Nitrate content in lettuce (Lactuca sativa L.) grown on aeroponics with different quantities of nitrogen in the nutrient solution

2002 ◽  
Vol 50 (4) ◽  
pp. 389-397 ◽  
Author(s):  
N. Kacjan-Maršić ◽  
J. Osvald

The influence of different quantities of nitrogen in the nutrient solution on growth, development and nitrate content was studied in aeroponically grown lettuce (Lactuca sativa L.). Three successive experiments were conducted in 1999 from April to September, in an aeroponic system. The lettuce plants, cv. Vanity, were grown in aeroponics using four different amounts of nitrogen in the nutrient solutions. The pH level was maintained between 5.5 and 6.5, and the EC between 1.8 and 2.2 mS/cm. Fresh weight measurements were made on all the material. The differences between the mean fresh shoot weights were statistically significant in all three experiments. In the first experiment, the maximum final fresh weight in the treatment with 8 mM nitrogen averaged 999.0 g. In the second and third experiments the largest amount of nitrogen, 12 mM NO3-N, significantly (p<0.05) increased the fresh shoot weight of lettuce plants. low levels of nitrate in the nutrient solution (4 mM NO3-N in the first and 1.2 mM NO3-N in the second aeroponic experiment) significantly (p<0.05) increased the fresh weight of the final roots compared with the level of nitrate in standard nutrient solution (12 mM NO3-N). The differences between the means for plant height were statistically significant (p<0.05) in all three experiments. In the first and third experiments the lengths of the primary roots of the lettuce plants were significantly (p<0.05) influenced by different NO3-N concentrations in the nutrient solution. The highest NO3- concentration in the lettuce leaves was recorded in plants grown in nutrient solutions with the highest NO3-N concentration (17 mM in the first, 12 mM in the second and third experiments). An acceptably low NO3- concentration was found in the leaves of lettuce treated containing with nutrient solution 4 mM NO3-N in all three experiments.

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 315
Author(s):  
Noémi Kappel ◽  
Ildikó Fruzsina Boros ◽  
Francia Seconde Ravelombola ◽  
László Sipos

The goal of this research was to investigate the effect of electrical conductivity (EC) levels of the nutrient solution on the fresh weight, chlorophyll, and nitrate content of hydroponic-system-grown lettuce. The selected cultivars are the most representative commercial varieties grown for European markets. Seven cultivars (‘Sintia,’ ‘Limeira,’ ‘Corentine,’ ‘Cencibel,’ ‘Kiber,’ ‘Attiraï,’ and ‘Rouxaï’) of three Lactuca sativa L. types’ (butterhead, loose leaf, and oak leaf) were grown in a phytotron in rockwool, meanwhile the EC level of the nutrient solutions were different: normal (<1.3 dS/m) and high (10 dS/m). The plants in the saline condition had a lower yield but elevated chlorophyll content and nitrate level, although the ‘Limeira’ and ‘Cencibel’ cultivars had reduced nitrate levels. The results and the special characteristic of the lollo-type cultivars showed that the nitrate level could be very different due to salinity (‘Limeira’ had the lowest (684 µg/g fresh weight (FW)) and ‘Cencibel’ had the highest (4396 µg/g FW)). There was a moderately strong negative correlation (−0.542) in the reverse ratio among the chlorophyll and nitrate contents in plants treated with a normal EC value, while this relationship was not shown in the saline condition. Under the saline condition, cultivars acted differently, and all examined cultivars stayed under the permitted total nitrate level (5000 µg/g FW).


Foods ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 677 ◽  
Author(s):  
Onofrio Davide Palmitessa ◽  
Massimiliano Renna ◽  
Pasquale Crupi ◽  
Angelo Lovece ◽  
Filomena Corbo ◽  
...  

Microgreens are gaining more and more interest, but little information is available on the effects of the chemical composition of the nutrient solution on the microgreen yield. In this study, three Brassica genotypes (B. oleracea var. italica, B. oleracea var. botrytis, and Brassica rapa L. subsp. sylvestris L. Janch. var. esculenta Hort) were fertigated with three modified strength Hoagland nutrient solutions (1/2, 1/4, and 1/8 strength) or with three modified half-strength Hoagland nutrient solutions with three different NH4:NO3 molar ratios (5:95, 15:85, and 25:75). Microgreen yields and content of inorganic ions, dietary fiber, proteins, α-tocopherol, and β-carotene were evaluated. Micro cauliflower showed the highest yield, as well as a higher content of mineral elements and α-tocopherol (10.4 mg 100 g−1 fresh weight (FW)) than other genotypes. The use of nutrient solution at half strength gave both a high yield (0.23 g cm−2) and a desirable seedling height. By changing the NH4:NO3 molar ratio in the nutrient solution, no differences were found on yield and growing parameters, although the highest β-carotene content (6.3 mg 100 g−1 FW) was found by using a NH4:NO3 molar ratio of 25:75. The lowest nitrate content (on average 6.8 g 100 g−1 dry weight) was found in micro broccoli and micro broccoli raab by using a nutrient solution with NH4:NO3 molar ratios of 25:75 and 5:95, respectively. Micro cauliflower fertigated with a NH4:NO3 molar ratio of 25:75 showed the highest dry matter (9.8 g 100 g−1 FW) and protein content (4.2 g 100 g−1 FW).


2015 ◽  
Vol 32 (2) ◽  
pp. 195-206
Author(s):  
Z. Kobierzyńska-Gołąb

320 bacterial strains isolated from the surface of cultivated plants, as well as from other parts of hydroponic cultures showed stimulating (49 bacterial strains) or inhibitory (9 bacterial strains) properties in respect to the investigated plant. The following bacteria were isolated: <i>Pseudomonas, Flavobacterium, Agrobacterium, Achromobacter</i> and <i>Chromobacterium</i>. The effects of active bacterial strains on the growth of seedlings were investigated in dependence on the kind of inorganic form of nitrogen present in the nutrient solutions. The same bacterial strains exerted a stimulating effect on seedlings growing on nitrates, weaker stimulation was observed in cultures with ammonium nitrate; the growth of lettuce seedlings on nutrient solution with ammonium only, was, as a rule, inhibited by the bacteria.


Revista CERES ◽  
2011 ◽  
Vol 58 (5) ◽  
pp. 619-624 ◽  
Author(s):  
Adriene Woods Pedrosa ◽  
Herminia Emilia Prieto Martinez ◽  
Edson Marcio Matiello ◽  
Paulo Cezar Rezende Fontes ◽  
Paulo Roberto Gomes Pereira

The objective of this work was to evaluate the quality of fruits and the nutritional status of cucumber CV. Aodai cultivated in nutrient solutions with different N:K ratios. The hydroponic cultivation was initially performed, during the vegetative growth, in nutrient solution with 1:2.0 mmol L-1 N:K, and, later, during fruit setting, in four different nutrient solutions with N:K (w/w) at the ratios 1:1.4, 1:1.7, 1:2.0 and 1:2.5. An additional treatment with a nutrient solution containing the ratio 1:2.2 (w/w) N:K during the vegetative growth and N:K 1:1.4 (w/w) during fruit setting, both with 10% ammonium (NH4+) was included. The treatments were arranged in a randomized design with six replicates. Irrigation was carried out with deionized water until seed germination, and then with nutrient solution until 30 days after germination, when plants were transplanted. Plants in the hydroponic growing beds were irrigated with the solutions for vegetative growth, and, after 21 days, the solutions were replaced by solutions for fruit setting. At 45 and 60 days after transplanting, the fresh weight, length, diameter, volume and firmness of the fruit were evaluated, and, at 45 days after transplanting, the macronutrient concentrations in the leaves were determined. The use of different N:K ratios during fruit setting influenced the cucumber production. The ratio of 1.0:1.7 N: K (w/w), with 10% of N in the form of ammonia, is recommended for the whole cycle.


2008 ◽  
Vol 65 (6) ◽  
pp. 652-658 ◽  
Author(s):  
Rodrigo Luiz Cavarianni ◽  
Arthur Bernardes Cecílio Filho ◽  
Jairo Osvaldo Cazetta ◽  
André May ◽  
Mariana Marotti Corradi

Empiricism in the use of nutrient solutions is frequent. Several times the same nutrient solution is used to grow different species based only on morphological similarities. This practice may lead to nutritional imbalances, affecting not only the production but also the quality of the product due to an accumulation of nitrate. An experiment under hydroponic conditions - the NFT system - was conducted with the aim of evaluating the effect of the concentration of nitrogen in the nutrient solution on the production and on the nutrient and nitrate contents of rocket (Eruca sativa) salad leaves. The experiment was carried out in spring 2003, in a randomized block design and in a 4 x 3 factorial design, with four replicates. Four nitrogen concentrations in the nutrient solution (60.8; 121.6; 182.5; 243.5 mg L-1) and three rocket salad cultivars (Cultivada, Folha Larga and Selvática) were evaluated. Cv. Cultivada produced the tallest plants and the highest leaf fresh fitomass, not differing from cv. 'Folha Larga' in the number of leaves, leaf nitrate content, root dry fitomass and root fresh fitomass. An increment in NO3, N, Ca and P and a reduction in Mg, K and S occurred when the concentration of N in the nutrient solution was increased. Cultivation of cv. Cultivada at the concentration of 93 mg L-1 is the most recommended as it provides the highest yield and low nitrate content.


Nutrients ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 451 ◽  
Author(s):  
Maria Gonnella ◽  
Massimiliano Renna ◽  
Massimiliano D’Imperio ◽  
Pietro Santamaria ◽  
Francesco Serio

The use of iodine-biofortified vegetables may be a health alternative instead of iodine-biofortified salt for preventing iodine (I) deficiency and related human disorders. In this study, four Brassica genotypes (broccoli raab, curly kale, mizuna, red mustard) were hydroponically grown with three I-IO3− rates (0, 0.75 and 1.5 mg/L) to produce iodine-biofortified vegetables. Crop performances and quality traits were analyzed; iodine content was measured on raw, boiled, and steamed vegetables. The highest I rate generally increased I content in all Brassica genotypes, without plants toxicity effects in terms of reduced growth or morphological symptoms. After 21 day-iodine biofortification, the highest I content (49.5 µg/100 g Fresh Weight (FW)) was reached in broccoli raab shoots, while after 43 day-iodine biofortification, genotype differences were flattened and the highest I content (66 µg/100 g FW, on average) was obtained using 1.5 mg I-IO3/L. Nitrate content (ranging from 1800 to 4575 mg/kg FW) was generally higher with 0.75 mg I-IO3/L, although it depended on genotypes. Generally, boiling reduced iodine content, while steaming increased or left it unchanged, depending on genotypes. Applying low levels of I proved to be suitable, since it could contribute to the partial intake of the recommended dose of 150 µg/day: A serving size of 100 g may supply on average 24% of the recommended dose. Cooking method should be chosen in order to preserve and/or enhance the final I amount.


1959 ◽  
Vol 5 (5) ◽  
pp. 425-430 ◽  
Author(s):  
L. F. Welch ◽  
A. D. Scott

An active culture of nitrifying bacteria was established by adding moist garden soil to a high-K nutrient solution and incubating the system at room temperature with adequate aeration. By a succession of transfers into a low-K nutrient solution the soil particles were eliminated and the K level reduced to 0.40 p.p.m. Inoculum from this soil-free, low-K nitrifying culture was then used to study nitrification in buffered nutrient solutions that contained even less K.When the nutrient solutions contained 0.40 p.p.m. K or more, there was no effect of the K level on the nitrification of NH4 added as (NH4)2SO4. Nitrification was impaired, however, when the K level was less than 0.35 p.p.m. In a solution that contained virtually no K there was negligible nitrification after a second transfer was made to eliminate the K added by the original inoculum. Under these conditions, the number of nitrifying bacteria apparently decreased, but some of them persisted for at least 48 days. Upon the addition of K, nitrification occurred to about the same extent as if ample K had always been present.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1484
Author(s):  
Maha Ezziddine ◽  
Helge Liltved ◽  
Randi Seljåsen

The aim of this study was to demonstrate how aquacultural sludge can be processed and utilized as an organic nutrient solution (ONS) for hydroponic lettuce production. By using a previous developed method, approximately 80% of the processed sludge was reclaimed as a clear, nutrient-rich solution. The performance of the recovered nutrient solution on lettuce growth was assessed in a nutrient film hydroponic system. The results were compared to the results obtained using a conventional nutrient solution (CNS). Yield, fresh weight, water consumption, and nutrient and heavy metal content in leaf tissue were measured. In spite of a 16% lower average fresh weight obtained in ONS compared to the weight obtained in CNS, there was no statistical difference of the yield of lettuce among the two nutrient solutions. After the cultivation period, 90% of the lettuce heads grown in ONS exceeded the marked weight of 150 g. Foliar analysis revealed a similar or higher content of all nutrients, except of magnesium and molybdenum in the leaves of lettuce grown in the ONS compared to lettuce grown in the CNS. This study shows that nutrients recovered from aquacultural sludge can be utilized as fertilizer, thereby reducing the dependency on mineral fertilizer in hydroponic and aquaponic systems.


2020 ◽  
Vol 1 (1) ◽  
pp. 27
Author(s):  
Fitra Gustiar ◽  
Munandar Munandar ◽  
Sekar Wahyu Ningsih ◽  
Muhammad Ammar

Calcium (Ca) is one of the essential macrominerals needed by the human body as a major component in the formation of bones and teeth. Calcium is fulfilled by eating calcium-rich foods, both animal and vegetable. Mustard and lettuce are vegetables that can be a source of Ca. Efforts to increase the Ca content in plants can be done through increasing the concentration of Ca given through fertilizer or in nutrient solution. However, excessive Ca application is not recommended because it will be toxic to plants. This study aims to determine the effect of various Ca concentrations in hydroponic nutrient solutions on the growth and yield of mustard vegetables (Brassica juncea L) and lettuce (Lactuca sativa L.). This study used a floating hydroponic system with a completely randomized design. Treatment of Ca concentrations of hydroponic nutrient solutions that were tried were 0, 100, 200, 300, and 400 ppm. The parameters observed were plant height, number of leaves, level of greenness of leaves, fresh and dry weight, and concentration of calcium in the leaves. The results showed that Ca treatment significantly affected the number of leaves and the level of leaf greenness. Application of 400 ppm Ca in hydroponic nutrient solution is the highest Ca concentration that could increase Ca content in mustard and lettuce plants. Application of Ca 300 ppm is the highest concentration of hydroponic nutrient solution that can increase the Ca content of plants without causing a decrease in plant biomass, and therefore the treatment of Ca 300 ppm can be used for biofortification of Ca by hydroponic in mustard and lettuce plants.


2007 ◽  
Vol 17 (2) ◽  
pp. 227-233 ◽  
Author(s):  
Alejandro R. Puerta ◽  
Suguru Sato ◽  
Yutaka Shinohara ◽  
Toru Maruo

In nutrient film technique (NFT) vegetable production, the use of low-concentration nutrient solutions might lead to a nutrient concentration gradient along the bed, which can translate into nonuniform plant growth. The authors modified a conventional NFT system (cNFT) and propose a modified NFT (mNFT) that enables the production of lettuce (Lactuca sativa) plants of uniform fresh weight along elongated cultural beds. Two experiments were carried out to compare the systems when long cultural beds are used (18 m) in terms of uniformity of plant and nutrient solution characteristics. The results indicated that fresh weight of plants in cNFT decreased as the distance from the nutrient inlet increased, whereas no such trend was observed in mNFT. Leaf nitrate concentration in mNFT was uniform, whereas it was higher near the outlet of cNFT. Ascorbic acid concentration was also uniform in mNFT, but it was found to be lower near the outlet of cNFT. During Expt. 2, the oxygen content along the bed decreased from inlet to outlet in cNFT; however, in mNFT, it remained relatively constant at all sampling positions. Regarding the concentration of the nutrient solution along beds, no significant differences were found between inlet and outlet in both systems. It is suggested that the lower concentration of oxygen found at the outlet of cNFT might have reduced nutrient uptake, thus attenuating the difference in concentration between inlet and outlet. The temperatures of the nutrient solution along mNFT during Expt. 2 tended to be slightly lower than those of cNFT. However, temperatures were still too high and plant growth was negatively affected. The results of this study demonstrate that plants of uniform size and quality can be achieved in long cultural beds (up to 18 m long) supplied with a low-concentration fertilizer solution by using the proposed mNFT.


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