Method for prescribing site-specific fertilizer application in agricultural fields
A map of site-specific amounts of a soil nutrient, to be applied in fertilizer to an agricultural field is created using a map of site-specific amounts of the soil nutrient needed to produce the maximum possible yield at the particular site. Subtracted from the site-specific amounts of nutrient needed are site-specific amounts of the nutrient currently existing in the field, thus producing the map of site-specific nutrient amounts to be added. The nutrient amounts may be added to the soil using the map and conventional variable-rate fertilizer application methods. In one embodiment, the amounts of the soil nutrient needed to produce the maximum possible yield at each site is created using a map of site-specific measures of biomass produced by the field in a past growing season or seasons, which in turn is created from a remotely sensed biomass image.
1. A method implemented in a computer program to provide a map of site-specific amounts of a soil nutrient to be applied in fertilizer to an agricultural field divided into sites, the method comprising:
calculating for the field, from a map of site-specific field characteristic data for the field, a map for the field of site-specific amounts of the soil nutrient needed to produce at each site a maximum possible crop yield, wherein the field characteristic is a measure of biomass produced by the field in one or more growing seasons; and
subtracting from the site-specific soil nutrient amounts for maximum yield for the field, site-specific measures of the soil nutrient existing in the field, thereby producing a map of site-specific amounts of the soil nutrient to be applied in fertilizer to the field.
2. The method of claim 1 , further comprising:
calculating, from a map of site-specific image data taken of the field during one or more past growing seasons, a map of site-specific measures of a leaf area index, the leaf area index serving as the measure of biomass produced by the field.
3. The method of claim 1 , further comprising:
calculating, from a map of site-specific image data taken of the field during one or more past growing seasons, a map of site-specific measures of a vegetation index, the vegetation index serving as the measure of biomass produced by the field.
4. The method of claim 1 , wherein the soil nutrient is nitrogen.
5. The method of claim 1 , wherein the soil nutrient is phosphorous.
6. The method of claim 1 , wherein the soil nutrient is potassium.
7. The method of claim 1 , wherein the soil nutrient is organic fertilizer.
8. The method of claim 7 , wherein the organic fertilizer is manure.
9. The method of claim 1 , wherein the soil nutrient is a micronutrient.
10. The method of claim 9 , wherein the micronutrient is Zn.
11. The method of claim 9 , wherein the micronutrient is Fe.
12. The method of claim 1 , further comprising:
calculating for the field, from a map of site-specific image data taken of the field in a bare soil state, a map of site-specific measures of soil brightness; and
calculating the site-specific measures of the soil nutrient existing in the field from at least the map of site-specific measures of soil brightness.
13. The method of claim 1 , wherein the site-specific measures of the soil nutrient existing in the field are calculated from at least a map of site-specific measure of soil electrical conductivity.
14. A method implemented in a computer program to provide a map of site-specific amounts of a soil nutrient to be applied in fertilizer to an agricultural field divided into sites, the method comprising:
calculating for the field, from a map of site-specific measures of the biomass of one or more past crops grown in the field, a map for the field of site-specific amounts of the soil nutrient needed to produce at each site a maximum possible crop yield;
calculating for the field, from a map of site-specific image data taken of the field in a bare soil state, a map of site-specific measures of soil brightness;
calculating site-specific measures of the soil nutrient existing in the field from at least the map of site-specific measures of soil brightness;
subtracting, from the site-specific soil nutrient amounts for maximum yield for the field, site-specific measures of the soil nutrient existing in the field, thereby producing a map of site-specific amounts of the soil nutrient to be applied in fertilizer to the field.
15. The method of claim 14 , wherein the soil nutrient is nitrogen.
16. The method of claim 14 , wherein the soil nutrient is phosphorous.
17. The method of claim 14 , wherein the soil nutrient is potassium.
18. The method of claim 14 , wherein the soil nutrient is organic fertilizer.
19. The method of claim 14 , wherein the soil nutrient is a micronutrient.
20. A computer program, residing on a computer-readable medium, for providing a map of site-specific amounts of a soil nutrient to be applied in fertilizer to an agricultural field divided into sites, the computer program comprising instructions for causing a computer to:
calculate for the field, from a map of sate-specific field characteristic data for the field, a map for the field of site-specific amounts of the soil nutrient needed to produce at each site a maximum possible crop yield, wherein the field characteristic is a measure of biomass produced by the field in one or more growing seasons; and
subtract, from the site-specific soil nutrient amounts for maximum yield for the field, site-specific measures of the soil nutrient existing in the field, thereby producing a map of site-specific amounts of the soil nutrient to be applied in fertilizer to the field.
21. The computer program of claim 20 , wherein the instructions further cause the computer to:
calculate, from a map of site-specific image data taken of the field during one or more past growing seasons, a map of site-specific measures of a leaf area index, the leaf area index serving as the measure of biomass produced by the field.
22. The computer program of claim 20 , wherein the instructions further cause the computer to:
calculate, from a map of site-specific image data taken of the field during one or more past growing seasons, a map of site-specific measures of a vegetation index, the vegetation index serving as the measure of biomass produced by the field.
23. The computer program of claim 20 , wherein the soil nutrient is nitrogen.
24. The computer program of claim 20 , wherein the soil nutrient is phosphorous.
25. The computer program of claim 20 , wherein the soil nutrient is potassium.
26. The computer program of claim 20 , wherein the soil nutrient is organic fertilizer.
27. The computer program of claim 20 , wherein the soil nutrient is a micronutrient.
28. The computer program of claim 20 , wherein the instructions further cause the computer to:
calculate for the field, from a map of site-specific image data taken of the field in a bare soil state, a map of site-specific measures of soil brightness; and
calculate the site-specific measures of the soil nutrient existing in the field from at least the map of site-specific measures of soil brightness.
29. The computer program of claim 20 , wherein the instructions cause the site-specific measures of the soil nutrient existing in the field to be calculated from at least a map of site-specific measure of soil electrical conductivity.