Ammonium Sulphate Liquor (ASL) is a product manufactured for the liquid fertiliser market and has been developed to provide a highly efficient Nitrogen fertiliser along with meeting the increasing demand for Sulphur from grass and arable farmers. ASL is now widely accepted as an alternative fertiliser product and is noted for its performance and effectiveness on all arable crops and grassland.


Research shows that Sulphur applied with Nitrogen optimises plant protein and maximises its’ response to Nitrogen. Any such application ensures that the Sulphur and Nitrogen are available together as the plant requires thus providing maximum yields and quality with a reduced susceptibility to leaching. All of the Sulphur within ASL is in readily available sulphate form which is essential for protein synthesis and has been shown to:

  • Improve the quality and yield of all cereal and oil seed rape crops;
  • Boost the quality and yield of grass and silage;
  • Improve the health and vigour of crops through inducing crop resistance to stress, fungal disease and drought.

Research by IGER has shown that Sulphur has a much more significant role in the utilisation of Nitrogen than scientists first thought. A three year trial programme on a sandy loam site compared Ammonium Nitrate treated plots to plots treated with Ammonium Sulphate with the final results concluding that by using Ammonium Sulphate:

  • Dry matter yields were increased by 38%;
  • Nitrate leaching was decreased by 70%.


Application of ASL supplies Nitrogen in a very efficient low leaching, low volatilisation form that results in:

  • Valuable slow release of Nitrogen resulting in a longer period for crop uptake;
  • Higher yield per unit of Nitrogen compared with Ammonium Nitrate fertilisers;
  • Preferred form of Nitrogen in Spring conditions;
  • Accurately applied as a liquid that is quality assured;
  • The Nitrogen and Sulphur combination leads to increased protein quality and quantity.

ASL for Grassland

Sulphur has been proven to be crucial in the conversion of Nitrogen to protein which in turn improves the feed quality of herbage with lower free Nitrogen. Ammonium Sulphate has been shown to substantially increase silage yield; 38% increase in DM yield on a three cut silage system where the Nitrogen is applied as Ammonium Sulphate. It is estimated that 75% of Britain received less Sulphur than the requirement for a cut grass crop. Application of Ammonium Sulphate can:

  • Increase the protein content of grass and silage resulting in improved outputs from grazing livestock;
  • Increase soluble carbohydrates;
  • Improve yields and lessen leaching so better for the environment;
  • 72% less prone to leaching than Nitrate (N) enabling earlier application.

ASL for Vegetable Growers

Because of its’ low leaching properties, ASL is now widely used as a source of early Nitrogen by being incorporated into the seed bed, particularly for potatoes and carrots.

Benefits of ASL:

  • Supplies Nitrogen and Sulphur in one dressing;
  • Can be applied early and is ideal for Spring conditions;
  • Very resistant to both leaching and volatilisation;
  • Applied directly to the soil and is immediately soluble and available to the crop;
  • Low hazardous;
  • Saves on time and labour costs – accurately applied by experienced contractors;
  • No storage costs or bag disposal;
  • Improves health and vigour of crops;
  • Cost effective alternative to conventional fertiliser products.

Product only available in bulk.

Typical Data for Ammonium Sulphate Liquor

Nitrogen: 8%

Sulphur (SO₃): 23%

pH: 5.5 – 6.5