自走式NFT水培生菜一次成苗栽培载体筛选试验

Screening Test of Cultivation Carriers for One‑Step Seedling Cultivation of Lettuce in the Moving NFT

摘要: 为提高水培生菜产能，降低劳动成本，近年来国内逐渐加大引进自动化水平更高的自走式浅液膜技术(Nutrient Film Technique，以下简称NFT)，但与之适配的水培载体多为国外进口，缺少本土化一次成苗水培载体。为探索自走式NFT水培载体的国产化替代，降低耗材成本，本试验创新载体类型，采用无纺布 + 复合基质组合，与商品化的进口椰糠压缩育苗块，以及市场上的几种新型水培载体(海绵、花泥、泥炭育苗钵、黑绵土)进行水培生菜对比研究。结果表明：(1) 自主创新的无纺布袋 + 复合基质水培生菜可一次成苗，成本仅是进口椰糠块的1/3~1/4；(2) 无纺布袋 + 复合基质的通气孔隙度和气水比显著高于其他各处理，具有较强的透气性与保水性；(3) 无纺布袋 + 复合基质保温性好，冬季低温天气水培生菜生长快，叶片多且舒展，株型紧凑适于密植，成苗期、定植后和采收期的单株叶面积、地上部同化物积累量显著高于其他处理，采收期单株地上部鲜重分别比进口40椰糠块和50椰糠块处理高36.4%、40.4%；(4) 无纺布 + 复合基质处理下生菜可溶性糖含量较高，比进口40椰糠块增幅27.4%，不同处理的维生素C含量和亚硝酸钠含量均无显著差异。综合分析，无纺布 + 复合基质载体最适用于自走式NFT水培系统生菜一次成苗栽培。

Abstract: In recent years, China has gradually increased the introduction of the moving Nutrient Film Technique (NFT) to improve the yield and automation level of hydroponic lettuce. However, the localized cultivation carriers compatible with such devices are still underdeveloped; most matching hydroponic carriers are imported from abroad. To explore the localized replacement of cultivation carriers and cut down on consumable costs, this experiment innovated the non-woven fabric bags with mixed substrate (peat:vermiculite:perlite = 3:1:1). A comparative study on hydroponic lettuce was conducted between this innovative substrate and several other new commercial substrates, including coco coir blocks, sponge, floral foam, Jiffypots, and black sponge soil. The results showed that: (1) The independently innovated non-woven fabric bag combined with composite substrate for hydroponic lettuce could achieve one-step seedling raising, with a cost only 1/3 to 1/4 of that of imported coco coir seedling blocks; (2) The aeration porosity and air-water ratio of non-woven fabric bag combined with composite substrate were significantly higher than those of other treatments, showing strong air permeability and water retention; (3) Non-woven fabric bag combined with composite substrate had excellent thermal insulation. Under low temperatures in winter, hydroponic lettuce grew fast with more and expanded leaves, and its compact plant type was suitable for dense planting. The leaf area per plant and aboveground assimilate accumulation at seedling establishment, post-transplanting and harvesting stages were significantly higher than those of other substrate treatments. The aboveground fresh weight per plant was 36.4% and 40.4% higher than that of imported 40 coco coir seedling block and 50 coco coir seedling block treatments, respectively; (4) In terms of quality, the soluble sugar content of lettuce under non-woven fabric combined with composite substrate treatment was relatively high, 27.4% higher than that of imported 40 coco coir seedling block. There were no significant differences in vitamin C content and nitrite content among all treatments. Based on a comprehensive analysis, the non-woven fabric bag combined with a compound substrate is the most suitable choice for one-step seedling cultivation of lettuce in MGS.