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Crimson Clover for Cover.
almost any time during the summer. Some idea of the dense growth of the vetch this year may be obtained when I say that one patch overcame and obscured a heavy growth of horse-radish which had been in the ground two years. I am confident that upon fairly good soil, good results can be obtained with vetch sown as late as the middle and possibly the last of July."
Crimson or scarlet clover was brought emphatically to the fore as a cover plant for orchards by the Delaware Experiment Station* in 1892. It has been the occasion of much speculation and much misunderstanding. Like all new things, it has been hailed by some as a plant which is bound to revolutionize orchard management and to make plantations productive; and others, who have failed, have discouraged its use entirely. The fact is, as already pointed out, that crimson clover is only one step or round in the ladder of cover crops, and it is ordinarily the last and the highest. By this it is meant that it will not thrive upon hard or poorly tiled land. It must be sown in midsummer or a trifle after, when the ground is likely to be dry. The seeds are small and oily, and the grower is very likely to fail in securing a "catch." Upon the better tilled lands, however, crimson clover may be expected to succeed as often as any other plant of its class will. People have also made a mistake in expecting too heavy a growth of herbage in the crimson clover. It is an annual plant, normally completing its entire
*Bull. 16, Del. Exp. Sta., March, 1892.
growth in a single season. When sown at midseason, therefore, it should not be expected to yield a very heavy crop. If it should arrive at that stage when it nearly or wholly covers the surface of the ground with a thin, close mat, it will have reached its most profitable condition. Neither is it necessary that the plant should stand the winter and grow in the spring. Turnips, maize, vetch, and other tender plants are known to be very useful as orchard cov
Fig. 21. A good stand of crimson clover as it looks before growth has begun in the spring.
ers, although they pass the winter in the dead state. If the crimson clover passes the winter and grows in the spring, much will be gained; but if it should not pass the winter, nothing will be lost. In respect to the proper time for sowing crimson clover, it may be said that if it is sown very early in the season (that is, before the first of July), it is likely to become too large and ripe, and be killed by the winter; if it is sown too late (that is, after the middle
Legumes as Fertilizers.
of August in the north), it will ordinarily not attain. sufficient foothold to be able to withstand the heaving by frost. Crimson clover may be sown amongst Indian corn at the last cultivation, but in orchards it is ordinarily sown from the middle of July to the middle of August in the north, upon a well prepared seed-bed, and is then lightly dragged in. In old orchards, six quarts to the acre is a sufficient amount of seed; in open lands, about eight quarts are required.
The following analyses show the fertilizer values of the various leguminous plants here discussed. The vetches and peas were analyzed at the Cornell Station. The analysis of cow peas is taken mostly from Professor Teller's recent studies in Arkansas, those of clovers from reliable sources for comparison:
PEAS, 2 TO 3 FEET HIGH, NO FLOWERS, ROOTS AND TOPS.
COW PEAS (WHIPPOORWILL) IN BLOSSOM, STRAW ONLY.
Having now discussed how, by tillage and cover crops, the land may be made fit for the growing of fruit plants, we come to the question of what plant-foods may be added to the soil. It should first be said that fruit plants use up plant-foods
NOTE. The following figures show the approximate quantities of seed which are recommended per acre for cover crops in young orchards :
Plant-food Removed by Trees.
the same as other crops, and yet the common neglect of orchards seems to show that many people think otherwise, or else do not think at all. In fact, the depletion of the land by fruit trees is more serious than by annual crops, from the fact that plantfoods are locked up for many years in the trunks and branches of the trees, whilst a large part of the fertilizing constituents in common crops returns to the soil each year. On the other hand, it should be said that the roots of trees have a larger foraging area than the roots of small crops do. This is well shown in Figs. 17 and 18 (pages 160 and 162). The former shows the roots running far away in the poorly tilled soil in search of food, and the latter shows the home-staying roots in the rich soil.
Roberts has computed,* from analyses, the values of nitrogen, phosphoric acid and potash taken from an acre by apple trees (the trees thirty-five feet apart) in twenty years, counting in ten crops of fruit:
"The value of nitrogen, etc., in any given case is so indefinite and variable that stress should not be laid on values as given above, but on the total amounts of plant-food used by the orchard.
*Bull. 103, Cornell Exp. Station.