20 Hydroponics-Low

Hydroponics FOCUS Question How can plants grow without soil?

No Soil? Plants only grow in soil, right? Wrong! People can grow plants without soil using a method called hydroponics. Plants need energy to make food and grow. They use energy from the Sun to convert carbon dioxide and water into oxygen and sugar. The sugar is the plants' food. This process is called photosynthesis. Plants also need nutrients, such as nitrogen, phosphorus, and potassium, to help them grow. Plants get carbon dioxide from the air. They normally absorb water and nutrients from the soil. In hydroponics, a nutrient solution—made of nutrients dissolved in water—contacts the plant's roots directly. No soil required! Word Wise Hydroponics comes from the Greek words hydro, meaning "water," and ponos. meaning "work."

Growing Fruits and Veggies Fruits and vegetables are tasty. They are also good for us. They contain many nutrients, such as carbohydrates, proteins, fats vitamins, and minerals, that our bodies need to survive. Hydroponics is used to grow many different fruits and vegetables. Some hydroponic techniques use a material called a grow medium to support the plants. With or without a medium, the water and nutrients go directly to the plants' roots. The plants grow to be strong and healthy. In fact, plants grown without soil are just as tasty and nutritious as those grown with it. HEALTH BENEFITS OF CERTAIN FRUITS AND VEGETABLES Fruit/Vegetable Vitamins and Minerals Health Benefits cucumbers vitamin B, vitamin C, folic acid, iron, potassium, calcium, zinc, magnesium helps get rid of cholesterol lettuce vitamin A, vitamin C, vitamin K, iron calcium, magnesium, potassium supports the immune system strawberries vitamin C, vitamin B9, potassium, manganese helps lower cholesterol and blood pressure tomatoes vitamin A, vitamin C, folic acid helps protect the heart

Hydroponic Techniques There are different hydroponic techniques, but they all have the same goal—to get nutrients and water to a plant's roots. Imagine visiting a humid rainforest— there's so much moisture in the air! Aeroponics uses a similar idea. Plant roots that hang in the air are misted with water and nutrients. In the nutrient film technique, plants are placed in a tilted plastic tray. A nutrient solution continuously flows across the tips of the plant roots. The force of gravity causes the solution to flow downward. The solution is then pumped back to the top, and the process continues.

In the deep water culture technique, plant roots sit in a pool, or reservoir, of nutrient solution. But plant roots also need oxygen to live. Oxygen is added to the nutrient solution using an air pump. The hydroponic wick system is the easiest way to grow plants without soil. It does not require pumps or electricity. A wicking material, such as cotton or nylon, sits in the nutrient solution. The plants sit nearby in a grow medium. The wicking material absorbs the nutrient solution and transports it to the plant roots.

In drip hydroponics, the nutrient solution is pumped to each plant through small tubes called drip lines. The solution drips slowly into the grow medium to give the plants the nutrients they need. The flood and drain technique is the only hydroponic technique in which plants are completely dry for a short period of time. Plants are placed in a tray A pump fills the tray. almost to the top with nutrient solution. Then the tray is allowed to drain completely. This happens a few times each day.