How do you use Liquid lime sludge in agricultural farms?

Answer 1

'Liquid Lime Sludge' can mean many things. Lime Sludge or Slurry is usually referring to one of the following:

Dry Ag Lime / Ground Calcium Carbonate mixed in water

Liquid Calcium Carbonate / Precipitated Calcium Carbonate produced for the paper industry

Liquid Lime produced for the agriculture and turf industry

Dry Ag Lime doesn't mix or suspend very well in water because limestone in any grade is insoluble. When mixing Ag Lime with water, constant and vigorous agitation is required. After agitating/mixing, the limestone particles will settle within 5-15 minutes. Few farmers have sprayers that enable them to continue this high level of agitation simultaneously while spraying the limestone solution. It is also important to note that this solution will line the equipment (tank, filter, pump, valves, lines, nozzles) with limestone particles/film which is extremely corrosive. Wash equipment thoroughly with 'tank cleaner' after use.

Liquid Calcium Carbonate or Precipitated Calcium Carbonate is produced for the paper industry. These liquids are extremely thick due to the added suspension agents. Although these liquids remain in suspension for a longer period of time, the solution is usually too thick to spray through an agricultural sprayer. It is also important to note that the chemicals added to these solutions are designed for paper and other industrial purposes - not agriculture. Watering down or diluting these solutions to create a thinner, easier to spray liquid is often ineffective. When these solutions are watered down, the suspension agents lose their suspending capabilities. As a result, thick lime sludge settles to the bottom of the tank.

Liquid Lime products marketed in the agriculture and turf industry are sometimes the exact same products mentioned above. Many companies are repackaging Liquid Calcium Carbonate / Precipitated Calcium Carbonate (designed for the paper industry) and misrepresenting their purpose and effectiveness in agriculture and turf applications.

Other Liquid Lime products contain trace amounts of Limestone, Calcium or Chelated Calcium. These heavily diluted Liquid Lime products are easier to spray but have minimal agronomic value. Limestone's primary agronomic purpose is to neutralize hydrogen thus raising the soils pH. Calcium by itself has no neutralizing effect on hydrogen. However, these products may be able to effectively remedy small calcium deficiencies. In order for Liquid Lime to be effective in neutralizing hydrogen, it must be in 'carbonate' form.

The most effective Liquid Lime products are 'micro-sized' suspensions. Micro-sized suspensions, often referred to as Micro Lime or Mojo Lime are measured by micron size. Micro Lime / Mojo Lime usually has a micron size less than 10. Ag Lime and some Liquid Lime suspensions are measured by mesh size.

Mesh size is measured by the number of openings in a 1 inch screen. A 4-mesh screen has 4 openings and a 100-mesh screen has 100 openings. 100% of the material must be able to pass through the opening to be rated.

Translating Mesh to Microns:

60 mesh = 250 micron

100 mesh = 149 micron

200 mesh = 74 micron

325 mesh = 44 micron

1250 mesh = 10 micron

Dry Ag Lime is considered to be 100% effective when in 60-mesh grade. However, the particle/micron size of 60-mesh grade (250 microns) is too large to be effective in a Liquid Lime slurry or suspension. Liquid Calcium Carbonate / Precipitated Calcium Carbonate (designed for the paper industry) ranges from 74-250 microns in size. Smaller micron sizes not only improve handling but improve the coverage and effectiveness of the application.

Conclusion:

Identify the micron size of a Liquid Lime product to determine its effectiveness and intended use. Liquid Lime products ranging from 74-250 microns (60-200 mesh) are difficult to handle and spray. In addition, the agronomic value and performance is limited as most of these products were not designed for agricultural use. Micro-sized Liquid Lime products are ideal for agriculture and turf applications.