Farm and Garden.

King Country Chronicle, Volume III, Issue 160, 31 May 1909, Page 4

Farm and Garden.

How Soils Lose Producing Capacity.

J. J. Edgerton, in a talk to the lowa State Board of Agriculture, said: —"It has been found by comparing native soils with those alongside of them that have been continuously grain-cropped for several years, that, great as is the loss of vegetable matter, the decrease in soluble plant food is still greater. On other farms that have been under cultivation just as long, but where a good system of rotation has been combined with nn occasional dressing of manure, there is no decrease in cither vegetable matter or soluble plant food. On farms lying side by side, under cultivation the same length of time, and originally of equal producing capacity, but conducted the one under a good system of rotation, and the other under that of continuous grain cropping without making any return of vegetable matter to the soil, those of the first class are found to yield just as large crops as when they were first broken up, while the returns from those of the second class have gradually been growing less from year to year until in some cases, where they have been under cultivation for 25 to 30 years, their producing capacity has been reduced over 50 per cent. The results of some rotation experiments, recently conducted on lands that have had their yields very much curtailed by continuous cropping, showed, at the end of the first complete rotation,a decided gain in the percentage of vegetable matter in the soil, and a stiil greater increase in the amount of soluble plant food present, while in check plots that were continuously cropped there was a still further decline both in the percentage of vegetable matter and soluble plant food.

Tbc amount of moisture in a soil is of no less importance in crop production than tbe amount of plant food there may be present. A shortage in crops is much more frequently due to lack of moisture than to lack of available plant food. A certain amount of moisture in the plant is necessary before there will be sufficient circulation and translocation of materials to produce any growth. If the moisture in the soil is sufficient more than this amount of growth will take place. If there is a large amount more there will be a large growth during the early stages of growth, but not enough to last until the crop matures, there may be a large growth of stalk and foliage, and a small yield of light and inferior grain.

Experiments have sbown that even in favourable seasons, a difference of five per cent, of moisture in the first four feet of soil at the time the grain is forming, would give an inrcease in yield of corn of nearly one-half. The greatest factor in controlling the amount of moisture in the soil is the vegetable matter that it contains, or should contain. As between a native soil,and one tbat has been continuously grain-crpped for 20 to 30 years, the moisture holding capacity of the latter is ha been reduced about 25 per cent.