Managing corn root systems through soil moisture sensing

Craig Marsh Seminar Presentation – Spring 2016

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Agenda

IntroductionPersonal BackgroundTopic Selection

ModuleWhy a Module Value of the ModuleAbout the Module Summary

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Background

Upbringing: Born and raised in Northeast Nebraska on an irrigated, row-crop farming operation.

Education: Bachelors of Science (Agronomy) University of Nebraska-Lincoln

Home: Crofton, NE

Family: Heidi (wife)Claire (5 yr. old daughter)Grant (2 year old son)

Interests: Spending time with my familyNebraska Cornhusker football Minnesota Twins baseballVolunteer Fire Department

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Author Name:

Professional Title:

Affiliation (Company / Department):

Current professional work / research interests:

Author Profile

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Craig Marsh

Agronomist / Crop Consultant

Complete Agronomy Solutions

• Co-owner of Complete Agronomy Solutions• Regional Ag Consulting firm • Providing crop consulting services to customers in

Nebraska, South Dakota, and Iowa

• Passion for finding more efficient ways to irrigate corn and soybeans in the Western cornbelt

• Utilizing different irrigation technologies with current clientele.

Background

Why a Module

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Teaching vs. Researching

Larger Pool of Possible Students

Capacitance technology is inherently “Unclear”

Why a Module Dilemma…

In-season corn root activity has always been somewhat of a mystery.

Difficult to physically dig out entire corn root system.

Misunderstanding corn root development adversely affects:Efficiency of applied irrigation waterEfficiency of applied fertilizer

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Why a Module

Solution…

Utilize capacitance moisture probes to identify rooting signatures during growing season

Use signatures as management triggers for irrigation and fertilizer application

Develop a learning module to advise agricultural professionals on the process

Post the module on Iowa State University’s Crop Adviser Institute

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Value of a Module

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John Deere consultation

Consumer / Product Disconnect

Value to…

• Grower• Dealership employee• Complete Agronomy employees

2015 Capacitance Probe Network

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About the Module

• Sensors measure dielectric constant of the profile

• Converts constant to volumetric water content of soil

• As crop roots grow and extract more water, the dielectric constant changes and is reflected as decreased water content.

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Capacitance Moisture Probes

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Identifying Rooting Signatures in Data

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Using Signatures as Management TriggersHas nitrogen leached below root zone?

Using Signatures as Management TriggersWhen should I start irrigating corn?

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July 19th

Silk StageBooks = 0.32” per dayProbe = 0.25” per day

Aug. 18th

Early Milk StageBook says 0.27” per dayProbe = 0.07” per day

Using Signatures as Management TriggersDo I need to keep watering?

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Using Signatures as Management TriggersWhen should I quit irrigating for the season?

Quiz

In the data above, name the date range where minimal root growth occurred due to oversaturation…

July 26th-28th

June 1st- June 25th**

September 12th – September 14th

July 18th – July 27th

Critical Thinking: By simply using the data above, what period of time causes the greatest concern for nitrogen leaching? Describe the timeframe and one possible solution.

June 1st-25th creates the greatest concern for nitrogen leaching. The main reason for concern is the lack of root activity in the 40” profile during most of that month. In combination with oversaturated conditions for much of the month, there is a strong likelihood that nitrogen has leached below the active root zone in June. Active root stepping doesn’t regularly occur until July 1st or later. I would recommend topdressing Urea/AMS (after shallow soil testing) during June to guarantee adequate nitrogen availability.

Summary

Utilize capacitance moisture probes to identify rooting signatures during growing season

Use signatures as management triggers for irrigation and fertilizer application

Develop a learning module to advise agricultural professionals on the process

Post the module on Iowa State University’s Crop Adviser Institute

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References

Ashok, A. and Fares, A. 1998. Evaluation of capacitance probes for optimal irrigation of citrus through soil moisture monitoring in an entisol profile. Irrigation Science, 19.2: 57-64. Available athttp://search.proquest.com/openview/cf5a1a38b82965d887677a8d80d2f723/1?pq-origsite=gscholar&cbl=54025 (Updated January 2000; verified 2 January 2016).

Casanova, J., Evett, S., Heng, L., and Schwartz, R. 2011. Soil water sensing for water balance, ET, and WUE. Doi:10.1016/j.agwat.2011.12.002 Available at https://www.researchgate.net/publication/254407672_Soil_water_sensing_for_water_balance_ET_and_WUE (Updated January 2011; verified 10 November 2016). Agric. Water Manage.

Davison, D., Peterson, J. and van Donk, S. 2012. Effect of amount and timing of subsurface drip irrigation on corn yield. West Central Research and Extension Center, North Platte. University of Nebraska. Paper 73. Available at http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1073&context=westcentresext(Updated 1 January 2012; verified 2 January 2016).

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References

Deere & Company. 2015. John deere field connect. Available at https://www.deere.com/en_US/products/equipment/ag_management_solutions/field_and_crop_solutions/john_deere_field_connect/john_deere_field_connect.page (Updated 2015; verified 10 November 2015).

Irmak, S., Payero, J., Rees, J., VanDeWalle, B., Zoubek, G., 2014. Principals and operational characteristics of watermark granular matrix sensor to measure soil water status and its practical applications for irrigation management in various soil textures. Biological Systems Engineering: Papers and Publications. Paper 332. Available at http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1334&context=biosysengfacpub (Updated May 2014; verified 10 November 2015).

Rhoads, F. and Younts, C. 1991. Irrigation scheduling for corn – why and how. Iowa State University Extension. NCH 20. Available at http://corn.agronomy.wisc.edu/Management/pdfs/NCH20.pdf (Updated October 2000; verified 2 January 2016).

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References

Ryser, P. 2006. The mysterious root length. Plant Soil. 286: 1-6. Springer Science. Available at http://www.efn.uncor.edu/departamentos/divbioeco/otras/ecolcom/compendio/ryser_2006.pdf (Updated 30 August 2006; verified 10 November 2015).

University of California – Davis. 2010. Dielectric soil moisture sensors. Available at http://ucmanagedrought.ucdavis.edu/PDF/DROUGHT_WEB%20_DIELECTRIC.pdf (Updated 2010 ,verified 14 March 2016).

USDA National Institute of Food and Agriculture. 2016. Soils – part 2: physical properties of soil and water. Plant and Soil Sciences eLibrary. Available athttps://passel.unl.edu/pages/informationmodule.php?idinformationmodule=1130447039&topicorder=10&maxto=10 (Updated 2016; verified 2 January 2016).

Xin, J. and Zazueta F. 1994. Soil moisture sensors. University of Florida Cooperative Extension Service. Bulletin 292. Available at http://infohouse.p2ric.org/ref/08/07697.pdf(Updated April 1994; verified 10 November 2016).

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