Nutrient and salinity management for spinach production under sprinkler irrigation in the low desert region of California


The efficiency of irrigation, as well as optimization of nutrients, affect spinach yield in all growth stages. In this study, the sensitivity of spinach (early and mature yields) to shallow saline groundwater and the effect of fertigation treatments on mature yield were experimentally investigated. The sprinkler irrigation experiments were conducted on 0.47 ha of silty clay soil at the University of California Desert Research and Extension Center (DREC) in Imperial Valley, California. Twelve beds in the experimental field were chosen randomly to investigate the effect of three fertigation treatments on spinach yield. Three rates of urea ammonium nitrate (UAN-32) fertilizer; T1: 200 kg ha−1 (150%), T2: 133.3 kg ha−1 (100%), and T3: 66.7 kg ha−1 (50%) in four replicates were applied. Soil samples to depths of up to 120 cm were collected at baby leaves and mature harvesting dates (17th October and 19th November 2019, respectively) for salinity measurements. Additionally, soil matric potential through the 120 cm soil depth was measured and groundwater levels in five observation wells were recorded during the growing season. Results showed that average soil salinity at baby leaves harvesting stage through the top 60 cm active root zone depth ranged from 0.61 to 1.48 dS m−1, which is lower than the spinach salinity threshold limit (2 dS m−1), while the average groundwater depth was 1.90 m with salinity ranging from 6.35 to 10.60 dS m−1. Correlation analysis showed that the baby spinach leaves yield was weakly correlated (r = 0.40) to the average soil salinity in the top 60 cm soil depth. Although groundwater and top 60 cm soil salinity showed an increase at the mature yield harvesting stage, the mature yield was weakly correlated to soil salinity (p = 0.116). As the UAN-32 rate increased, the mature spinach yield increased. The mature spinach yields were 17.31, 14.00, and 12.54 ton ha−1 for T1, T2, and T3 fertigation treatments, respectively. However, only a 10% reduction in yield occurred in T3 treatment corresponding to a 50% reduction in UAN-32 rate by 66.7 kg ha−1. Based on the results of this study, shallow saline groundwater has little impact on spinach yield. In addition, the 50% increase in UAN-32 rate had a significant impact on mature spinach yield. The 150% UAN-32 rate resulted in an increase in spinach yield and could be used in arid and semiarid regions with similar conditions to the Imperial Valley but additional measures to minimize the leaching of nitrate from the root zone and to reduce the load of nitrogen in drainage water are needed to minimize the potential negative impact of over-fertigation on the environment.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8


  1. Abdelraouf EA (2016) The effects of nitrogen fertilization on yield and quality of spinach grown in high tunnels. Alexandria Sci Exchange J 37(3):488–496

    Google Scholar 

  2. Allen RG, Pereira JS, Raes D, Smith M (1998) Crop evapotranspiration: guidelines for computing crop water requirements, vol 56. FAO, Food and Agriculture Organization of the United Nations, Rome, p 300

    Google Scholar 

  3. Brouwer C, Prins K, Heibloem M (1989) Irrigation water management: irrigation scheduling. Training Manual 4

  4. Charlesworth PB, Muirhead WA (2003) Crop establishment using subsurface drip irrigation: a comparison of point and area sources. Irrig Sci 22:171–176.

    Article  Google Scholar 

  5. CIMIS, California Irrigation Management Information System Available online: Accessed on 1st Sep 2019

  6. Corwin DL, Rhoades JD, Simunek J (2007) Leaching requirement for soil salinity control: steady-state versus transient models. Agric Water Manag 90:165–180.

    Article  Google Scholar 

  7. Cramer D (1998) Fundamental statistics for social research. Routledge, London

    Google Scholar 

  8. Di Mola I, Cozzolino E, Ottaiano L, Nocerino S, Rouphael Y, Colla, El-Nakhel C, Mori M (2020) Nitrogen use and uptake efficiency and crop performance of baby spinach (Spinacia oleracea L.) and Lamb’s Lettuce (Valerianella locusta L.) grown under variable sub-optimal N regimes combined with plant-based biostimulant application. Agronomy 10(2):278

    Article  Google Scholar 

  9. Doane DP, Seward LE (2011) Measuring Skewness. A forgotten statistic? J Stat Educ 19(2):1–18.

    Article  Google Scholar 

  10. Eltarabily MG, Burke JM, Bali KM (2019) Effect of deficit irrigation on nitrogen uptake of sunflower in the low desert region of California. Water 11:2340.

    CAS  Article  Google Scholar 

  11. Eltarabily MG, Burke JM, Bali KM (2020) Impact of deficit irrigation on shallow saline groundwater contribution and sunflower productivity in the Imperial Valley, California. Water 12(2):571.

    Article  Google Scholar 

  12. Ferreira JFS, Sandhu D, Liu X, Halvorson JJ (2018) Spinach (Spinacea oleracea L.) response to Salinity: nutritional value, physiological parameters, antioxidant capacity, and gene expression. Agriculture 8:163.

    CAS  Article  Google Scholar 


  14. Accessed on 1st Oct

  15. Accessed on 10th Mar 2021

  16. Accessed on 1st Sep 2019

  17. Accessed on 1st Sep 2019

  18. Accessed on 1st Sep 2019

  19. Accessed on 1st Sep 2019

  20. Accessed on 1st Jun 2020

  21. Koike ST, Cahn M, Cantwell M, Fennimore S, Lestrange M, Natwick E, Smith RF, Takele E (2011) Spinach production in California. UC Agricultural and Natural Resources: Davis, CA, USA; pp 1–6 (Publication 7212). ISBN-13: 978-1-60107-719-6.

  22. Marvi MSP (2009) Effect of nitrogen and phosphorous rates on fertilizer use efficiency in lettuce and spinach. J Hortic for 1(7):140–147

    Google Scholar 

  23. Nemadodzi LE, Araya H, Nkomo M, Ngezimana W, Mudau NF (2017) Nitrogen, phosphorus, and potassium effects on the physiology and biomass yield of baby spinach (Spinacia oleracea L.). J Plant Nutr.

    Article  Google Scholar 

  24. Ors S, Suarez DL (2016) Salt tolerance of spinach as related to seasonal climate. Hortic Sci 43(1):33–41.

    CAS  Article  Google Scholar 

  25. Ors S, Suarez DL (2017) Spinach biomass yield and physiological response to interactive salinity and water stress. Agric Water Manag 190:31–41.

    Article  Google Scholar 

  26. Patel VK, Vikram B, Sikarwar PS, Sengupta J (2021) Effect of different levels of nitrogen and phosphorus on growth and yield of spinach (Spinacea oleracea L.) cv. all green. J Pharmacogn Phytochem 10(1):2229–2231

    Google Scholar 

  27. Qiu W, Wang Z, Huang C, Chen B, Yang R (2014) Nitrate accumulation in leafy vegetables and its relationship with water. J Soil Sci Plant Nutr 14(4):761–168.

    Article  Google Scholar 

  28. Razali NM, Wah YB (2011) Power comparisons of Shapiro-Wilk, Kolmogorov-Smirnov, Lilliefors, and Anderson-Darling tests. J Stat Model Anal 2(1):21–33

    Google Scholar 

  29. Rogers G (2008) Optimising crop management and postharvest handling for baby leaf salad vegetables. Horticulture Australia Ltd. Level 7, 179 Elizabeth Street, Sydney NSW 2000. Project number VG05068. Accessed on 1st Sep 2019

  30. Sanchez CA, Smith R (2018) Field evaluation and demonstration of controlled release N fertilizers in the western United States. Fertilizer Research% Education Program, CDFA (Ed.), In proceeding of 26th annual conference; October 22–24, 2018, Seaside, California

  31. Seaman A (2016) Organic production and IPM guide for spinach. In: Cornell University Cooperative Extension. New York State, NYS Integrated Pest Management, IPM Program. Publication no. 139.

  32. Shapiro SS, Wilk MB (1965) An analysis of variance test for normality (complete samples). Biometrika 52(3/4):591–611

    Article  Google Scholar 

  33. Smith R, Cahn M, Hartz T (2014) Evaluation of N uptake and water use of leafy green grown in high-density 80-inch bed planting and demonstration of best management practices. Fertilizer Research & Education Program, CDFA (Ed.), In proceeding of 22nd annual conference; October 29–30, 2014, Modesto, California

  34. Snyder L, Orang M, Bali K, Basic Irrigation Scheduling Program (BISe) (2014) Oakland: University of California land, air, and water resources biomet website. Accessed on 1st Sep 2019

  35. Tourte L, Smith RF, Klonsky K, Sumner D, Tumber KP, Stewart D (2015) Sample costs to produce and harvest organic spinach: High density, sprinkler irrigated, 80-inch beds. In: The University of California (Ed.), Agricultural and Natural Resources.

  36. Wang Z, Li S (2005) Effects of nitrogen and phosphorus fertilization on plant growth and nitrate accumulation in vegetables. J Plant Nutr 27(3):539–556.

    CAS  Article  Google Scholar 

  37. Wang Z, Li S, Malhi S (2008) Effects of fertilization and other agronomic measures on nutritional quality of crops. J Sci Food Agric 88(1):7–23.

    CAS  Article  Google Scholar 

  38. Xu C, Mou B (2016) Responses of spinach to salinity and nutrient deficiency in growth, physiology, and nutritional value. J Am Soc Hortic Sci 141(1):12–21.

    CAS  Article  Google Scholar 

  39. Zhang CL, Gao ZM, Zhao YD, Tang WM (1990) The effects of different nitrogen forms and their concentration combinations on the growth and quality of spinach. J Nanjing Agric Univ 13(3):70–74

    Google Scholar 

  40. Zikalala BO, Nkomo M, Araya H, Ngezimana W, Mudau FM (2016) Nutritional quality of baby spinach (Spinacia oleracea L.) as affected by nitrogen, phosphorus, and potassium fertilization. South Afr J Plant Soil 34(2):79–86.

    Article  Google Scholar 

Download references


We would like to acknowledge the support from the US Fulbright program that provided funding for Eltarabily to conduct this work during his stay in California. We thank the staff of the University of California Desert Research and Extension Center for providing the necessary resources and facilities for conducting this experiment.

Author information



Corresponding author

Correspondence to Mohamed G. Eltarabily.

Ethics declarations

Conflict of interest

The authors have declared that no conflict of interest.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Communicated by Samuel Ortega-Farias.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Bali, K.M., Eltarabily, M.G., Berndtsson, R. et al. Nutrient and salinity management for spinach production under sprinkler irrigation in the low desert region of California. Irrig Sci (2021).

Download citation