240 likes | 450 Views
SOIL 4213 BIOEN 4213. Grid Sampling, and the Future of Soil Sampling. Oklahoma State University. 490ft 2 43560ft 2. = 0.01. 1 Acre Grid, 16 Acres. x x x x x x x x x x x x x x x x. Forage yield NDVI MehlichIII P. 70 60 50 40 30 20 10. 70 60 50 40 30 20 10. 70 60 50 40
E N D
SOIL 4213BIOEN 4213 Grid Sampling, and the Future of Soil Sampling Oklahoma State University
490ft2 43560ft2 = 0.01 1 Acre Grid, 16 Acres x x x x x x x x x x x x x x x x
Forage yield NDVI MehlichIII P 70 60 50 40 30 20 10 70 60 50 40 30 20 10 70 60 50 40 30 20 10 lb/ac 8400 7200 6000 4800 3600 2400 1200 0 ppm 56 49 42 35 28 21 14 7 0 0.84 0.78 0.72 0.66 0.60 0.54 0.48 0.42 0.36 0.30 Distance, ft Distance, ft Distance, ft 1 3 5 7 1 3 5 7 1 3 5 7 Distance, ft Distance, ft Distance, ft
SOIL SAMPLING….RESOLUTION? Grid: 1 acre, 43560ft2 (1) 1 Yield Monitor: 900 ft2 (0.02) x48 Resolution Study: 490ft2(0.01) x89 OSU-VRT: 10ft2 (0.0002) x4356
160 acre field ($10/soil sample) Sensor Based $7,744,000 9 ft2 100 x 4840 Map Based $77,440 900 ft2 48.4 1 Acre 43560 ft2 Grid Based $1600
Mean surface soil test P and fertilizer P recommendations, bemudagrass pasture, Burneyville, OK 70 30 Mehlich III 60 P Fertilizer 25 50 20 P FERTILIZER, kg/ha 40 MEHLICH III P, mg/kg 15 30 10 20 5 10 0 0 0 2 4 6 8 10 12 14 16 18 20 22 DISTANCE, m
Mean surface soil test NH4-N + NO3-N and fertilizer N recommendations, bemudagrass pasture, Burneyville, OK 30 140 25 120 20 100 NH4-N + NO3-N, mg/kg 80 N FERTILIZER, kg/ha 15 60 10 40 NH4-N + NO3-N 5 20 N Fertilizer 0 0 0 2 4 6 8 10 12 14 16 18 20 22 DISTANCE, m
‘Precision agriculture’ and ‘variable rate’ technologies must operate at the resolution where real differences are encountered in the field. OSU Team VRT
TEMPORAL VARIABILITY (South Carolina) Management Zones (PIONEER), Tom Doerge GRID SOIL SAMPLING (SOIL DOCTOR) last graph = every 6 square feet Soil Sampling as a Basis for Fertilizer Application, NDSU, Dave Franzen Systematic Evaluation of Precision Farming Soil Sampling Requirements, USDA-ARS, South Dakota Soil Sampling Strategies for Site Specific Management, Manitoba, CANADA (go to definition of Grid Soil Sampling) University of Georgia (NESPAL) http://www.cropquest.com
x x x x x x x x x x x x x x x x
Class Presentations (turn in title by February 23) Netscape Navigator (hyperlinks are dead) Make – up lecture……. 005 Computer Lab, Will Answer questions 2:30-3:20 Spatial Variability
National Geographic 1996 Southern Russia
45 40 35 30 25 20 15 10 5 0 0 5 10 15 20 25 30 35 40 • FR1 FR1 C1 VR1 VR2 C2 • FR2 FR2 Bermudagrass, Burneyville, OK Prefertilization May 28 Distance, m Distance, m
45 40 35 30 25 20 15 10 5 0 0 5 10 15 20 25 30 35 40 • FR1 FR1 C1 VR1 VR2 C2 • FR2 FR2 Bermudagrass, Burneyville, OK First harvest following fertilization June 27 Distance, m Distance, m
120’ • 1.33 • PNSI • 1.12 • 130’ 0N,0P 100N, 120P Hasil Sembiring OSU Soil Fertility
N Fertilization Rate, lb/ac 0 10 20 30 40 50 60 70 80 90 100 Distance, ft 25 50 75 100 125 150 175 200 225 250 4 14 24 34 44 54 64 Variable N Rate: 36.3 lb N/ac Fixed N Rate: 80.0 lb N/ac 43.7 lb N/ac
Resolution of Soil Fertility Variables Organic MatterRange:1.6-3.5