Apr 19, 2023
Kiwa Farms. Credit: Henry Gordon Smith
Written by: Niko Simos and Henry Gordon-Smith
April 19, 2023
Desert regions are known for their extreme temperatures, lack of water, and arid soils, making it almost impossible to grow crops. However, with the increasing global population and the need to meet food demand, finding ways to grow crops in arid regions has become a pressing concern.
Credit: Kiwa Farms.
Sandponics, also referred to as IAVS (Integrated Aqua Vegeculture System), is an approach to agriculture that could provide a solution to food insecurity in desert regions. It is an aquaponic-related growing technique for cultivating plants that utilize sand as a primary medium for mechanical filtration, biofilter, and crop-growing media. It is a promising, sustainable production option for several crops, including vegetables, vines, and fruits.
The system can easily be applied since sand is readily available in most areas and is a versatile medium that can be sterilized and recycled. It’s also cheaper than soil, thus making it a more efficient, affordable, and low-risk technology option. However, there are some drawbacks to a sandponics system, including operators requiring specialized training, crop nutritional deficiencies due to insufficient fertilizers, finding suitable sand for crops that require cooler climates, and expensive heated systems.
This blog post will explain how sandponics works, its key considerations, and how it can help desert populations with food security.
How Sandponics Works
Sandponics combines hydroponics, which is the technique of growing plants in water, and aeroponics, which is the technique of growing plants in air. It uses fish to create ammonia that then gets converted to nitrates by beneficial bacteria, which serves as food for the plants. The main difference when compared to aquaponics is that it does not require separate mechanical and biofilters as the sand acts as both.
Credit: Kiwa Farms.
Sand is an ideal growing medium because it provides physical support for the plants while allowing for good drainage, air circulation, and root growth. It also has a high water-holding capacity, which means that it can hold onto water for extended periods, reducing the amount of water required for plant growth.
The water solution used in sandponics comprises the minerals and nutrients that plants require for growth. The solution is circulated through the sand, delivering nutrients directly to the plant's roots, resulting in plants growing faster and healthier when compared to those grown in traditional soil.
“When soluble and insoluble fish waste is deposited on the sand, the enormous counts and diverse types of bacteria transform this rich waste to all plant nutrients required. Therefore as long as fish are healthy and well fed, no external fertilizer is required.” - Omar Badran, Founder and CEO at Kiwa.
Key Considerations for Sandponics
There are several key considerations when it comes to sandponics.
The first consideration is the type of sand used. Not all sand is suitable for growing plants, and it's important to use sand that is free from toxins and heavy metals. Ideally, the sand should be coarse and have a low clay content to ensure good drainage.
The second consideration is the nutrient-rich water solution. The water solution must be carefully balanced to provide the correct amount of nutrients for plant growth. The solution should be regularly monitored and adjusted to ensure that the plants are receiving the correct nutrients.
Additional considerations for growing plants are lighting conditions and temperature. The amount of light a plant receives is crucial for its growth, and in areas with limited natural light, artificial lighting may be necessary. In contrast, desert regions with abundant sunlight can utilize natural light. Temperature control is also critical for plant growth, and cooling systems may be required in hot desert regions to maintain optimal temperatures.
How Sandponics can help Desert Populations with Food Security
Credit: Kiwa Farms.
Sandponics has the potential to revolutionize agriculture in desert regions and provide a sustainable solution to food insecurity. Here are some ways in which sandponics can help desert populations with food security.
Requires less water. Sandponics requires significantly less water than traditional soil-based agriculture. This is because sand has a high water-holding capacity, which means that it can hold onto water for extended periods, reducing the amount of water required for plant growth. In addition, the use of a nutrient-rich water solution means that water is used more efficiently, reducing water waste.
Can be used anywhere. Sandponics can be used anywhere, regardless of the quality of the soil. This means that it can be used in areas where traditional agriculture is not possible, such as desert regions, making it an ideal solution for providing food security in areas that are prone to droughts and other extreme weather conditions.
Provides year-round food production. Sandponics can provide year-round food production, regardless of the weather conditions. This is because sandponics can be grown indoors, allowing for temperature and lighting control. This means that crops can be grown throughout the year, providing a consistent food source for desert populations.
Reduces food transportation costs. Desert regions often import food from other regions, which can be costly and unsustainable. Sandponics can help to reduce food transportation costs by providing a local source of food production. This can also help to create job opportunities for local communities and stimulate the local economy.
Increases food diversity. Sandponics can be used to grow a wide range of crops, including fruits, vegetables, and herbs. This can help to increase food diversity in desert regions, providing a variety of fresh, healthy, and nutritious foods for local populations. For example, Kiwa has cultivated leafy greens, arugula, parsley, spinach, peppermint, lemongrass, tomatoes, cucumber, zucchini, hot pepper, radish, kale and more.
Supporting Research on Sandponics
Sandponics is a relatively new method of growing plants, and there are not a lot of scientific studies proving its efficiencies and capabilities. The two we know of are summarized below.
This study followed a completely randomized design with one aquaponic system and three sandponic systems. The second and fourth sandponics systems resulted in the highest plant heights, and the aquaponics system had approximately 40% less biomass than plants in the third and fourth sandponic systems. All systems minimized water consumption, ranging from 1.5 to 1.96 L/m2/day. The crop protein content ranged from 11.84 to 18.72 mg/100 g dry weight.
The study ultimately recommends using fish effluents under sandponics systems to increase crop production while increasing water and fertilizer efficiency to close the crop yield gap.
The paper investigates the response and productivity of kale and Nile tilapia grown in an Integrated Aqua-Vegeculture System (IAVS) under different brackish water salinity levels. The IAVS system recycles water and uses fish effluents as crop fertilizers to increase productivity, making it a sustainable agricultural strategy for arid and semi-arid regions affected by freshwater scarcity.
The study found that kale could tolerate salinity levels of up to 6000 ppm without significantly compromising its growth, yield, and nutritional composition of leaves. Similarly, Nile tilapia can be cultured in an IAVS system under different salinities (3000, 6000, and 9000 ppm) without significantly detrimental effects on its growth performance, feed utilization, and survival.
The paper also discusses the effect of soil pH and soil salinity on plant growth and indicates that kale can tolerate soil pH values above 6.5.
Conclusion
Credit: Kiwa Farms.
Sandponics is a new approach to desert agriculture that has the potential to provide a sustainable solution to food insecurity. By using sand as a growing medium and a nutrient-rich water solution, sandponics requires less water than traditional soil-based agriculture, can be grown anywhere, provides year-round food production, reduces food transportation costs, and increases food diversity. Sandponics could provide a vital solution to food insecurity in desert regions, helping to ensure that everyone has access to fresh, healthy, and nutritious foods. As desert regions continue to face challenges related to food security, it's important to explore innovative solutions like sandponics to address these challenges and create a more sustainable future for all.