Introduction
Progress & Preliminary Results
References

In their 1997 session, the Texas legislature approved a new agricultural initiative that supported investigating the revolutionary advances taking place within precision agriculture (PA) in Texas. This effort was initially funded for 2 years and was channeled through Texas A&M's CIAPSE, the Center for Improved Agriculture in an Semi-Arid Environment, of which the Agricultural Research and Extension Centers (TAES & TAEX) at Amarillo and Lubbock are members. Other research agencies involved in the initiative are the USDA -Agricultural Research Service (ARS) - Bushland and Lubbock, Texas A&M University (TAMU), West Texas A&M University (WTAMU) and Texas Tech University (TTU). The research sites involved in the total effort are located at the Ag-Cares Farm - Lamesa, the North Plains Research Field - Etter, TAES Agricultural Research and Extension Center - Halfway, TAES James Bush Farm - Bushland, TAES - Bushland and USDA-ARS - Bushland. For this report, only the results of the Amarillo units will be expressed. For a listing of all the projects, refer to the Precision Agriculture: Brief Overview of the Texas High Plains Initiative (Marek, 1998).

Partnership was key to the success of this initiative and strong efforts are continuing to be pursued to involve both the industrial as well as public sectors. Public partnering agencies supporting the Amarillo efforts include the North Plains Underground Water Conservation District #2 - Dumas, the High Plains Underground Water Conservation District #1 - Lubbock, the Panhandle Underground Water Conservation District #3, the Texas Corn Producers Board, the Texas Wheat Producers Board, the Texas Grain Sorghum Producers Board and the Texas Sugar Beet Growers Association. A list of industrial partners associated with the Amarillo/Bushland/Etter units includes John Deere, Monsanto, Resource 21, Veris Technologies, Satloc, Senninger and Valmont Industries.


Precision agriculture, or site specific farming as it is sometimes referred to, is essentially the application of management parameters on a site specific basis whereby the optimization of production and feasibility are attained. The precision agriculture concept itself is not all that new but the ability to readily alter and implement input parameters and controls in real time is what is revolutionary. This in large part has been brought about not only by the advent of computers some time ago but by the continued integration and enhanced utilization of these items into the home, business and farm operations. In addition, the ability to utilize real time differential global positioning systems (DGPS) and geographical information systems (GIS) is beginning to allow the concept of doing what, where, how and when to be implemented. The mechanisms, hardware and controls, to allow these site specific operations to occur is being developed and highly promoted by the industrial sector. The knowing of exactly what to do where however is another matter. This type of information relating the integrated parameters of soils type, soil depth, water holding capacity, crop water use (ET), irrigation scheduling, variety selection, insect pressure, weed pressure, fertility, disease impact, runoff, and topography are not available to the degree needed for inputs to the variable rate controllers. This is what the scientists of the Amarillo units are continuing to pursue in the Texas Precision Agriculture Initiative. Other important areas of address are assessment of associated variability within the Texas High Plains region regarding soils, water and irrigation capacity, environmental impacts and feasibility analysis.


The area effort involves approximately 17 scientists and agricultural engineers from the various agencies. In addition, the AgriPartner effort continues to involve cluster groups with part time personnel in the field gathering data from grower and associated study sites. In particular, the study sites in the northern district are located near meteorological sites of the North Plains Potential Evapotranspiration (NPPET) Network (Howell,et al.,1998). A brief description of the individual projects of the Amarillo/Bushland/Etter units and specific objectives being addressed under this initiative is provided in the adjacent frames.

Much activity and information has been attained this past year regarding individual project objectives. Several statewide and many in-house meetings were held to ensure that coordinated efforts were conducted among the projects. In addition, this type communication ensured timelines were met in regards to effort, delivery and awareness of activity for associated parties. Selected summary activity results of each project are related below.


The Amarillo units procured several new pieces of equipment for use in these studies. Two yield mapping combines were procured with the latest versions of instrumentation and software

to assess and assist researchers and growers with their efforts in using this basic precision agriculture tool. Three portable, differential global positioning systems (DGPS) units were procured for mapping purposes. A visional sprayer was loaned to the unit for evaluation and performance characteristics. Infrared thermometers (IRT) were procured for assessing stress detection. Several computer related items were procured for database compilation, manipulation and evaluation purposes.

The multi-objective project at the North Plains Research Field (NPRF) resulted in assessing and establishing a suitable site for researching variable rate soil depths. This requirement was basic to the premise that precision agriculture could be applied to maximize production in analogous fields. Although depth characterization was extensive at the NPRF (Marek, et al., 1998), personnel are still procuring and assessing area wide data to determine the extent of the type variability found at the NPRF. This task is being hindered from full attainment due to the non-availability of digital soil databases by the NRCS mapping team of Forth Worth. (This is a huge task and not to viewed as a negative toward the NRCS. As with many other entities, the electronic information needs today have outpaced the current capabilities and resources of most agencies). In addition to soil depth, plant population and level of crop water use (crop PET) with corn were determined to be significant in the large study at the NPRF. This means that these factors were determined to be the ones controllable or alterable through variable control, which would produce different results from those of broadcast or uniform activity. Effects of these parameters were pronounced. Fertility in the first year?s assessment did not show to be significantly different. This result coincides with similar results of studies in the Midwest. These results suggest that variable rate irrigation and seeding can be controlled through precision agriculture technologies. The experimentation is being replicated in 1999.

Another NPRF project objective addressed was that of evaluating a visional control sprayer whereby chemical reduction and control effectiveness could be assessed. Limited evaluations conducted during the first season indicated that in-furrow type control could be effective with ample application volume applied per unit area even though the applications were made in ?spirts?. Another way to relate this is to ensure that the nozzle size is larger enough to apply adequate spray and material for control. The limitation of this system still exists in controlling weeds in the plant row. Banded types, over the row type, assessments with compatible control agents are being planned for assessment in the summer of 1999.

Preliminary economic and environmental comparisons were made for site specific versus conventional management practices of corn production. Computations show that there is only a breakeven cost of 6.2 bushels at $2.20 per bushel corn in using high over medium PA nitrogen levels. This is in comparison to the treatment difference of 20 bushels per acre for the high versus medium yield potential. Thus, a yield advantage of almost 14 bushels per acre exists from the first year?s data in using PA over conventional methods. Similar type comparisons existed for the medium versus shallow profiles. Thus, it is apparent that fertility was not a limiting factor in production potential in terms of cost. Runoff data however collected from the NPRF study indicated that nitrates were high compared to the other constituents of nitrites and ortho-phosphates. The only concern to this data is that all nitrogen was applied in liquid form with the largest portion applied as preplant due to the late initiation of the study. 1999 applications are through a more typical combination of anhydrous and side-dressing through the linear sprinkler system.

Examination of sensory instrumentation to assess numerous stress factors has been ongoing at the Bushland location. Tentative results indicate that stress can be detected with the use of IRT?s. However, sometimes there can be confounding and masking effects. Thus, a combination of supporting data will be needed and utilized in determining specific stresses. Plans continue to be to demonstrate appropriate sensors in a field environment when sufficient data has been verified within the lab and greenhouse.

Yield mapping has been conducted and studied at all Amarillo unit sites. Much unknown variability has been detected in reference to anticipated regions of uniformity. In some cases, unknown differences in soil types were exposed. In addition, yield variability due to cultivars, row spacing, plant density and irrigation level was easily detected by yield mapping in grain sorghum and soybeans. Excess nitrogen, lack of water, and root aphids combined to reduce sugarbeet yields 29% on the lower end of furrow irrigated fields. Likewise, root aphids were threefold worse on the lower end of furrow irrigated fields.

A new state-of-the-art center pivot was procured and installed at Bushland to study PA technologies with regard to pathogen infested soils on sugarbeets, grain sorghum and corn. The relationship between the amount of irrigation and incidence of disease was studied and preliminary results indicate that irrigation frequency is more important in reducing losses to soil borne pathogens than amount of irrigation. Irrigation of wheat and sugarbeets at full crop evapotranspiration (ET) each week resulted in significantly more disease than irrigation at full crop ET every other week. Even with lower total yields, the data indicates that producers would be able to gross more profit from fields infested with plant pathogens by reducing irrigation amounts and frequency because they would have less loss to disease and less irrigation expense. Graduate student personnel will continue to evaluate these findings in the 1999 season.

Numerous greenhouse studies have been conducted at the Bushland station to evaluate remote sensing instrumentation under controlled greenhouse conditions and for studying remote sensing instrumentation. This was done to control the conditions and to study the relationship between irrigation, planting density and aphid populations in sorghum. This work was done with the development of an automated sensor platform in the greenhouse. In using this platform, IRT instrumentation and programming was ?perfected? before sensors were taken to the field.

Results from these experiments with greenbug-infested wheat canopy differed from an aphid free wheat canopy. Infested wheat averaged 0.15 and 0.39 degrees C warmer than infested wheat for average daily minimum and maximum temperature, respectively. This indicates that detection is possible with the use of IRT?s. In another experiment, canopy temperature deviations from ambient air temperature for greenbug-infested, uninfested and water stressed wheat followed predictable patterns progressing from uninfested through infested, water stressed and water stress combined with greenbug infestations. Greenbug density was generally higher on plants normally watered in comparison with those receiving 50% of normal watering. Greenbug density did not seem to affect leaf water potential to any significant degree.

A note about the transfer of technology to the field and growers relationships should also be commented on. To date, a local, northern TX High Plains crop consultant has procured an electroconductivity (EC) mapping unit and a portable backpack DGPS unit to assist producers in attaining additional data for their production databases. This additional data was being desired from the producers themselves and Texas A&M is pleased to provide and work with these individuals in providing assessment information to them concerning performance. In addition, Etter unit personnel have provided several local and county demonstrations on the requirements and uses of DGPS for use by producers and consultants. City and urban clientele have expressed a desire for such information through training session as well. Time constraints of the personnel, however, have not allowed this address to be made as yet.

Finally, the AgriPartner component of this PA effort resulted in the acquisition of much supporting data, especially for the NPPET, of which PA heavily relies on. This data will possibly have further benefit in assessing the actual percentages of PET being applied in the field by producers from the southern to the northern Texas High Plains. Since irrigation is key to High Plains production, the level of water applied will be invaluable. In addition to water use data, much insect and plant development data has been gathered and is reported in it?s entirety in the Annual Report 1998 Panhandle AgriPartner (Robinson, et al., 1998).

Further documentation of the Amarillo work completed in year one of this initiative can be found in the Amarillo portion of the Precision Agriculture Initiative for the Texas High plains- 1998 Annual Report.

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Howell, Terry, Thomas Marek, Leon New and Don Dusek. 1998. The Texas North Plains PET Network. 1998 North Plains Research Field Ag Day Report. Texas Agricultural Experiment Station, Amarillo, TX. Publication 98-21. pp.12-17.

Marek, Thomas. 1998. Soil Variability at the North Plains Research Field Precision Agriculture Site. 1998 North Plains Research Field Ag Day Report. Texas Agricultural Experiment Station, Amarillo, TX. Publication 98-21. pp. 4-8.

Marek, Thomas, Brent Bean, Erica Cox and Wyatte Harman. 1998. Precision Agriculture: Brief Overview of the Texas High Plains Initiative 1998 North Plains Research Field Ag Day Report. Texas Agricultural Experiment Station, Amarillo, TX. Publication 98-21. pp. 9-11.

Marek, Thomas and John Sweeten.(eds.) 1998. Precision Agriculture Initiative for the Texas High plains- 1998 Annual Report. Texas Agricultural Experiment Station, Amarillo, TX. 149 p.

Robinson, Bob,. Leon New, Brent Bean, Reggie Jones, Carl Patrick and Greta Schuster. 1998. Annual Report 1998 Panhandle AgriPartner. Texas Agricultural Extension Service, Amarillo, TX.



[1] Research Engineer and Superintendent, Texas Agricultural Experiment Station, Amarillo/Etter and

TAMUS Northern Texas High Plains Precision Agriculture Representative.