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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Water Management and Conservation Research » Research » Publications at this Location » Publication #377350

Research Project: Advancing Water Management and Conservation in Irrigated Arid Lands

Location: Water Management and Conservation Research

Title: Revising petiole nitrate sufficiency/deficiency guidelines for irrigated cotton in the desert southwest

Author
item Bronson, Kevin
item NORTON, E.R - University Of Arizona
item SILVERTOOTH, J.C. - University Of Arizona

Submitted to: Soil Science Society of America Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/7/2020
Publication Date: 4/11/2021
Citation: Bronson, K.F., Norton, E., Silvertooth, J. 2021. Revising petiole nitrate sufficiency/deficiency guidelines for irrigated cotton in the desert southwest. Soil Science Society of America Journal. 85(3):893-902. https://doi.org/10.1002/saj2.20213.
DOI: https://doi.org/10.1002/saj2.20213

Interpretive Summary: Petiole nitrate-nitrogen (NO3-N) sampling and testing remains a popular in-season nitrogen (N) management practice in the Western US for cotton (Gossypium hirsutum). However, the present guidelines used by Arizona are greater than 35 years old and are in need of updating. The objectives of this study were to relate in-season petiole NO3-N levels with lint yields and revise the former critical deficiency levels by growth stage guidelines. Petioles were sampled between first square and peak bloom in nine site-years of cotton N management field trials in Maricopa and Safford, AZ from 2014-2018. Irrigation type in Maricopa was overhead sprinkler (OSI) (2014-2015), and subsurface drip irrigation (SDI) (2016-2018). In Safford (2014-2017), surface irrigation (SI) was used. Petiole NO3 in SDI was dramatically lower than with SI or OSI, mostly in the deficient range. Lower lint yields in zero-N treatments compared to pre-plant soil NO3 test-based reference treatments occurred in 8 site-years (Safford 2016 crop lost to late hailstorm) and were considered N deficient. Critical petiole NO3-N levels from 1984 were revised downward 1g N kg-1, since several N-fertilized plot means of petiole NO3-N were in that range and did not exhibit an N rate-related yield depression.

Technical Abstract: Petiole nitrate-nitrogen (NO3-N) sampling and testing remains a popular in-season nitrogen (N) management practice in the Western US for cotton (Gossypium hirsutum). However, the present guidelines used by Arizona are greater than 35 years old and are in need of updating. The objectives of this study were to relate in-season petiole NO3 levels with lint yields and N deficiencies and to revise the former critical deficiency levels by growth stage guidelines. Petioles were sampled between first square and peak bloom in nine site-years of cotton N management field trials in Maricopa and Safford, AZ from 2014-2018. Irrigation type in Maricopa was overhead sprinkler (OSI) (2014-2015), and subsurface drip irrigation (SDI) (2016-2018). In Safford (2014-2017), surface irrigation (SI) was used. Petiole NO3 in SDI was dramatically lower than with SI or OSI, mostly in the deficient range. Lower lint yields in zero-N treatments compared to pre-plant soil NO3 test-based reference treatments occurred in 8 site-years (Safford 2016 crop lost to late hailstorm) and were considered N deficient. Critical petiole NO3-N levels from 1984 were revised downward 1g N kg-1, since several N-fertilized treatment means of petiole NO3 were in that range and did not exhibit an N rate-related yield depression. Sampling cotton plants for petiole NO3 analysis should start within one week of first bloom. Petiole NO3 dynamics and critical levels in SDI cotton required further study.