Comprehensive information on Nitrogen Use Efficiency for cereal crop productionMexico Sensor Results
Influence of Residue on NDVI in wheat
1. Analysis of Wet vs Dry Soil Readings (follow this link)
    RICE, flooded
2. Foliar Application of UAN in Corn
3. INSEY Equation for Spring Wheat (Ciudad Obregon)
4. Predicting Durum Wheat Grain Yields (Rust Breeding Nursery), El Batan

Figure X. Coefficient of variation from NDVI readings taken over time from 4 different corn rows, 27 m in length, Texcoco, MX. The average number of sensor readings per meter is 18.

The date where CV's start to decrease coincide with the physiological stage where the in-row canopy begins to close.  Recognition of the point where the maximum amount of variability is expressed might also be the time where variable rate treatments will have the greatest benefit.


September 6th, 2002, Corn Sensor Readings

 

Fine-silty, mixed, Fluventic Hapludoll (click here to see the profiles, El Batan)


 
 

Single row (27 m in length, 125 individual corn plants) NDVI readings collected at different stages of growth, beginning on the 12th of August, 2002 (V4), to August 28th (V7).

When does a corn plant in monoculture corn become a weed?

 

 



By plant NDVI readings from corn, V12, Texcoco Mexico (above) and picture of the same corn row below

 

 

Data collected by Paul Hodgen, Ken Sayre, and Matthew Reynolds in Ciudad Obregon, MX shows a trend for improved prediction of yield using Green NDVI (versus Red NDVI) for data below that included 48 genotypes and 3 N rates. 

The chart above plots cumulative distance (actual location of plants) and NDVI.  We will use some of this information to predict distance between plants using sensor readings.

 
Foliar P Experiment, Ciudad Obregon, Spring Wheat, 2002
Table 1. Treatment structure including preplant and foliar applications of KH2PO4 
for spring wheat production, Ciudad Obregon, Sonora, MX
 
Trt Preplant P Method Foliar P Growth Stage Grain Yield Grain P Grain N
  kg/ha   kg/ha   kg/ha kg/ha kg/ha
 
1 0 - 0 - 6650 10.4 109
2 0 - 2.5 Feekes 6 6470 11.4 104.7
3 0 - 5 Feekes 6 6954 12.3 116.3
4 0 - 10 Feekes 6 6750 11 111
5 60 BRP 0 - 7332 14.3 125.3
6 60 BRP 2.5 Feekes 6 7372 14.3 124
7 60 BRP 5 Feekes 6 7754 14.9 132.7
8 60 BRP 10 Feekes 6 7475 14 127.3
9 0 - 5 Feekes 10 6897 12 116.3
10 60 BRP 5 Feekes 10 7448 13.8 125
11 0 - 5 Feekes 10.5 6903 12.4 115.7
12 60 BRP 5 Feekes 10.5 7842 15.3 135.3
13 60 BA 0 - 7206 12.4 119.7
14 60 BA 5 Feekes 6 7091 13.2 120
 
SED 154 0.8 4.6
 
BRP, P applied broadcast preplant as 0-20-0 (N-P-K)
BA, P band applied at planting as 0-20-0 (N-P-K)
 

A significant and consistent trend for increased wheat grain yields was noted for the 5 kg/ha foliar P application both at the 0 and 60 kg P/ha preplant rate.  At the higher 10 kg/ha foliar P rate, no differences were observed.

 
Nitrogen Use Efficiency, Nitrogen Fertilizers,nitrogen algorithms, NUE, Nitrogen and the Environment
Trimble Pocket Sensor, Greenseeker, NDVI, nitrogen