PRECISION AGRICULTURE INITIATIVE FOR TEXAS HIGH PLAINS
2002 ANNUAL COMPREHENSIVE REPORT
| Principal Investigators |
|||
| Name |
Title/Agency |
Location |
|
| Bordovsky, J. |
Res. Ag. Engineer/TAES |
Halfway |
j-bordovsky@tamu.edu |
| Bronson, K.F. |
Assist. Prof./TAES |
Lubbock |
k-bronson@tamu.edu |
| Bynum, E. D. |
Res. Scientist/TAES |
Lubbock |
e-bynum@tamu.edu |
| Lascano, R. |
Professor/TAES |
Lubbock |
r-lascano@tamu.edu |
| Nesmith, D. |
Farm Res. Service Mgr. |
Halfway |
d-nesmith@tamu.edu |
| Officer, S.J. |
Post Doc/TAES |
Lubbock |
sjofficer@lbk.ars.usda.gov |
| Payne, B. |
Assist. Prof./TAEX |
Lubbock |
b-payne@tamu.edu |
| Peterson, G. |
Professor/TAES |
Lubbock |
g-peterson@tamu.edu |
| Rosenow, D. |
Professor/TAES |
Lubbock |
d-rosenow@tamu.edu |
| Segarra, E. |
Professor/Texas Tech |
Lubbock |
Eduardo.Segarra@ttu.edu |
| Trostle, C. |
Assist. Prof./TAEX |
Lubbock |
c-trostle@tamu.edu |
| Xu, W. |
Assist. Prof./TAES/TTU |
Lubbock |
w-xu@tamu.edu |
| Wilson, T. |
Professor/TAES/TAEX |
Beaumont |
lt-wilson@aesrg. tamu.edu |
Primary Research Location: Helms Farm at Halfway
Project Title: Precision Agriculture on Summer Grain Crops
Project Objectives:
1) To describe the interactive biological effects of site-specific water, nutrient, and pest management on crop growth and production in an irrigated corn system in rotation with cotton.
2) Quantify the economic and environmental cost-benefit of managing multiple stresses in site specific agriculture compared to conventional systems.
Reporting Period: January 1, 2001 – December 31, 2001
Summary of Progress: (Summarize progress on each specific objective listed above)
1) To describe the interactive biological effects of site-specific water, nutrient, and pest management on crop growth and production in an irrigated corn system in rotation with cotton.
Extensive data collection was successfully carried out in 2001. Similar to the 2002 season, data collection was made at 100 locations that were spaced 30 m apart around three irrigation spans. Soil fertility was sampled in May 1, 2001, by compositing two cores of 51 mm width, cut into depths of 0-152 mm, 152-305, mm 305-610 mm and 610-914 mm. Soils (air dry, <2 mm) were tested for available nitrate, phosphorus (P), cation exchange capacity (CEC), pH, soluble salts (SS), excess lime, organic matter (OM), potassium (K), sulfate sulfur, zinc (Zn), iron (Fe), calcium (Ca), magnesium (Mg) and sodium (Na). Soil fertility was also sampled in August and November, from a single soil core of 25.4 mm width, cut into depths of 0-152 mm and 152-305 mm. The later soil samples were tested for available nitrate and P only. A short season drought tolerant corn hybrid (Pioneer 3223) was planted at 28,354 seeds/acre on 21 May 2001. Irrigation was applied at a single rate of 80% ET. Herbicide was applied after planting. Plant density was counted after emergence for 5.31 m lengths in four rows centered on the GPS location points. Three N fertilizer rates were applied on June 14 (liquid 32-0-0 at 110, 185, and 240 lb/acre based on the yield potential of 100, 150, and 200 bu/acre respectively) to randomized blocks in each of the three pivot spans. Soil moisture was measured by neutron probe at one tube buried at each GPS location in five increments of 305 mm, to a depth of 1.52 m at approximate two week intervals between June 20 and August 13, 2001 (Table 1).
Table 1. Dates of neutron probe measurement.
| Locations 0-50 |
Locations 51-100 |
| June 20 |
June 20 |
| July 3 |
July 2 |
| July 16 |
July 17 |
| July 30 |
- |
| - |
August 6 |
| August 13 |
- |
The crop was sprayed with Asana in late June for corn borer. An attempt to infect one site at each of the 100 locations with spider mites, similar to 2000, was judged to be unsuccessful, and the crop was sprayed with Dimenthoate and Capture in late July and early August to remove the mites. Plant parameters were sampled by randomly selecting three plants from a 6 m radius around each GPS location point. Plants were measured every two weeks (Table 2) for plant height, leaf area and number, number of leaves and cobs, and oven dry weight (100oC) and nitrogen and carbon content of leaf, stem, ear and tassel.
Table 2. Dates of plant measurement in 2001.
| Locations 0-50 |
Locations 51-100 |
| June 20 |
June 20 |
| July 2 |
July 2 |
| July 16 |
July 16 |
| July 30 |
- |
| - |
August 6 |
| August 13 |
- |
| - |
August 20 |
| August 28 |
- |
Canopy reflectance was measured during the season (Table 3) for bands centered at 460, 485, 500, 560, 600, 660, 700, 750, 800, 830, 880, 940, 1100, 1260, 1480, and 1650 nm by a Multispectral Radiometer (CROPSCAN, Inc). Leaf area index (LAI) was measured remotely by Sunscan (Delta-T) on July 3, August 2, and August 8.
Table 3. Dates of canopy reflectance measurement.
| Locations 0-50 |
Locations 51-100 |
| June 7 |
June 7 |
| June 20 |
June 20 |
| July 3 |
July 3 |
| - |
July 17 |
| July 27 |
- |
| - |
August 8 |
| August 20 |
August 19 |
Yield data was collected by hand on October 22 at each location by harvesting cobs for two lengths of 5.31 m in the row on either side of each GPS location point (Fig 1). Plant parameters were also measured at these positions, including total plants, total ears, lodged plants and ears and damage to ears by mold, smut and corn borer. Corn borer damage to 20 plants split open at each location was also measured on October 22. Lodged plants were also counted for four sets of 25 plants at each location on October 25. The crop was machine harvested on October 29, with a yield monitor fitted to the harvester (Fig 1).
Data analysis
Data
analysis is continuing. The N application treatments formed an unbalanced
RBD anova design, when data was collected from all 100 locations. When the
reflectance data was collected from the first or second 50 locations only,
then only a limited anova test of either block one or block three was possible.
Outlyers were removed and skew greater than one was corrected by a log transformation.
All the data sets are currently being tested using these designs (Tables 4
and 5). If the N treatment effects are not significant then all the locations
can be combined and the data sets are suitable for principal component analysis,
which will summarize the data sets in terms of the correlations between the
variables.
  |
| Figure 1. Raw yield data collected in 2001 by yield monitor (upper) and kriged yield pattern from data collected by hand (lower). |
Table 4. Anova results of 100 locations in an unbalanced RBD, showing p-value indicating significance of whole model and type three SS error for the block effect, the N rate treatment effect and block treatment interactions for each attribute tested.
| Attribute |
Model |
Block |
N rate |
Block/Nrate interaction |
| Hand collected yield t/ha |
0.0042 |
0.0009 |
0.0521 |
0.2883 |
| Kriged yield monitor data |
0.0003 |
<.0001 |
0.0040 |
0.9105 |
| Yield/ear (hand collected) |
0.0166 |
0.2531 |
0.0005 |
0.7336 |
| Yield/plant (hand collected) |
0.0176 |
0.3424 |
0.0052 |
0.0853 |
| Population |
<0.0001 |
<0.0001 |
0.0004 |
0.0232 |
| Soil fertility May, pH, 0-152 mm |
0.0931 |
- |
- |
- |
| Lodging (%) |
0.0049 |
0.1892 |
0.0480 |
0.0062 |
| Corn Borer (%) |
0.0082 |
0.0021 |
0.4676 |
0.1656 |
| Soil fertility May, soluble salt, 0-152 mm |
0.0001 |
0.0005 |
0.0511 |
0.0218 |
| Soil fertility May, OM, 0-152 mm |
<.0001 |
<0.0001 |
0.6608 |
0.0176 |
| Soil fertility May, K, 0-152 mm |
0.0636 |
- |
- |
- |
| Soil fertility May, Zn, 0-152 mm |
0.2903 |
- |
- |
- |
| Soil fertility May, Fe, 0-152 mm |
<.0001 |
<.0001 |
0.5135 |
0.4477 |
| Soil fertility May, Ca, 0-152 mm |
0.0004 |
<.0001 |
0.8919 |
0.6481 |
| Soil fertility May, Mg, 0-152 mm |
0.1383 |
- |
- |
- |
| Soil fertility May, Na, 0-152 mm |
0.0067 |
0.0413 |
0.5614 |
0.0113 |
| Soil fertility May, CEC, 0-152 mm |
<.0001 |
<.0001 |
0.8455 |
0.2217 |
| Soil fertility May, P, 0-152 mm |
0.7608 |
- |
- |
- |
| Soil fertility May, Nitrate, 0-152 mm |
0.0734 |
0.0114 |
0.1140 |
0.5653 |
| Soil fertility August, P, 0-152 mm |
0.0001 |
0.0004 |
0.2052 |
0.0056 |
| Soil fertility August, P, 152-305 mm |
0.0256 |
0.0186 |
0.0436 |
0.4661 |
| Soil fertility August, Nitrate , 0-152 mm |
<.0001 |
0.0101 |
0.0012 |
0.0032 |
| Soil fertility August, Nitrate , 152-305 mm |
0.0299 |
0.6190 |
0.0011 |
0.6892 |
| Neutron probe July 2/3, depth a |
0.0065 |
0.2903 |
0.0061 |
0.0688 |
| Neutron probe July 2/3, depth b |
0.3995 |
- |
- |
- |
| Neutron probe July 2/3, depth c |
0.9463 |
- |
- |
- |
| Neutron probe July 2/3, depth d |
0.7337 |
- |
- |
- |
| Neutron probe July 2/3, depth e |
0.6337 |
- |
- |
- |
| Neutron probe July 16/17, depth a |
0.0015 |
0.0163 |
0.0034 |
0.0714 |
| Neutron probe July 16/17, depth b |
0.8915 |
- |
- |
- |
| Neutron probe July 16/17, depth c |
0.8447 |
- |
- |
- |
| Neutron probe July 16/17, depth d |
0.9631 |
- |
- |
- |
| Neutron probe July 16/17, depth e |
0.1237 |
- |
- |
- |
Table 5. Anova results of canopy reflectance values, June 7, 2001, for blocks one or three in an unbalanced nested anova, showing p-value to indicate the significance of whole model and type three SS error for the N rate treatment effect.
| Locations 1-28 |
Model |
N rate |
Location |
| Blue (460 nm) |
<.0001 |
0.2117 |
<.0001 |
| Green (560 nm) |
<.0001 |
0.0089 |
<.0001 |
| Red (660 nm) |
<.0001 |
0.0080 |
<.0001 |
| Near infra red (830 nm) |
<.0001 |
0.0793 |
<.0001 |
| Gndvi |
<.0001 |
0.0625 |
<.0001 |
| Ndvi |
<.0077 |
0.1046 |
0.0093 |
| Locations 63-100 |
Model |
N rate |
Location |
| Blue (460 nm) |
<.0001 |
<.0001 |
<.0001 |
| Green (560 nm) |
<.0001 |
<.0001 |
<.0001 |
| Red (660 nm) |
<.0001 |
<.0001 |
<.0001 |
| Near infra red (830 nm) |
<.0001 |
<.0001 |
<.0001 |
| Gndvi |
<.0001 |
0.0049 |
<.0001 |
| Ndvi |
<.0001 |
0.0673 |
<.0001 |
2) Quantify the economic and environmental cost-benefit of managing multiple stresses in site specific agriculture compared to conventional systems.
In the 2002 season, the 2001 results, as well as results from the prior years, will be used to build crop growth and economic models. Conditional simulation techniques will then be applied to integrate the field variability into the models. The profitability of various land management scenarios can then be investigated and tested in the field.
Milestones achieved:
· Continued evaluation of the drought resistant corn hybrid Pioneer 3223. In 2001, the hybrid was grown in field trails with three rates of nitrogen fertilizer.
· Implementation of remote sensors to measure canopy color and cover. Measurements were made throughout the season using a Multispectral Radiometer (CROPSCAN, Inc) and a Sunscan (Delta-T).
· Successful collection throughout 2001 of detailed field trial information that included: soil fertility and soil moisture, plant yield (collected both by hand and by yield monitor), pest infestation and lodging, plant populations, and detailed measures of plant parameters including height, leaf and ear numbers and dry weights, nitrogen and carbon contents of the stalks tassels, cobs and leaves.
· Implementation of a mixture of traditional (unbalanced anova) and nontraditional statistics (principal component analysis and state space modeling) to precisely identify factors that influence the spatial variability of crop yields from which management units can be drawn.
· Economic analysis of the corn SSF research results (2001) is in progress. The incorporation of the economic analysis results with the field results will enable management zones to be demarcated to increase the efficient management of inputs.
Other developments: (Anything that impacted research progress, positive or negative)
The principal investigator position has been vacant for this project for since June 2001. The data collection continued as planned. The new investigator arrived in February 2002. Analysis of the 2001 data has commenced, as well as planning for the 2002 season.
Publications:
Machado, S, E.D. Bynum, Jr., T. L. Archer, R.J. Lascano, L.T. Wilson, J. Bordovsky, E. Segarra, K. Bronson, D.M. Nesmith, and W. Xu. 2000. Spatial and Temporal Variability of Corn Grain yield: Site-Specific Relationships of Biotic and Abiotic Factors. Precision Agriculture 2:343-360.
Machado, S, E.D. Bynum, Jr., T. L. Archer, J. Bordovsky, E. Segarra, K. Bronson, D.M. Nesmith, D.T. Rosenow, and G.C. Peterson. 2000. Spatial and Temporal Variability of Sorghum Grain yield: Site-Specific Relations of Soil, Water, Pests, and Diseases. Precision Agriculture (in press).
Machado, S, E.D. Bynum, Jr., T. L. Archer, R.J. Lascano, L.T. Wilson, J. Bordovsky, E. Segarra, K. Bronson, D. M. Nesmith, and W. Xu. Spatial and Temporal Variability of Corn Growth and Grain Yield: Implications for Site-Specific Farming. Crop Science (in press).
Machado, S., E.D. Bynum, Jr., T. L. Archer, R.J. Lascano, L.T. Wilson, J. Bordovsky, K. Bronson, D.M. Nesmith, E. Segarra, D.T. Rosenow, G.C. Peterson, W. Xu. 2000. Spatial and Temporal Variability of Sorghum and Corn Yield: Interactions of Biotic and Abiotic Factors. Proceedings of the International Conference on Precision Agriculture, Bloomington, Minnesota (07/00)
Wan, C. G., W. Xu, R.E Sosebee, S. Machado, and T. Archer. 2000. Hydraulic lift in drought-tolerant and –susceptible corn hybrids. Plant and Soil 219:117-126.
Machado, S., E.D. Bynum, Jr., D.T. Rosenow, G.C. Peterson, T. L. Archer, R.J. Lascano, K. Bronson, and E. Segarra. 1999. Spatial Variability of Sorghum Yield: Site-Specific Interactions of Soil, Water, and Pests. Proceedings of the National Grain Sorghum Producers Convention, Tucson, Arizona, U.S.A.
Machado, S., E.D. Bynum, Jr., T. L. Archer, R.J. Lascano, K. Bronson, E. Segarra, and D.M. Nesmith. 1999. Spatial and Economic Variability of Corn Yield: Site-Specific Interactions of Soil, Water, Pests, and Diseases. Poster presented at the American Society of Agronomy Meetings, Salt Lake City, UT