Method for Ascertaining the Fertilizer Requirement, in Particular the Nitrogen Fertilizer Requirement, and Apparatus for Carrying Out the Method

• US 20130338931A1
• Filed: 03/02/2012
• Published: 12/19/2013
• Est. Priority Date: 03/04/2011
• Status: Active Grant

• Current Assignee: Technische Universitat Munchen
• Original Assignee: Technische Universitat Munchen
• Inventors: Maidl, Franz-Xaver
• Granted Patent: US 10,007,640 B2
• Time in Patent Office: Days
• US Class Current: 702/19
• CPC Class Codes: A01B 79/005 Precision agriculture
• CPC Class Codes: A01B 79/02 combined with other agricultural processing, e.g. fertilising, planting
• CPC Class Codes: A01C 15/00 Fertiliser distributors combined with seeders A01C7/06
• CPC Class Codes: A01C 17/00 Fertilisers or seeders with centrifugal wheels
• CPC Class Codes: A01C 17/006 Regulating or dosing devices
• CPC Class Codes: A01C 17/008 Devices controlling the quantity or the distribution pattern
• CPC Class Codes: A01C 21/00 Methods of fertilising , sowing or planting
• CPC Class Codes: A01C 21/007 Determining fertilization requirements
• CPC Class Codes: G06F 15/00 Digital computers in general details G06F1/00 – G06F13/00; Data processing equipment in general

Abstract

A method and a device for discharging fertilizer for agricultural cultivated plants are disclosed. According to the invention, the required quantity of fertilizer is determined depending on the current nutrient uptake (nutrient status), optimum nutrient uptake (nutrient requirement) by the fertilizing deadline, and optimum nutrient uptake (nutrient requirement by the next fertilizing deadline, wherein other influencing factors are taken into consideration via a correction factor DIMA.

Claims

1. A method for ascertaining the nutrient requirement, in particular the N fertilizer requirement of an agricultural cultivated plant, comprising the steps of:

(a) storing characteristic diagrams/tables for the current nutrient uptake (N_cur) of the plant as a function of a vegetation index, a stage of development (EC) and/or the yield to be expected in a data memory;

(b) storing characteristic diagrams/tables for the optimum nutrient uptake (N_opt) of the plant as a function of the stage of development (EC) and/or the yield to be expected in a partial agricultural plot to be fertilized;

(c) measuring the vegetation index in the partial agricultural plot and reading out the current nutrient uptake (N_cur) from the characteristic diagram/table as a function of the yield and/or the stage of development (EC);

(d) reading out the optimum nutrient uptake (N_opt) with the current stage of development (EC) and/or the yield to be expected front the characteristic diagram/table;

(e) calculating the quantity of nutrient (N) from the difference between the optimum nutrient uptake (nutrient requirement N_opt) and the current nutrient uptake (current nutrient status N_cur), and correcting this amount by offsetting against a correction factor (DIMA) in which at least one of the parameters of duration of effect of the fertilizer (D), fertilizer immobilization (I) in the soil, mineralization (M) from the soil, and fertilizer utilization rate (A) is included.

2. The method according to claim 1, wherein the quantity of nutrient (N) to be discharged is calculated from the difference pursuant to step (e) plus the difference from the optimum nutrient uptake (N_opt+1) by the next fertilizing deadline and the current nutrient uptake.

3. The method according to claim 1, wherein the characteristics depending on the vegetation index are formed in a first approximation from straight lines

N_cur=(a)*(vegetation index)+y

or from sections of straight lines, wherein a is the slope and y is the intercept.

4. The method according to claim 3, wherein the intercept y is determined by a straight line

y=(a*)*(N*)+b*

wherein N* is the medium N uptake of the plant in the stage of development and with the assumed yield potential and y decreases with increasing medium N uptake (N*) (negative slope).

5. The method according to claim 3, wherein the slope a is determined by a straight line

a=(a**)*(N*)+b**

wherein a increases with N* (positive slope).

6. The method according to claim 3, wherein the characteristics/tables are established also as a function of the plant quality.

7. The method according to claim 1, wherein the vegetation index is the REIP.

8. The method according to claim 1, wherein DIMA is greater than 0.5 and less than 1.5.

9. The method according to claim 8, wherein DIMA depends on the stage of development.

10. A device for discharging nutrient, comprising a memory for storing characteristics/tables for the current nutrient uptake or the optimum nutrient uptake as a function of the stage of development of the plant in the partial agricultural plots to be fertilized, the quality of the plants in the partial agricultural plots, and/or the yield to be expected in the partial agricultural plots, and of correction factors (DIMA), comprising a sensor for collecting a vegetation index, an evaluation unit for selecting the suitable characteristic/table and for reading out the current nutrient uptake (nutrient status N_cur), the optimum nutrient uptake (N_opt), and the correction factor (DIMA), and for calculating the optimum quantity of nutrient (N) from these parameters pursuant to the method according to any of the preceding claims, and for outputting a control signal a fertilizer distributor, and comprising a fertilizer distributor for dosing nutrient in accordance with the control signal.