DEEP PLOUGHING

New Zealand Listener, Volume 22, Issue 546, 9 December 1949, Page 18

DEEP PLOUGHING

FPLOUGHMANS WiSDOM, by Norman Carew; Faber and Faber, HIS book is an answer to Edward Faulkner's much discussed Ploughman’s Folly; but it is much more than | that. The author is a field superintend- | ent of the Colonial Sugar Refining Com- | pany in Fiji, of whose history, holdings, | and methods he first gives a | short but adequate account. His field | experience convinces him that soil aera- | tion is a first essential to successful plant | growth; and therefore he advocates all [ae operations that make for aera- | tion, and among them ploughing-deep _ploughing-as of prime importance. In | his enthusiasm he even hopes to see atomic energy harnessed for his purpose, and used for shattering the lower sub- | soil, a type of sub-surface cultivation | that by simpler methods was tried’ in New Zealand years ago. But why is aeration so important? Here Mr. Carew breaks new ground indeed. He is convinced of the significance of "deep water" -the water from the permanent water-table-in' nourishing plants. But how is it lifted? He scouts current explanations. of the upward rise of water in soils. Some simple experiments, elaborately described, with columns of soil in glass tubes satisfy him

that the carbon dioxide gas. dissolved in the soil water under pressure supplies the explanation-the explanation also of that problem baffling to botanists of how water from the plant rootlets rises to the leaves of the highest trees. Thence he is led, and leads the reader, to his novel theory that plants derive the carbon dioxide used in the synthesis of carbohydrates not from the air but, with all the rest of their nutriment, from the soil water. The book is written, not in the sedate manner of the scientist, but with all the zest, and the irrelevancies and the colloquialisms of a popular tale of adventure. But it is worth reading. Anyone interested in the soil will find it stimulating; the serious student; provocative.

L. J.

Wild