Did you know that peas, beans, lentils, chickpeas, alfalfa, carob, soybean, peanuts, and tamarind all belong to the same family of plants? They are known as leguminous plants and they all produce seed pods. The most important characteristic of a legume is that it has a symbiotic relationship with nitrogen-fixing bacteria in nodules on the plant’s root system. Most people are used to pulses, which are the dry seeds that are cheap and readily available. However, did you know that fresh versions of legumes are also equally delicious and nutritious? In fact, they play an important role in farming systems and are often planted as commercial greenhouse crops. Read on to find out what legumes can do, and how you can grow them in your very own backyard using hydroponics.
Understanding nitrogen fixation
As mentioned, legume plants are characterized by their symbiotic relationship with nitrogen-fixing bacteria. Nitrogen fixation by the legume plant happens when a specific symbiotic bacteria live and grow in the root system and root nodules. The bacteria absorb nitrogen gas from the surrounding air and convert it into ammonia. The plant takes in the gas and uses it, and it gives the bacteria a carbohydrate food supply in return. For plants and crops where growth is impeded due to a lack of nitrogen, such a symbiotic relationship is definitely helpful as it helps to facilitate the absorption of nitrogen and becomes a source of free nitrogen fertilizer. For hydroponic crops where nitrogen is supplied directly into the solution, nitrogen fixation plays a less important role and is not as useful.
With increasing awareness and attention towards organic nutrients and hydro-organic systems, nitrogen-fixing crops like legume plants become highly sought after and have major advantages. Most plants require nitrogen for growth, and nitrogen can be depleted quickly from organic solutions and systems when the growth of plants happens rapidly. Organic nutrients and systems thus run into the problem of having a lack of nitrogen nutrition. This is where legume plants come in, as they are able to balance out the problem and help provide nitrogen to plants by converting into ammonia gas for absorption.
Common legumes in hydroponics
In hydroponic systems, legume plants planted tend to exclude the usual dried seeds like pulses and instead focus on fresh vegetable, gourmet, garnish types which are of higher values. There have also been new developments and cultivation of ‘dwarf’ and ‘container-sized’ varieties of peas and beans. Such miniature plants are useful in areas of small sizes where space is limited. They can grow in indoor gardens, and survive well even in small hydroponic systems. They also produce high yields for relatively small and compact plants, as they do not require support compared to other tall climbing crops. Peas and beans have become popular as microgreens for being space-efficient when planting, and also due to its short time period between seeding to harvest. Compared to other mature plants, miniature peas and beans only require a few days for the entire process of seeding to harvest and can be produced quickly.
For hydroponic systems, peas are extremely versatile crops and can be cultivated for many purposes. Most peas have edible pods, and their flowers, shoots, and lentils can also be grown as fresh vegetables or used as garnishes on salads. The best peas to grow in hydroponic systems are snow peas, snap peas and pea shoots since they take up less space compared to others like fresh shell peas. Fresh shell peas take up quite a bit of space compared to the yield of young peas produced. Snow peas of every kind are highly sought after and are highly-priced as a fresh produce item. As such, they are grown and cultivated in greenhouses all year round. Snow peas are easy to grow but you must pay special attention to when they are harvested. They need to be harvested right before the young seeds inside the pod begin to develop. For Afila type pea varieties, both tall and shorter varieties can be grown in hydroponic systems. Taller ones will require some form of support while the shorter varieties are mostly self-supporting. In areas where space is a constraint, the shorter varieties are preferred since they can be planted in double rows or groups.
Fresh beans are used in a variety of cuisines and for many purposes. It is a popular vegetable and is commonly grown in hydroponic greenhouses throughout the year. Out of the many varieties of beans, the most commonly grown ones include the green pole and runner bean. Other beans grown in hydroponic systems include the broad bean, soybean, and lima. Broad beans are able to tolerate colder temperatures compared to other types of beans. As such, they can be grown and cultivated in many climates and even under unheated conditions. However, they require more space as they tend to become larger and taller once matured. For soybeans that are cultivated for edamame, they are best produced under hydroponic conditions and taste best immediately after picking. French beans like bush or dwarf snap beans are suitable for smaller hydroponic systems as they take up less space and can grow easily. They are self-supporting and highly productive, being able to self-pollinate in indoor environments and thus require less attention. However, any temperature above 30 degrees celsius can limit their flowering and pollination.
Legume plants are an interesting species that are not only yummy, delicious, and nutritious, they are also useful and beneficial crops that can benefit other plants. The nitrogen-fixing quality of legume plants helps them become a free source of nitrogen fertilizer for other plants. Since they are usually short and small in size, they can be grown and cultivated in hydroponic systems. They are also highly sought after since the entire process from seeding to harvest only takes a few days but yet the crops remain nutritious and yummy. As such, if you’re thinking about planting some legumes at home, it is highly recommended!