A LIQUID MANURE INJECTION TOOL ADAPTED TO DIFFERENT SOIL CONDITIONS
Injection of liquid manure into soil can reduce nutrient loss through volatilization, reduce odor emission, reduce 
surface runoff pollution, and increase plant uptake of nutrients. A liquid manure injection tool was developed based on the 
following design criteria: easy adaptation, low draft force and surface exposure of injected manure, and suitability for 
different soil conditions and for variable manure application rates. The tool featured a chisel with a sweep and a shank. The 
first prototype was tested using swine manure in a field with clay soil and wheat stubble to examine the draft forces and the 
resultant manure exposure indices under different injection depths and manure application rates. Based on the field test results 
of the first prototype, a second prototype was designed with a narrower tool cutting width and a smaller rake angle, and was 
compared with the first prototype in an indoor soil bin (loamy sand soil and no residue cover). The tool geometry and features 
implemented in the design met the proposed design criteria. The second prototype required lower draft force and caused less 
soil disturbance when compared with existing injection tools reported in the literature.