Biosolids are being used as fertilizer and soil conditioner. Though there are many doubts that surround the application of biosolids on agricultural land, a lot of farmers are now using this organic matter for the benefits that it poses. It is a cheaper alternative to non-organic and chemical fertilizers, of course, but this isn’t the only benefit of using biosolids as fertilizer.
Soil organic matter can be lost because of intensive arable farming where there is no alternative organic matter source. But since this is a major determinant of soil fertility, water holding capacity, and biological activity and diversity below and above ground, it is important to find a source for organic matter. The loss of organic matter leads to soil erosion and loss of ground fertility.
Instead of using chemical methods of sourcing nitrogen for crops, biosolids are now widely being applied on agricultural land. Depending on the crops and product type, biosolids can supply around 10% of the nitrogen needed by the crops. When nitrogen is sourced through biosolids, it will be slowly released as the soil warms up. This ensures that nitrogen is present during the crops’ growth cycle.
To eliminate the need for bagged phosphate fertilizer, biosolids are now being used to provide the needed phosphate for cereals and oilseed rape. A single application of biosolids can provide two years worth of phosphate supply that the crops need. In case it is needed, biosolids can be used to build up the phosphate soil index.
As deposition of Sulphur from the atmosphere decreased, Sulphur is now being sourced from biosolids. In the past years, it has become increasingly important as a crop nutrient and that is why biosolids are now being applied on agricultural land. The Sulphur in biosolids is enough to help in the growth of cereals and oilseed rapes.
If you see light, sandy acid soils, this means that it needs the magnesium boost from chemical fertilizers or biosolids. The organic basis of biosolids provide enough amounts of magnesium sufficient to answer the deficiency symptoms seen on light and sandy soil.
The amount needed for trace elements depend on the crop and soil type. Although this can also be sourced from other chemical fertilizers, none is as “complete” as biosolids, which contains all the important ones—boron, copper, zinc, iron, sodium, mangarese, aluminum, and molybdenum.
All of these nutrients are sourced from biosolids, which will somehow make you understand why its use is such an important debate in today’s modern world.