http://www.extension.org/67619 Weather conditions impact land application of manure. Wet soils hinder equipment from accessing fields. Regulations prohibit application on frozen or snow cover soils. Uncertain soil and atmospheric conditions can cause the best plans to fail. Nutrient management plans that are expected to succeed might fail given any particular year’s weather. Incorporating fieldwork days information into nutrient management plans can make them more robust to uncertain weather conditions.
The USDA publishes the number of fieldwork days for different crop reporting districts within states. These data are from field reporters who provide their opinion on the number of days that were available for farmers to conduct fieldwork such as disking, planting and harvesting. USDA Fieldwork Days data cover the growing season (approximately April to December). Estimates of fieldwork days do not exist for the non-growing season (approximately December to April). However, certain states have agricultural weather station networks that collect soil temperature and other critical information that can be used to estimate the number of fieldwork days that exist for manure application within regulatory limits.
This project integrates fieldwork days from the USDA Fieldwork Days data with the Missouri Agricultural Weather Station Network winter soil temperature and precipitation data for the corresponding crop reporting district. This compiled database gives a complete year of fieldwork day estimates. The data are used in a model that allows nutrient management planners to incorporate climatological impacts into their land application plans. Users specify their equipment complement and size, quantity of manure, and desired beginning and ending dates. The model reports output in a cumulative distribution function that estimates the probability of completing fieldwork within the specified parameters and a sensitivity table of ending dates.
3. April through November
USDA data –
▪ Reporters’ opinion of soil conditions allowing
equipment into the field
▪ Reported as “days per week”
▪ Over 30 years of data
▪ http://www.nass.usda.gov/Statistics_by_State/Missouri/
Publications/Crop_Progress_and_Condition/
Probability tool originally developed for
Missouri.
Work to expand to IA, IL, and KS.
16. Equipment Inputs to EstimateApplication
Time
Capacity of spreader/tanker
Application width
Application travel speed
Applicator discharge rate
Travel time
Infield travel time
Road travel time
Applicator load time
20. Equipment Inputs to EstimateApplication
Time
Capacity of spreader/tanker
Application width
Application travel speed
Applicator discharge rate
Travel time
Infield travel time
Road travel time
Applicator load time
21. 4,800 Grow-Finish Operation
Generates enough manure to provide N for 400 acres of corn.
Application rate 175 lbs N/A (4,375 gal/A)
Fields average 1 mile from barn
LandApplication Equipment
6000 gallon tanker
15-foot swath injector
Travel speeds:
▪ Road: 10 mph
▪ In field, not applying: 7 mph
▪ In field, applying: 3.4 mph (requires 450 gal/min discharge rate)
▪ Loading time: 10 minutes/load
Application time estimate: 200 hours
Application efficiency estimate: 0.36
22. Scenario 1
Northwest Missouri
Apply in April
Run tanker up to 12 hours per day, 6 days per week
Need 200 hours
Analysis
Mean:
130 hours fieldwork in April
12 % probability of success
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 50 100 150 200 250 300
ProbablityofCompletion
Hours Available
23. 0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 100 200 300 400 500 600
ProbablityofCompletion
Hours Available
Solution 1 (need 200 hrs):
Expand application to May
(ApplyApril to June 2 (2 months))
Mean:
305 hours fieldwork in April-May
87% probability of success
April-May
24. 0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 50 100 150 200 250 300
ProbablityofCompletion
Hours Available
Solution 2:
Increase tank size to 7200 gal.
Get a nurse tank
(road time goes to zero)
Need 130 hours
Mean:
130 hours fieldwork in April
53% probability of success
April
25. 0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 100 200 300 400 500 600
ProbablityofCompletion
Hours Available
Solution 3:
Increase tank size to 7200 gal.
Get a nurse tank
(road time goes to zero)
ApplyApril to June 2 (2 months)
Need 130 hours
Mean:
305 hours fieldwork inApril plus May
April 1 – June 2
96% chance of success
April - May
26. 0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 50 100 150 200 250 300
ProbablityofCompletion
Hours Available
Solution 4:
Increase tank size to 7200 gal.
Get a nurse tank
(road time goes to zero)
Move 33% of application to fall
Need 130 hours.
86 hours April
71 % chance of success
44 hours from Nov. 18 -30
80% chance of success in Nov.
April
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 20 40 60 80 100
ProbablityofCompletion
Hours Available
Nov. 18-30
27. 165
170
175
180
185
190
195
200
205
Field
Distance (-)
Swath
Width (+)
Tanker size
(+)
Road
Travel
Speed (+)
FieldTravel
Speed (+)
Hourstocover400acres
Base
20% change
Field distance: 1.0 to 0.8 miles Tanker size: 6000 to 7200 gal. Field travel speed: 7.0 to 8.4 mph
Swath width: 15 to 18 feet Road travel speed: 10 to 12 mph
28. Expand to other states
Integrate into nutrient management reporting software
Quantitative approach for April - November
29. Not covered by the Fieldwork database
Factors to consider
Soil temperature below 32oF (frozen soils)
Snow cover
Precipitation
Saturated soils