Soil chemical sensor and precision agricultural chemical delivery system and method

A system for sensing substantially instantaneously at least one chemical constituent of a soil while traversing a field of said soil and determining substantially simultaneously therewith an amount of corrective chemical to be added to said soil, comprising:

• means for penetrating the soil while traversing a first soil sample;
• means for supporting a plurality of multivalent electrodes at about the depth of said soil penetration means;
• means for applying a solvent to a portion of the soil at about such depth and creating a leachate electrically coupling said electrodes to the soil sample surrounding said leachate;
• and
• means for applying a voltage differential across said leachate through said electrodes, whereby said system determines the magnitude of an electrochemical component of said leachate proportional to the chemical constituent thereof.

A sensor system for sensing a chemical constituent of a soil, comprising:

• shank means for penetrating the soil and supporting a multivalent electrode thereon, said shank means being at least partially formed of a multivalent conductive material;
• means cooperating with said shank means for applying a solvent to a portion of the soil and creating a leachate electrically coupling said shank means and electrode to the soil surrounding said leachate;
• and
• means for applying a voltage differential across said leachate through said shank means and electrode and determining the magnitude of an electrochemical component of said soil proportional to the chemical constituent thereof.

A system for sensing substantially instantaneously at least one chemical constituent of a soil while traversing a field of said soil and determining substantially simultaneously therewith an amount of corrective chemical to be added to said soil, comprising:

• means for penetrating the soil while traversing a first soil sample;
• means for applying a solvent to said first soil sample to create a leachate while traversing said soil sample;
• means for applying a voltage differential across said leachate and determining a parameter proportional to said soil constituent while traversing said sample;
• and
• means for determining the amount of corrective chemical to be added to said sample while traversing said sample.

A method for calibrating means for rapidly determining soil constituent concentrations while traversing a field of such soil, comprising the steps of:

• penetrating the soil of a plurality of soil samples while respectively traversing such samples;
• applying a solvent to said plurality of samples to create a plurality of leachates while traversing such samples;
• appyling a potential across each said leachate and determining the respective values of a parameter proportional to said soil constituent while traversing such samples;
• determining a first representative value of such respective values;
• comparing said first representative value with a second representative value;
• and
• calibrating the determination of said first representative value so as to compensate for said second representative value.

A system for calibrating means for rapidly determining soil constituent concentrations while traversing a field of such soil, comprising:

• means for penetrating the soil of a plurality of soil samples while respectively traversing such samples;
• means for applying a solvent to said plurality of samples to create a plurality of leachates while traversing such samples;
• means for applying a potential across each said leachate and determining the respective values of a parameter proportional to said soil constituent while traversing such samples;
• means for determining a first representative value of such respective values;
• means for comparing said first representative value with a second representative value;
• and
• means for calibrating the determination of said first representative value so as to compensate for said second representative value.