PLANTS GROWN IN TANKS

Southland Times, Issue 24600, 24 November 1941, Page 4

PLANTS GROWN IN TANKS

Experiments By City Gardeners

The growing of vegetables in tanks of nutrient solution has become the hobby of at least half a dozen enthusiastic gardeners, who are testing out for themselves the science of hydroponics, which has been developed by chemists abroad. The roots of the plants are suspended in a solution of small quantities of inexpensive chemicals, which provide an ideal plant food. Calcium, phosphorus, potash and nitrogen are the principal elements required by plants, but several others, including sulphur, magnesium, manganese, iron, boron, copper and zinc, are required in minute quantities.

Several home gardeners have tanks of peas in an advanced stage and they expect to pick well-filled pods shortly. One man said that if he had known of the system earlier he could have finished his first crop and . had another well on the way by this time of tlie year. Growth is said to be very rapid when the hydroponic method is used. A variety of vegetables are being tested in Invercargill for their adaptability to water culture and they include lettuce, marrows, cucumbers, beans and potatoes. It is claimed that the great advantage of tank growth is the quantity which can be grown in a small area, TESTS WITH TOMATOES One commercial tomato-grower in Invercargill is growing several plants in a tank alongside others in the soil of his glass-houses. Raised together as seedlings at the same time, the plants should give an indication of the relative returns from the old and new methods. Another gardener with a small glass-house has adapted the science of hydroponics to his own facilities and is growing some tomatoes in pots of sandy soil to which he gives frequent applications of nutrient solution. Those plants have made much more rapid progress than others growing in ordinary soil moistened with pure water. Water culture has already been used extensively by some commercial tom-ato-growers in the United States. In one experiment in a heated glass-house, 80 plants, occupying 130 square feet, yielded more than half a ton of fruit in 12 months, the first tomatoes being picked at the equivalent of October in a New Zealand season. Single plants grown in sand watered with the nutrient solution have yielded up to 201 b of fruit. Tomatoes grown by the hydroponic method have been found to contain a higher concentration of essential minerals and actually sell at o premium in the United States.

An English social worker has written a book on the results of her own experiments and has urged that hydroponics should be extensively adopted in the thickly populated cities so that householders could produce fruit and vegetables in their small backyards where there is insufficient space for gardens. She claims that British requirements of foodstuffs from overseas in war tim° could be greatly reduced through the establishment of tanks in the backyards of apartment houses or even in window boxes. She contends that up to three crops of vegetables can be raised in the same tanks in one season and that the plants occupy only a fraction of the space needed by those grown in soil.