Assuming a legume in the cropping scheme, the fertility of the soil may be maintained by yard manure alone or by commercial fertilizers alone.
Assuming a given type of management, the question is, How much of the required nitrogen will be obtained from the legumes in the cropping system, how much from the manure, and how much must be purchased in commercial fertilizers?
Commercial fertilizers of a nature especially adapted to the potato crop form the chief reliance of the growers.
Chicken, pigeon, and sheep manures rank high as fertilizers, their value being somewhat greater than ordinary barnyard manures, and almost as great as some of the lower grades of commercial fertilizers.
The presence of plenty of organic matter in the soil is very important, especially where large quantities of commercial fertilizers are to be used.
If for several years before potatoes are planted the land has been properly manured with farm manures, or with green crops plowed under, commercial fertilizers can be advantageously used on most soils.
Land which receives only plant-food, as may be the case when fertility is supplied in commercial fertilizers, loses good physical condition.
Examples of the best modern skill in farming may be found in the rational selection and use of commercial fertilizers.
The plant-food in commercial Fertilizers is largely in a soluble or quickly available condition.
An important value of commercial Fertilizers is to use them to start off the plants quickly in the spring.
If live stock cannot be kept on a dry-farm, the most direct method of maintaining soil-fertility is by the application of commercial fertilizers.
If so large a reduction could be secured in practice, it would seem to justify the use of commercial fertilizers in years when the dry-farm year opens with little water stored in the soil.
The entire subject of commercial fertilizers is based almost entirely on the fact of the lack of these four elements in the soil in sufficient available quantities to grow profitable crops.
But lest it should, attention should be given to fertilizing the land occasionally with farmyard manure, or with phosphoric acid and potash applied as commercial fertilizers.
These may be supplemented when necessary by commercial fertilizers.
While growing it in many instances will not render unnecessary the use of commercial fertilizers, it will greatly reduce the quantity of these that would otherwise be necessary.
The reader will remember a statement in Mr. Hale's letter on commercial fertilizers confirmatory of this view.
In the use of commercial fertilizers, there should be a constant and intelligent effort to keep up a supply of all the essential ingredients.
I fully share the average farmer's partiality for barn-yard manure in preference to most, if not all, commercial fertilizers.
I cannot speak so confidently of buying commercial fertilizers; but these I will discuss in my next chapter.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "commercial fertilizers" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.
