Sensor research and algorithm development for corn in ND L.K. Sharma, D.W. Franzen, H. Bu, R. Ashley, G. Endres and J. Teboh North Dakota State University, Fargo, ND

 Area and production million acre and 5.5 MT million acre and 8.5 MT Corn acreage in North Dakota is increasing at a very high rate in the last 10 years. INTRODUCTION

Day 1 Day 45 Day 80 Day 120 Corn N timeline Application Period of greatest uptake

The first 6 weeks of growth, little N is needed Source: Dr. Jim Schepers, NUE conference presentation, Fargo-

In high clay soils Leaching is not an issue. Downward movement of water in a high clay soil (Fargo soil series) is about inches per hour, or about 1/3 inch per day.

Image taken June 28, 3 days after area was covered by 6 inches of water

Active optical sensors have been identified as a tool to increase nitrogen-use efficiency GreenSeeker™ (Trimble) Holland Crop Circle Sensor™ (Holland Scientific)

Holland Crop Circle-470 LED Red TARGET SENSOR Red Edge User Selected Filters ACS-470 NIR Source: Dr. Jim Schepers, NUE conference presenattion, Fargo-

 Greenseeker emits two bands visible and near infrared: NDVI= (NIR – Red)/(NIR+Red) (774nm reading – 656nm reading)/(774nm + 656nm) Or (774nm reading – 710nm reading)/(774nm + 710nm) (New GreenSeeker)  Crop Circle-470 emit three bands visible, red edge, and near infrared: NDVI= (NIR – Red/(NIR+Red) (760nm reading – 670nm reading)/ ( ) Or NDVI= (NIR – Red Edge/NIR+Red Edge) (760nm reading – 730nm reading)/ ( )

Materials and Methods Locations and Treatments  51 sites were selected in  Six nitrogen treatments: 0, 40, 80, 120, 160, and 200 lb/acre.  Experimental design: Randomized complete block design with four replications.  Plot size: 20 feet long by 10 feet wide  Soil was sampled to 2-feet in depth for residual nitrate- N preplant.  P and K applied, if found deficient and cooperator application not practical

Crop History & Soil Texture  Previous crop  Tillage history  Surface-subsurface soil texture Sensor readings  Approximately 45 samples/row  The NDVI values were averaged for each plot as well as for each treatment.  Both sensors Crop Circle and Greenseeker were used 8 and 12 leaf stage over the top

Location segregation All research Sites No till Sites East High Clay Sites Medium Textured Sites Conventional till Higher yields/lower yields Western sites

SensorWavelength for NDVI G-SBasic Yield Prediction FormulaMinimum INSEY for N rate GSRedV6Yield = ( X INSEY) GSRed EdgeV6Yield = ( X INSEY) CCRedV6Yield = ( X INSEY) CCRed EdgeV6Yield = ( X INSEY) GSRedV12Yield = (71686 X INSEY) GSRed EdgeV12Yield = ( X INSEY) CCRedV12Yield = ( X INSEY) CCRed EdgeV12Yield = ( X INSEY) West River No-Till

SensorWavelength for NDVI G-SBasic Yield Prediction FormulaMinimum INSEY for N rate GSRedV6Yield = (85506 X INSEY) GSRed EdgeV6Yield = ( X INSEY) CCRedV6Yield = (94286 X INSEY) CCRed EdgeV6Yield = ( X INSEY) GSRedV12Yield = ( X INSEY) GSRed EdgeV12Yield = (89991 X INSEY) CCRedV12Yield = ( X INSEY) CCRed EdgeV12Yield = ( X INSEY) High Clay Soils Eastern North Dakota

SensorWavelength for NDVI G-SBasic Yield Prediction FormulaMinimum INSEY for N rate GSRedV6Yield = (59103 X INSEY) GSRed EdgeV6Not established CCRedV6Yield = (91892 X INSEY) CCRed EdgeV6Yield = (55652 X INSEY) GSRedV12Yield = (89116 X INSEY) GSRed EdgeV12Not established CCRedV12Yield = (88306 X INSEY) CCRed EdgeV12Yield = ( X INSEY) Medium Texture Soils Eastern North Dakota

SensorWavelength for NDVI G-SBasic Yield Prediction FormulaMinimum INSEY for N rate GSRedV6Yield = ( X INSEY) GSRed EdgeV6Not established CCRedV6Yield = ( X INSEY) CCRed EdgeV6Not established GSRedV12Not established GSRed EdgeV12Not established CCRedV12Not established CCRed EdgeV12Yield = ( X INSEY) Long-term No-Till Eastern North Dakota

Procedure to use algorithm

INSEY Yield Reference INSEY Reference Yield INSEY in field Field Yield estimate Corn yield difference in kg/ha. X 1.25 % N in corn grain divided by efficiency factor 0.6 = N rate in kg/ha

Example- Reference yield predicted- 120 bushels In-field yield estimated- 60 bushels difference = 60 bushels X 56 lb N/bushel = 3360 pounds X = 42 lb N 42 /0.6 efficiency factor = 70 lb N at that location.

Wavelength evaluation of two ground based active optical sensors to detect sulfur deficiency in corn using N rich within field areas

Locations Tillage System GPS Coordinated Soil Type Planting Dates First Sensing (V6 stage) Second Sensing (V12 stage) Arthur Convention al-tillage 47 o 06’ ” N, 97 o 57’ ” W Coarse-silty, mixed, superactive, frigid Pachic Hapludolls 05/15/1306/20/1307/10/13 OakesNo-till ’38.066’’ N ’55.219’’ Coarse-silty, mixed, superactive, frigid Aeric Calciaquolls 05/11/1306/18/1307/09/13 Tillage system, soil type, planting date and date of the first and second sensing of experimental sites.

Relationship between N rate and Crop circle red edge INSEY (Crop circle red edge wavelength reading/growing degree-days), V6 at Arthur Relationship between N rate and Crop circle red edge INSEY (Crop circle red edge wavelength reading/growing degree-days), V12 at Arthur

Relationship of Crop Circle red edge INSEY (sensor red edge NDVI/growing degree-days from planting to sensing) and N rate, V6 stage at Arthur Relationship of Crop Circle red edge INSEY (sensor red edge NDVI/growing degree-days from planting to sensing) and N rate, V12 stage at Arthur

Overall Conclusion  Multiplying INSEY by the corn height improve the relationship between INSEYS and Yield.  Red edge NDVI is better at 2 nd stage than Red NDVI.  Crop circle red edge was found better as compared to Greenseeker 2 nd stage.  V12 leaf stage was found better in predicting yield as compared to V8.  Inseason N rate algorithm was successfully build with help of sensors.

This algorithms is a starting point for growers. NDSU Computer Science (Anne Denton- a ICPA presenter) are developing a ‘machine learning’ tool, which will help growers to add their data into the existing algorithm to make the algorithm their ‘own’.

ACKNOWLEDGEMENTS Special Thanks Dr. Dave Franzen (PhD Advisor) Dr. Tom DeSutter (PhD Committee member) Dr. R. J. Goos (PhD Committee member) Dr. Joel Ransom (PhD Committee member) Thanks to the North Dakota Corn Council, IPNI and Pioneer Hi-Bred International for their support of this project. Also to Dr. Anne Denton, NDSU Computer Science Department and the National Science Foundation. Also to Honggang Bu, Brad Schmidt and Eric Schultz.