УПРАЖНЕНИЯ. 1. Заполните пропуски в предложениях соответствующими словами из текста:1.When there is not enough potassium in the soil

1. Заполните пропуски в предложениях соответствующими словами из текста:1.When there is not enough potassium in the soil, we say the soil is... in potassium. 2.... is the process which removes excess of soil moisture. 3. Best yields of maize are achieved on soils of medium... and high.... 4. Nitrogen fer­tilizer should be... into the soil, otherwise much of it will be lost by.... 5. Cultivations and... help to control.... 6. The average temperature for the... of maize is over fifty de­grees F.

2. Определите, какие предложения не соответствуют со­держанию текста, и внесите необходимые исправ­ления:

1).It's advisable that nitrogen be applied much before plow­ing. 2).They recommend that maize land should be free drain­ing. 3). It's necessary that the students know the different va­rieties. 4). It is not desirable that maize be planted in warm soil. 5). Chemical means are seldom used in weed control. 6). To obtain quick germination the seed-bed must be fine.

3. Ответьте на следующие вопросы:

1.Why should soils of medium texture be preferred? 2.What are the opinions about soil pH for maize? 3. How are seeds controlled? 4. Can maize survive any degree of frost? Why do you think so? 5. How does it happen that the leaves maize use solar energy efficiently?

4. Прочтите без словаря следующий текст и расскажите, как вносятся удобрения:

Maize can be fertilized at three different times. A corrective broadcast application is done before plowing. Soil deficiencies are corrected with large amounts of fertilizers. A starter fertilizer is applied with the planting equipment, e purpose of this application is to aid a small maize plant get a more rapid start. It is best to place fertilizer about 1 inch below and 2 inches at the side of the seed. When maize follows a good legume crop no additional nitrogen may be required. But when maize follows maize additional nitrogen is usually needed. This may be applied before crop is planted or between the rows until the crop is 15 18 inches tall.

OATS.

Soil. The cultivation of oats may take place on a wide range of soil types with a reasonable degree of success. Oats can be found on all the light to medium soils in the higher rainfall areas and will give high yielding crops of good quality can also produce good crops on some of the heavier, clay and silts, in the drier areas of Britain where there significant moisture reserves in the soil which can be drawn upon during a particularly dry time.

It is true that oats will grow well where barley will fail completely and wheat produces only moderate crops but extreme acidity even with oats cannot be tolerated.

Climate. The oat crop is particularly suited to the cooler, humid climate of the western and northern regions of in where growth is relatively slow and as a result the grains have plenty of time to fill out to produce good plump samples.

Oat crops which do not suffer through lack of moisture will produce high grain yields of good quality and on the average the straw will weigh slightly more than the grain. Most of the world's oats are supposed to be produced at elevations below 2,000 feet and probably half below 1,000 feet.

Seed-bed Preparation. Oats are said to be the best cereal to follow the ploughing up of grassland but this is only true if the grass is turned in timely and well, the furrow slice be­ing properly inverted and no large air pockets left which tend to accentuate drying out.

Ploughing depths should be 6 inches except where grass or surface trash need to be buried deeper and then 8-9 inch­es plough depths may be required. Where early ploughing has been carried out it is often only necessary to give the land a light-medium harrowing to obtain the desired tilth in the top 3 inches of the soil.

Drilling. Optimum drilling depth with oats lies in region of 1.5-2 inches. When seed-beds have an irregular surface tilth, drilling depth becomes uneven and in order to ensure that all the seed is covered, it will often go in well below the optimum in many areas and this will be responsible for patchy stands.