Agricultural Engineering Serves the Farmer
Extension Circular 455
1958
With Gravity Flow Equipment, It’s Easy to Convert To Liquid Fertilizers
by C. L. Hill, Agricultural Engineering,
Purdue University Agricultural Extension Service, Lafayette, Indiana
Low cost equipment for applying liquid fertilizer mixtures can be put together from tanks, pipe, valves and hoses not specifically manufactured for the purpose but which will give good service for a period of time. If you desire to give liquids a trial, you may prefer to rig up your own applicator.
Many farmers who have tried liquid fertilizers with their corn planters have decided to continue their
the day may come when you will want to try using liquid fertilizers on your farm. Gravity flow equipment for non-pressure and even low pressure liquids offers you a chance to try these fertilizers with inexpensive equipment.
The use of gravity to move a liquid fertilizer follows a natural law which states that a column of liquid exerts pressure at the base proportional to the height of the column. This pressure is used to force the fertilizer through an opening called a metering orifice. The liquid stream can be sent in any direction since the pressure is exerted in all directions.
Liquids can be a time and labor saver on the farm if used intelligently. Their transfer from bulk or storage tank to applicator tank can be made with little effort on the operator’s part. \\ ith gravity How feed and metering by an orifice sized to give the desired fertilizer application rate at certain speeds of the tractor, no drive mechanism, pump or pressure regulating devices are needed.
Because of the simplicity of parts needed, liquid fertilizers can be applied very inexpensively by gravity flow equipment. You can either build or buy such equipment. The first commercially available equipment was on the planter shown in operation above. Also available from manufacturers are trailing broadcast spreaders using gravity flow and tanks and other necessary parts.
Figure 1. The corn planter has been the most popular machine for liquid fertilizer use. Tanks mounted on the planter frame have calibration chart pasted on for easy reference. Commercially available equipment incorporated long lasting materials and convenient controls.
use. If you wish to profit from their experience you will want to purchase parts manufactured specifically for liquid fertilizers.
Low pressure solutions can be DILUTED with water to bring their pressure down to practically zero if you desire to simplify the equipment necessary. or for other reasons. See Table 3.