Nisar Muhammad Mohsin, Mahmood Rashid, Tayyab Salman, Anees Moazzam, Nadeem Faisal, Bibi Sadia, Waseem Faiza, Ahmed Nazir, Li Jing, Song Zhao
Key Laboratory for New Technology Research of Vegetables, Vegetable Research Institute, Guangdong Academy of Agricultural Science, Guangzhou, China.
Department of Horticulture, University of the Punjab, Lahore, Pakistan.
Front Plant Sci. 2024 Mar 1;15:1340641. doi: 10.3389/fpls.2024.1340641. eCollection 2024.
The cultivation of summer vegetables in open-air nutrient film technique (NFT) hydroponics is limited due to the elevated nutrient solution temperature (NST). In this regard, non-electric evaporative-cooling techniques were explored to maintain NST in open-air NFT hydroponics. Four cooling setups were employed by wrapping polyvinyl chloride (PVC) grow pipes with one and two layers of either wet or dry jute fabrics and attaching them with coiled aluminum pipe buried inside a) wet sand-filled brick tunnels (Cooling Setup I), b) two inverted and vertically stacked earthen pots (Cooling Setup II), c) two inverted and vertically stacked earthen pots externally wrapped with wet jute fabric (Wrapped Cooling Setup II), and d) an earthen pitcher wrapped with wet jute fabric (Cooling Setup III). Wrapping grow pipes with two layers of wet jute fabric reduced NST by 5°C as compared to exposed (naked) grow pipes. The double-layer jute fabric-wrapped grow pipes produced 182% more reduction in NST in comparison to single layer-wrapped grow pipes. Additionally, the installation of Wrapped Cooling Setup II and Cooling Setup III outperformed Cooling Setup I and Cooling Setup II through NST reduction of approximately 4°C in comparison to control. Interestingly, Cooling Setup III showed its effectiveness through NST reductions of 193%, 88%, and 23% during 11 a.m.-12 p.m. as compared to Cooling Setup I, Cooling Setup II, and Wrapped Cooling Setup II, respectively. In contrast, Wrapped Cooling Setup II caused NST reductions of 168%, 191%, and 18% during 2-3 p.m. in comparison to Cooling Setup I, Cooling Setup II, and Cooling Setup III, respectively. Thus, the double-layer jute fabric-wrapped grow pipes linked with Wrapped Cooling Setup II can ensure summer vegetable cultivation in open-air NFT hydroponics as indicated by the survival of five out of 12 vegetable plants till harvest by maintaining NST between 26°C and 28°C.
由于营养液温度（NST）升高，露天营养膜技术（NFT）水培中夏季蔬菜的种植受到限制。在这方面，人们探索了非电蒸发冷却技术来维持露天NFT水培中的营养液温度。采用了四种冷却装置，分别是用一层和两层湿或干黄麻织物包裹聚氯乙烯（PVC）种植管，并将其与埋在以下物体内的螺旋铝管相连：a）湿沙填充的砖砌隧道（冷却装置I）、b）两个倒置并垂直堆叠的陶罐（冷却装置II）、c）外部用湿黄麻织物包裹的两个倒置并垂直堆叠的陶罐（包裹冷却装置II）、d）一个用湿黄麻织物包裹的陶壶（冷却装置III）。与裸露（未包裹）的种植管相比，用两层湿黄麻织物包裹种植管可使营养液温度降低5°C。与单层包裹的种植管相比，双层黄麻织物包裹的种植管使营养液温度降低的幅度多了182%。此外，安装包裹冷却装置II和冷却装置III在降低营养液温度方面比冷却装置I和冷却装置II表现更优，与对照相比，营养液温度降低了约4°C。有趣的是，与冷却装置I、冷却装置II和包裹冷却装置II相比，冷却装置III在上午11点至12点期间使营养液温度分别降低了193%、88%和23%。相比之下，包裹冷却装置II在下午2点至3点期间与冷却装置I、冷却装置II和冷却装置III相比，分别使营养液温度降低了168%、191%和18%。因此，如12株蔬菜中有5株存活至收获所示，与包裹冷却装置II相连的双层黄麻织物包裹的种植管通过将营养液温度维持在26°C至28°C之间，可确保露天NFT水培中夏季蔬菜的种植。
