Drained Nutrient Solution Research Articles

Multi-Sensors based smart nutrient reuse management system for closed soilless culture under protected cultivation

A low-cost customized automated fertigation system for closed soilless culture under protected cultivation was developed; the hardware includes a programmable logic controller (PLC), a touch panel (HMI), and multichannel sensors. The controller unit was used to automate the whole fertigation process from preparing the fresh nutrient solution, its application in the field, and reuse of the drained nutrient solution (leachate) by balancing the nutrient with the addition of freshly prepared nutrient solution. The performance of the developed system was evaluated for cucumber cultivation with three fertigation levels (T1- 100 % fresh nutrient solution, T2- 90 % fresh nutrient solution with 10 % leachate, and T3- 80 % fresh nutrient solution with 20 % leachate) and three growing media (S1-cocopeat + cocochips v/v 1:1; S2- cocopeat + cocochips v/v 7:3 and S3- cocopeat) with three replications. Our findings showed crop yield (3.3–3.7 kg plant−1), total soluble solids (3.3–4.3 Brixo), total phenolic contents (0.81–0.88 mg/100 g), firmness (30.6–33.5 N) and antioxidant capacity (22.3–23.6 %). The highest yield was recorded under substrate S2 i.e. 3.7 kg plant−1 followed by under substrate S3 (3.4 kg plant−1) and S1 (3.3 kg plant−1) which may be attributed to better physical properties (low bulk density, high water retention capacity and high porosity) that enhanced the aeration and drainage in the media. However, there was no statistically significant difference found in the yield for the fertigation treatments which showed that we can successfully use 100 % of the leachate. Overall, the fruit yield and water use efficiency of cucumber crop fertigated with the automated system was found about 25–30 % and 50 % respectively higher as compared to the conventional fertigation system. In addition, the proposed system was found efficient in preparing and supplying fresh nutrient solution and reusing the drained nutrient solution after making the solution balance and disease-free.

Effect of NaCl or Macronutrient-Imposed Salinity on Basil Crop Yield and Water Use Efficiency

Cascade hydroponics, that is, the application of the circular economy concept in greenhouse hydroponic crops, may be considered as an alternative means to increase water and nutrient use efficiency in greenhouses. In such systems, the drained nutrient solution from a crop may be used as input in a second crop. However, the second (secondary) crop in the loop must be a crop that is less sensitive to salinity than the first (primary) crop. In the present study, the salinity tolerance of basil plants grown in rockwool and nutrient film technique (NFT) systems was investigated in order to study the potential of using a basil crop as a secondary crop in a cascade hydroponic system. In total, 4 electrical conductivity (EC) levels of the irrigation nutrient solution were tested (2, 4, 6, and 8 dS m−1), and salinity was imposed by NaCl or by macronutrients. Plant growth varied across the different substrates, with those grown in the NFT system being less affected as opposed to the rockwool-grown basil plants, which showed a significant growth decrease with EC values higher than 4 dS m−1. This relatively low growth pattern was associated with a decrease in water use efficiency (WUE) in the rockwool system. On the contrary, in the NFT system, the continuous flow of the nutrient solution in the root zone of the plants contributed to the alleviation of negative salinity effects, yielding up to 30 kg FM m−2 WUE even for the plants irrigated with the highest salinity treatment (8 dS m−1). The majority of macro- and micronutrients in the leaf tissue of basil were positively affected by the higher levels of conductivity in the nutrient solution. Therefore, basil cultivation could be efficiently incorporated as a secondary crop in a cascade NFT cropping system. This would contribute to drainage management in hydroponics, as the crop could be irrigated through the moderately saline drainage from a primary crop due to either NaCl or high nutrient accumulation in the leachates.

Development and evaluation of nutrient reuse system in soilless media grown cucumber under protected cultivation

Cucumber was grown in soilless media under protected cultivation by reusing the drained nutrient solution. The experiment was laid in a completely randomized design with a total of 9 treatments. Fertigation management included three levels of fertigation with F1 = 80% fresh nutrient solution with 20% leachate, F2 = 90% fresh nutrient solution with 10% leachate and F3 = 100% of complete nutrient solution required under optimal microclimatic conditions. Three cultivars of cucumber namely, V1 (Kafka), V2 (Multistar) and V3 (Punjab Kheera-1) were planted in three replicates. The slow sand filtration was used to remove the pathogenic organisms before reusing the drained nutrient solution. The yield per plant was found to be statistically similar in all the three fertigation levels. It means 100% of the leachate can be reused. However, the highest yield of 2.89 kg/plant was found in treatment F3 (100% Fresh nutrient solution), followed by 2.83 kg/plant in treatment F2 (90% Fresh nutrient solution with 10% leachate) and 2.76 kg/plant in treatment F1 (80% Fresh nutrient solution with 20% leachate) showing almost no significant difference in the yield between the treatments. Thus, the study showed that the cucumber crop can be successfully grown in closed soilless system by applying 80% of fresh nutrient solution and 20% leachate solution (i.e., 100% of the drained nutrient solution as 20-25% nutrient solution applied to the crop is drained out).

Water and fertilizers productivity in closed and open hydroponic systems of tomato production

The amount of water and fertilizers used in the production of vegetables, specifically tomatoes ( Solanum lycopersicum L.) is high. This study was conducted to determine water and fertilizer productivity in closed and open hydroponic system for tomato production in greenhouse. Two treatments with eight replications were assessed; each replication consisted of 67 pots with two plants each. One treatment was a closed hydroponic system (with nutrient solution recirculation), and the other was an open hydroponic system (with non-recirculating nutrient solution). We quantified the amounts of water and fertilizers applied, as well as losses (drained nutrient solution), in the two treatments during the entire cycle. Also, we measured different parameters in the nutrient solution: electric conductivity, pH, volume applied, and volume drained; and in plants: total weight of fruits (25 pickings). There were no significant differences between the two treatments in fruit production. Water productivity was 59.53 kg fruit m -3 for the closed system and 46.03 kg fruit m -3 in the open system. The productivity of the fertilizers was higher in the closed system, 22.68% more efficiency was obtained with respect to the open system. Tomato production in the closed hydroponic system was higher by 13.50 kg fruit m -3 of water and there were applied 10.31 grams less of fertilizer per kilogram of fruit produced in relation to the open system.

Water and fertilizers use efficiency in two hydroponic systems for tomato production

ABSTRACT The amount of water and fertilizers used in the production of vegetables, specifically tomatoes, is high. This study was carried out to determine water and fertilizers use efficiency in closed and open hydroponic systems for tomato production under greenhouse conditions. Two treatments with eight replications were assessed; each replication consisted of 67 pots with two plants each. One treatment was a closed hydroponic system (with nutrient solution recirculation), and the other was an open hydroponic system (with non-recirculating nutrient solution). We quantified the amounts of water and fertilizers applied, as well as the losses (drained nutrient solution), in the two treatments during the entire cycle of tomato. In the nutrient solution (NS) we also measured electric conductivity (EC), pH, volume applied, and volume drained, and total weight of fruits (25 pickings). There were no significant differences between the two treatments on fruit production. Water use efficiency was 59.53 kg/fruit/m3 for the closed system and 46.03 kg/fruit/m3 in the open system. In comparison to the open system, the closed system produced 13.50 kg more fruit per cubic meter of water, while 10.31 grams less fertilizers per kilogram of fruit produced were only applied. Water and fertilizers use efficiency were higher in the closed system, by 22.68% and 22.69%, respectively. More efficiency was obtained in the closed system, regarding the open system. We concluded that the closed system is a good alternative to produce tomato and preserve the resources involved in the process (like water and fertilizers), thus reducing pollution.

Changes in Inorganic Element Concentrations in Leaves, Supplied and Drained Nutrient Solution according to Fruiting Node during Semi-forcing Hydroponic Cultivation of ‘Bonus’ Tomato

Changes in Inorganic Element Concentrations in Leaves, Supplied and Drained Nutrient Solution according to Fruiting Node during Semi-forcing Hydroponic Cultivation of ‘Bonus’ Tomato

Changes in Inorganic Element Concentrations of Drained Nutrient Solution and Leaves in Compliance with Numerical Increment of Fruiting Node during Hydroponic Cultivation of Cherry Tomato

Changes in Inorganic Element Concentrations of Drained Nutrient Solution and Leaves in Compliance with Numerical Increment of Fruiting Node during Hydroponic Cultivation of Cherry Tomato

Consórcio de salsa e cebolinha para produção de maços comerciais mistos de cheiro-verde

RESUMO: O objetivo do trabalho foi testar um sistema de cultivo consorciado de salsa e cebolinha em substrato visando a produção de maços comerciais mistos. O experimento foi realizado no Departamento de Fitotecnia da UFSM entre 12 de setembro e 22 de outubro de 2012, empregando vasos de polipropileno com areia (2,5 L), dispostos sobre bancadas e fertirrigados em sistema fechado (com coleta e reutilização da solução nutritiva drenada). Foram comparadas cinco condutividades elétricas (CE) da solução nutritiva, 0,5; 1,5; 2,0; 2,5 e 3,0 dS/m e oito arranjos de cultivo sendo quatro consorciados e quatro solteiros. Os arranjos consorciados foram formados plantando lado a lado em cada vaso, mudas de salsa e de cebolinha provenientes de um alvéolo das bandejas comerciais (1S+1C); de dois alvéolos de salsa e um alvéolo de cebolinha (2S+1C); de um de salsa e dois de cebolinha (1S+2C); de dois de salsa e dois de cebolinha (2S+2C). Os quatro arranjos solteiros, considerados testemunhas, foram formados por mudas de um alvéolo de salsa (1S); de um alvéolo de cebolinha (1C); de dois alvéolos de salsa (2S); e de dois alvéolos de cebolinha (2C) por vaso. As parcelas foram os vasos, em esquema bifatorial (5x8) e DIC, com cinco repetições . No final do experimento, as plantas das duas espécies foram separadas e determinadas a massa verde (MVPA) e seca (MSPA) da parte aérea. O arranjo de cultivo consorciado 1S+1C, formado por mudas de salsa e cebolinha provenientes de um único alvéolo das bandejas e fertirrigado com a solução nutritiva com a CE de 2,0 dS/m foi o mais eficiente para produzir maços comercias mistos de cheiro verde.

Producción de lechuga en invernadero con y sin recirculación de la solución nutritiva

Hydroponic systems with nutrient solution recycling provide more efficient water and fertilizer use, but over time it becomes difficult to sustain the nutritional balance and control diseases that attack plant roots, which eventually results in lower yield compared to systems where nutrient solution is not recycled. The aim of this study was to evaluate the yield and earliness of butter lettuce (Cortesana M1 variety) grown with different hydroponic systems and their efficiency in terms of water and nutrient use. A randomized block experimental design with four replicates and three treatments (T) was used: T1: tezontle substrate beds without recycling the drained nutrient solution; T2: tezontle substrate beds with recycling the drained nutrient solution; and T3: floating root system. Yield and earliness variables were measured and also the savings and efficiency in water and fertilizer use were estimated. Data were subjected to analysis of variance and Tukey’s multiple comparisons of means test (P = 0.05). The best yield, earliness and efficiency in water and nutrient use occurred with the floating root system. There were no differences in yield or earliness between the substrate systems with or without nutrient solution recycling.

Agronomic parameters assessment in hydroponic tomato crop

In this study we present the results of a comparative analysis of nutrient solution (NS) recycling and non-recycling treatments in hydroponic tomato crop. The established aims are to evaluate water consumption, pH and conductivity variation along the productive cycle in both treatments, to establish the differences in fruit yield and to assess the viability of the recycling system. Watering times and drained nutrient solution volume were counted on a daily basis. Emitter and drained water samples from both treatments were analyzed once per week in the Agricultural Institute of Fraisoro (Gipuzkoa). Tomato samples were collected, weighed and measured three times per week once the harvest had started. There was an 8% reduction in water supply; irrigation excess was between 11-38% and water supply efficiency was 6.7% higher in the recycling treatment in comparison to the non-recycling treatment. Drainage pH values fluctuated from 3.9-7.6 and conductivity varied from 1.9-3.6 mS/cm. Average yield per plant was 7.17 kg/plant. No significant differences were found regarding fruit yield, except for the commercialized smaller size tomatoes (diameter 57-67 mm) whose production was 226% higher in the non-recycling area. Fruit yield was not increased by the recycling technique in hydroponic crop. Recycling treatment viability has to be measured in terms of water and fertilizers saving and minimization of polluting waste in drainage solutions.

Uptake of nutrients and water by paprika (Capsicum annuum L.) as affected by renewal period of recycled nutrient solution in closed soilless culture

One of the problems in closed soilless cultures is to find a solution in order to reduce ion imbalance in recycled nutrient solutions when the drained nutrient solution is re-used. To reduce ion imbalance in recycled nutrient solutions, determination of renewal period is required, since uptake of individual ion by plants changes throughout the growing period. The aims of this study are to determine the appropriate renewal period to reduce ion imbalance in the recycled nutrient solution and to investigate the uptake of nutrients and water by the paprika plant and to measure fruit yield and mineral contents in plant as influenced by renewal period of recycled nutrient solution in a closed soilless culture. Paprika plants were grown in rockwool slabs with either 4-, 8-, or 12-week renewal period in the closed as compared to the open hydroponic system (control). The electrical conductivity (EC), pH, and volume of the nutrient solutions were measured every three days. The nutrient solution in the reservoir tank was constantly maintained at EC 2.5 dS·m−1 and pH 5.5–6.5. As results, the uptake of K+ was significantly influenced by the renewal period. Changes of cation and anion ratio in the recycled nutrient solution could be reduced by discharging every 4 weeks. The significantly lowest fruit yield was observed in a closed hydroponic system using a 12-week renewal period. Regarding the ion balance in the recycled nutrient solution, renewing every 4 weeks was found to be the most effective in this study. However, considering the yield along with nutrients and water uptake, a 8-week interval could also be used.

Transpiração do tomateiro cultivado em substrato e sua influência na fração lixiviada e na condutividade elétrica da solução nutritiva drenada

The objective of this work was to evaluate the influence of tomato transpiration on the leaching fraction and electrical conductivity (EC) of the nutrient solution drained in the sand substrate under greenhouse growing conditions. Two fertigation techniques were used, one denoted by conventional control system and the other by computerized control system. In the conventional control system, the nutrient solution was applied by using fixed time intervals between fertigation events. In the other system, the application occurred according to transpiration estimates, which were performed by the control algorithm of the computerized system. Under cloudy conditions, the EC of the drained nutrient solution decreased in both systems as a result of low transpiration and high leaching fractions, which mitigated substrate salinization. However, under high values of solar radiation, EC increased due to low leaching fractions. The results demonstrated that, under cloudy conditions, the computerized control system reduced effluent volumes by 54% as compared to the conventional control system and, simultaneously, prevented substrate salinization by maintaining mean EC values of the drained solution in the range from 2.9 to 3.5 dS m-1.

GREEN SALAD PRODUCTION IN SOILLESS CULTURE UNDER SALINE IRRIGATION PRACTICE

This study was carried out under protected conditions, using soilless culture inert substrates: Pozzolana (PZ), Gravel (GR) and Perlite (PR) to evaluate the possibility of using saline water as an irrigation source for producing the green salad lettuce variety 'Delia' (winter variety), and endive variety 'St. Levrent Midori' (spring variety). Mean daily water consumption (L m -2 day -1 ) varied with crop variety and substrates; higher values were found for plants grown on PZ (1.2 and 4.4) than those for plants grown on GR (0.6 and 2.3) and PR (0.8 and 3.5) for lettuce and endive varieties, respectively. The pH of drained nutrient solution was with an average value of 7.9 for lettuce and 8.5 for endive, while the EC-values were around 4.0 for lettuce and 4.5 for the endive variety. The pH values of the investigated substrates for both varieties showed a high value (8.7) for the GR exceeding the ones around 8.1 reached in PZ and PR. Regarding the EC-values, two pictures appeared under successive irrigation with saline water: the first, gradual increments in the EC-values of the collected drained nutrient solution reaching 4 dS/m and 4.5 4 dS/m for lettuce and endive varieties respectively and the second, regarding the substrates showing no changes in its EC-values, being more or less equal to their initial values. This clearly indicates that with the use of inert substrates, the accumulated salts due to frequent irrigation with saline water could be easily leached out, keeping the growing media at a relatively low salt concentration level, indicating the high potentiality of using saline water (EC=4 dS/m) for the production of green salad. The plant growth parameters did behave similarly under the different investigated substrates for both varieties. The yield of lettuce was nearly three times greater than that of endive (2.14 and 0.83 kg m -2 , respectively); for both varieties higher yields were observed on PZ and lower on GR. The yield on PR was intermediate.

Crescimento e desenvolvimento do tomateiro cultivado em substrato com reutilização da solução nutritiva drenada

Dois experimentos foram conduzidos em ambiente protegido no outono e na primavera de 2001, com semeaduras em 17 de fevereiro e 3 de julho. O transplante foi feito aos 41 (1º experimento) e 36 dias (2º experimento) após a semeadura, em sacolas de polietileno com 5,5 dm³ de substrato comercial, instaladas no interior de calhas, com 3,3 plantas m-2. Os tratamentos constituíram-se de três soluções nutritivas, contendo o tratamento T1, em mol L¹: 0,04 de KNO3; 0,027 de Ca(NO3)2; 0,012 de MgSO4, com adição de 1,5 g L-1 de superfosfato simples e solução de micronutientes. Em T1, forneceu-se uma vez por semana o volume de 1 L de solução nutritiva por planta, totalizando 14,9 g L-1 de macronutrientes. Os tratamentos T2 e T3 consistiram na dose duplicada e triplicada T1, totalizando, respectivamente, 29,8 e 44,7 g L-1 de macronutrientes, fornecidos também uma vez por semana. Os volumes drenados em cada irrigação foram recolhidos e reutilizados nas fertirrigações seguintes, completando-se as quantidades de fertilizantes necessárias para atingir as doses de cada tratamento. Os valores médios de condutividade elétrica (CE) da solução drenada foram de 3,7; 6,8 e 8,9 dS m-1 no primeiro e de 3,3; 5,2 e 7,4 dS m-1 no segundo experimento, respectivamente em T1, T2 e T3. Entre os 40 e 82 dias após o transplante (DAT) no outono e os 37 e 79 DAT na primavera, foram feitas coletas de plantas para determinar o crescimento e o desenvolvimento. Na primavera, os frutos maduros nas plantas remanescentes foram colhidos e pesados para determinação da produtividade. Não foram observadas diferenças significativas no número de frutos entre os tratamentos. No outono, a massa seca total e vegetativa foi mais baixa no tratamento T3, enquanto a massa seca de frutos foi mais elevada nesse tratamento. Na primavera, as médias das duas primeiras variáveis foram mais baixas em T3, porém a massa seca de frutos não diferiu entre os tratamentos. A produtividade de frutos maduros decresceu com o aumento da CE. Concluiu-se que é possível reutilizar integralmente a solução nutritiva drenada no cultivo do tomateiro em substrato e que os efeitos negativos da CE elevada sobre a produtividade de frutos são observados somente com valores superiores a 4,9 dS m-1.

土壌を培地としたトマトの循環型潅水施肥システムにおける排液イオン組成の変動

The effects of soil and rockwool as substrates, soil-and rockwool-system, respectively, on the fluctuation of ion concentration in a drained nutrient solution of a closed fertigation system and the growth and yield of tomato (Lycopersicon esculentum Mill. cv. Hausu-Momotaro) were compared. The following results were obtained 149 days after transplanting. 1. The pH of the drained nutrient solution fluctuated less in the soil-system than it did in the rockwool-system. 2. The composition of both cations and anions was more stable in the soil-system than it was in the rockwool-system. In the rockwool-system, sodium and sulphate concentrations increased between 89 to 126 days after transplanting while those of potassium and nitrate decreased. 3. Physiological disorders were not observed in both soil-and rockwool-systems. 4. Vegetative growth was more vigorous and total yield was higher in tomato plants grown in the rockwool-system than in the soil-system but the percentage of marketable fruits was higher in the latter. There was no significant difference in the marketable yields between the two systems. 5. Closed-fertigation soil-system may be more suitable for tomato fruit production than the rockwool-system because of the stability of the pH and ion composition of the drained nutrient solution.