The sulphate status of soils from north scotland

✍ Scribed by Norman M. Scott; John Munro

• Publisher: John Wiley and Sons
• Year: 1979
• Tongue: English
• Weight: 347 KB
• Volume: 30
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/jsfa.2740300104

✦ Synopsis

Abstract

In a survey of soils from 125 farms in northern Scotland, calcium phosphate extractable sulphate values ranged from 4 to 55 mg S kg soil^−1^. In 46% of the samples the values were below 14 mg S kg^−1^, a limit which in countries such as Australia and USA is regarded as representing marginal soils likely to respond to added sulphur. Low values occurred throughout the area examined. Five soils representative of the group and varying in extractable sulphate from 5 to 18 mg S kg soil^−1^ were studied in a pot experiment to assess the sulphur supplying power. The first cuts of ryegrass contained <0.2% S in the dry matter and had N:S ratios upwards of 15:1, both indicative of inadequate sulphur. Addition of sulphur improved the nutrition of the plants and increased yields, but in some cases N:S values in excess of 15:1 were still obtained. A similar result was found in the second cut, indicating that under these conditions the five soils were unable to provide an adequate supply of sulphur to the crop.