Optical sensing for N management
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Transcript of Optical sensing for N management
Optical Sensing for Nitrogen Management
Sulochana Dhital, PhD Student
Oklahoma State University
Stillwater, OK
Mt. Everest
NEPAL
N
S
19811983
19851987
19891991
19931995
19971999
20012003
20052007
20092011
0
2,000
4,000
6,000
8,000
10,000
12,000
14,000
US Consumption of Nutrients
Nitrogen (N) Phosphate (P2O5) Potash (K2O)years
Thou
sand
Ton
s
Ammonia Cost and Natural Gas Price
Source: NYMEX Henry Hub, Fertecon, PotashCorp (August, 2014)
Nitrogen Use Efficiency (NUE)
World Nitrogen Use Efficiency (NUE): ~33%
(Raun and Johnson, 1999)
Dead Zone, Northern Gulf of Mexico
For 2014 August 1, the area of Hypoxic zone is 13,080 sq.km (5,052 sq. miles) is below 5 year average.
Source: Nancy N. Rabalais http://water.epa.gov/type/watersheds/named/msbasin/images/hypoxia_size_2013_lg.jpg
Dead Zone, Northern Gulf of Mexico
Source: http://www.gulfhypoxia.net/overview/
Excess nitrogen flowing down the Mississippi each year is estimated to be worth $750,000,000 (Science, Malakoff, 1998)
Hypoxia Worldwide Problem
Source: http://www.gulfhypoxia.net/overview/
Challenge
Increase Nitrogen Use Efficiency Decrease input cost Increase production/Yield
Nitrogen Application
Nitrogen: required in highest quantity. Only preplant application have lowest NUE. Top-dress or side-dress mid-season N applications can
increase NUE (>50%). Fall N application has higher risk of N loss. Spring application can minimize risk and optimize
profitability regardless of tillage (Vetsch and Randall, 2004).
Nitrogen related facts Optimum N rate and NUE changes from year to year.
0 50 100 150 200 2500
2
4
6
8
10
12
14
16
f(x) = − 0.0114034013944196 x + 6.1159539638405R² = 0.116258206654275
f(x) = 0.019879677243769 x + 5.79616716875192R² = 0.293346145128153
Central Great Plains, (1958-2010)
High N
Optimum N rate, kg ha-1
Yie
ld,
Mg h
a-1
Free Environmental N: Total Atmospheric N
Source: National Atmospheric Deposition Program, 2014
Soil organic matter, N supply
The pattern of supply of N made available through net mineralization of soil organic matter N at three sites in Ireland.(Humphreys et al., 2002)
Current Oklahoma State University Approach
Nitrogen Rich Strip OSU GreenSeeker Sensors/Pocket Sensors Variable Rate Applicator Sensor Based Nitrogen Rate Calculator Wheat and Corn Algorithm Web-Based N recommendations Grain Protein Optimizer Ammonia Loss Calculator GreenSeeder Hand Planter
Nitrogen Rich Strip
An area of field with high rate of nitrogen or non-N limiting conditions.
40-50 pounds N/acre, over the average rate. 10 ft wide, 300 ft long. Simple, affordable. Starting from preplant application to 30 days planting
wheat.
Nitrogen rich Strip
Compare N Rich with farmer practice (visual difference)
Sensors to calculate needed N Mid-season N application Approach helps determine N coming from the
environment Minimize environmental damage from excess N
N Rich Strips
Conrad, Montana
N Rich Strip tells You:Yes, I need Nitrogen: If you see strip.No, I do not Need any: If you don’t see Strip.
Cow pox, farmers field
Source:www.osunpk.com
OSU GreenSeeker Sensors/Handheld Sensors (1992-2002)
Measure crop vigor through Normalized Difference Vegetative Index (NDVI).
NDVI is calculated using the equation.
NDVI = NIR ref – red ref / NIR ref + red ref
NDVI values range from 0-0.9. Values near 0.9 are likely non limiting N/healthy plant,
OSU GreenSeeker Sensors/Pocket Sensors (1992-present)
OSU Commercial release GreenSeeker™ in 2002. Optical Sensor/active sensor based technology Emits near infrared and red light which is reflected by
the crop Pocket sensors are more affordable, portable and
lower cost (500 $)
Comparison of NDVI reading
N rich strip Farmers Field
GreenSeeker Sensor
GreenSeeker Handheld Sensor
Variable Rate Technology
Sensor Based Nitrogen Calculator (SBNRC)
GreenSeeker NDVI data (wheat, corn, other crops). Yield potential for a crop is identified using NDVI and
planting date (can then compute GDD) INSEY = NDVI (each date) / (GDD) days from planting
Where GDD= Growing Degree Days from planting Guides producer to apply the optimum N rate
Sensor Based Nitrogen Rate Calculator
United States Outside the States
US Grain Belt-Winter Wheat US-Spring Wheat-Rainfed US Grain Belt-Corn(Rainfed and Irrigated)
S.Australia E.Australia Mexico-Spring Wheat-RainfedBrazil
Bermudagrass-ForageWheat-Forage-PastureGreat Plains, Kansas-SorghumMinnesota, Ohio- CornNorth Central-CottonSouth West Irrigated-Cotton
ArgentinaCanada- Spring Wheat, CanolaIndia-Rice, Spring WheatKenya Rice-Dominion Farms Colombia-Corn Zimbabwe-Corn
Nitrogen Fertilization Algorithm
YP0: Estimate grain yield potential using NDVI and cumulative GDD
RI :N Responsiveness estimated using NDVI in the N Rich Strip and NDVI in the farmer practice or check
CV: Coefficient of variation determined from NDVI sensor readings collected in each plot
Response Index
Yield response to additional N changes N responsiveness = Response Index (RI) RI = Grain yield (Highest N rate or N rich Strip)/Grain
yield (Check 0-N) In season RI : Highest NDVI / NDVI from check N response (RI) changes each year
Response Index
Long term Wheat experiment, Lahoma OK
Response Index
Long term Corn Experiment (1971-2010) Mead, Nebraska
Yield potential and nitrogen response are independent
(Arnall et al., 2013, Agron J. 105:1335-1344)
Optical sensor based Winter Wheat Algorithm
INSEY = NDVI/(days where GDD>0) YP0 = 590exp(INSEY*258.2)
RI = 1.69(NDVI168kgN/NDVI28kgN) - 0.7
YPN = YP0 * RI N rec = ((YPN-YP0) * Grain N)/ fertilizer N efficiency Assumptions:
Grain N = 2.39%
Fertilizer efficiency = 50%
Max Yield = (local cap determined by the producer)
Optical sensor based algorithm for Corn N fertilization
OSU Maize Algorithm
YP0=1291*(EXP(NDVI/Sum of GDD*2649.9) V8 to V12
RI = NDVI- N Rich Strip/ NDVI – Farmer Practice YPN = YP0 * RI N Rate = ((YPN – YP0)* 0.0125)/expected fertilizer use
efficiency
Extension: Oklahoma
More than 500, 000 acres in Oklahoma use N rich Strip
Producers have adopted this technology after seeing the success of their neighbors
Use of GreenSeeker sensor has been a key in Oklahoma
Saving 10 $/acre (Either cutting N rate or gaining yield by increasing N rate)
United States
N rich strip used for different crops rice, cotton, wheat, corn soybean etc.
Louisiana Kansas, Nebraska, Arizona, Iowa Montana Arkansas, Missouri etc. more than 35 US states are using GreenSeeker sensing technologies.
Around the world
NGO’S effective for the extension CIMMYT (Mexico, India, China,) CIAT,CARE, CGIAR OSU Nitrogen Fertilization Algorithm (Wheat and Corn)
are used in Argentina, China and India USAID: Grant allowed GreenSeeker Sensors to be
delivered in China, India, Turkey, Mexico, Argentina, Pakistan, Uzbekistan, and Australia.
Mexico
Mexico
2011-2012
The GreenSeeker Sensor Calibration program in Mexico
N savings Using GreenSeeker In Yaqui Valley, Mexico
Average wheat yield 2011-2012 : 7.2 t/ha Average N rate 250 kg/ha Savings: 68 kg N/ha 13.5 pesos/kg N= 918 pesos/ha ~ 70$/ha While maintaining the same yield By 2012 = 4000 ha
Australia farmer using Green Seeker
Australia
Africa
India
N Rich Strips guides to additional N application Yield potential can be predicted in corn, wheat,
and rice (biomass produced per day). Response to applied N is variable from year to
year and can be predicted. N rate changes from year to year. Nutrient removal is tied to yield level. Need to account freely available N in our N rate.
Conclusion
Thank You