Assessing Opportunities and Difficulties in Hydroponic Farming

Different systems
 
There are various methods of hydroponics namely Kratky (Kratky, 2002), Wick, DFT, NFT, DWC, Ebb and Flow, Drip system, Aeroponics. In this study, the researchers applied three methods - Kratky, Wick and DFT to grow ladyfinger, spinach, marigold, daisy, basil (tulsi), cucumber, cauliflower, broccoli, tomatoes, peas, paper mint, Coriander leaves plants during the study period. Moreover, these methods of hydroponics technique are helpful in water conservation, no use of pesticide; requires less space and it proved to be eco-friendly (Sardare and Admane, 2013).
 
Kratky method
 
The Kratky method of growing plants suspended above a reservoir of nutrient-rich water is a passive hydroponic approach. Because it is a non-circulating approach, no extra water or nutrient inputs are required after the initial application and there is no requirement for energy, pumps, or water and oxygen circulation systems. The Kratky method can be used for commercial food production as well as a small-scale, low-maintenance strategy for home gardeners. It has been called “the most basic hydroponic system.”

In Kratky (Kratky, 2003), mustard, spinach, cucumber, lady finger, peas, cauliflower, broccoli and tomato’s plants of vegetables  were grown in useless plastic bottles by tailor-made method. Each point size was 16 cm long × 8 cm wide. Each pot was prepared by cutting 1/5th of upper part of the bottle and a hole is drilled in the lid of the bottle; which was mounted into the remaining part of the bottle with inverted neck. The selected plants were transferred to plastic beakers containing one liter nutrient solution. The plants were also grown in 4 inches PVC pipes with a 2 inch diameter hole at equal distance. The plants were supported with the help of sandstone and coco peat, were then placed on each point with 3 cm height in upper cut plastic bottles placed at the roof of researcher’s home in an open area with full sunlight (in open environment of North Indian climate from December 2019 to April 2020). The researcher used Kratky method at home from 4^th July, 2020 to 31^st March 2021 and had grown lady finger, spinach, coriander leaves, marigold, daisy, basil, cucumber, cauliflower, broccoli, tomato, peas, pepper mint leaves.
 
Wick method
 
The procedure of Wick method is same as Kratky method. But there is an addition to the procedure in which a cotton cloth was hanged as a wick. As a precaution to keep the nutrient safe in summer season from UV radiation, the plastic bottles were wrapped with a metal foil or a black polythene. However, the researcher didn’t observe any direct intervention of Ultraviolet radiation on the nutrient solution.
 
DFT technique
 
Plants are supplied with nutrients through ponds using DFT, a hydroponic technique that uses water as the medium. Plants are grown in drainage channels filled with a nutritional solution that runs continuously and is roughly 4-6 cm deep, keeping the roots of the plants immersed at all times.

Wick and DFT Systems (Suryawanshi, 2021) were used for growing vegetables and basils. The handling of systems is discussed in detail (Sardare and Admane, 2013). It is also known as the Liquid Hydroponics method. Plants grown in solution culture have their roots suspended directly in a nutrient solution (Sardare and Admane, 2013), (Raviv et al., 1998) (AL-Mehadee and Sarheed, 2021).
 
Solutions used in the present study
 
Researcher purchased these hydroponics nutrient solutions from Dhakad Hi-tech Nursery (Agriculture farm) situated at a village of district-Ratlam, Madhya Pardesh, India by Arvind Dhakad.They were named as Solution “A”, Solution “B” and Solution “C”. These nutrients contains the exact ratio of primary nutrients such as N:P:K (19:19:19), secondary nutrients contains magnesium, calcium, sulphur etc. and micronutrients(trace elements) contains boron, cobalt, zinc, chelated iron, molybdenum, copper and manganese.

Using a liter of water, these nutrients were diluted to form a 1:1 mixture of each nutrient with the water (Took 1 ml of each dilute solution of nutrients separately in one liter of low TDS water with maintained pH and required TDS for plants and adjusted with an increase in the amount of dilute nutrients solutions with the required TDS water). These nutrients used in rainy season for the growth of lady finger, basils, spinach, peppermint leaves and cucumber in all techniques. In winter the solutions were used to grow peas, Marigold, daisy, mustard, tomatoes, coriander leaves, broccoli and cauliflower.

The researchers separately added 1 ml of each solution in 1 liter water and checked the pH and TDS of whole nutrient solution. The pH Metre (brand name: LAPHM001, Microseal) measured the pH of the solution, which was based on a true range for growth of a plant (5.5-6.5); the pH of the solution was balanced using pH Up and Down reagents purchased online from Maxigrow brand used in winter season up to April 2020. The TDS meter of range 9999 ppm (brand name: Nexqua Dew Digital LCD Meter) was used to measure the accurate TDS of the solution. The oxygen level in the root of the plants was maintained with the help of a supply of 1% hydrogen peroxide solution in a regular period (Burke et al., 2020).
 
Experimental hydroponics methods/techniques
 
Kratky, Wick and DFT methods were used to grow vegetables and flowers.
It can further be classified into-
 
i) Non-Circulating methods (closed system)
 
ii) Continuous flow solution culture
 
Experimental set up
 
Three systems of Hydroponics technique - Kratky method (Kratky, 2005), Wick system and Deep Flow Techniques were used in the present study to grow plants and vegetables in two years. The set up arrangement and working of hydroponics system were looks like similar to Fig 1 (a), (b) and (c). The nutrient solution (Kratky, 1993) was added on a requirement basis without replacing the used solution. The nutrients were rich in ions and salts necessary for plant growth and purchase from Dhakad Hi-tech Nursery (Agriculture farm) situated at a village of district - Ratlam, Madhya Pardesh, India by Arvind Dhakad.







Initially, seeds of Indian mustard (Brassica) of variety Pusa-31 were germinated in soil soaked with water at 8-16°C in December 2019 for 15 days and Eight plants of tomatoes were taken from a plant nursery and 3 plants of basil, broccoli and cauliflower, collected from a nursery, were planted and recorded the study from 4^th July 2020 to 21^st March 2021 within temperature range from 10-36°C to be used randomly in both techniques, While spinach, coriander leaves, cucumber,10 plants of Ladyfinger, 5 plants of Marigold, pot marigold and daisy and 10 pea plants were grown in a seed tray containing coco peat (Arancon et al., 2015). These plants were germinated separately in a coco peat shell and get replaced in the flowing water holes with the help of a mesh cup.

In DFT system, the stored nutrient solution is regulated with the help of a tool pump or through air pump in 4 inch PVC pipes type of pot used. The water is supplemented with nutrient solution and the plant absorbs the same through their roots passing from the mesh cup fixed on the PVC pipe equipment or all containers used. This technique is regulated under environmental and climatic temperature conditions (less than 35°C) and with pH (5.5-6.5) balance of the nutrient solution.

The experiment was conducted at two different locations - Laboratory of Department of Chemistry, Markanda National College, Shahabad Markanda, District Kurukshetra, Haryana (India) and at the Principal researcher’s house at Kurukshetra. The experiment was constructed on a tailor method basis. The period of study was from December 2019 to April 2020 with different temperature variations (5°C to 35°C) according to Climate of Northern India and 4^th July 2020 to 21st March 2021 with a temperature range from 10-36°C. The reliability of the hydroponics technique was assessed by growing plants and vegetables during the study period with variable temperatures. The researcher planted the plants with equal spacing of 4-6 inches are shown in Fig 2(a), (b), (c)  and Fig 3 (a) (b).





The plants were also grown in 4 inches PVC pipes with a 2-inch diameter hole at an equal distance. The plants were supported with the help of sandstone and coco peat were then placed on each point with 3 cm height in uppercut plastic bottles placed at the roof of the researcher’s home in an open area with full sunlight (in an open environment of North Indian climate from December 2019 to April 2020). In the rainy season, the researcher used the Kratky method at home from 4^th July 2020 to 31^st March 2021 and had grown ladyfinger, spinach, marigold, Pot marigold, daisy, basil, cucumber, cauliflower, broccoli, tomato, peas, paper mint are shown in Fig 2(b), (c) and 3(a), (b), (c).

In the Wick method, the procedure is the same as the Kratky method, but there is an addition to the procedure in which a cotton cloth was hanged as a wick. As a precaution to keep the nutrient safe in the summer season from UV radiation, the plastic bottles were wrapped with metal foil or black polythene. However, the researcher didn’t observe any direct intervention of Ultraviolet radiation on the nutrient solution (AlShrouf, 2017) (Asao, 2012) are shown in Fig 2(b) and 3 (a), (b).

In DFT system was operated in the open lobby with proper sunlight from 4^th July 2020 to 21^st March 2021. Sixteen points were prepared in the 4-inch plastic PVC pipes; each point was prepared by cutting a 3-inch hole of the size 10.16 cm wide x 7.16 cm long on the upper part of the pipe. The selected plants were transferred to the spot point with a 3-inch mesh cup filled with coco peat on the running nutrient solution in the pipes are shown in Fig 2(a) and (c). The nutrient solution was made to stir continuously for at least 10 h a day through the water pump; to maintain the level of conductivity of nutrients in the pipe, time to time, PH value and TDS of the nutrient solution were monitored (Håkansson and Lund, 2019) (Despommier, 2017).

The use of the parameters of the pH and TDS from Table 1, the researchers obtained better results in all hydroponics techniques especially in DFT method. The yield was satisfactory in all techniques proved to be promising and resulted to be fruitful in the study (Maurya et al., 2017). The results and findings of the study are reported in Table 1.


 
Effect of high TDS water on plants growth
 
The suitability of water had been studied using four types of water-rain, ground water with high TDS, Distilled water and ground water with TDS less than 250 ppm. The best results were obtained in distilled water and low value of TDS to make nutrient solutions for plants. The pH level and TDS were maintained by adjusting the quantity of nutrients to make the solutions. The growth of plants was greatly affected in high value TDS of nutrient solution at different stages (Hakim, 2019). Therefore, use of high TDS water to make nutrient solution and feed to the plants, the plants almost dead.
The following points were discussed during the study:
 
An extended growing season
 
The working person attains an extended growing season due to controlled environment. These vegetables and plants can be grown hydroponically under controlled conditions of temperature, light and nutrition supply, obtained best results of different vegetables throughout a year.  
 
Higher plant density
 
The hydroponic systems to deliver more nutrient charged solution to the roots of the plants. Therefore, the plants can be grown faster with competing for root space. 

Plants can grow anywhere
 
 It is easily incorporated in outdoor as well as indoor because it can be possible on the roof of houses, verandahs, balconies and free space available at home/office or anywhere. 
 
Less water consumption in the hydroponics systems
 
More than 80 to 90% water saved when using hydroponics agriculture farming. Therefore, it helps in water conservation. 
 
Use of low TDS drinking water, distilled water and rainwater
 
These type of water qualities have great effect on the growth of plants hydroponically. Because water is the primary carrier of nutrients, it is critical that it be free of pollutants. Plants may suffer from stunted growth, nutrient deficits, bacterial contamination and other issues as a result of poor water quality. Unfortunately, drinking water, distilled water and rainwater are frequently treated with chemicals to make it safe for human use.
 
Use of waste plastic bottles and containers
 
In Kratky and wick systems, we can use waste plastic bottles and containers.
 
No use of pesticides
 
Absolutely, it is a great technique to try growing plants at minimum vacant space of the home/verandahs/anywhere hydroponically. Just remember, to observe the nutrition management according to the growth of the plants like pH and TDS of the nutrition solution, temperature etc. Therefore, requires constant monitoring and nutrition management, maintenance of the growing environment, vigilant about pH and TDS and refill the nutrition solution in pipes or containers after a regular interval of time. In the view of the demand of more consumers, the selection of hydroponic techniques to grow healthy and nutritious plants and get safe food from hydroponic plant is increased day by day because it is free from pesticide residues. 

Hydroponic farms provide a way to a more sustainable food ethic that focuses the health of our food, bodies and environment while limiting the use of dangerous chemicals. Hydroponic farming is far from a pipe dream; it is currently being actively integrated into present food networks. Hydroponic farming had not yet been established at the time of the revolution. Only 20 years later, the industry has gained traction and is already influencing agricultural methods and the future of our food industry.
 
Suggestions and challenges
 
1. Flowing solution culture systems can provide a consistent nutrient environment for roots (Viljoen et al., 2021).
2. Rapid plant desiccation happens if the flow of the solution stops or the efficiency of the solution is affected for any reason. Thus, frequent attention is required.
3. Controlled temperature, TDS and pH range of the nutrient solutions need to be maintained. In this technique, the right temperature range, PH and proper TDS with growth must lie up to ~30°C. After 30°C, many plants did not grow and got damaged, but some vegetables and plants like capsicum, tomato, daisy, marigold grew at more than 30°C temperature (Meric et al., 2011).
4. The plants grown through hydroponics are eco-friendly because no waste product was produced.
5. Only plants and vegetables grew no extra weeds were grown, hence, no use of pesticide was observed. If any species of insect is grown, an organic compound pesticide was used. But in traditional farming more weeds grow with the crops and more use of pesticides and insecticides is inevitable (Muda et al., 2020).
6. This technique is very helpful in water conservation because the same quantity of water is recycled for the crops and vegetables i.e. Water conservation. Hence, keeping in view the future, hydroponics will be the biggest necessity.
7. This technique can use waste plastic bottles, tubs, glass and glass pots so that it helps in green chemistry (Sharma et al., 2018).
8. Initially, the cost is involved to set up, however, once launched only the cost of seeds or nutrients for the plants will be a recurring cost.
9. It demands technical expertise; hence competency can be enhanced through training only.
10. The water will be changed after 20-25 days otherwise the growth of microorganisms and algae would affect the growth and production of the crops (Sardare and Admane, 2013).
 
Challenges
 
Challenges related to temperature, nutrient flow in setup, High intensity of sunlight and rain were faced in Kratky and Wick method (Suryaningprang et al., 2021). The experiments proved to be successful in all techniques. Mustard plant and other plants (Tomatoes, Ladyfinger, basil, peas, Cauliflower, broccoli, paper mint, spinach, cucumber and marigold) were grown successfully by all techniques. So when these initial costs are met, more challenges must be solved in order to make sure a profitable and secure hydroponic farm.

There are some challenges (Raviv et al., 1998) for adopting hydroponic as an advanced agricultural technique due to the following reasons:
a) Less interest of farmers because of the uncertainty of yield (Sisodia et al., 2020).
b) It demands a high initial cost, but once a setup builds up, no more infrastructure is required, only demand of nutrient solution will be required.
c) Initial training is compulsory for setting up an infrastructure and must feel the experience of hydroponic growing crops  (Suryaningprang et al., 2021).
d) The crops grown by hydroponics methods should be considered organics if follow the USDA guidelines.
 
Disadvantages of hydroponics
 
Hydroponics has some disadvantages also. Technical training at the initial stage is very compulsory. The high-cost setup requires a skilled and trained farmer with great care of plant health control and then only a high yield can be obtained. Otherwise, the hydroponics system fails. Finally, courage, moderation and determination inputs are necessary to run the system (Khan, 2018), (Sisodia et al., 2020), (Sayara et al., 2016), (Cifuentes Torres et al., 2021).
 
Advantages of water culture
 
There are many advantages of growing plants in water culture over traditional soil-based culture (Raviv et al., 1998). Hydroponics farming produces the healthiest crops with more yields over traditional soil-based culture. These are considered reliable because this farming is safe for the environment and wants 3-5 hours in a day for the work, so it is very easy farming with very little effort (Silberbush and Ben-Asher, 2001). The nutrients are supplied through the roots of the plants as a result plants grow faster than traditional farming. Water should be changed only with the supply of nutrient solution, no more water be used again and again like traditional farming. It can be started from a small area and then exceed in scale. It requires a small area as compared to traditional soil-based farming  (Silberbush and Ben-Asher, 2001). It is also very effective for the regions of the World that has a range of human and climatic factors including degradation, climate change, soil constraints, urban encroachment and unequal land distribution and low water level, high pH value of soil or fertile land for agriculture (Cifuentes Torres et al., 2021), (Asao, 2012).
 
Opportunity
 
Several studies of hydroponics suggested that it is the best agriculture technique for crops and vegetable production as well as fit into environmental scenarios (Sharma et al., 2018), (Pandey et al., 2009), (Upadhyay et al., 2019).

In 2007, Euro fresh farmers grew more than 200 million pounds of tomatoes by hydroponics system (Allaby et al., 2020). In India, Hydroponics was introduced in the year 1946 by an English scientist, W.J. Shalto Duglas and he established a laboratory in the Kalimpong area, West Bengal. He collated his work in the form of a book named ‘Hydroponics: The Bengal System’. During the 1980s, many automated and computerized hydroponics farms were established around the world. Home hydroponics kits for the kitchen and yard became very popular during the 1990s. As in 2017, the Government of Canada acquired a land on large scale for hydroponic greenhouses system and producing peppers, tomatoes and cucumbers (Upadhyay et al., 2019), (Meric et al., 2011).

Due to a decrease in land proportion with the increase in population, the food security and management system requires new ways and means of production (Pandey et al., 2009) (Yeole, 2016) (Sharma et al., 2018). Therefore, this technique will be highly helpful in the future. Especially, in a country like India, where the urban and industrial sector is growing each day, there is no option but to adopt a water culture to help improve the yield and quality of the product so that the food security of the country can be ensured (Khan, 2018) (Cifuentes Torres et al., 2021). The establishment of the new market for hydroponics crops and vegetables in India is a great challenge as the market demand is driven by traditional or terrestrial farming (Cifuentes Torres et al., 2021) (Muda et al., 2020). Therefore, the main aim of the researchers is to be spread the knowledge and its scientific attitude of different agricultural techniques such as hydroponics methods, which will be very helpful in solving the food scarcity (Tom et al., 2021) in our country and also helpful in water conservation in an eco-friendly way.

This study was an attempt to grow some mustard plants, tomato plants, basil, broccoli, spinach, cauliflower, cucumber, peas, meant leaves, ladyfinger and some flowers through the different methods of hydroponic. We significantly gained success through the techniques. These vegetables were grown in a natural, open and uncontrolled environment by using Kratky, Wick and DFT methods. Some challenges faced by the authors i.e. training, controlled TDS and pH of the nutrient solution, supply oxygen to the roots, change and cleanliness of supporting media (hygienic conditions) and controlled temperature. Another focus of the research was to spark interest in a future and sophisticated hydroponic farming technique in India among students and farmers from the neighbouring institute and home. The food security and management system necessitates new ways and means of production due to a decline in land proportion with the increase in population. Therefore, this technique will be highly helpful in the future. Especially, in a country like India, where the urban and industrial sector is growing each day, there is no option but to adopt a water culture to help improve the yield and quality of the product so that the food security of the country can be ensured.