• Гідрологія і Гідрометрія
• Господарське право
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• Економіка природокористування
• Економічна теорія
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• Міжнародний маркетинг
• Основи екології
• Предмет Політологія
• Соціальне страхування
• Технічні засоби організації дорожнього руху
• Товарознавство продовольчих товарів

TILLAGE ACCESSORIES AND OTHER MACHINES

Tillage Accessories. After a good job of plowing, the planter runner will often give enough tillage in the row to pro­vide a good seed-bed. For difficult soil conditions or for more complete soil pulverization, a number of attachments can be used on the planter or plow. These devices are quite effec­tive because they are operated in fresh-plowed soil that has the correct moisture for easy pulverizing. They till the soil in the row beyond the seed depth, and some act as leveling devices to bring about more uniform planting depth.

Other Tillage Machines. Research has demonstrated that normally the mold-board plow is the most efficient machine for pulverizing the soil and covering the trash to provide a satisfactory seed-bed. Extra tillage can be obtained during the plowing and planting operations so that no additional trips over the field are necessary. Other tillage machines have been studied, however, and deserve mention.

On soils that are easy to pulverize, a seed-bed can be prepared with a field cultivator without using a plow. Narrow chisels on the machine make it possible to till deeper with less power. These chisels tend to leave the soil open, which is an advantage in the fall because rain and snow can enter the open soil easily. If chisels are used in the spring, however, moisture may be lost from the open soil, so it is desirable to pull a harrow behind the cultivator to level the soil.

For the operations just before planting, it is good to use narrow sweeps to leave the soil level. More sweeps on the cultivator will require more power, but if the field is weedy, the extra sweeps are needed to remove the soil from the roots.

Powered rotary tiller machines can be used to prepare a seed-bed in one or two trips over the field. The rotating blades cut the soil loose, pulverize it, and mix the residue throughout the tilled layer. These actions result in what appears to be a satisfactory seed-bed. However, more of the row width is tilled to a finer clod size than is necessary. This finely pulverized soil tends to be quite loose under normal conditions, but after a heavy rain it becomes very compacted and crusted, sometimes to the point of retarding germination.

Since the machine has a high power requirement, travel speed is slow even with a large tractor and labour per acre is greater than for most of the other methods.

TEXT 5

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