Agricultural implement with sensors for measuring soil properties

Abstract

An agricultural implement with various sensors for measuring properties of soil while performing normal planting or other operations. The sensors include a plurality of flexible tine assemblies used as electrodes for measuring soil EC. The flexible tine assemblies each have a lower end arranged to contact soil, and an upper end with a coil spring configuration attached to an electrically isolated support structure. The coil spring configuration allows the flexible tine to flex rearwardly to shed residue and clear obstructions. The flexible tine is arranged behind a soil engaging tool, such as an opener assembly or a residue clearing device, with the lower end contacting soil exposed by the soil engaging tool. Other soil sensors on the implement include sensor modules positioned in furrows behind the opener assemblies, and non-contact optical sensors arranged to measure reflectance of soil exposed by the opener assemblies.

What is claimed is: 
     
         1 . An agricultural implement, comprising:
 a row unit attached to a tool bar, said row unit comprising at least one soil engaging tool; and   a non-contact optical sensor arranged to measure reflectance of soil exposed by the soil engaging tool.   
     
     
         2 . The agricultural implement according to  claim 1 , wherein said at least one soil engaging tool comprises an opener assembly for opening a furrow, and a closing wheel assembly for closing the furrow, and wherein said non-contact optical sensor is arranged to measure reflectance of soil exposed by the opener assembly before the soil is closed by the closing wheel assembly. 
     
     
         3 . The agricultural implement according to  claim 2 , wherein said non-contact optical sensor comprises a first light source arranged to emit light at a first wavelength toward the soil exposed by the opener assembly, and at least one reflectance sensor arranged to measure light reflected off the soil from the first light source. 
     
     
         4 . The agricultural implement according to  claim 3 , wherein said non-contact optical sensor further comprises a second light source arranged to emit light at a second wavelength toward the soil exposed by the opener assembly, and wherein the at least one reflectance sensor is arranged to measure light reflected off the soil from the second light source. 
     
     
         5 . The agricultural implement according to  claim 4 , further comprising a means for estimating soil moisture by comparing an index of optical values to reflectance data provided by the at least one reflectance sensor corresponding to the first and second wavelengths. 
     
     
         6 . The agricultural implement according to  claim 1 , further comprising a contact sensor on the row unit for measuring a soil property selected from the group consisting of soil EC, soil reflectance, soil moisture and soil temperature, said contact sensor being used in tandem with said non-contact optical sensor. 
     
     
         7 . An agricultural implement, comprising:
 a row unit attached to a tool bar, said row unit comprising at least one soil engaging tool; and   a non-contact optical sensor arranged to measure crop residue on a soil surface behind the soil engaging tool.   
     
     
         8 . The agricultural implement according to  claim 7 , wherein said non-contact optical sensor is arranged to measure crop residue within a seed furrow created by said at least one soil engaging tool. 
     
     
         9 . The agricultural implement according to  claim 7 , wherein said non-contact optical sensor is arranged to measure crop residue on a ground surface outside of a seed furrow created by said at least one soil engaging tool. 
     
     
         10 . An agricultural implement comprising:
 at least four row units attached to a tool bar, each row unit comprising a furrow opener;   at least four sensor modules attached to said four row units and positioned behind said furrow openers to engage soil within furrows created by the furrow openers; and   said sensor modules each having a conductive metal contact on an outer surface thereof to engage soil within the furrows, and said sensor modules are aligned with each other so that the metal contacts of the sensor modules form an array of electrodes for measuring soil EC.   
     
     
         11 . The agricultural implement according to  claim 11 , wherein at least one of said sensor modules has an additional sensor incorporated therein for measuring a soil property selected from the group consisting of soil moisture and soil temperature. 
     
     
         12 . The agricultural implement according to  claim 11 , wherein at least one of said sensor modules has an additional sensor incorporated therein for measuring soil organic matter.