Упражнения

1. Найдите в тексте синонимы выделенных слов и словосочетаний:

To check erosion, decrease in yields, to keep high fertility, to break down, to add, especially, the following crop.

2. Выпишume из текста «Fertilization» все интернациональные слова и дайте их русские значения.

3.Прочтите без словаря следующий текст, разделите его на абзацы и озаглавьте каждый абзац:

APPLICATION OF FERTILIZERS.

Fertilizer must be put into the seed-bed, where it will do most good to the young plant as it grows. This is done in two ways: a) fertilizer is spread on the seed-bed before the seed is sown and usually harrowed in; b) fertilizer is put in at the same time as the seed and usually near to it in the soil. Top-dressing means putting a fertilizer onto a growing crop. It is commonly done with nitrogen fertilizers on growing grain crops such as a spring dressing of sulphate of ammonia for a crop of winter wheat. If the nitrogen had been applied in seed-bed, most of it would be washed out during the winter. Lime and plant foods in fertilizers are not all used up in the year they are applied to the land. Some of the value is left over for a year or more and helps later crops.

WHEAT.

Wheat-growing was extensively practiced throughout Europe in prehistoric times and this cereal was of great importance in the ancient civilizations of Persia, Greece and Egypt. It spread to all the temperate countries where it now plays a major part in the food supply of many nations and it is also widely cultivated in tropical and subtropical areas.

Cultivation. It is often said that winter wheat does best on a well-formed seed-bed. Ploughing should be done as early as possible and the normal depth would be in the region of 6 inches. The type of seed-bed required for winter wheat can be described as one with a reasonable tilth in the top 2-3 inches, with a surface containing a high proportion of clods the largest of these being about the size of a man's hand. This is to prevent capping, a condition which can easily arise with heavy rain, when the soil surface runs together forming a crust.

Manuring. With all crops it is essential to ensure that adequate supplies of phosphate and potash are available dur­ing the first few weeks of growth. Once observed it is not possible to correct properly any deficiency and both of these major elements are required either in advance of drilling or they may be combine-drilled with the seed. Combine-dril­ling is the most economical way of applying these fertilizers, but with winter wheat time of sowing being of prime impor­tance, the faster method of application using fertilizer spin­ners is more often preferred. For average conditions 30 units (one unit is equal to 1.12 lb. and is the same as 1% on anal­ysis) each of phosphate and potash will be sufficient. If the soil is rich in nitrogen, then 30 units/acre of fertilizer nitro­gen would suffice, but under average conditions levels up to 60 units are considered economic rising to 80 units in the low rainfall areas. Previous cropping, local environment and to some extent cultural techniques can also influence the opti­mum level of this nutrient. When the soil is likely to supply some nitrogen for early growth of a winter crop, then it is unlikely that any autumn fertilizer nitrogen would be re­quired.

The short, stiff-strawed varieties of wheat can stand high levels of fertilizer nitrogen whereas the taller one used to produce quality straw will only tolerate moderate amounts. Of all the cereals winter wheat will give the highest response on this fertilizer and to obtain the best return the proper dres­sing should be applied at the correct time.

As far as spring wheat is concerned up to 60 units of ni­trogen can be economic. It should be applied prior to drilling or combine-drilled with the seed.

Seeding Rates. The amount of seed required for autumn wheat will vary between 1 and 2.5 cwt/acre. Early sowing need the least since the temperature for germination are higher than those later on and a larger number of the seeds produce plants.

Harvest. Winter wheat is normally harvested from August to October (in Britain), depending on the type of summer experienced and also the geographical location. Spring wheat matures much later than winter wheat and later than the cereals.

Following a hot, dry summer grain may be combine-harvested under very good conditions; and if the moisture does exceed 14% then it can be stored without drying. Moisture can be carried out at harvest and these are often used to indicate the stage of ripeness or readiness for combining.

Date: 2015-10-19; view: 810; Нарушение авторских прав