Nitrogen Use Efficiency, Nitrogen Fertilizers, NUE, Nitrogen and the Environment Library of Yield Prediction Equations
Outline for Generating New Crop Algorithms for N Fertilization
What Do N Rich Strips Say About N Rate Algorithms, and Geostatistics and Sampling NDVI, John Solie, University Perspective
Yield Potential Prediction Equations:  Coefficients
Wheat:  INSEY = (NDVI / days from planting to sensing where GDD>0)
Corn:  NDVI/ cumulative GDD


 

Condition Crop Year Equation Units plus 1 SD Yrs Locations RI Adjustment Equation
Dryland Winter Wheat  2002 YP0=344*EXP(INSEY*267.65) kg/ha yes 4 22
Dryland Winter Wheat  2003 YP0=500*EXP(INSEY*267.65) kg/ha yes 5 26
Dryland Winter Wheat 2004 YP0=359*EXP(INSEY*324.4) kg/ha yes 6 30
Dryland Winter Wheat 2005 YP0=522*EXP(INSEY*274.7) kg/ha yes 7 34 RI Harvest = 1.69(RI-NDVI) -0.70
Dryland Winter Wheat 2006 YP0=532*EXP(INSEY*270.1) kg/ha yes 8 38 RI Harvest = 1.69(RI-NDVI) -0.70
Dryland Winter Wheat 2007 YP0=590*EXP(INSEY*258.2) kg/ha yes 9 43 RI Harvest = 1.69(RI-NDVI) -0.70
Dryland Winter Wheat 2007 Mod CoefA = 0.383516x2 - 91.989634x + 6214.147063
CoefB = -0.000423x2 + 0.099424x - 3.746111
YP0 = (CoefA * EXP (CoefB * NDVI))		 kg/ha yes 10   RI Harvest = 1.69(RI-NDVI) -0.70
Dryland Winter Wheat-Forage 2007 YP0 = 159.57*EXP(3.909*NDVI) kg/ha yes 6    
Dryland & Irrigated Durum Wheat 2006 YP0=322*EXP(INSEY*211.5) kg/ha yes 2 4 RI Harvest = 1.69(RI-NDVI) -0.70
Dryland & Irrigated Durum Wheat (for increased protein) 2006 YP0=322*EXP(INSEY*211.5)* kg/ha yes 2 4  
      *apply 20 kg N/ha when projected yield exceeds 4000 kg/ha          
Rainfed Wheat-Southern Australia, David Cox 2006 YP0=1800*EXP(INSEY*85) kg/ha no 1 1 RI Harvest = 1.69(RI-NDVI) -0.70
Rainfed Wheat, E. Australia, R. Heath 2006 YP0=580*EXP(INSEY*244.94) kg/ha no 1 1 RI Harvest = 1.69(RI-NDVI) -0.70
Irrigated Corn 2003 YP0=2332.9*(EXP(INSEY*132.46) kg/ha
Dryland Corn 2003 YP0=1633*(EXP(INSEY*132.46) kg/ha
Dryland & Irrigated Corn 2004 YP0=1565*(EXP(INSEY*154.7) kg/ha yes 3 7 RI Harvest = 1.64(RI-NDVI) - 0.5287
Rainfed Corn (1st planting, Argentina) 2005 YP0=1941*(EXP(INSEY*162) kg/ha yes 3   RI Harvest = 1.64(RI-NDVI)-0.5287
Irrigated Corn (2nd planting, Argentina) 2005 YP0=624*(EXP(INSEY*149.41) kg/ha yes
Rainfed Corn (USA) 2006 YP0=1202*(EXP(INSEY*169.6) kg/ha yes 4 15 RI Harvest = 1.64(RI-NDVI)-0.5287
Irrigated/Rainfed Corn USA, Cummulative GDD 2007 YP0=2592*(EXP(NDVI/Sum of GDD*1775.6) kg/ha       RI Harvest = 1.64(RI NDVI) -0.5287
Rainfed Corn Ohio 2008 YP0=1287*(EXP(NDVI/Sum of GDD*2655) kg/ha   3   RI Harvest = 1.64(RI NDVI) -0.5287
Irrigated/Rainfed Corn (USA) Using days from planting to Sensing 2007 CoefA = 11.777*(days*days) - 1485.4*(days)+48533
CoefB = -0.0008(days*days) + 0.1402*(days)-3.3851
YP0 = (CoefA * EXP (CoefB * NDVI))

days = days from planting to sensing

 kg/ha yes 5 a lot RI Harvest = 1.64(RI NDVI) -0.5287
Irrigated/Rainfed Corn (USA) Using Cumulative GDD 2007 CoefA=641.4158203057011+4207.148880805758/(1.0+EXP(-(x-897.0822110817790)/(-32.78891349907328)))

CoefB=1.46923333343772+1.8752166665474/(1+EXP(-(x-912.164821648278)/2.66689327528455))
(x = cumulative GDD)
YP0 = (CoefA * EXP (CoefB * NDVI))

 kg/ha yes 5 a lot RI Harvest = 1.64(RI NDVI) -0.5287

This algorithm uses cummulative GDD, where GDD are expressed in °F
Rainfed Sorghum 2005 YP0=72*(EXP(INSEY*296.2) kg/ha yes 2 4 none
  Sorghum KSU-OSU 2006 YP0=633*(EXP(INSEY*141.94)          
Sorghum KSU  2007 update YP0=58.689*(EXP(INSEY*273.47) kg/ha yes RI-Harvest=2.104*RI NDVI -1.044
Irrigated Spring Wheat Mexico 2003 YP0=701*EXP(INSEY*154.91) kg/ha yes 3 6  
Irrigated Spring Wheat Mexico 2006 YP0=989*EXP(INSEY*130.65) kg/ha yes 4 11
Irrigated Spring Wheat
Mexico (Melgas)		 2007 YP0=1250*EXP(INSEY*106.12) kg/ha yes 6 15  
Rainfed Spring Wheat INDIA (67-73 days after planting) 2006 YP0=838*EXP(INSEY*177.12) kg/ha yes 2 6  
Rainfed Spring Wheat
Argentina		 2007 YP0=680,547*EXP(NDVI*2701) NDVI a inicios de encaņazon kg/ha yes      
Dryland Spring Wheat Canada 2005 YP0 = 1659*(exp(732.72*INSEY)) kg/ha yes 1
Dryland Spring Wheat
Canada		 2008 YP0 = 996.3*(exp(1779*INSEY)) INSEY = NDVI/sum of GDD in F kg/ha yes 5   RI Harvest = 1.69(RI-NDVI) -0.70
Dryland Bermudagrass 2006 YP0 = 728.8*(exp(639.5*(INSEY)) kg/ha yes 4 2 none
Dryland Canola Canada 2005 YP0=1408.3*exp(744.61*INSEY) kg/ha yes 1
Dryland Canola Canada 2008 YP0=885.7*exp(881.5*INSEY), INSEY = NDVI/sum of GDD kg/ha yes 2