Response of hydroponic lettuce to aeration, nitrate and potassium in the nutrient solution
Purpose: Floating hydroponic system for lettuce greenhouse production consists of plants inserted in styrofoam platform floating in a 15 cm-tall nutrient solution, which is aerated by some growers while others maintain the solution static. The present investigation had the objective of determining t...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Taylor & Francis Group
2020-05-01
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| Series: | Acta Agriculturae Scandinavica. Section B, Soil and Plant Science |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1080/09064710.2020.1730430 |
| Summary: | Purpose: Floating hydroponic system for lettuce greenhouse production consists of plants inserted in styrofoam platform floating in a 15 cm-tall nutrient solution, which is aerated by some growers while others maintain the solution static. The present investigation had the objective of determining the effect of ${\rm NO}_3^-$-N and K in Romaine lettuce cultivated in floating hydroponic system and the impact of nutrient solution aeration. Materials and methods: Plants were transplanted into 34 L rigid plastic containers with aerated or non-aerated solutions containing either 15/7, 12/8.5 or 12/2.85 meq L−1 of ${\rm NO}_3^-$/K concentration. Results: Aeration of the nutrient solution promoted plant growth, leaf K, P, and Mg, and water uptake, however, photosynthesis and transpiration rates were enhanced under non-aeration conditions. Decreasing N did not affect leaf N uptake and accumulation; however, decreasing K markedly decreased leaf P and K in aerated plants. Despite the higher transpiration and stomatic conductance in non-aerated plants, water uptake was higher in aerated plants. Non-aerated plants exhibited decreased leaf K accumulation. Conclusions: non-aeration or reduction of K concentration of the nutrient solution may be a strategy to reduce leaf K in lettuce; leaf N concentration was unaffected by aeration. |
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| ISSN: | 0906-4710 1651-1913 |