(2) When a plant dies the tendency is for some other plant to take its place ; just as oaks may follow hemlock or pines, so weeds take the places of grasses unless prevented by the farmer.
(3) The changes in the texture or condition of the soil influence the herbage. When land is newly seeded certain grasses may thrive which will not do so when the soil becomes more compact. The treading of animals further compacts the soil and it is not so well " aerated." The air space in the soil is partially maintained by the death of plants and decay of their roots.
In the Genesee valley on Dunkirk clay soil, when it has been eroded, Canada blue-grass, oxeye daisies and white clover constitute the bulk of the herbage, but if grazed for twenty or thirty years, the land improves sufficiently so that Ken tucky blue-grass begins to come in and in two or three decades more the herbage consists largely of Kentucky blue-grass, meadow fescue and white clover.
(4) Climatic conditions are important. Late spring frosts kill early-growing or early-maturing grasses, as orchard-grass and meadow foxtail; but if such are protected by manure, or even cut straw; they may survive similar conditions. Favorable spring weather may enable such grasses to develop unusually well, and crowd out later-growing species.
Changeable autumn and winter weather, freezing and thawing, and even heavy rains are more in jurious to some grasses than to others. On the heavy clay lands of New York the chief factor in determining the life of alsike, red clover and even timothy is the winter. In changeable winters many of the plants are heaved out and their places are later taken by oxeye daisies, live-for-ever and other weeds.
Drought injures grass-land in several ways. It not only reduces the water content of the soil, because of which some grasses suffer more than others, but it causes the soil to bake and crack and so injures the roots. Under such conditions, deep-rooted grasses, as tall oat-grass and awnless brome, may survive; and grasses having nar row, bristle like leaves, such as sheep's f e s cue, tend to increase, while such grasses a s red-top, which have flat leaves, will lose ground. Thus the changing seasons may be one of the prime causes for changes in the herbage of a pasture.
(5) Injudicious management. Timothy may be ruined by too early cutting, time not having been given for food to be stored in its thickened stem, which would tide the plant over the summer droughts. Grazing too close has the same effect, especially if done late in the fall. Grasses may be pulled up by animals or the land may be poached by the stock if they are turned on when it is too wet.
Certain grasses, such as timothy, are perennial by means of stolons. The stolons are formed about the same time the seed is developed. Anything which prevents the formation of the stolon causes the death of the plant and a bare spot in the pasture.
Renovation of worn-out meadows and pastures.
One of the best ways to renew grass-land or to maintain it in good condition is to fatten cattle or sheep on it, feeding the animals concentrated feeds and, in some cases, hay and forage in addition. Sheep are most highly esteemed, because they eat so many weeds and because their droppings are scattered uniformly over the land. In the case of cattle or horses, the droppings should be distributed every two or three months by running a chain harrow or a weeder over the land.
The application of barnyard manure, lime or fertilizers is profitable in many cases. Barnyard manure has a more lasting influence than most fer tilizers. To determine which is the most profitable fertilizer to use, a fertilizer test should be made and maintained for a term of years. Lime may be applied at the rate of 1,000 pounds per acre, once in every three to five years. In addition to the above. the pasture should be harrowed in the spring or fall as soon as it shows signs of becoming thin or sod-bound, the disk-harrow being an excellent tool for the purpose, although the spring-toothed or spike-toothed harrows may be used in some cases. The weeds should be mown either once or twice a year before they bloom, and liberal appli cations of grass seed made every two or three years, in spring or fall after the harrowing. Under such management, not only may land that is now good meadow or pasture be maintained as such, but much of the poor meadow and pastures of the country may be converted into good ones.