SUCCESS WITH VEGETABLES

Wairarapa Times-Age, 13 January 1939, Page 9

SUCCESS WITH VEGETABLES

ROTATION OF CROPS.

The principal object in a system of crop rotation is to arrange the order of planting so that crops of a like nature do not follow each other directly. As is well-known to gardeners, the soil requirements of any one particular kind of plant generally differ from those of others. If one kind is grown exclusively on a plot of ground, the available supplies of essential food will soon be exhausted, and the crop soon ceases to be profitable. It may be argued that it is possible to place the food supplies in the soil for each crop. This may be so, but there is the factor to take into consideration, that certain plants excrete toxins which accumulate, until the soil becomes crop sick for that particular plant. Further, there is the definite possibility of disease attacking plants when they are regularly grown on the same plot: this is most marked in crops of the cabbage, tribe.

It is obvious that such root crops as parsnips and carrots require a deeper soil than cabbages. Their roots break up the lower strata of soil, and so release plant foods which otherwise would remain locked up.

Thus, in a good system of rotation, cabbage and cauliflower would follow the root croops. A plan of the vegetable garden should always be made, and the cropping of previous years referred to when making plans for the crops of the coming year. In a small garden, a three years' rotation is usually as much as can be practised, but the longer the rotation, the better the crops.

When making the rotation plan, the first subjects to be considered are the permanent crops. These include rhubarb, asparagus and seakale. Such crops will remain on the same ground so long as they continue to produce satisfactory results. The remaining crops are grown as annuals. The quantities are a matter for the owner to decide, but as a rule most space is allowed for potatoes, the cabbage tribe, and parsnips in the order named. In view of the danger of club root in cabbage, cauliflower, broccoli, Brussels sprouts, turnips and radishes, the plots should be arranged so that, as far as possible, there is a break of two years before these kinds again occupy the same soil. It should not be forgotten when making out the rotation, that turnips, radishes and kohlrabi are members of the cabbage tribe and not root crops. In some gardens it is found that onions, and less often carrots, will only thrive, in a certain position, so that ordinary rotation may have to be ignored in the cultivation of these. Spinach, lettuce, and other salad plants may be looked upon in rotation as catch crops, and fitted in where space permits, as they do not occupy the soil for long. Leguminous plants like peas and beans are nitrogen gatherers, and arc an excellent crop to prepare the soil for any of the cabbage tribe. Such catch crops as lettuce and spinach do well between rows of peas and beans, and thus make more use of the ground. Further, both of these green crops are best frosh, and small sowings should be made .at intervals to keep up a succession.