Legumes

In general, legumes are more valuable as cover and green manure crops than non-leguminous plants, because as a rule they are more rank growers and more deeply rooted, as well as because they add nitrogen to the soil. But it is rather more



difficult to secure a good stand of most legumes than it is of the crops previously mentioned for several reasons. As a rule the seeds are smaller and a large seed usually has greater germinating power than a small one. This often means much at the time of the year when the cover crop is sown. Then legumes are more difficult to grow, requiring better soil conditions. Still these should be present in good orchard soils. Drainage must be good, the soil must be at least average in fertility and physical condition, it must not be sour--hence it is often necessary to use lime--and soils frequently require inoculation before they will grow legumes satisfactorily. Where the clovers grow well they make excellent cover crops as well as green manure crops. The chief difficulty with them is that of obtaining a good stand in a dry midsummer. The mammoth red and the medium red clovers are probably the best of their genus on the heavier soils, while crimson clover is best on sandy soils and where it will grow, on the lighter gravel loams. The latter is especially well adapted to building up run down sandy soils. Although it is somewhat easier to secure a stand of this clover, alsike does not grow rank enough to make a good cover or green manure crop. Most clovers are deep rooted plants and therefore great soil improvers physically as well as being great nitrogen gatherers. The amounts of seed required per acre for the different kinds are about as follows: mammoth fifteen to twenty pounds; red (medium) twelve to fifteen pounds; crimson twelve to fifteen pounds; and alsike ten to twelve pounds. Where it can be readily and successfully grown alfalfa is really a better cover and green manure crop than the clovers. It is deeper rooted, makes a better top growth, and therefore adds more nitrogen and more humus to the soil than the clovers. It cannot be recommended for common use, however, as it is so difficult to grow except under favorable conditions. It requires a more fertile soil than clover, a soil with little or no acidity, good drainage, and usually the soil must be inoculated. Only where these conditions prevail can alfalfa be generally recommended. Vetch is an excellent cover and green manure crop, forming a thick, close mat of herbage which makes a good cover for the soil. It is very quick to start growing and a rapid grower in the spring. It also adds larger quantities of nitrogen. The hairy or winter vetch lives through the hard freezing winters. Summer vetch, although an equally good grower, is killed by freezing. One bushel of seed is required per acre and the seed is expensive, which is the greatest objection to the use of this excellent crop. Two other less well known and used leguminous crops are well worth trial as cover crops--soy beans in the North and cow peas in the South. Both are great nitrogen gatherers and as they are rank and rapid growers add large quantities of humus to the soil. Under favorable conditions they will cover the ground with a perfect mat of vegetation in a very short time. Being larger seeded, it is considerably easier to obtain a stand on dry soils and in dry seasons than it is of the smaller seeded clovers. It is usually best to sow in drills the ordinary width, seven inches, apart. Cow peas are universally used as a cover and green manure crop in the South, but they do not thrive so well in the North. One and one half to two bushels of seed are required per acre. In the North the earlier maturing varieties of soy beans are almost equally good. One to one and one half bushels of seed are sown per acre. Leguminous cover crops are also the best and the cheapest source of nitrogen for the apple orchard, after they are well established. Their use may be overdone, however. Too much nitrogen results in a growth of wood at the expense of fruit buds. To avoid this it is often advisable to use non-leguminous and leguminous crops alternately, when the orchard is making a satisfactory growth. Sometimes also these two kinds of crops, as buckwheat and clover for example, may be combined with good results. When this is done one half the usual amount of seed of each should be used.

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