A silo (from the Greek –siros, “pit for holding grain”) is a structure for storing bulk materials.  Silos are used in agriculture to store grain or fermented feed known as silage.  Silos are commonly used for bulk storage of grain, coal, cement, carbon black, woodchips, food products and sawdust.

Methods of silo construction evolved over time, allowing silos to be larger, more efficient, and increasingly popular.  These changes occurred through construction, engineering, and design as new material and building techniques became available. 

One of the primary advantages of a tower silo is that silage tends to pack well due to its own weight.  There are three primary types of Tower Silos – Concrete Stave silos, Monolithic (cast in place) silos, and Steel, glass lined silos.  Each has features unique to their design which contribute to the versatility of that structure depending on a particular application.  One could speculate that there is a tower silo design available for every type of bulk storage need.  

One misconception about Tower Silos is that they are slow filling and unloading.   This is simply not true.  In response to slow filling rates; towers exceed the rates possible using methods that require manual packing.  ISA has reports of producers and custom harvesters across the country filling towers at speeds exceeding 100 tons per hour, and several who are filling at speeds over 120 tons per hour.  In regards to unloading, ISA has reports of producers unloading at a rate of 800 pounds per minute.

The use of a modern Tower Silo today lends itself to get more nutrient value from crops such as corn or grass, with less physical labor, and at less cost than with any other method of crop handling and preservation. 



The purpose of the International Silo Association is to promote “Tower Silos” and educate the public. 

Adopted by the ISA at its annual board meeting in Madison, Wisconsin on the 29th of November, 2016, what is called the “CAPS” program.  This program outlines the goals of the ISA moving forward.


C - Communication

Create and present information to the membership to assist in generating sales of Tower silos for use with new Feed Automation technology.

A - Automation

Create and present information to the “Automation” industry as to the benefits of Tower silo use with their equipment.

P - Promotion

Promotion and integration of Tower silo storage and feed automation, including total turnkey operations that include robotics.  With tower silos and high tech automation, farmers can reduce the time, effort and cost of operating a modern dairy farm operation.  Tower silos in conjunction with automation will also realize less feed loss, higher quality feed, higher milk production, and better animal health.

S - Safety                               

Continue to develop and present Safety Bulletins, notices and Public Information articles on the safe use and maintenance of a Tower silo.