CORRECT CULTIVATION OF SOIL

Sun (Auckland), Volume III, Issue 750, 24 August 1929, Page 32

CORRECT CULTIVATION OF SOIL

The different methods of turning the soil, or as it is properly known, •‘digging,’* have the three following objects: (1) To break up the soil and so permit the roots of plants more freedom of movement; (2) to allow the air to penetrate it, and by coming in contact ■with the soil’s chemical constituents, to so react upon them that certain foods r e made available for the growing plants, and (3) to mix up the stratas of soils, and to mix in with the soil manures, fertilisers and other substances such as the operator thinks beneficial. Many people believe that plants do best when their roots have a limited root run, and this is probably so when plenty of fertilisers and water arc available, but nothing can give the permanence and resistance to drought conditions which deep digging or trenching can give. It is impossible to estimate the advantages conferred

upon a plant of fair size by a root run of some five feet, and we can confidently say that no surface cultivation or fertilising can make up for the lack of this freedom. Now let us look at the methods of cultivation of the soil. These quite easily fall into two groups, (1) digging; (2) trenching. In the former are placed all those operations which do not disturb the soil for more than a spade depth, and the latter all those operations which exceed that depth. And, by the way, in trenching, it is usual to speak of the depth as being so many “spits,” i.e., so many spades deep. The simplest form of digging consists of just turning over the ground one spit deep. The spade is driven in its full depth, pulled toward the operator to loosen the soil from its surroundings, lifted and turned upside down in site and this is generally found to be quite sufficient when the ground is fairly free from weeds, and is in good condition, and the usual method followed when the garden soil has been kept up to the mark by frequent applications of manure and fertiliser. It is also found to be the best method of working in manures, lime, fertilisers and similar substances, and also for removing short weed growth. Now, though this simple operation of digging has its uses, it is found in

many cases most garden soils require more thorough preparation than this before they receive a crop, and for all strong growing and long standing crops, trenching is absolutely. TRENCHING. —In trenching, unlike digging, we may turn over, instead of one spit, two, three or more as required, and as the nature and Quality of the lower starat permits. The whole principle of trenching is as follows: First of all a trench is opened up along the whole length of one end of the bed to be trenched, to the depth it is desired to trench. The soil taken from this trench is removed by a barrow to the other end of the bed ! opposite to that from which it was re- j moved. The trench which has been opened is now filled in with soil taken ; from a strip of laud the same immediately beside it, so that it. becomes filled in and a new trench is formed by the removal of the soil by which the first trench was filled, and then a third, fourth and so on are formed, the soil from each being used to fill in the former trench, till finally the soil taken from the first trench is filled into the last one. If the whole body of the soil be uniformly good in quality, the lower strata to a depth of from three to four feet may be brought to the surface, but as a rule the lower layers of soil are sour, raw and unfertile, and should not be placed over the upper strata which has been rendered fertile by the deposit of humus and the effects j of the atmosphere. It will be found \ that two spits of fertile soil are ex- | ceptional except on alluvial land. i Below the fertile soil lies the raw, j unfertile soil known as subsoil, and as has been said, should net be brought •; near the surface in trenching. It ; must, however, be well broken up, and have some manure worked into it, but , should be left in position at the bottom j of the trench. This process, known j as bastard-trenching, is most gener- | ally useful for all but the exception- • ally deep and fertile soils. Trenching Large Lots. —In dealing with a large piece of ground, *say, about 20ft by 30ft, it is a good idea to divide the surface into two equal pieces lengthways, marking the division with a line or peg. The trench is then opened across the end of one or the halves, and the soil is thrown upon the other portion. Trench right down the first piece and then fill in the last trench in that piece with the soil taken from the first trench made in the other portion. A Few Things to Remember. —In trenching you will find it a great help to try and keep the trenches all of a similar width, the same depth, and to see that the sides are vertical, and unless you can trust your eye to be accurate, these ought to be ascertained by measuring them from time to time. Manure in trenches. —The addition of manure to the soil is most easily made during the operation of digging or trenching. The trenching offers a means of getting food down where the roots of deep-rooting plants w'ill most readily find It. After the trench is opened, a layer of manure some three inches deep is placed on the bottom of the trench and roughly turned into the subsoil. The top of the next trench is then removed and placed upon the manure, thus burying the weeds, etc., which it may contain as deeply as possible. Now a second layer of manure is spread over the soil and further soil is placed over this, and so it is continued till the trench is filled up. Surface Cultivation. —And now, in conclusion, we must touch upon the importance of surface cultivation which is almost as important as the deep stirring of the ground by trenching. It will be found that the most useful tool for this purpose is the Dutch hoe, and it should be kept going all through the dry season so as to prevent the soil caking, and to keep the moisture in the soil by the formato a size when they begin to become a pest.