Soil and Vitamin Values

New Zealand Listener, Volume 9, Issue 217, 20 August 1943, Page 18

Soil and Vitamin Values

| (Written for "The Listener’ by DR.

MURIEL

BELL

Nutritionist to the

Department of Health)

Tx point is raised by a correspondent (see page 3) as to the effect of natural manures on the vitamin content of the foods grown in the soil containing the manures. It will be of interest to readers to know that this type of question has received some attention in experimental work. The nutritive value of wheat as affected by manuring has been investigated in the famous Rothamsted Station -by Russell and Watson, in 1940. They state that "of recent years, it has been suggested that wheat grown with organic manure is of greater nutritive value than that grown with artificial fertilisers, The Broadbank experiments afford no evidence for this claim. Tests made at the Dunn Nutritional laboratories (Cambridge), have given the following relative values of vitamin B1 content in wholemeal flour made with different samples of Broadbalk wheat; the vitamin potency of the flour wes 100 with no manure; 80 with no nitrogen; 100 with farmyard manure; 120 with complete artificials; 120 with sulwhate*of. ammonia only," A Surprise from Hydroponics It may also be of interest to know the surprise that awaited the New Zealand. Nutrition Research Department when it tested tomatoes grown by hydroponics-

one sample only has been tested, for want of more (and we should be glad to receive more, if anyone cares to send them);

they were found to have a higher vitamin C content than tomatoes grown in garden soil! They were grown against 4 sunny wall, and perhaps King Sol had something to do with it! © Then again, someone sent us treetomatoes from his garden in Auckland. Some of these had been grown close to the compost heap, and the others had been grown on a dry bank, They both had the same amount of vitamin C per unit weight. But the one grown near the compost heap had the advantage in this respect-that it had a heavier crop. Thus the sum total of vitamin C value was greater, There is no doubt in any gardener’s mind about the _ beneficial effect of compost on his yield of produce, and on the flavour of the product, But we know too little as yet about the conditions which enhance the vitamin value to state categorically that we need vitamins out of a bottle, because our foods grown with artificial manures are likely to be lacking in them. In fact, evidence to date is against this view. And I will still trust the cow to gather my vitamins for me and put them into her milk; a pint of pasteurised milk contains: about 0.25 milligrams of thiamin (B1); 0.90 mg riboflavin (B2); 1.5 pantothenic acid: and 900 units of vitamin A. These, together with 0.68gm calcium, 0.55gm phosphorus, 18gm protein, 22 gms fat, 26gms lactose; making 380 calories-all for 312d. Good old Brindle (or Primrose, or whatever she is called)!