[ArtIcle] Urban Farming: Opportunities and Challenges

Traditionally, urban societies employed a variety of methods to cultivate food crops in their yards. Malaysian Agricultural Research and Development Institute (MARDI) and the Department Of Agriculture (DOA)'s introduction of innovative technology has enticed urban residents to adopt and utilize them in their home gardens or community farms. Aquaponics, aeroponics, hydroponics, and vertical farming are Malaysian communities' four most prevalent urban gardening technologies. Aquaponics is a technique that combines traditional aquaculture (raising fish and crayfish in tanks) and hydroponics (growing plants in water) in a symbiotic environment. Hydroponics and fertigation use nearly identical techniques to ensure that nutrients or fertilizers are delivered directly to the roots of the plants, hence preventing root infections. Hydroponics is one of the most popular techniques for quick and simple farming. Crops planted vertically are referred to as vertical farming. More crops can be grown on a smaller amount of land with this strategy. This means that more food can be produced with less land at the same time it opens many windows for urban citizens.

[Article] The Future of Indoor Vertical Farming

The future of indoor vertical farming looks bright, as this innovative method of growing crops continues to gain popularity and develop new technologies. Indoor vertical farming offers numerous benefits over traditional outdoor farming methods, including the ability to grow crops in urban areas, reduced water usage, and the ability to grow a wider variety of crops. As the world's population continues to grow and urbanization increases, the demand for fresh, local produce will only continue to rise, making indoor vertical farming an increasingly important part of the global food system.

One of the key developments that will shape the future of indoor vertical farming is the increased use of automation and data analytics. As indoor vertical farms become larger and more complex, automation will play a crucial role in managing and optimizing the growing process. For example, sensors and other technologies will be used to monitor and control factors such as temperature, humidity, and lighting, allowing for precise control over the growing environment. Data analytics will also be used to analyze vast amounts of data collected from sensors and other sources, helping farmers to make more informed decisions and improve their operations.

Another important factor that will shape the future of indoor vertical farming is food security. As the global population continues to grow, there will be increasing pressure on the world's food supply, and indoor vertical farming will play a crucial role in meeting this demand. Indoor vertical farms can produce fresh, healthy food even in areas where traditional outdoor farming is not possible, such as in cities and other urban areas. This will help to ensure that people have access to the food they need, even in regions where outdoor farming is not feasible.

The future of indoor vertical farming will also be shaped by advances in lighting technology. As we continue to develop new and more efficient lighting systems, indoor vertical farmers will be able to grow more diverse and nutritious crops, even in areas where sunlight is limited. For example, new LED lighting systems will allow farmers to simulate the natural light spectrum, providing plants with the specific wavelengths of light they need to thrive. This will help to improve crop yields and reduce the energy consumption of indoor vertical farms.

Finally, the future of indoor vertical farming will be influenced by advances in our understanding of plant biology and agriculture. As we continue to learn more about how plants grow and thrive, we will be able to develop new growing techniques and strategies that will allow us to grow even more diverse and nutritious crops in indoor vertical farms. This will help to further improve the sustainability and efficiency of indoor vertical farming, and will allow us to produce even more healthy, delicious food for people around the world.

Overall, the future of indoor vertical farming looks bright and full of promise. As technology continues to advance and our understanding of plant biology grows, indoor vertical farming will become an even more important part of the global food system, helping to feed a growing population and provide access to fresh, healthy produce in urban areas.

The contents of this article is generated by AI

[Research] The Effect of Water Temperature on Plant Growth

Introduction

The growth and development of plants can be influenced by water temperature in hydroponic cultivation. The physiological process of plants will be affected by the plant metabolic activities such as phenolic compounds, nutrient uptake, chlorophyll pigment formation, and photosynthesis. (Nxawe et al., 2011). The main function of plant roots is to absorb water and nutrients from the growing medium and later conduct them to the stem of the plant. Thus, besides electrical conductivity value, pH value and environment temperature, regulating water temperature is a crucial part in hydroponic cultivation because the temperature in the root zone may make a notable difference in plant growth.

[Article] Urban Farming in Malaysia

[Research] Effects of Photoperiodism on Plant Growth

[Research] Effects of Photoperiodism on plant growth (single 12 hours session vs multiple sessions cumulatively 12 hours)

Introduction

        Following the increasing interest in urban farming and hydroponics, many users are slowly looking to grow their own food with household farming setups. For these urban farmers, not all of them have sufficient outdoor spaces that provide sufficient natural sunlight to the plants, instead, they look towards artificial horticulture growlights as a substitute. In comparison, as natural sunlight is much stronger, plants only require approximately 8 hours of sunlight per day for healthy growth, whereas for artificial lighting, it is recommended that these indoor setups are exposed to at least 10 to 14 hours of lighting per day to achieve similar growth results (D’anna, 2021).

        However, the usual concern with the statement above is related to none other than the expensive electricity costs that accompany the long hours of turning on the growlights. Additionally, following the Enchanced Time of Use (ETOU) tariff scheme launched by TNB which offers different tariff rates at different times of the day, urban farmers have a better chance at evaluating and reducing their operational costs while growing their passion (Tenaga Nasional Berhad, n.d.).

        As seen below, Figure 1 shows the exact timing of the time zones for Peak, Mid-Peak and Off-Peak on weekdays, while Figure 2 shows the different charges for these respective time zones. Subsequently, the lighting requirement for indoor hydroponic farming can be carefully planned according to this information to achieve maximum energy savings without affecting the plant growth. This experiment is carried out to observe the practicality of splitting the lighting requirement for indoor plants into shorter periods, so that these plants have the same cumulative amount of lights across the day instead of a consecutive lighting for 10 hours a day to fit into the Off-Peak time zones. Thus, it is hypothesised that if the plants receive the same cumulative amount of lighting per day (despite splitting it into shorter, separate periods), the plants would have a similar growth rate.

Figure 1. TNB Enhanced Time of Use (ETOU) time zones

Figure 2. ETOU rate for different categories

Materials

• Digital Timers x 2

https://cityfarm.my/products/timer 

• 4ft 2”x4” NFT Channels x 4

https://cityfarm.my/products/4-feet-120-cm-nft-channel 

• Kintons 101 5W Pump

https://cityfarm.my/products/kintons-101-pump-5watt-1m-800l-h 

• Hanna Instruments GroLine Monitor for Hydroponic Nutrients HI981420

https://cityfarm.my/products/groline-monitor-for-hydroponic-nutrients 

• A & B Liquid Fertiliser for Leafy Greens

https://cityfarm.my/products/hydroponics-fertilizer 

• 4ft Cityfarm Horticulture Full Spectrum T8 Growlights (Pin Connection)

https://cityfarm.my/products/new-2020-model-samsung-led-diodes-4-feet-cityfarm-horticulture-full-spectrum-led-t8-tube 

Types of Vegetable Used

• Romaine Lettuce (germinated on 15/9)

• Half-Red Amaranth (germinated on 18/9)
• Hong Kong CaiXin (germinated on 18/9)
• Thai Basil (germinated on 11/9)

Methodology

        This experiment started on the 29th of September and ended on the 30th of October. It was conducted in a City Vertical Farm M (Figure 3), which consists of 2 layers. The top layer was set up as the control plants, which the timer for the growlights were set to run for 12 consecutive hours every day from 6am to 6pm. On the other hand, the bottom layer was the experimental layer where the plants in this layer were exposed to 3 different sessions of 4-hour-period lighting throughout the day, these periods are 6am - 10am, 12pm - 4pm as well as 6pm - 10pm. It is important to note that both setups are still exposed to 12 hours of light per day.

Each layer holds two 4ft NFT channels which provide a total capacity of 32 plants for the experiment, 4 seedlings from each vegetable type were placed within the NFT channels as seen below in Figure 2. Aside from the lighting alterations made for the experiment, the remaining setup for the Vertical Farm M is identical to the usual hydroponic practices. The EC readings for the water tank was measured and maintained daily between 1.2 - 1.4 mS/cm, while the pH levels of the water was maintained above 5.5 to ensure the healthy growth for the plants.

Additionally, pictures of the plants were taken every 3 days from the start of the experiment to help visualise the differences between both setups as well as the differences between the locations of each plant within the same setup (due to the slight differences of light exposure from the plants’ positions). At the end of the experiment, the plant growth was measured using the fresh weight of the full plant after the harvest period, the mean weight of the plants were used to compare between both setups.

Figure 3. A 3D computer generated model of City Vertical Farm M

Results

Table 1. Post-experiment Fresh Weight Measurements

        As mentioned above, pictures of the plants were taken throughout the experiment, as there were a lot of pictures from the experiment, only the pictures from Day 1, Day 14, and Day 30 will be shown below to help visualise the differences of the plants.

Half Red Amaranth

 Day 1 Control                                                 Day 1 Experimental

Day 14 Control                                                 Day 14 Experimental

Day 30 Control                                                  Day 30 Experimental

Hong Kong Caixin

 Day 1 Control                                                 Day 1 Experimental

Day 14 Control                                                Day 14 Experimental

Day 30 Control                                             Day 30 Experimental

Romaine Lettuce

Day 1 Control                                                    Day 1 Experimental

Day 14 Control                                                    Day 14 Experimental

Day 30 Control                                                 Day 30 Experimental

Thai Basil

 Day 1 Control                                                  Day 1 Experimental

Day 14 Control                                                      Day 14 Experimental

Day 30 Control                                                         Day 30 Experimental

Discussion

Photoperiodism, otherwise defined as the physiological reaction of organisms to the length of the dark period, is one of the most researched topics on both animals and plants. For plants, photoperiodism is particularly important as certain plant species require a specific duration of dark period in order to achieve their flowering and fruiting process.

        In this experiment, it is observed that all control plants (aside from the Romaine Lettuce) grew slightly better when compared to its experimental counterparts. For the experimental plants, there is clear evidence of stem elongation throughout the growing phase, as seen in the pictures above. This is particularly visible for the Thai Basil as well as the Half-Red Amaranth plants. However, there were also slight differences between the experimental samples as some of the plants may not have received sufficient lighting due to its positioning in the NFT channels (especially around the edges of the NFT channels where the plants were not directly exposed to the lighting, which led to poor growth and stem elongation.

Additionally, it is also noted that most of the control plants managed to accumulate a higher biomass. Aside from the Romaine lettuces which showed little to no differences among the two setups, the remaining plant species recorded visible average weight differences. It is also important to note that there were cases of pest infestations during the experiment, which severely affected the Hong Kong Caixin plants. While immediate pest management measures were immediately taken once the issue was spotted, the end result still showed poor growth for both the control and experimental setups.

        In a similar study conducted by Folta in 2019, the team experimented on ways to reduce energy requirements for farming in controlled environments. Rather than setting multiple 4-hour sessions of lighting, they experimented on various light-dark cycles, ranging from hours to seconds. Unfortunately, most of the longer cycles (6 hours, 3 hours, 1 hour, 30 minutes) showed that the plants grew as if they were in a light-deficient environment, thus the stems elongated to search for an alternative light source. However, when they further reduced the duration of light-dark cycles to approximately 5-20 seconds, the seedlings grew as if they had received 12 hours of regular lighting.

        In conclusion, while the findings by Folta correspond to the findings in this experiment, it seems that it is difficult for everyday users or hobbyists to be able to tackle the energy cost without sufficient access to technology to alter the lighting cycles without affecting plant growth. As of now, in order to save on energy costs for indoor farms, the only method now would be to operate these farms during off-peak hours.

References

D’anna, C. (2021). The Basics of Hydroponic Lighting. Retrieved from https://www.thespruce.com/hydroponic-lighting-basics-1939224 

Folta, K. (2019). Micro-naps for plants: Flicking the lights on and off can save energy without hurting indoor plants. Retrieved from https://explore.research.ufl.edu/micro-naps-for-plants-flicking-the-lights-on-and-off-can-save-energy-without-hurting-indoor-agriculture-harvests.html 

Tenaga Nasional Berhad (n.d.). TNB Enhanced Time of Use (ETOU). Retrieved from https://www.tnb.com.my/faq/etou/ 

[Article] Get to know your lettuce!

Lettuce Categories

Cos lettuce

Also known as Romaine lettuce, it is medium to large in size and is believed to be one of the oldest varieties in the world. Its physical characteristics are elongated and stiff, with leaves averaging about 10-15cm in length and having a firm rib that runs down the centre. With red and green varieties, the intensity of the colours is strongest at the tip, displaying a dark red or green colour that fades into a near-white colour at the base of the leaf. The taste and texture of Cos lettuce are described as crisp, succulent, and crunchy with a mildly bitter taste.

Growing

Butterhead lettuce

Also known as Boston or Bibb lettuce, it is a medium sized lettuce. Its physical characteristics are short and attractively rose-like, with leaves averaging to about 10cm in length. With red and green varieties, the intensity of the colours is achievable with strong lighting. Red varieties are a blend of red, purple, and burgundy that slowly fade green at the base, whereas green varieties are intensely coloured that stays consistent from tip to base. The leaves are described as soft, loose, wavy, and wide growing in a rosette fashion, with taste and texture being described as lightly sweet and tender.

Growing

Lolla

Lolla lettuce, also known as coral lettuce, is a medium to large sized lettuce that is one of the most common lettuce seen in stores. Its physical characteristics are that it has extremely dense, soft, and wavy leaf tips, while having firm and fleshy ribs. It comes in red and green varieties, Lolla rossa and Lolla bionda respectively, that are intensely coloured. The taste is mild and texture is described to be smooth, crunchy, and light.

Growing

Oakleaf

Oakleaf lettuce is a type of looseleaf lettuce that does not form a compact head that grows large in size. As the category suggests, its physical characteristic is a loose, bushy bunch that extends out from a narrow base. Its leaves are described to be hook-shaped, tender, broad, and curled that are fragile and tear easily. Oakleaf comes in two colour varieties, red and green, with both colours not being very intense even when exposed to strong lighting. It’s taste is described to be nutty and mildly bitter or sweet depending on the variety.

Growing

Batavia

Batavia is a more heat tolerant lettuce that grows to a medium or large size. Its physical characteristics is a wide, wavy and dense leaf arrangement at the top that stems from a small base. As mentioned, its leaves grow out from the centre point at the bottom, spreading out large and having wavy tips. The intensity of the waves are dependent on the variety. Like other lettuces, Batavia comes in both red and green varieties. Red varieties are usually only red at the tips, with visible transitions to green 2-3cm from the tip. Its taste and texture is described to be earthy and smooth.

Growing

Special Varieties

Salatrio

Salatrio lettuce is not a specific variety of lettuce, but a special combination of three different lettuce varieties in one pot. Rijk Zwaan, one of the industry leaders in vegetable breeding, has specially selected combinations that grow well together. In total, there are 12 different combinations available worldwide. 

Eazyleaf

Eazyleaf is a category of lettuce varieties produced by Enza Zaden. The main attraction of these varieties is its ease of preparation. Eazyleaf plants are specially made for a one-cut preparation that will split the vegetable into many, equally sized leaves. These varieties are highly suitable for food processing and commercial use, where automation is common and operations are time sensitive.

Salanova

Salanova is a category of lettuce varieties produced by Rijk Zwaan. Varieties under the Salanova product line are specially produced for use in hydroponic systems, providing better taste, quality, and production. Benefits include 40% more yield, improved taste and texture, and increased shelf life. 

Types of Seeds

Unpelleted

Unpelleted seeds are your typical seeds you would buy or collect. These seeds have not been processed after harvest and come in its original shape and for, therefore managing these seeds may be a challenge, especially with machinery.

Pelleted

Pelleted seeds are coated to make them round, smooth, and uniform. This is done so that commercial growers can handle them easier. Certain plants produce very small seeds, and a commercial farmer may find it difficult to manage them at a small size. By coating them, all seeds are equal in size and round. This is especially useful when being used with machinery, such as a mechanical seeder.