Reducing Nitrate Accumulation and Fertilizer Use in Lettuce with Modified Intermittent Nutrient Film Technique (NFT) System
Reducing Nitrate Accumulation and Fertilizer Use in Lettuce with Modified Intermittent Nutrient Film Technique (NFT) System
复制标题
采用改良间歇营养膜技术 (NFT) 系统减少生菜中硝酸盐积累和肥料使用
DOI：
10.3390/agronomy10081208
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
G. Nervo
中科院分区：
文献类型：
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作者：
V. Tabaglio;Roberta Boselli;A. Fiorini;C. Ganimede;Paolo Beccari;S. Santelli;G. Nervo
生菜(Lactuca sativa L.)是一种主要的温室种植蔬菜。然而，硝酸盐(NO3-−)在叶片中的积累仍然是一个主要问题。本研究的目的是：(I)试验改良间歇营养膜技术在无土生菜栽培中的应用，该技术将植株生长在托盘中的泥炭块上，并间歇供应营养液，(Ii)调整施肥方案，以提高产量，同时控制NO3-−浓度。在2013年秋季至2014年春季期间进行了两次温室试验。结果表明，无论是秋季栽培还是春季栽培，30d周期都是鲜生物量产量的最佳周期。由于不利的生长条件，在最后一季减少施氮量并未影响秋季试验期间叶片中N3-−的浓度。相反，在春季试验期间，在收获前2天暂停施肥，在不影响产量的情况下，叶片中NO3-−浓度大幅下降(从20%降至36%)，效果一致。因此，间歇免耕收获前2~4天暂停受精，平均可使NO3-−积累量减少29-58%，受精率降低7-16%。然而，生长条件是使这一体系有效的关键。
Lettuce (Lactuca sativa L.) is a leading greenhouse-grown vegetable. However, nitrate (NO3−) accumulation in leaves remains a major issue. The aims of this research were: (i) to test the modified intermittent Nutrient Film Technique (NFT) in the cultivation of soilless lettuce in which plants are grown on peat blocks in trays and supplied with an intermittent flow of nutrient solution, and (ii) to calibrate the fertilization scheme to increase yield performance, while keeping NO3− concentration under control. Two greenhouse trials were performed between autumn 2013 and spring 2014. Results showed that a 30-day cycle is the optimum duration in terms of fresh biomass yield, both for autumn and spring cultivation. Reducing N fertilization in the last cropping days never affected NO3− concentration in leaves during autumn trial, due to unfavourable growing conditions. Conversely, suspension of fertilization 2 days before harvest had a consistent effect during the spring trial, when NO3− concentration in leaves was highly reduced (from 20 to 36%) without yield penalties. Thus, suspending fertilization 2–4 days before harvesting in intermittent NFT may reduce, on average, NO3− accumulation by 29–58% and the fertilization rate by 7–16%, respectively. Yet, growing conditions are crucial to make this system effective.