Fuzzy Logic Controller for Automating Electrical Conductivity and pH in Hydroponic Cultivation

This study proposes a fuzzy logic controller for adjusting the electrical conductivity (EC) and pH of the nutrient solution in a hydroponic system. The proposed control system detects the EC and pH of the solution through sensors and adjusts the working time of the solution pump through the fuzzy controller. Specifically, the EC and pH of the nutrient solution are maintained at specific values. A Raspberry Pi3 development board is used in the proposed control system to realize and solve the problem of adjusting the EC and pH of the solution. In the fuzzy controller, the inputs are EC and pH sensors, and the output is the operating time of the pump. Experimental results indicate that the proposed control system can effectively reduce the measurement burden and complex calculations of producers by adjusting nutrient solutions.

Opportunities and constraints in hydroponic crop production systems: A review

Hydroponic crops can be grown using a variety of media and production systems (NFT system, wick system, drip system, ebb flow system etc.). EC and pH management are required to successfully handle these hydroponic systems (water quality and nutrient solution maintenance). These hydroponics systems have gained rapid adoption due to disciplined management of their resources and food production. Although the hydroponic system was developed in a closed-loop system, and substrate nutrition increases production, it is not cost-effective to develop this system on big scale. It is critical to design a low-cost hydroponic structure that decreases reliance on human labour and lowers overall startup cost in order to increase the commercialization of hydroponic farms. We need more research to develop more productive and cost-effective organic nutrient solutions and improve hydroponic crop production systems. In this review paper, we will discuss the opportunity and challenges in hydroponic crop production systems.

Nutrient Dosing Framework for an Emission-Free Urban Hydroponic Production

The urban hydroponic production system is accelerating industrialization in step with the potentials for reducing environmental impact. In contrast, establishing sustainable fertilizer dosing techniques still lags behind the pace of expansion of the system. The reproducibility of root-zone nutrient dynamics in the system is poorly understood, and managing nutrients has so far primarily relied on periodic discharge or dumping of highly concentrated nutrient solutions. Here, we assayed root-zone nutrient concentration changes using three possible nutrient dosing types. Three Brassica species were hydroponically cultivated in a controlled environment to apply the nutrient absorption and transpiration parameters to the simulation analysis. We found that nutrient dosing based on total ion concentration could provide more reproducible root-zone nutrient dynamics. Our findings highlight the nutrient absorption parameter domain in management practice. This simplifies conventional nutrient management into an optimization problem. Collectively, our framework can be extended to fertilizer-emission-free urban hydroponic production.

Optimisation of Nitrogen, Phosphorus, and Potassium for Soilless Production of Cannabis sativa in the Flowering Stage Using Response Surface Analysis

Following legalisation, cannabis has quickly become an important horticultural crop in Canada and increasingly so in other parts of the world. However, due to previous legal restrictions on cannabis research there are limited scientific data on the relationship between nitrogen (N), phosphorus (P), and potassium (K) supply (collectively: NPK) and the crop yield and quality. This study examined the response of a high delta-9-tetrahydrocannabinol (THC) Cannabis sativa cultivar grown in deep-water culture with different nutrient solution treatments varying in their concentrations (mg L–1) of N (70, 120, 180, 250, 290), P (20, 40, 60, 80, 100), and K (60, 120, 200, 280, 340) according to a central composite design. Results demonstrated that inflorescence yield responded quadratically to N and P, with the optimal concentrations predicted to be 194 and 59 mg L–1, respectively. Inflorescence yield did not respond to K in the tested range. These results can provide guidance to cultivators when formulating nutrient solutions for soilless cannabis production and demonstrates the utility of surface response design for efficient multi-nutrient optimisation.

The Impact of LED Light Spectrum on the Growth, Morphological Traits, and Nutritional Status of ‘Elizium’ Romaine Lettuce Grown in an Indoor Controlled Environment

The study examined the influence of light quality on the growth and nutritional status of romaine lettuce grown in deep water culture with a floating raft system using two different nutrient solutions. Four spectra of LED light were used with different ratios of R, G, and B lights (80:10:10, 70:10:20, 60:10:30, and 70:18:12). Two nutrient solutions with a low (A) and moderately high (B) nutrient content were used. Regardless of the nutrient solution, the RGB 70:18:12 light promoted the production of leaf biomass as well as inhibited the accumulation of K and Mg in the leaves. Moreover, those plants were characterized by a low Nitrogen Balance Index (NBI) and a high flavonol index. In the last week of cultivation, there was a strong decrease in K, P, and nitrates in the nutrient solution, and an increase in Ca. In the final stage of growth, symptoms of withering of the tips of young leaves (tipburn) were observed on the plants. The most damage was observed on the plants growing under 70:10:20, 70:18:12, and with the higher concentration of minerals in the solution (B).

Evaluation of nutrient solution dose and harvest time on forage sorghum (Sorghum bicolor L. Moench) in hydroponic fodder system

This study aims to evaluate the effects of adding nutrient solutions and different harvest ages to the productivity and quality of sorghum forage hydroponically. The study was conducted experimentally using a 3x3 factorial randomized block design with 5 groups. Factor A dose of commercial nutrient solution (0, 3, and 5 ml/l). Factor B is the age of harvest (7, 10, and 13 days). The observed variables were plant productivity, nutrient, fiber fraction, and Hydrogen cianide (HCN) content. The results showed that there was a very significant interaction (P<0.01) between the nutrient solution factor and the age of harvest on the content of dry matter (DM), crude fiber (CF), ether extract (EE), ash, and nitrogen free extract (NFE), while the single factor of harvest age had a very significant effect (P<0.01) reducing the content of DM, CP, EE, and NFE. There was no interaction between the addition of nutrient solution and age of harvest to the content of fiber fractions. A single factor in nutrient solution significantly increased (P<0.01) content of acid detergent fiber (ADF), neutral detergent fiber (NDF), cellulose, and lignin, but not hemicellulose. The conclusion is the addition of a nutrient solution to increase growth and fresh production, the content of CF, ash, ADF, NDF, cellulose, lignin and HCN, but a decrease in the content of DM, CP, EE, and NFE. The longer the harvest age will increase growth and fresh production, the content of CF, ash, ADF, cellulose, lignin and HCN, but reduce DM, CP, EE, and NFE.

Pengaruh Jenis Sumbu Dan Konsentrasi Nutrisi Terhadap Sawi Samhong (Brassica juncea L.) Dengan Hidroponik Sistem Sumbu

The wick system is a hydroponic by utilizing the principle of capillarity of nutrient solutions that are absorbed by plant roots through the wick. Flannelette is a material that has the best water absorption and can be used as a wick, another alternative is stove wick. The concentration of nutrients given to plants must also be in needs. Samhong mustard is a type of mustard in the same class as pakcoy. This study aims to determine the effect of the type of wick and nutrient concentration on plant height, number of leaves, and plant weight using hydroponic wick system. The research method was carried out using two independent variables, namely the type of wick consisting of flannelette (S1) and stove wick (S2), and the nutrients concentration consisting of N1 (1,000 ppm), N2 (1,200 ppm), and N3 (1,400 ppm). The measurements results were compared using the Anova two-factorial design test with a level of 5%, and if the results were significantly different, then continued with the BNJ test at a significant level of 5%. The results showed that there was an effect of using different types of wicks and nutrient concentrations on the measurement results of samhong mustard. Flannel wick (S1) has better effect than the stove wick (S2), and the concentration of N1 nutrients has better effect than the concentrations of N2 and N3, with average plant height is 27.9 cm, average number of leaves are 18.8 strands, and the average plant weight is 128.6 g.