growing rice using center pivot irrigation. earl vories ph.d. - agricultural engineering...

Growing Rice Using Center Pivot Irrigation

Earl Vories• Ph.D. - Agricultural Engineering• Professional Engineer - Arkansas• University of Arkansas: 1988 - 2004• USDA-ARS: 2004 - present• Agricultural Engineer, Lead Scientist• Delta Research Center, Portageville, MO• Earl.Vories@ars.usda.gov

Mention of trade names or commercial products is solely for purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.

CEU Credit

• This 60 minute seminar is worth 1 CEU• CEUs are only available to those who

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More than half of US rice produced in Mid-South

• Almost half in Arkansas• Mostly produced in flooded culture • Generally requires more irrigation water

than other crops produced in the regionPublished estimate for Arkansas: 760 mm,

based on several years of on-farm observationsVories et al. (2006) reported 460 - 1435 mm for

33 Arkansas fields during 2003 through 2005Smith et al. (2006) reported 382 - 1034 mm in

Mississippi in 2003 and 2004

Mid-South Rice Production

Dry-seeding system most common• crop flooded ~V-4 growth stage • continuous flood until after heading

– insufficient irrigation water results in dry portions of the fields• increased weed problems• fertilizer problems• low yields

Mid-South Rice Production

Dry-seeding system common in Mid-South• excessive water also problem

– wastes water– wastes energy to pump excess water– increases pressure on levees– soil, fertilizers, pesticides may be in runoff

• Insufficient water generally of more concern to producers, at least when energy prices were lower

WellRice Field

Levee spill

Irrigation Tubing

Levee

(~60 mm VI)

Field Slope

(~0.1%)

Field Drain

By 1915 the alluvial aquifer, principal water source for agriculture in eastern Arkansas and surrounding areas, already being tapped at rate exceeding recharge in some areas (Corps of Engineers)• problem exacerbated as Arkansas rice production

increased to >650,000 ha; also increased in Mississippi, Louisiana, and Missouri

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Harvested rice area in Arkansas

(from www.anrc.arkansas.gov)

Surface Irrigation

• Burt et al. (2000) reported potential application efficiency for continuous flood irrigation 80% under practical conditions– within center pivot systems range (75 - 90%)

• added that surface irrigation systems "require the most 'art' of all the irrigation methods, both to obtain a high distribution uniformity and a high application efficiency. In general, people have not learned the art.”

Surface IrrigationIn practice, much water lost from surface irrigated fields• Mid-South operations spread over large

areas• farmers simultaneously managing several

irrigation systems• one worker responsible for several fields• each field waters differently

– often differences within fields due to highly variable soils.

Rice Production Systems• Different production systems investigated

to reduce water requirement with varying levels of success– furrow irrigation– delayed flooding– intermittent flooding– multiple inlet rice irrigation– 0 grade

• Only multiple inlet and 0 grade have been very widely adopted so far

Center Pivot Rice Production

Center pivot irrigated rice production investigated in 1980's• Problems observed precluded adoption

weed control disease (blast) towers got stuck low yield (maybe due to others)

Center Pivot Rice Production

• renewed interest in US and especially internationally– improved cultivars and hybrids–additional herbicides– Improved tower/sprinkler arrangement

Traction Alternatives

3- and 4-wheeldrive on towers

Boomback puts sprinkler behind wheel (if only

running in one direction)

Tracks

Center Pivot Rice Production

Valmont began working with University of Missouri/ARS and several Mid-South growers on pivot-irrigated rice in 2008

Irrigation Method• When rice produced in

flooded culture, water uniformly available across the field

• With a center pivot (sprinkler) system– distribution uniformity of the

irrigation system impacts how much water is delivered to an area• well designed/maintained

systems have high uniformity

Irrigation Method• With a center pivot (sprinkler) system

– soil variability combined with distribution uniformity leads to site-specific differences in how much of that water available to plants

Soil Mapping UnitsCm: Commerce silt loamCn: Convent fine sandy loamSk: Sharkey-Crevasse complexSm: Sharkey-Steele complexSo: Steele loamy sandTu: Tunica silty clay

Irrigation Method• Center pivot systems typically have

application efficiencies as high as 90%• Combination of alluvial, wind, and seismic

activity has resulted in highly variable soils in the Mid-South– common to have sand - clay in same field

• Will highly variable Mid-South soils negatively impact the spatial distribution of yield with sprinkler irrigation?

• Can variable rate irrigation (VRI) adequately compensate?

field where center pivot rice study conducted

field where earlier drip irrigation and flood comparison (Brian Ottis); flooded treatments that were filled in the morning would have exposed soil by evening

Water savings (relative to flood) not always goal; in many cases goal is to bring rice into crop rotation where flooded production was not practical

MU Delta Center Marsh Farm

How do Flood and Center Pivot Rice Production Compare

• With new interest in center pivot irrigated rice, many producers have questions concerning how the yields compare to flooded production and the costs involved

• Working with area farmer, able to compare grain yield and costs between RRVP flooded rice field and field grown by same producer with center pivot irrigation

Rice Research Verification Program (RRVP)

• University of Arkansas Cooperative Extension Service established RRVP, interdisciplinary program that represents public exhibition of implementation of research-based Extension recommendations in an actual field scale farming environment in 1983.

• The producer agrees to pay production expenses, provide expense data, and implement university recommendations in a timely manner from planting to harvest.

• RRVP has been conducted on over 300 commercial rice fields in more than 30 rice-producing Arkansas.

McCarty pivot rice field

McCarty Farms participated in RRVP, also cooperated with Lindsay on center pivot rice on field near Osceola, Arkansas

McCarty RRVP rice field

2009 aerial images of rice fields showing soil mapping units within fields.

a) RRVP Field b) Center Pivot Field

Soil Mapping UnitsCm: Commerce silt loamCn: Convent fine sandy loamSk: Sharkey-Crevasse complexSm: Sharkey-Steele complexSo: Steele loamy sandTu: Tunica silty clay

• RiceTec hybrid 'Clearfield XL745‘• Both fields scouted; pesticides applied as

needed, with different applications to each field based on observed problems

• Ground application used for fertilizers and pesticides in RRVP field during early season; aerial application used after flood initiation

• Ground application was used for all pesticides on the center pivot rice; combination of aerial application, ground application, and fertigation used for fertilizer

Methods and Materials

• Irrigated with diesel-powered pumping plant flood initiated at approximately the V-4 growth stage maintained until after heading

• Multiple Inlet irrigation used• propeller-type flowmeter installed between the

well and irrigation tubing• 690 mm of rainfall recorded at field• 589 mm of irrigation water applied to crop

FindingsRRVP field

• electric pump and center pivot system• pivot used to germinate seed, incorporate herbicide• no established recommendations for center pivot

rice production, so 18-mm applications made ~every other day in absence of rain, mid-May until ~80% of rice kernels brown

• Rainfall not recorded at field 690 mm recorded at RRVP field - 12 km 660 mm recorded at U Ark NEREC - 6 km

• 460 mm of irrigation water applied to the crop

Findingscenter pivot field

Estimated irrigation costsIrrigation component Total cost, $ ha-1

RRVP Pivot

Construct leveesz 18.5Levee gatesz 4.8Gate installation with installerz 4.3Tubing installation, setup and removal (multiple inlet)y 25.5Labory 0.9 0.7Electricityx 72.6Diesel fuelw 92.9Remove levee gatesz 4.3Tear down leveesz 23.1

Total estimated irrigation cost 174.1 73.3z from Watkins et al., 2008y from Hogan et al., 2007x amount billed by provider minus 10% used for soybean irrigationw estimated from Lipsey (date unknown) for northeast Arkansas conditions

Estimated irrigation costs• The differences between total estimated costs

influenced by the different power sources (i.e., electric for pivot; diesel for the RRVP).– Electric systems have higher efficiencies so electricity

generally used when 3-phase power is available.– An electrically powered system on RRVP would have

been expected to have total cost of $139 ha-1, or $57 ha-1 less than the diesel system.

• Many agricultural areas in Arkansas do not have access to 3-phase power– < one-third of irrigated area in Arkansas used electric

systems in 2008.

Yields• The observed grain yields were similar

– 10.1 Mg ha-1 average (dry) – RRVP field– 9.7 Mg ha-1 average (dry) – center pivot field

• Irrigation water use efficiency (IWUE; ratio of yield and irrigation water applied) higher than reported for conventional (0.9 kg m-3) and multiple inlet (1.2 kg m-3)*– 1.7 kg m-3 for RRVP field– 2.1 kg m-3 for pivot irrigated field

* Vories et al., 2005

Interpolated surfaces of grain yield (Mg ha-1) measured by the yield monitors.

a) RRVP Field b) Center Pivot Field

Dry Yield(Mg ha-1)

Dry Yield(Mg ha-1)

Variety test harvested separately

Pesticide applications and associated costsDate Product Active ingredient Application method Total costz, $ ha-1

RRVP Pivot

25 April insecticide chlorantraniliprole seed treatment 54.4

25 April herbicide clomazone ground 45.1

27 April herbicide clomazone ground 53.9

5 May herbicide imazethapyr ammonium salt ground 47.9

16 May herbicide imazethapyr ammonium salt

+ carfentrazone-ethyl ground 53.8

27 May herbicide pendamethalin ground 24.7

31 May herbicide imazethapyr ammonium salt

+ fenoxaprop-p-ethyl ground 107.1

11 June herbicide imazethapyr ammonium salt

+ halosulfuron-methyl aerial 72.6

1 July herbicide imazamox ammonium salt ground 62.0

14 July herbicide cyhalafop-butyl aerial 88.8

15 July fungicide azoxystrobin aerial 51.9

Total pesticide cost, including application 374.3 287.9z total cost includes cost of product + cost of custom application

Fertilizer applications and associated costsDate Application, kg ha-1 Material Method Total costz, $ ha-1

RRVP Pivot

20 May 112 ammonium sulfate aerial 47.5

10 June 224 urea ground 104.8

10 June 45 ammonium thiosulfate fertigationy 17.5

12 June 336 urea aerial 179.5

28 June 45 ammonium thiosulfate fertigation 17.5

5 July 45 ammonium thiosulfate fertigation 17.5

9 July 112 ammonium sulfate aerial 47.5

12 July 45 ammonium thiosulfate fertigation 17.5

19 July 45 ammonium thiosulfate fertigation 17.5

1 August 78 urea aerial 41.9

Total fertilizer cost, including application 268.8 239.8

z total cost includes cost of product + cost of custom application

y no application cost included for fertigation

Total costs (pesticide, fertilizer, and estimated irrigation, exclusive of

ownership costs)

• $817 ha-1 for RRVP field• $601 ha-1 for pivot irrigated field

Conclusions• Acceptable yield obtained with center pivot

irrigation (9.7 Mg ha-1, 192 bushels/acre)• Average yields consistent among soil mapping

units– Interpolated yield maps did not indicate patterns

corresponding to the mapping units or other factors– Highly variable Mid-South soils did not appear to

negatively impact the spatial distribution of yield

• Water was probably saved relative to flooded production (no direct statistical comparison)

Conclusions

• Results suggest center pivot irrigated rice is viable production system.

• Other studies (Vories et al., 2010) and demonstrations (J. LaRue, personal communication, 2009) also resulted in satisfactory production with center pivot irrigation.

• Additional research should soon lead to production recommendations for producers interested in the system.

Scheduling Irrigation on Non-Flooded Rice

Irrigation Management

Irrigation scheduling more difficult in sub-humid regions than arid• Clouds, rainfall, temperature swings all

complicate irrigation scheduling• Weather conditions vary greatly year to

year and within year• Most scheduling methods measure or

estimate soil water content– highly variable soils limited measurements

Irrigation Management

• Methods that estimate soil water content rely on crop coefficient to relate ETc (crop) to ETo (reference)– single coefficient: effects of transpiration and

evaporation combined (Kc)

– dual coefficient: effects of crop transpiration and soil evaporation determined separately• basal coefficient (Kcb) describing plant transpiration

• evaporation coefficient (Ke) describing evaporation from the soil surface

Irrigation Management

Since US rice almost always produced with flood irrigation, little work devoted to

scheduling rice irrigation

Objective: develop procedure for scheduling irrigations on sprinkler

irrigated rice

Methods• Cultivar/hybrid and fertility studies with

center pivot irrigation• Field irrigated 13 mm on alternate days• Watermark sensors placed in four locations• Irrigation ceased when grain color

suggested maturity• Experimental crop coefficient developed

and included in beta version of AIS• Daily ETo calculated from weather data

collected on site

Pivot Rice at Portageville, 18 acres

Variety test

Large-scale Variety test

Nitrogen

Weed control

No Fungicide

No Fertigation

Basal Rice Crop Coefficient, Short Grass ReferenceFAO 56 - assuming 5 days planting to emergence

Arkansas Irrigation Scheduler beta version

Center Pivot Rice Study Area Showing Soil Mapping Units

Soil Mapping Units

Dd = Dundee sandy loam

De = Dundee silt loam

Re = Reelfoot loam

Rf = Reelfoot sandy loam

Tp = Tiptonville silt loam

Real-time Weather at University of Mo. Delta Research Center Marsh Farm (http://agebb.missouri.edu/weather/realtime/portageville.asp)

Observed weather conditions at University of Missouri Delta Research Center Marsh Farm (from AgEBB; http://agebb.missouri.edu/).

Year Weather parameter

April May June July August September 6-month average

Average daily maximum air temperature (°C)

2009 21 25 32 30 30 27 28 2010 24 28 34 33 34 30 31

Average daily minimum air temperature (°C)

2009 9 16 21 21 19 18 17 2010 12 17 23 23 23 17 19

Average daily short grass reference evapotranspiration* (ETo, mm)

2009 3.3 3.6 5.1 4.2 4.3 3.0 3.9 2010 3.8 4.3 5.4 5.1 4.8 3.6 4.5

Cumulative rainfall (mm)

2009 127 183 79 112 48 155 117 2010 130 178 33 74 10 48 79

* ETo reported on AgEBB beginning 22 July 2010; previous values calculated with PMday (Snyder, 2001) using weather data from AgEBB.

Watermark data posted on web page

Watermark sensors - 2009

Estimated SWD, rainfall and irrigation between emergence and final irrigation - 2009

Irrigationfirst: 6/19final: 9/1134 d - 414 mm

Rain during irrigation period 31 d -296 mm

Watermark sensors - 2010

Estimated SWD, rainfall and irrigation between emergence and final irrigation - 2010

Irrigationfirst: 5/24final: 9/145 d - 503 mm

Rain during irrigation period 27 d -219 mm

Conclusions

• AIS appeared to respond as expected and yields from different studies suggested crop not drought stressed

• AIS and Watermark data suggested more irrigation water may have been applied than necessary for optimal crop growth

Conclusions• Next phase will use beta version of AIS to

schedule irrigations based on allowable SWD or MAD– Use two levels of MAD to learn about

acceptable irrigation interval– Variable rate irrigation system added to pivot

to allow multiple application amounts for each level of MAD

– Soil moisture sensors to indicate how well the AIS describes soil moisture

Conclusions

– Data should indicate whether current crop coefficient is adequate

– Additional research should soon lead to production recommendations for producers interested in the system

Blast disease in untreated plots

17 bushels/acre 144 bushels/acre

159 bushels/acre 167 bushels/acre

• Don’t select an older high-maintenance system• Be sure pivot can apply at least 13 mm in two

days (more in arid areas)• Carefully check for missing/plugged sprayheads• Consider tracks and/or larger tires on outer

towers or trouble spots• Consider VRI if soil is variable

Recommendations

• Plant Blast resistant cultivars/hybrids and scout for diseases

• Do not over-fertilize with nitrogen• Stay ahead of weeds• Use an irrigation scheduling program and/or soil

moisture sensors• Chemigate/fertigate to save time and money

Recommendations