Fig. 38. View further along the valley, woodland and arable above rough grass land near the river
As the plant root is alive it wants air. The effect of keeping air out can be seen by sowing some barley or onion seeds in the ground and then pouring a lot of water on and plastering the soil down with a spade. Sow another row in nicely crumbled soil, not too wet, press the seeds well in, but do not plaster the soil. This second lot will generally do much better than the first. If the ground round a plant is frequently trodden so that it becomes very hard the plant makes much less growth than if the soil were kept nice and loose. A good gardener takes very great pains in preparing his ground before he sows his seeds, and he is careful that no one should walk on his beds lest his plants should suffer.
SUMMARY. We may now collect together the various things we have learnt in this chapter. Plants require water, air, warmth, food, and light, and they will not grow if harmful substances are present. The rain-water that falls remains for some time in the soil, and does not at once run away or dry off: water can also move from wet to dry places in the soil. Therefore the plant does not need rain every day, but can draw on the stock in the soil during dry weather. A sandy soil is usually drier than a loam or a clay, especially if it lies rather high: plants growing on a sandy soil make less growth and have narrower and smaller leaves than those on a moister soil.
Situations more than five or six hundred feet above sea level are, in England, as a rule, too bleak and exposed for the ordinary cultivated crops. Such land is, therefore, either grass land, moorland, downland or woodland.
The roots of plants are living and require air. The soil must not be trodden too hard round them or air cannot get in, nor can it if too much water is present.
Grass can put up with more water and less warmth than most cultivated crops.
