NRCS-CIG Drought Adaptation Project


Project tittle:  Demonstration of Innovative Water Conservation Technologies to Enhance Resilience to Drought While Optimizing Farm Profits

Grantee Name: Clemson University

Project Director:   Dr. José Payero, Extension/Research Associate, Edisto Research and Education Center

Contact Information:

Phone Number: (803) 284-3343 ext 229; E-Mail: jpayero@clemson.edu

Project End Date: March 31, 2016
Project Summary
This is a three-year demonstration project funded by a NRCS Conservation Innovation Grant (CIG), which started in April, 2013. The overarching goal of this demonstration project is to assist row crop, fruit, and vegetable farmers in South Carolina to adopt innovative and proven water conservation technologies to enhance resilience to drought and increase farm profits.  The technologies demonstrated in this project include: (1) conservation tillage and controlled traffic, (2) cover crop, (3) drought tolerant varieties, (4) skip-row configurations, (5) deficit-irrigation, (6) sensor-based irrigation and, (7) variable rate irrigation. Our objectives are to 1) establish six “Prototype Fields” per year to directly train growers to adopt innovative and proven water conservation technologies; 2) demonstrate and evaluate the effects of water conservation technologies on enhancing drought resilience and farm profits; and 3) implement an aggressive training program for crop consultants, technology providers, and county extension agents to become the primary providers of water conservation technologies for growers beyond the geographic and time limitations of this project. Here we present preliminary results obtained in 2013.
Establishment of Prototype Fields
During 2013 we established farm demonstrations sites for all of the seven water conservation and drought adaptation technologies, in different counties in South Carolina. These demonstration sites (“Prototype Fields”) were established on farmer’s fields that have agreed to collaborate with us in this project and at the “Permanent Technical Training Center” located at the Edisto Research and Education Center (Edisto REC). We have also conducted a series of extension activities to showcase and promote the adaption of these practices among growers. Specific activities conducted for each of the seven technologies are as follows:

(1) Conservation Tillage and Controlled Traffic:

Demonstration plots (144) were established in Barnwell County in October 2013 to demonstrate the effects of controlled traffic combined with advanced minimum tillage operations on soil moisture dynamics, soil water holding capacity, and crop responses. Three fields with different soil types (Faceville loamy sand, Fuquay sandy loam, and Lakeland sand) were used for this purpose. We have already collected intensive soil samples from these different soil types for measuring depth to the hardpan and determining soil texture. The demonstration sites were mapped for variation in soil physical properties, using a soil electrical conductivity (EC) measurement system (Veris-3100). This equipment resembles a small disk and simultaneously measures soil EC across a field in either the top 12 or 36 inches of soil (Fig.1). Sixteen different conservation practices were replicated three times in each soil type. Wheat, rye, and tillage radish were planted in these plots with and without deep tillage. Deep tillage operations were performed utilizing bent-leg (Terra Max) conservation tillage equipment prior to planting winter crops. Cover crops will be terminated this spring using appropriate herbicides and cash crops (cotton or corn) will be planted. No surface or deep tillage operations will be performed prior to planting cotton or corn.

figure one

 (2) Cover Crop:

Cover crop demonstration sites were established at two locations (Fig. 2) using a cover crop mixture of rye, oats, radish, turnip, vetch, and clover.  Burndown treatments at both sites were applied on April 25th.  Phytogen Widestrike 499 cotton was planted on May 22nd at site 1 and May 21st at site 2.  Each strip treatment was applied using farmer’s equipment.  Strip plot dimensions were 12 rows wide (~39 ft) by 800 ft long strip plots replicated 4 times.  POST1 was applied on June 19, 2013, POST2 on July 10, 2013, and Layby was applied on August 6, 2013.  Data collected included percent cotton injury and Palmer amaranth control plus population counts at preemergence (pre) application timing, early postemergence (post1) application timing, and mid-post application timing.  Seed cotton yield was collected using yield monitors on December 6 and 9, 2013 at location 1 and 2, respectively.

figure two

(3) Drought Tolerant Varieties:

Two “Prototype Fields” were established at the Edisto REC farm to demonstrate the performance of different cotton and peanuts varieties under four irrigation levels, including the range from dryland to fully-irrigated. The four irrigation treatments applied irrigation to replace either 0, 30, 80, or 100% of crop evapotranspiration (ET). The cotton demonstration included seven varieties, and the peanuts demonstration included two variety types (Runner and Virginia) (Fig. 3). Irrigation and variety treatments were replicated four times. Yield and plant height were measured.

figure three

(4) Skip-row Configurations:

Two “Prototype Fields” were established to demonstrate skip-row configuration technology with dryland cotton. One of the fields was located at a Farmer’s field in Barnwell County and the other one at Edisto REC farm. At the farmer’s farm, a farm-scale demonstration site was established comparing skip-row and solid-planted cotton. In this farm, three 12-row strips were planted. The center strip was planted to single-skip cotton and the other two strips, to solid-planted cotton. Each strip was 800 ft long and was then divided into three blocks (replications) (Fig. 4). To evaluate the water use pattern of each of the two planting configurations, soil moisture was continuously measured during the entire growing season in each of the six plots included in the demonstration (Fig.4).  Soil moisture was measured using EC-5 capacitance moisture sensors  (Decagon Devices) installed at four depths (6”, 12”, 18” and 24”). An automatic rain gauge was also installed to measure rainfall. Em50R wireless radio data loggers were used to collect and store the soil moisture and rainfall data (Fig. 5). At the end of the season, yield from each plot was measured.

figure fourfigure five

The demonstration site at the Edisto REC farm compared the performance of four cotton planting configurations using four replications. The planting configurations included Solid, Single Skip, Double Skip, and Alternate Skip (Table 1). Yield from each plot was collected at harvest using a cotton plot combine instrumented with a yield monitor.

Table 1. Row configurations (x = planted row).

 

Crop Row (R1…R8)

Planting Configuration

Description

R1

R2

R3

R4

R5

R6

R7

R8

Solid (S)

Plant all rows

x

x

x

x

x

x

x

x

Single Skip (SS)

Plant 2 rows , then skip 1 row

x

x

 

x

x

 

x

x

Double Skip (DS)

Plant 2 rows , then skip 2 row

x

x

 

 

x

x

 

 

Alternate Skip (AS)

Plant 1 row , then skip 1 row

x

 

x

 

x

 

x

 

(5) Deficit-Irrigation:

Deficit irrigation was demonstrated in the same fields used to demonstrate drought tolerant varieties (as described above). The four irrigation regimes compared for cotton and peanuts included irrigation to replace 0, 30, 80, or 100% of the crop evapotranspiration (0%ET, 30%ET, 80%ET, and 100%ET). Irrigations were applied using a lateral move system and were based on daily crop evapotranspiration (ET) estimated from an on-site electronic weather station. An irrigation scheduling spreadsheet was developed to perform a daily soil water balance to determine irrigation timings and amounts. Fig. 6 shows a sample output from the scheduling spreadsheet for cotton in 2013.

figure six

(6) Sensor-based Irrigation:

Three “Prototype Fields” were established to demonstrate the use and benefits of sensor-based irrigation technology in horticultural crops. These included:

  • Peach Field : in this Prototype Field, 40 acres of drip-irrigated peach (4 year old) field in Edgefield county was split in half (Fig. 7). One half was irrigated with sensor-based irrigation technology while the other half was irrigated by the grower, using his traditional irrigation practice, based on historical water requirement averages.  The sensor-based irrigation was triggered at 15% available water deficit (AWD) in top 30 cm soil.  For this, soil volumetric moisture content was automatically measured with two Sentek EasyAG 50 soil moisture probes (Fig. 8), one located at the drip emitter and one in between emitters.
  • Watermelon Field:  in this Prototype Field, we established sensor-based irrigation technology in 19 acres of drip-irrigated watermelon field in Barnwell county, which was irrigated as described above.  In this field, we also demonstrated automatic application of crop nutrients with fertigation.  Fertigation was applied at 100 ppm N and K during each irrigation.
  • EREC “Permanent Technical Training Center” (Barnwell County): in this Prototype Field, we established one acre of drip-irrigated watermelons and compared sensor-based irrigation versus typical on-farm irrigation programs. In this field we also compared irrigation cycle duration, including: (a) Short irrigation cycle triggered at 15% AWD in the top 30 cm soil, (b) 1 inch of water applied per week with one daily irrigation cycle, and (c) 1 inch of water applied per week with three daily irrigation cycles.

figure sevenfigure 8 

(7) Variable Rate Irrigation:

In 2013 we converted a two-tower lateral move irrigation system to variable rate irrigation (VRI). We installed solenoid valves and pressure regulators on each sprinkler hose and built the control electronics (Fig. 9). We used  Clemson’s Lateral VRI software to operate the VRI system using a laptop computer. Prior to planting, a VERIS machine was used to measure the soil electro-conductivity (EC) at a regular grid, which was used to create an EC map of the field. The EC map showed soil spatial variability (mainly due to changes in soil texture) and allowed dividing the field into distinct irrigation management zones (Fig. 10). The variable rate lateral was used to irrigate the cotton and peanuts variety and deficit irrigation demonstration plots described above. We used this site to demonstrate to farmers the requirements for doing Variable Rate Irrigation during a field day conducted at Edisto REC. We also included VRI technology in many educational activities and training for growers.

figure 9figure10

Educational activities conducted in 2013

In addition to the establishment of Prototype Fields, our team conducted many educational activities to demonstrate and train growers, crop consultants, equipment dealers and county extension agents on the water conservation practices (Fig. 11). Some of the educational activities included:

  • Presented at the Irrigation and Water Management Workshop organized by the Richland, Calhoun, and Orangeburg Conservation Districts, in St. Matthews, SC (March 14, 2013). Trained farmers on how to schedule irrigations. The meeting was attended by more than 100 growers, crop consultants and extension agents.  
  • Trained farm managers at a Peach Farm in Edgefield county on how to properly install soil moisture sensors and how to interpret the data needed for sensor-based irrigation (March 18, 2013).
  • Trained Barnwell Watermelon Growers, including farm owners and farm managers on how to properly install soil moisture sensors and how to interpret the data needed for sensor-based irrigation (March 25, 2013).
  • Presented at the Irrigation Water Management Workshop. Pee Dee Research and Extension Center, Florence, SC. (March 28, 2013).  Trained farmers on soil moisture sensors available for irrigation scheduling.
  • Conducted the “Watermelon Field Day” at Edisto REC (July 11, 2013), which was attended by more than 225 growers, industry representatives and county Extension Agents. Presented information on sensor-based irrigation and how the technology can be used on the farm to save water, improve crops, reduce farm costs and reduce environmental risk due to leaching of applied nutrients.
  • Presented at The InfoAg 2013 Conference (http://infoag.org), July 16-18, 2013, Springfield, IL.  Gave a talk about “Precision Irrigation technology” to more that 100 farmers, industry personnel, extension agents and scientists from the across USA and overseas.
  • Presented at the Clemson County Agent In-Service Training. Pee Dee Research and Extension Center, Florence, SC, 5 Aug 2013.  Trained County Extension Agent about tools available to improve irrigation and conserve water. 
  • Presented the paper:  “Payero, J.O., Khalilian, A., Miller, G., and Marshall, M. 2013. Adapting to drought through education and demonstration of innovative on-farm water conservation and irrigation management technologies in South Carolina at the Water Education Summit, Sept 24-26, 2013, Chattanooga, TN. This conference was attended by about 300 researchers, industry personnel, government agencies, and extension agents from across the Southeast USA.
  • Presented our work at the Clemson Administrators Tour Field day. Edisto REC, Clemson University, Blackville, SC, 9 Oct 2013.
  • Presented our work at the cotton and soybeans field day at Edisto REC, Blackville, SC, 10 Oct 2013. Specifically, we demonstrated the use of Variable Rate Irrigation, Deficit Irrigation, Skip-row planting and Drought Tolerant Varieties at our demonstration site at Edisto REC. More than 200 farmers and crop consultants attended this field day.
  • Presented display about “Clemson’s Irrigation Research and Extension Program,” which included showcasing the activities under this project, at the PEE DEE Irrigation Showcase hosted by the B.B. Hobbs Company, Florence Civic Center, Florence, SC, October 30, 2013. This meeting was attended by more than 100 people.
  • Presented information on sensor-based irrigation at the Irrigation Seminar in Florence, SC, (October 30, 2013), which was attended by more than 75 growers, industry representatives and county Extension Agents. Presentation focused on how the technology can be used on the farm to save water, improve crops and reduce farm costs and reduce environmental risk due to leaching of applied nutrients.
  • Presented the following poster about this project: “Payero, J.O., Khalilian, A., Miller, G., and Marshall, M. 2013. Field Demonstrations of Drought Adaptation Farming Strategies in South Carolina” at the South East Climate Consortium (SECC) Program Planning 2013, Gainesville, FL, 12-15 Nov, 2013.
  • Trained crop consultants about how to improve irrigation management and conserve water as part of the “Santee Certified Crop Adviser Workshop,” Nov 19-21, 2013, Santee, SC.
  • Trained crop consultants about how cover crops help improve weed suppression in cotton and help conserve water as part of the “Santee Certified Crop Adviser Workshop,” Nov 19, 2013, Santee, SC.
  • Trained new County Extension Agents about Center Pivot Irrigation, including Variable Rate Irrigation, at the Clemson PSA Extension Conference, Clemson (Dec 12, 2013).

figure11

Preliminary results obtained in 2013

The 2013 growing season was extremely wet in South Carolina, with rain events occurring almost every day. Despite this difficulty we were still able to demonstrate the different drought adaptation and water conservation technologies to many growers via farm demonstrations and other educational activities. Although we are still in the processes of analyzing data from 2013, here we include some preliminary results:

  • Preliminary results of cotton variety and deficit irrigation demonstration: In our 2013 cotton deficit irrigation and variety demonstrations near Blackville, irrigation had no effect on lint yield, but we were able to detect significant differences among the seven cotton varieties tested (Table 2 and Fig. 12). The fact that we did find significant differences among irrigation treatments demonstrated the potential for saving water in a wet year, especially if sensors are used to guide irrigation scheduling. We also showed that even using a simple irrigation scheduling spreadsheet (using daily weather data as input), could be an effective, convenient and inexpensive way to schedule irrigation and save water, without reducing yield. 

Table 2. ANOVA for the effect of Variety and Irrigation on cotton lint yield near Blackville, SC, in 2013.   

Factor

DF Sum Sq Mean Sq F value Pr(>F)
Irrigation 1 0.132 0.132 0.484 0.230
Variety 6 1.522 0.254 2.849 0.021 *
Block 3 0.066 0.022 0.246 0.863
Irrigation x Variety 6 0.110 0.018 0.206 0.972
Residuals 39 3.472 0.0898

 figure 12

  • Preliminary results of peanuts variety and deficit irrigation demonstration:  Table 3 and Fig. 13 show that irrigation had no significant effect on crop yield, biomass, plant height or plant width in 2013 due to the unusually wet season. Variety, on the other hand, had a significant effect on all these measured variables, except for biomass. The yield for the Virginia variety was 41% higher than for the Runner, increasing from 3009.8 lb/ac to 4235.9 lb/ac, a difference of 1226.1 lb/ac. The Virginia variety also produced 23% more biomass, increasing from 2288.8 lb/ac for the Runner to 2825.9 lb/ac for the Virginia, a difference of 537.1 lb/ac. The Virginia type plants were also significantly taller (measured on 9/9/2013), averaging 12.59 inches compared to 10.65 inches for the Runner type. The Virginia canopy was also significantly wider, averaging 29.87 inches compared to 24.58 inches for the Runner. It is expected that the difference in canopy development between the two variety types would result in differences in water use pattern.   

Table 3. ANOVA of peanuts yields, biomass, height and width at Edisto REC during 2013.

Source of Variation DF Pr(>F)
Yield Biomass Height Width
Irrigation 3 0.761 0.5284 0.825 0.071
Variety 1 0.0008 *** 0.0658 <0.0001 *** <0.0001***
Rep 1 0.0006 *** 0.0211 * <0.0001 *** <0.0001***
Irrigation x Variety 3 0.5245 0.2234 0.529 0.9416
Residual 23
Signif. Codes: '***' 0.001; '**' 0.01; '*' 0.05

 figure13

  • Preliminary results of sensor-based irrigation demonstration:  
      • In the Peach demonstration field (Final data pending), the grower estimated as much as 35% reduction in water use using sensor-based irrigation.
      • In the Watermelon demonstration field, the extremely wet year (23.5” rain from planting to final harvest) made for an extremely poor watermelon yield and difficulties in on-farm demonstration and evaluation of sensor-based irrigation.  Knowledge, however, was gained which will aid in 2014 demonstrations.  At this site, in cooperation with the grower and an irrigation company, we planned on automatically applying fertilizers by fertigating at 100 ppm N & K each time the sensors called for irrigation.  Due to the extremely wet year, there had few sensor-triggered irrigations.  Consequently the crop initially suffered from lack of nutrients.  We learned that if such a wet year occurs in the future, daily fertigation programs will need to be included in addition to the irrigation program.
      • At the EREC “Permanent Technical Training Center” – Sensor based irrigation was compared to typical on-farm drip irrigation programs. At this site we compared three irrigation cycles, two of them simulating current farmer’s practices of using a fixed irrigation amount of 1 in a week, applied on one or two irrigation cycles per day. The third treatment was based on sensors, resulting in variable cycles per day and variable irrigation application depths. We found that by using the sensor-based irrigation, we produced similar yield with only 25% of the water (Table 4).

Table 4. Comparison of three irrigation treatments on watermelon production in 2013.

Treatment

Irrigation Cycles/day

Irrigation Time/Cycle

Yield (lb/Ac)

Water use (gal/Acre)

Water Use (in)

WUE (lb/gal)

1

2

64 min

74,683

383,229

14.11

0.195

2

1

128 min

75,064

383,229

14.11

0.196

3

Sensor-based

25 min

84,743

97,265

3.58

0.871

  • Preliminary results of cover crop demonstration:  In 2013, two cover crop demonstration sites were established at two locations (Fig. 14a and 14b). Here we present some preliminary results regarding crop development and the effectiveness of weed control program with cover crop and without. Soil water data were collected, but are still under analysis and are not reported here. In 2013 we found that:
      • Biomass averaged 1386 lb/acre at site 1 and 1659 lb/acre at site 2.  No differences were detected between locations on cover crop biomass production.  At planting, both sites were clean and the preplant burndown programs provided excellent early season weed control (Table 5).
      • After application of the PRE treatments, weed control was excellent across all treatments (Table 6).  Rainfall in the beginning of the season was adequate to get activation of the herbicides.  From late May through end of August, excessive rainfall and numerous cloudy days impacted cotton growth and development and timely field operations.  For Palmer amaranth control, treatments lacking an aggressive residual program (i.e., treatment 2), Palmer amaranth and sicklepod were observed (90% and 85% control, respectively).  In the glyphosate-based program, Palmer amaranth escapes were observed (85% control), due to glyphosate resistance and long delay between Warrant applications.  In the treatments lacking an aggressive residual program (i.e., treatment 2), Palmer amaranth and sicklepod were observed (90% and 85% control, respectively).  In the glyphosate program, Palmer amaranth escapes were observed (85% control), due to glyphosate resistance and long delay between Warrant applications.
      • No Palmer amaranth was observed at the PRE application timing (data not shown).  Due to the late planting of the cover crop, no differences were observed between the systems (Table 7).  Abnormal precipitation levels ensured all soil herbicides were properly activated.  As rainfall continued through the summer proper timing of herbicide applications became troublesome.  When POST herbicide operations occurred, we saw a decline in Palmer amaranth populations regardless of treatment.
      • No Palmer amaranth was observed at the PRE application timing (data not shown).  Similar to location #1, no differences were observed between the systems (Table 7).  Overall, we observed lower populations in the Liberty-based programs compared to the Glyphosate systems.  However, populations did decline across all systems, even in the glyphosate system.  Although populations seemed low, there was still a significant weed population at both locations due to untimely rain events and long-term wet soils/ponding in the fields.
      • Significant cotton visual injury was not observed during the summer (data not shown).  Yield differences (Table 8) were only noted with the cover crop treatment at location 2.  The low input LL program (TRT 2) yield was significantly less than TRT 1 (High Input glyphosate).  It appears that the no cover side yielded slight better than the cover side due to the delay in cotton emergence and early season growth and development (from the cover crop residue and saturated soil moisture conditions).  These growth differences were not obvious later in the season, but could have affected the number of bolls set in the cover crop side.  More work is needed to validate the effects of cover crops and herbicide programs on Palmer amaranth control.  The delay in field operations affected treatment efficacy and were a confounding factor in this demonstration.  Growers can still benefit from these results when planning their herbicide programs.

 figure 14

Table 5.  Herbicide Programs* for Replicated Strips:

Treatment 1: (High Input RR program; Using Widestrike Cotton)

Burndown:            Roundup (22 oz/A) + 2,4-D (1 qt/A) + Valor (2 oz/A)  [30 preplant]

PRE:                       Reflex (1 pt/A) + Diuron (1 pt/A) + Paraquat (2 pt/A) [~4 weeks after preplant]

EPOST:                  Roundup (22 oz/A) + Warrant (3 pt/A) [2 weeks after PRE]

MPOST:                Roundup (22 oz/A) + Warrant (3 pt/A) [2 weeks after EPOST]

Layby:                   MSMA (2.67 pt/A) + Diuron (1 pt/A) [2-3 weeks after MPOST]

Treatment 2: (Low Input LL program; Using Widestrike Cotton)

Burndown:            Roundup (22 oz/A) + 2,4-D (1 qt/A) [30 preplant]

PRE:                       Reflex (1 pt/A) + Diuron (1 pt/A) [4 weeks after preplant]

EPOST:                  Liberty (29 oz/A) + Dual Magnum (1.3 pt/A) [2 weeks after PRE]

MPOST:                Liberty (29 oz/A) [2 weeks after EPOST]

Layby:                   MSMA (2.67 pt/A) + Diuron (1 pt/A) [2-3 weeks after MPOST]

Treatment 3: (High Input LL program; Using Widestrike Cotton Variety)

Burndown:            Roundup (22 oz/A) + 2,4-D (1 qt/A) + Valor (2 oz/A)  [30 preplant]

PRE:                       Reflex (1 pt/A) + Diuron (1 pt/A) + Paraquat (2 pt/A) [4 weeks after preplant]

EPOST:                  Liberty (29 oz/A) + Staple (2.5 oz/A) [2 weeks after PRE]

MPOST:                Liberty (29 oz/A) + Dual Magnum (1.0 pt/A) [2 weeks after EPOST]

Layby:                   MSMA (2.67 pt/A) + Diuron (1 pt/A) [2-3 weeks after MPOST]

 Table 6.  Palmer amaranth population counts at three evaluation periods as affected by herbicide program at Location 1.

Treatment

Palmer Amaranth Count (per m2) – Location 1

 

Cover Crop

No Cover Crop

 

6/21/13

7/10/13

7/29/13

6/21/13

7/10/13

7/29/13

1

0

0.25

0

0

0.5

0

2

1.5

0

0

1.5

0.25

0

3

0

0.5

0

0

0.5

0

LSD (0.05)

0.4

0.3

NS

0.6

0.2

NS

 Table 7.  Palmer amaranth population counts at three evaluation periods as affected by herbicide program at Location 2.

Treatment

Palmer Amaranth Count (per m2) – Location 2

 

Cover Crop

No Cover Crop

 

6/21/13

7/10/13

7/29/13

6/21/13

7/10/13

7/29/13

1

2

3.5

1.25

2

3.5

0.5

2

0.25

0

0

1.5

2

2.5

3

1.25

0.25

0.75

1.5

3.5

0.25

LSD (0.05)

0.6

0.5

0.4

0.3

0.4

0.8

Table 8.  Seed cotton yields as affected by herbicide program.

Treatment

Seed Cotton Yield (lb/A)

 

Location 1

Location 2

 

Cover

No Cover

Cover

No Cover

1

1545

1675

1895

2062

2

1365

1450

1312

1856

3

1632

1720

1568

1974

LSD (0.05)

NS

NS

365

NS