Although soilless gardening has been practiced since the first century AD, it wasn’t until 1699 that John Woodward carried out experiments to try to find out how plants obtained their food supplies.
In 1929 Professor W.F. Gericke of the University of California transformed the previous experiments into practical crop growing without soil – he called it Hydroponics. Since then it has gone from strength to strength and was put into practice during the second world war and directly after, in areas where soil was too poor to grow plants effectively.
Today, growers use many different recipes of nutrients when growing their tomatoes but the main basic formula that has been followed and accepted as the standard was developed by a fellow called Hoagland in 1938. Most of todays formulas are based on his work.
One point to remember is that nutrients often come in two’s – Calcium Nitrate for example (the ingredients of Chempak Calcium). This contains both calcium and nitrate nitrogen. So if we are adding Chempak Calcium to help us avoid Blossom End Rot, we need to keep in mind we are also adding extra nitrate nitrogen.
There are two types of nitrogen that we feed to our plants – nitrate and ammonium. Too much ammonium can cause toxicity which can damage leaf tissue. You will notice on the side of your feed container that ammonium nitrogen is given in smaller amounts than nitrate for this reason.
The study of nutrients and how plants absorb them is a fascinating subject and there are still areas that scientists have yet to fully understand.