Automated soil measurement device

• US 8,472,024 B2
• Filed: 09/19/2012
• Issued: 06/25/2013
• Est. Priority Date: 05/07/2009
• Status: Active Grant

• Current Assignee: Winfield Solutions LLC (Land O'Lakes Incorporated)
• Original Assignee: Solum, Inc. (Corteva, Inc.)
• Inventors: Preiner, Michael John, White, Justin Stewart, Strachan, John Paul, Koshnick, Nicholas Carelton
• Primary Examiner(s): STAFIRA, MICHAEL PATRICK
• Application Number:
  US13/622,495
• Publication Number:
  US 20130019664A1
• Time in Patent Office: 279 Days
• Field of Search: 356432-437, 356244-246
• US Class Current: 356/432
• CPC Class Codes: G01N 2033/245 for agricultural purposes
• CPC Class Codes: G01N 21/00 Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light G01N3/00 - G01N19/00 take precedence
• CPC Class Codes: G01N 21/276 with alternation of sample and standard in optical path
• CPC Class Codes: G01N 21/33 using ultraviolet light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/552 Attenuated total reflection
• CPC Class Codes: G01N 33/24 Earth materials G01N33/42 takes precedence

Abstract

A system and a method are disclosed for combining a soil sample and extractant in a mixing chamber to produce a liquid extractant-soil mixture. A portion of the liquid extractant-soil mixture is directed from the mixing chamber through a sample measurement chamber coupled to the mixing chamber. The sample measurement chamber is coupled to a light source so that light propagates from the light source through the portion of the liquid extractant-soil mixture to an optical detector which generates an attenuation spectrum indicating light received by the detector at different wavelengths. The sample measurement chamber may include an attenuation cell having a specified optical path between a first measurement window and a second measurement window and angular surface directing particulates in the liquid extractant-soil mixture away from the attenuation cell.

Claims

1. A method for measuring characteristics of a soil sample comprising the steps of:

adding a soil sample to an automated soil measurement device, the soil sample comprising a soil portion and at least some water;

determining a weight of a soil portion of the soil sample;

determining a moisture content of the soil sample based on the weight of the soil portion;

determining a volume of extractant to mix with the soil sample to achieve a soil to water ratio, the volume of extractant based on the moisture content and the weight of the soil portion;

adding, using the device, the volume of extractant to the device;

mixing, using the device, the soil sample and the extractant to produce an extractant-soil mixture; and

analyzing, using the device, the extractant-soil mixture to determine one or more characteristics of the soil sample.

2. The method of claim 1, wherein analyzing the extractant-soil mixture to determine the characteristic of the soil sample comprises:

transmitting light from a light source through a portion of the extractant-soil mixture; and

detecting, with an optical detector, light propagating from the light source, the light attenuated by the portion of the extractant-soil mixture;

generating an absorption spectrum indicating the attenuated light received by the optical detector at different wavelengths; and

determining components of the soil sample from the attenuation spectrum.

3. The method of claim 1, wherein the characteristics of the extractant-soil mixture comprise at least one from the group consisting of a viscosity of the extractant-soil mixture, a conductivity of the soil sample, a reflection spectrum of the soil sample, a pH of the soil sample, and a temperature of the extractant-soil mixture.

4. The method of claim 1, wherein a characteristic of the extractant-soil mixture is a nitrate-nitrogen concentration of the soil sample.

5. The method of claim 1, wherein a characteristic of the extractant-soil mixture is a phosphorous concentration of the soil sample.

6. The method of claim 1, wherein a characteristic of the extractant-soil mixture is a potassium concentration of the soil sample.

7. The method of claim 1, wherein mixing the soil sample and the extractant to produce the extractant-soil mixture comprises at least one of sonication, heating, addition of a chemical, and motorized mixing.

8. The method of claim 1, wherein weighing the soil sample comprises manually weighing the soil sample.

9. The method of claim 1, wherein weighing the soil sample comprises automatically weighing the soil sample.

10. The method of claim 1, wherein determining the moisture content of the soil sample comprises subtracting a weight of the soil sample from the weight of the soil portion of the soil sample.

11. A method for measuring characteristics of a soil sample comprising the steps of:

receiving a soil sample in an automated soil measurement device, the soil sample comprising a soil portion and at least some water;

receiving, using the device, a first volume of extractant into the device;

producing, using the device, a first extractant-soil mixture by mixing the soil sample and the first volume of extractant, the first extractant-soil mixture comprising a first soil to extractant ratio;

analyzing, using the device, the first extractant-soil mixture to determine a first characteristic of the soil sample;

receiving, using the device, a second volume of extractant into the device;

producing, using the device, a second extractant-soil mixture by mixing the first extractant-soil mixture and the second volume of extractant, the second extractant-soil mixture comprising a second soil to extractant ratio more diluted than the first extractant-soil mixture; and

analyzing, using the device, the second extractant-soil mixture to determine a second characteristic of the soil sample.

12. The method of claim 11, wherein the first soil to extractant ratio is 1:

1.2, and wherein the second soil to extractant ratio is 1;

1.5.

13. The method of claim 11, wherein analyzing the first extractant-soil mixture to determine the first characteristic of the soil sample comprises:

transmitting light from a light source through a portion of the first extractant-soil mixture; and

detecting, with an optical detector, light propagating from the light source, the light attenuated by the portion of the extractant-soil mixture;

generating an absorption spectrum indicating the attenuated light received by the optical detector at different wavelengths; and

determining components of the soil sample from the attenuation spectrum.

14. The method of claim 11, wherein the second characteristic of the second extractant-soil mixture comprises at least one from the group consisting of a viscosity of the second extractant-soil mixture, a conductivity of the soil sample, a reflection spectrum of the soil sample, a pH of the soil sample, and a temperature of the second extractant-soil mixture.

15. The method of claim 11, wherein one of the characteristics of the extractant-soil mixture is at least one from the group consisting of a nitrate-nitrogen concentration of the soil sample, a phosphorous concentration of the soil sample, and a potassium concentration of the soil sample.

16. The method of claim 11, wherein the mixing comprises at least one from the group consisting of sonication, heating, addition of a chemical, and motorized mixing.