Long-term effects of land use and fertiliser treatments on sulphur transformations in soils from the Broadbalk experiment

• Published in: Soil biology & biochemistry 2001-10, Vol.33 (12), p.1797-1804
• Main Authors: Knights, J.S, Zhao, F.J, McGrath, S.P, Magan, N
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Broadbalk; Fertilisers; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Immobilisation; Land use; Mineralisation; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Sulphur; Wilderness
• ISSN: 0038-0717; 1879-3428
• DOI: 10.1016/S0038-0717(01)00106-7

Sulphur transformations were monitored in a unique set of arable, grassland and woodland soils from the Broadbalk Classical Experiment, which started in 1843. In an open incubation experiment with periodic leaching, 14–35 mg SO 4 2−-S kg −1 was mineralised in 28 weeks at 25°C, equivalent to 4.4–8.3% soil organic S. Cumulative amounts of S mineralised increased linearly during the 28 weeks, indicating constant rates of mineralisation. The rate of mineralisation was the greatest in the woodland soil (170 μg SO 4-S kg −1 day −1), followed by the grassland (120 μg SO 4-S kg −1 day −1) and the arable soil from the farmyard manure (FYM) plot (110 μg SO 4-S kg −1 day −1). Three soils from arable plots receiving different inorganic fertiliser treatments but no FYM had similar rates of S mineralisation (~70 μg SO 4-S kg −1 day −1). In an incubation experiment with 35SO 4 2−, addition of glucose greatly enhanced S immobilisation. In 132 days, the woodland and grassland soils immobilised more S than the arable soils, with or without glucose amendment. Immobilisation and mineralisation of S occurred concurrently, and both were stimulated by glucose addition. The results show that S mineralisation and immobilisation were influenced strongly by the type of land-use and long-term organic manuring, whereas annual application of sulphate-containing fertilisers for over 150 years had few effects on short-term S transformations.