Soil pH Soil pH Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. pH is defined as the negative logarithm (base 10) of the activity of hydronium ions ( or, more precisely, ) in a solution. In soils, it is measured in a slurry of soil mixed with water (or a salt solution, such as 0.01 M ), and normally falls between 3 and 10, with 7 being neutral. Acid soils have a pH below 7 and alkaline soils have a pH above 7. Ultra-acidic soils (pH < 3.5) and very strongly alkaline soils (pH > 9)
Alkali Act 1863 Alkali Act 1863 Under the British Alkali Act 1863, an alkali inspector and four subinspectors were appointed to curb discharge into the air of muriatic acid gas (gaseous hydrochloric acid) from Leblanc alkali works. In 1874, under the Alkali Act 1874, the Inspector became the Chief Inspector. The first Chief Inspector was Dr Robert Angus Smith, he was statutorily responsible for the standards set and maintained by the Inspectorate, and reported directly to the Permanent Secretary of his department. For the first sixty years of its existence, the Inspectorate was solely concerned with the heavy chemicals industry, but from the