Precision Nutrient Management: Grid-Sampling Basis - PowerPoint PPT Presentation

Loading...

PPT – Precision Nutrient Management: Grid-Sampling Basis PowerPoint presentation | free to download - id: 6813e4-OTcyY



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Precision Nutrient Management: Grid-Sampling Basis

Description:

Precision Nutrient Management: Grid-Sampling Basis Hailin Zhang and Gordon Johnson Department of Plant and Soil Sciences Precision Nutrient Management Strategies Grid ... – PowerPoint PPT presentation

Number of Views:1
Avg rating:3.0/5.0
Date added: 26 August 2019
Slides: 31
Provided by: Hailin3
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Precision Nutrient Management: Grid-Sampling Basis


1
Precision Nutrient Management Grid-Sampling
Basis
  • Hailin Zhang and Gordon Johnson
  • Department of Plant and Soil Sciences

2
Precision Nutrient Management Strategies
  1. Grid soil sampling
  2. Apparent Electrical Conductivity
  3. Yield monitor/mapping
  4. Sensing techniques

3
Purposes of Soil Sampling
  1. Measure the nutrient content or availability of
    the soil
  2. Identify nutrient deficiencies
  3. Predict crop response to added nutrients
  4. Build a nutrient management plan

4
Recognize Field Nutrient Variability
Nitrate - Nitrogen lbs/acre 0-30 31-40
41-50 51-60 61-80 gt80
(Nitrate-N within a 75 x 75 plot)
5
(No Transcript)
6
(No Transcript)
7
Limiting Factors for Crop Growth
  1. Factors are different for every field, therefore,
    remediation should be different too
  2. Factors change from year to year
  3. Factors limiting yield will interact

8
Considerations for Soil sampling Strategies
  1. Locate variability responsive to fertilizer and
    lime
  2. Obtain a sample that accurately represents the
    area sampled
  3. Balance cost of sampling with the value of
    information

9
The greatest potential for error in soil
testing is in taking the sample
10
Soil Sampling Strategies
  1. Whole field composites Composite sample
    representing the average nutrient status of the
    field















11
20 cores are needed to make a representative compo
site sample in order to get reliable soil test
results
12
Scooping samples for extraction One acre to 6
inch deep contains about 2 million lbs of soil
13
P Changes with Depth (no-till)
Depth
P (ppm)
0
2
55
6
35
12
31
24
14
(No Transcript)
15
Soil Sampling Strategies
  • 2. Zone composites Break field based on known or
    expected source of variability

16
Soil Sampling Strategies
  • 3. Grid Sampling Break field based on ordered
    pattern
  • Grid cell method similar to whole field
  • Grid center method point sampling

X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
17
Field Soil Sampling, Soil Testing, and Making
Fertilizer Recommendations Exercise
  • 1. Random sampling of the entire field ,
  • 25 cores of soil from a 0-6 depth
  • filling two soil sample bags from the composite
    mixture
  • 2. Grid-cell sampling
  • 15 cores of soil from a 0-6 depth
  • 3. High resolution
  • 15 cores of soil from a 0-6 depth

18
  • Whole field
  • 1 acre grid
  • Sub-grid

X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
19
Whole field sample pH Team 1 6.0, 6.1 Team
2 6.4, 6.4
20
Whole field sample nitrate Team 1 19, 18
Team 2 28, 28
21
(No Transcript)
22
(No Transcript)
23
127
Whole Field Sampling 114 117, 188 190
24
188
Whole Field Sampling 206 196, 186 180
25
5.6
Whole Field Sampling 5.9 5.9, 5.6 5.6
26
(No Transcript)
27
Why Account for Spatial Variability of Soil
Properties
  1. Improve performance of ag. practices
  2. Either costs go down and/or returns go up
  3. Avoid over application that might be
    environmentally harmful

28
Analysis Costs of Various Sampling Intensities
Grid Spacing Area/sample Costs
Feet Acres /acre
66 0.1 100
104 0.25 40
148 0.5 20
209 1 10
330 2.5 4
467 5 2
660 10 1
Conventional 40 0.25
at 10/sample
29
Analysis Costs of Various Sampling Intensities
Grid Spacing Area/ sample Analysis Cost Sampling Cost Total Cost
Feet Acres /acre /acre /acre
66 0.1 100 20 120
104 0.25 40 10 50
148 0.5 20 5 25
209 1 10 2.5 12.5
330 2.5 4 1.25 5.25
467 5 2 0.65 2.65
660 10 1 0.40 1.40
Conventional 40 0.25 0.25 0.50
at 10/sample at 10/hour and collecting 1 to
5 samples per hour
30
Choosing a Soil Sampling Strategy
  • Level of management and the resources to account
    for variability
  • Whole field sampling most appropriate when
    fertility is high and variability is low
  • Zoning/sub-field sampling may be most appropriate
    when
  • Location of variation known
  • Sampling areas are large
  • Limited resource
  • Grid sampling maybe appropriate if location of
    variation is unknown and variable rate applicator
    is available
About PowerShow.com