Biosolids

Depending on the crop type, time of year and product type, biosolids can supply around 10-15% of the nitrogen needed. The nitrogen supplied is mainly in the organic form and, as such, releases slowly as the soil warms. Thus, it remains present over the crop's entire growth cycle.

A typical biosolids application will replace crop offtake and help maintain or build up soil phosphorus (P) to target levels. This will help with obtaining optimal yields by reducing the risk of P deficiency.

Sulphur has become an important crop nutrient as deposition from the atmosphere has decreased. Used at standard application rates, biosolids contain enough sulphur to meet the typical requirements of cereal and oilseed rape crops.

Biosolids applications contain significant amounts of magnesium. This can help provide a maintenance dressing for soil and prevent deficiencies (sometimes seen on light sandy or acidic soils).

Micronutrients are normally required in relatively small amounts, depending on the crop and soil type. If not addressed properly, they can cause crop deficiencies. Biosolids contain a wide range of micronutrients. This includes boron, copper, zinc, iron, sodium, manganese, aluminium and molybdenum.

Biosolid products contain a large amount of organic matter. This is a vital component of good quality agricultural soils and helps provide a good growing medium for crops. Repeat applications of biosolids can help maintain organic matter levels in soil. This is especially so in intensive arable farming, where there is often no alternative source of organic matter. The key benefits of organic matter include improved: soil structure rooting drainage soil workability water retention soil biology reduction in soil erosion.