Result for: Crops: Almonds
4R Practices: Time Place

Nitrate-sensitive salinity management: An advanced 4R practice to optimize nutrient and water uptake under microirrigation

Dr. Patrick Brown

Lead Researcher:

Dr. Patrick Brown


University of California-Davis

Start Date: 2019

End Date: 2024

Collaborating scientists and universities

  • Dr. Thomas Buckley, Assistant Professor, University of California-Davis

Matching Funds

  • Almond Board of California
  • Netafim Irrigation
  • UC Agriculture and Natural Resources
  • Toro
  • Jain
  • Wilbur Ellis
  • Koch
  • Nutrien
  • American Farmland Trust

Project Summary

This study addresses a specific technical problem that the California almond industry is currently facing: How do you prevent nitrate leaching in micro-irrigated almonds orchards while simultaneously preventing salt accumulation in the root zone? Salinity imposes a significant impact in many areas of the central Valley of California and is greatly exacerbated in drought years when groundwater replaces surface water supplies. Californian agriculture is also now legislatively mandated to reduce nitrate leaching. Salinity has historically been managed by the application of water in excess of plant demand to leach salts (particularly Cl) below the active root-zone, NO3 however, leaches at essentially the same rate as Cl and hence will also move to the saline periphery of the root zone, where it is subject to loss. The control of salinity buildup by leaching, has not been optimized for the microirrigated context, and requires access to adequate water supplies and thus has a high potential risk of nitrate leaching and groundwater contamination. To develop irrigation and fertigation practices that achieve nitrate-sensitive salinity management, will require a deep understanding of root responses to micro-irrigation and the dynamics of nitrate and salinity uptake and movement in saline affected microirrigated orchards. To address this challenge, we propose an integrated study of root architecture and distribution, root physiology and plasticity, under micro-irrigation in almond. This study places a special focus on determining the ‘right place’ and ‘right time’ so that irrigation and fertigation strategies can be optimized to achieve nitrate-sensitive salinity management.

Project Goals:

  • To model/measure/validate patterns of root nitrate, water and salt uptake when roots are exposed to spatial and temporally heterogeneous conditions by the use of open-source tools (R and python among others) to characterize the structural and functional response of roots to micro-irrigation.

  • To model/measure/validate solute movement in the soil under different scenarios such as soil types, environmental conditions, irrigation frequency/length, and water qualities to characterize the environmental determinants of nitrate and salt movement.

  • To integrate modeling/validation processes that will be developed to improve our understanding of the ‘right place’ and ‘right time’ to achieve more accurate N-fertilization practices for almond orchards. This approach is applicable to all micro-irrigated tree crops in California, with relevance globally.

Project Results:

  • No preliminary results

Annual Reports