Date: 1/15/02
Report Name: LA-17F FY01 Final Report
I.
Statement of the project objectives.
Objective 1 – To continue the improvement of mid-south soybean production efficiency
(profit potential) through the incorporation and unbiased evaluation of “precision
agriculture” technology into existing on-farm soybean production systems via multistate soybean research verification programs.
Objective 2 – Evaluate the potential for more profitable soybean production by
implementing Extension recommendations more precisely utilizing the Global
Positioning System (GPS) and other precision agriculture technology including remote
sensing, aerial photography, etc.
Objective 3 – Identify and quantify factors that are major contributors to yield
differences as determined by yield monitors, remote sensing, aerial photographs, and
other generated maps.
II. Statement of quantifiable progress toward project objectives achieved during this
reporting period.
We selected three fields in the fall of 2000 where the grower had the use of a GPS yield
monitor. They are located as follows:
Acadia Parish, LA – Mike and Jimbo Hundley Farm—Barrett Courville, County
Agent. This was a 21.6 acre irrigated, full season soybean field following rice. This field
was grid sampled and maps were made to indicate plant nutrient variability in the soil.
(SeeAttachment 1) . We used the Veris 3100 on April 10 to measure electrical
conductivity in the soil. There were 2 measurements taken, one at the 0-12” depth, and
one at the 0-36” depth. Based on these maps, we then grid sampled in areas of like
electrical conductivity. There were 16 grids constructed, 1.35 acres each. For all data
maps, refer to Attachment 1. We also have yield monitor data from last year’s rice crop
which we have not yet analyzed to determine if a correlation exists between best yielding
areas based on 2000 rice yields.
Hartz 5999 RR was planted on May 11 on 32" rows and the result was an ideal stand.
We monitored the field weekly until right before harvest. We “ground truthed” the field
right before harvest to record the coordinates of weak spots and potential low yielding
areas with a notation as to cause, if known. This field was irrigated only once, due to an
abnormally good year for rainfall distribution.
We harvested the field with a John Deere CTS2 combine on 10-03-01and recorded the
data on a yield monitor card. The field yielded 34.7 bushels per acre, which is slightly
above the state average this year of 32.0. (See Attachment 2). Maurice Wolcott,
Research Associate, is in the process of trying to correlate electrical conductivity
measuresments taken earlier with fertility data and with yield monitor data. Most of the
weak spots in the field were due to severe cuts when the field was leveled for rice
production several years ago. There were also scattered spots of morningglory which
probably resulted in some yield loss at harvest. These areas were noted right before
harvest and will be compared to the yield monitor data to see if much loss can be
attributed to this factor.
Concordia Parish, LA. -- Lee Bean and Tommy Ellet, Angelina Plantation—Glen
Daniels, County Agent. This was a 58.6 acre, early season, irrigated soybean field
following rice. Grid soil sampling was completed on April 11 following the determination
of differences in electrical conductivity. There were 31 grids constructed, each with 1.95
acres. Sampling was done as with the Acadia field, to get grids which were placed in
areas of like soil electrical conductivity. (See the maps in Attachment 3). We hoped to
correlate these measurements with differences in soil test data. Our plans for data
collection and analysis were the same as for the Acadia field.
Deltapine 3478 was planted on May 1 with a grain drill on 10" rows and an acceptable
stand was achieved except for two rounds of the grain drill on the west side of the field
where untreated seed were used. This area had to be replanted. Since plants emerged
over about a 2-3 week period, maturity may vary and may give an interesting variation
to yields at harvest. Weekly monitoring of this field was carried out until just before
harvest. Yield potential was reduced due to heavy rains occurring from emergence to the
R4 stage (16.34 inches from May 1 until July 15). This caused some scalding and
Phytophthora which reduced populations in the wettest parts of the field. Some of these
weak areas also contributed to late season weed problems. Coordinates of these areas
were noted so that variations in yield monitor data could be explained more clearly.
The field was harvested with a Case IH 2388 combine with a yield monitor attached on
09-21-01, which was about 3 weeks late due to continuous rains during the first twothirds of the month. These conditions reduced yields and seed quality further. Weight
tickets indicated an average yield of 34.3 bushels per acre with a test weight of 53 and
damage of 3.5%. We are in the process of analyzing the data collected during the season
as we did for the Acadia field. Unfortunately the original yield monitor on the combine
malfunctioned and a replacement unit provided the farmer by Case gave us data which
was not compatible with our programs. We are still trying to work out the data
obtained and get it in a format that we can handle. Most of the yield variability in the
field is expected to be due to heavy cuts made in the leveling process and to low areas
where water stood for long periods of time.
St. Landry Parish, LA. —C & F Farms—Keith Normand, County Agent. We
designated two fields which were considered our precision agriculture field, with areas
of 35.3 and 37.2 acres. Both were subject to irrigation, however, conditions were such
that we never had to apply water. This was a full season soybean field, following rice.
Soil sampling was done in the spring and followed electrical conductivity measurements
taken on April 10. Procedures for grid sampling were similar to those used in the above
two fields. We have established 35 grids, each being 2.08 acres. (See data in
Attachments 4 and 5).
Hutcheson soybeans were planted on June 17 with a grain drill in the West field in 7 ½"
rows and the East field with a narrow row planter on 18" rows. Excellent stands were
obtained from each planting. Delays in planting occurred because of an early spring
drought that occurred in this area. Following planting the same conditions occurred as
in the Concordia field. Heavy, continuous rains occurred from shortly after emergence
through the R4 stage of growth. Areas of the field where water stood and where it
stayed excessively wet for long periods of time have poorer stands due to scalding and
Phytophthora. These areas were noted as we did above using our GPS equipment.
Weekly monitoring was carried out on this field until harvest. All decisions to irrigate
our Precision Agriculture Fields are based on the Arkansas Irrigation Scheduling
Program which computes water use per day and predicts when the soil moisture reaches
50% of field capacity. Even though planting was delayed, timely rains for most of the
season resulted in very good yields for this location and the scheduling program never
indicated a need to irrigate.
Prior to harvest we observed a breakthrough of weeds, primarily Texas weed, in some
areas of each plot (mainly the South end). Because of this we took our GPS equipment,
marked those areas and rated plant population, weed population and drainage. Our
objective was to correlate yield loss with these factors. (See the maps in Attachment 6).
Both parts of the verification field were harvested using multiple combines. Although we
had assurances that the field would be harvested with a yield monitor, the growers were
in a hurry to harvest and did not consult us before the harvest, resulting in only partial
yield monitor data on one of the two plots. The yields were as follows: 45.0 bushels/A–
18"rows, 47.1 bushels/A -- 7 !/2" rows, for a composite average of 46.1, which was very
good for this part of the state and for soybeans planted after the optimum planting
period.
We have corn and rice yield monitor data from these fields in 1998, 1999 and 2000 (See
Attachment 5) and will compare that data to the soil test data to see if there are
correlations. Thus far we have not seen any correlation between soil test levels and yield,
between soil test levels and soil conductivity, nor between yield and soil conductivity.
Our plans for further analysis on this field can not be done because of the lack of yield
monitor data.
In addition to the three fields cited above, all 14 soybean research verification fields
were mapped to obtain exact acreages and in some cases elevation and hard pan depth.
(See Attachment 7).
III. Activities planned between now and the next reporting period.
We will continue to analyze 2001 data where available, to improve our ability to relate
yield variability to measured variables. Some of the variables which we will try to
correlate to yield differences include soil nutrient levels, organic matter, soil texture, soil
compaction and depth, plant height, elevation, plant populations, and soil conductivity.
Our soil sampling approach this year was concentrated in areas of the field with similar
electrical conductivity instead of random grid sampling.
Each of the above three fields are part of our soybean research verification program and
have been monitored weekly and recommendations made by a team of specialists and
county agents, when appropriate.
Because of the support from this grant, we have been able to update the knowledge of
our county agents and growers on the use of Precision Agriculture Technology in
practical farm situations. Darryl Rester and Maurice Wolcott who have contributed
heavily to this project are planning a “Precision Agriculture Conference” for Monroe,
LA, on Jan. 18-19, 2002. This will involve presentations and a trade show designed for
interested growers in Louisiana. Mr. Rester has used data from the project to present at
field days and producer meetings in 2000 and 2001.
We still have a considerable amount of data to analyze. Due to several changes in job
responsibilities of persons involved in this project, all analyses are not complete at
present. Hopefully, we will finish this shortly.
IV.
Problems, obstacles, new developments or market/industry/research changes that
impacted or may impact the completion date, cost, or scope of the project.
We have had a problem with continuity of this project because growers with GPS
yield monitors who grow soybeans are scarce in Louisiana. Malfunctions of yield
monitors have contributed to loss of critical data at harvest. We have also had
problems getting fertilizer and lime precision applied, due to only two outlets in the
state that do this. We would have liked to get into remote sensing on these fields but
have not been able to find anyone in Louisiana or nearby who would cooperate with
us at a reasonable price. We have been told that it is hard to get flyovers done in a
timely manner and that cloudy days hamper photographic abilities.
V.
Message, questions, comments or requests.
Of great assistance to me in this project besides the growers and county agents
already mentioned are the following people:
Darryl Rester, Extension Agricultural Engineer
Maurice Wolcott, Research Associate, Dean Lee Research Station
Curt Riche, Extension Associate, Agronomy
For the 2002 year we are asking that P.I. status be transferred from Walter C.
Morrison to Darryl Rester. This is due to a change in job responsibilities for Walter
Morrison. A formal request will come from the Extension Director in Louisiana
shortly.