Plants in aquaponics
Water quality for plants
Section 3.3 discussed water quality parameters for the aquaponic system as a whole. Here specific considerations for plants are considered and further expanded. pH The pH is the most important parameter for plants in an aquaponic system because it influences a plant’s access to nutrients. In general, the tolerance range for most plants is 5.5-7.5. The lower range is below the tolerance for fish and bacteria, and most plants prefer mildly acidic conditions.
· Food and Agriculture Organization of the United NationsPlanting design
The layout of the grow beds helps to maximize plant production in the available space. Before planting, choose wisely which plants will be grown, bearing in mind the space needed for each plant and what the appropriate growing season is. A good practice for all garden design is to plan the layout of the grow beds on paper in order to have a better understanding of how everything will look. Important considerations are: plant diversity, companion plants and physical compatibility, nutrient demands, market demands, and ease of access.
· Food and Agriculture Organization of the United NationsPlant selection
To date, more than 150 different vegetables, herbs, flowers and small trees have been grown successfully in aquaponic systems, including research, domestic and commercial units. Appendix 1 provides a technical summary of, and detailed growing instructions for, the 12 most popular herbs and vegetables. In general, leafy green plants do extremely well in aquaponics along with some of the most popular fruiting vegetables, including tomatoes, cucumbers and peppers. Fruiting vegetables have higher nutrient demands and are more appropriate for established systems with adequate fish stocks.
· Food and Agriculture Organization of the United NationsPlant health, pest and disease control
Plant health has a broad meaning that goes far beyond just the absence of illnesses; it is the overall status of well-being that allows a plant to achieve its full productive potential. Plant health, including disease prevention and pest deterrence and removal, is an extremely important aspect of aquaponic food production (Figure 6.8). Although the most important advances in plant health have been achieved through the management of pathogens and pests, optimal nutrition, intelligent planting techniques and proper environmental management are also fundamental to secure healthy plants.
· Food and Agriculture Organization of the United NationsMajor differences between soil and soil-less crop production
There are many similarities between in-ground soil-based agriculture and soil- less production, while the basic plant biology is always the same (Figures 6.1 and 6.2). However it is worth investigating major differences between soil and soil-less production (Table 6.1) in order to bridge the gap between traditional in-ground practices and newer soil-less techniques. Generally, the differences are between the use of fertilizer and consumption of water, the ability to use non-arable land, and overall productivity.
· Food and Agriculture Organization of the United NationsBasic plant biology
This section comments briefly on the major parts of the plant and then discusses plant nutrition (Figure 6.3). Further discussion is outside the scope of this publication, but more information can be found in the section on Further Reading. Basic plant anatomy and function Roots Roots absorb water and minerals from the soil. Tiny root hairs stick out of the root, helping the absorption process. Roots help to anchor the plant in the soil, preventing it from falling over.
· Food and Agriculture Organization of the United Nations