Biological and chemical nitrogen fertilizer impact on cumin (Cuminum cyminum L) under different irrigation regimens

Abstract

Introduction: Water and nitrogen deficits are the most important limiting factors for plant growth and crop production in the world. Drought stress would be amplified by the global warming. Moreover, nitrogen scarcity is occurred in most arid and semi-arid areas. Cumin (Cuminum cyminum L.) is an important plant due to export benefits and low water demand. This study was aimed to evaluate nitrogen fertilizer effect on yield and some physiological characteristics of cumin under different irrigation regimens. Methods: The experiment was performed based on a split plot as randomized complete block design. Experiment treatments were irrigation regimens (field capacity, irrigation by draining 40% of soil water as middle stress, and irrigation by draining 80% of soil water as severe stress) and nitrogen fertilizers (60 kg ha-1 urea, 30 kg ha-1 urea, Nitroxin, and Nitroxin + 30 kg ha-1 urea). Results: Drought stress reduced cumin dry weight, seed yield, and chlorophyll content. In contrary, proline content, malondialdehyde (MDA) rate, phenol content, anthocyanin amount, and activity of catalase (CAT) and peroxidase (POX) increased by water stress. Increment urea use resulted in amending cumin growth and seed yield in the field capacity. Also, nitrogen use and raising its rate under the middle water stress caused to improve cumin drought tolerance. However, under the severe water stress, nitrogen application had not a significant impress on drought acclimation and seed yield. Conclusion: Nitroxin inoculation with use of 30 kg ha-1 urea was the most effective treatment to ameliorate seed yield and drought tolerance.

Nitrogen supplement attenuates drought stress for non‐leguminous hybrid plant fescue and does not affect nitrogen‐fixing alfalfa

“…Improved photosynthesis leads to effective photosynthates transfer to roots, higher below‐ground biomass and better overall plant performance (Gonzalez‐Dugo et al, 2010; Pishva et al, 2020). Water shortage strongly affects growth and N metabolism and in turn can reduce plant nitrogen demand (Pishva et al, 2020). On the contrary, N application can contribute to drought resistance in many plant species (Wang et al, 2016).…”

“…Nitrogen is the most necessary nutrient for plants, and its availability is considered one of the main limiting factors in crop production (Glass, 2003). Its content in plants is between 2% and 4% on average, which may reach 6% (Pishva et al, 2020). Nitrogen is involved in biosynthesis of many important compounds, and the lack of N causes a serious imbalance in photosynthesis, stomatal conductance, the maximum potential quantum efficiency of photosystem II and chlorophyll content.…”

“…Water shortage strongly affects growth and N metabolism and in turn can reduce plant nitrogen demand (Pishva et al, 2020). On the contrary, N application can contribute to drought resistance in many plant species (Wang et al, 2016).…”

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Estimated anthropogenic global warming is currently increasing at 0.2°C per decade and will likely reach 1.5°C between 2030 and 2050 (Pishva et al, 2020). As a result, the evapotranspiration rate is enhanced and therefore increases the likelihood of drought stress in plants (Yang et al, 2010).

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“…Drought frequency and intensity in drylands is projected to increase from 1% to 30% by 2100 (Dai, 2013). Globally, about one-third of the land area is affected by drought (Pishva et al, 2020). It is a major threat and the most unpredictable constraint, causing considerable adverse effects on crop production worldwide (Anjum et al, 2017;Hussain et al, 2018).These effects include a variety of plant functional and biochemical disorders, such as reduction in the rate of carbon uptake and turgor, increased oxidative damage, changes in leaf gas exchange, activity of enzymes and ion balance, resulting in impaired development, growth…”