/115680