Short‐term alteration of nitrogen supply prior to harvest affects quality in hydroponic‐cultivated spinach (Spinacia oleracea). (30th September 2013)

• Record Type: Journal Article
• Authors: Lin, Xian Yong; Liu, Xiao Xia; Zhang, Ying Peng; Zhou, Yuan Qing; Hu, Yan; Chen, Qiu Hui; Zhang, Yong Song; Jin, Chong Wei
• Is Part Of: Journal of the science of food and agriculture. Volume 94:Number 5(2014:Mar. 30)
• Page Start: 1020
• Page End: 1025
• Publication Date: 2013-09-30
• Subjects: Food -- Periodicals; Agriculture -- Periodicals; 664
• DOI: 10.1002/jsfa.6368
• Languages: English
• ISSNs: 0022-5142

Abstract

<abstract abstract-type="main" id="jsfa6368-abs-0001"> <title>Abstract</title> <sec id="jsfa6368-sec-0001" sec-type="section"> <title>BACKGROUND</title> <p id="jsfa6368-para-0001"> <bold>Quality‐associated problems, such as excessive <italic>in planta</italic> accumulation of oxalate, often arise in soillessly cultivated spinach (<italic>Spinacia oleracea</italic>). Maintaining a higher level of ammonium (NH<sub>4</sub><sup>+</sup>) compared to nitrate (NO<sub>3</sub><sup>−</sup>) during the growth period can effectively decrease the oxalate content in hydroponically cultivated vegetables. However, long‐term exposure to high concentrations of NH<sub>4</sub><sup>+</sup> induces toxicity in plants, and thus decreases the biomass production. Short‐term application of NH<sub>4</sub><sup>+</sup> before harvesting in soilless cultivation may provide an alternative strategy to decrease oxalate accumulation in spinach, and minimise the yield reduction caused by NH<sub>4</sub><sup>+</sup> toxicity</bold>.</p> </sec> <sec id="jsfa6368-sec-0002" sec-type="section"> <title>RESULT</title> <p id="jsfa6368-para-0002"> <bold>The plants were pre‐cultured in 8 mmol L<sup>−1</sup> NO<sub>3</sub><sup>−</sup> nutrient solution. Next, 6 days before harvest, the plants were transferred to a nutrient solution containing 4 mmol L<sup>−1</sup> NO<sub>3</sub><sup>−</sup> and 4 mmol L<sup>−1</sup> NH<sub>4</sub><sup>+</sup>. This new mix clearly reduced oxalate accumulation, increased levels of several antioxidant compounds, and enhanced antioxidant capacity in the edible parts of spinach plants, but it did not affect biomass production. However, when the 8 mmol L<sup>−1</sup> NO<sub>3</sub><sup>−</sup> was shifted to either nitrogen‐free, 4 mmol L<sup>−1</sup> NH<sub>4</sub><sup>+</sup> or 8 mmol L<sup>−1</sup> NH<sub>4</sub><sup>+</sup> treatments, although some of the quality indexes were improved, yields were significantly reduced</bold>.</p> </sec> <sec id="jsfa6368-sec-0003" sec-type="section"> <title>CONCLUSIONS</title> <p id="jsfa6368-para-0003"> <bold>Short‐term alteration of nitrogen supply prior to harvest significantly affects quality and biomass of spinach plants, and we strongly recommend to simultaneously use NO<sub>3</sub><sup>−</sup> and NH<sub>4</sub><sup>+</sup> in hydroponic cultivation, which improves vegetable quality without decreasing biomass production. © 2013 Society of Chemical Industry</bold> </p> </sec> </abstract>