The term “Soil” is used when we speak about the superficial portion of the earth’s surface composed of broken, and disintegrated rock mixed with varying proportions of decayed and decaying animal and vegetable matter. Below the soil lies the subsoil which is distinguished from the surface soil mainly by a smaller percentage of organic matter and greater compactness. Plants derive all of their mineral content arid a large part of their nitrogen content from the soil. Nitrogen is one of the most important components of soil. The other principal elements of mineral food include sulphur, phosphorus, potassium, calcium, magnesium and iron. Apparently, sodium, silicon and manganese are also needed by plants. The ability of assimilation of all these elements varies. This is why humus which contains many of, the nutritive elements that are readily assimilated by plants from decayed organic products is so highly valuable. The productiveness of a soil also depends to a great extent on its mechanical properties (especially upon texture and structure) and also on the presence of useful bacteria, the chief function, of which is to help to fix free nitrogen.
Soils must be well supplied with humus so as to develop bacterial life adequately. An important property of soils, which is partly chemical and partly physical, is their absorptive power for fertilizing components.
In respect of texture and also age, soils can be subdivided into fine sandy soil, sandy soil, loam soil, sandy-loam soil, silt-loam soil, shale-loam soil, muck soil, podzol soil, limy soil, solonetz soil, chernozem (black earth soil), brown soil, red soil. Various crops are adaptable to various soils. Naturally, the contents of humus, greatest in black soil, permits of a vast choice of the best cash crops, notably cereals and gives rich yields. Indeed, bumper crops are obtained on chernozem soils.
Of late various soil amendments are being introduced, principally high molecular substances improving soil structure.
Surface Features
It must also be stated that besides soil, surface features are of considerable importance in deciding upon the choice of a particular crop.
Land may be flat, undulating, or rugged and this is by all means to be considered in farm planning. Take for example vineyards which thrive best on hillsides as contrasted to plainland more suitable for arable farming.
It is interesting by the way to note that of late in Moldavia a definite classification of terrace altitude for growing different varieties of vine has been developed. It appears that different kinds of grapes give the best yields at the particular height suitable for that variety. Thus, viticulture, to take just one example, is to a considerable extent dependent not only upon soil and precipitation, but also upon elevation.
Improving fertility
Naturally good crops will thrive only with proper seed selection, timely seed-bed preparation, weeding and other advanced practices. But good seed varieties will also thrive provided the natural fertility of the soil is maintained or best of all raised. A plant lives through its growth and development. In addition to photosynthesis, where solar light is effective in transforming carbon dioxide into nutrients, the plant must obtain its nutrients from the soil.
In planning a farm or a system of farming for a whole area one has to consider the natural fertility of the soil. For innumerable centuries nature has grown plants and allowed them to decay. This is humus, the chief factor determining the fertility of a soil. And it must be there to produce a good crop, for it is humus which contains the main chemical ingredients necessary for the thriving of plants. But if humus is partly or completely lacking this deficiency has to be compensated.
In terms of chemistry, phosphorus, potassium and nitrogen make up the most important components of a rich soil. Most of the soils that are rich in nitrogen, potassium and phosphorus are productive. If a soil contains a poor amount of these ingredients the deficiency has to be compensated by adding fertilizers or manure.
At the same time soil fertility can also be improved by good crop rotation which prevents exhaustion of soil.
Crop rotation means that crops are grown in definite succession so that a certain crop following in the sequence restitutes to a certain extent to the soil the elements taken away by the preceding crop, so that the ground is never “sick”. Every year the crop sown down on a definite plot and subsequently harvested is replaced by another while the former crop is shifted over to another field. Crop rotations are named after the number of fields or courses that regularly follow one another, each sown to a successive crop; thus, we have four-course, five-course and other multifield systems. Sometimes the ground is left to lie fallow to clear the ground from weeds and to accumulate nutritive substances.
The principal advantages of crop rotation are: 1) all plants tend to exhaust the soil, but in different manner, hence a rotation tends to maintain the balance; 2) all plants do not take up the same ingredients in the same proportion from the soil and air thus, crops rich in carbonaceous matter take up relatively small amounts of food from the soil, but large quantities from the air; 3) certain crops help in accumulating humus, such as various grasses; 4) legumes are often sown which enrich the soil with nitrogen.
Of course the rotation system has most frequently to be used together with the application of fertilizers and it sometimes comprises fallow for the ground to rest and be freed from weeds by tillage.
Speaking about crop rotation it is necessary to mention specially catch crops. A catch crop is sown between regular crops. The growth of catch crops in crop rotation is recognized as good farm practice. These comprise peas, beans, alfalfa, red clover which makes a splendid hay because of its, large protein content, white clover, a perennial plant, and soybeans, also rich in protein and fat which make not only an excellent catch crop but also a nutritious household food. They all absorb nitrogen from the air and add it to the soil, thus replacing the nitrogen taken from the soil by other plants.
Fertilizers
The life of plants comprises the processes of nutrition, breathing, growth, generation and responses to environment. All these processes of the live organism involve consumption of energy and of the matter which is to constitute the texture of the organism.
The chemical elements constituting the organism are numerous, and they are either assimilated from the soil or - if the soil is poor or exhausted - they are provided artificially by means of applying various fertilizers, or else by liming and the use of gypsum.
The fertilizers used in modern agriculture may be subdivided into organic and mineral. Organic fertilizers comprise: barnyard manure, peat, green manure (from certain plants assimilating nitrogen from the air) and various composts. Composts contain not only organic, but also mineral matter. Inorganic fertilizers comprise various ingredients, but the most important elements are nitrogen, potassium and phosphorus. The primary for obtaining nitrogenous or nitric fertilizers is ammonia. Ammonia is obtained synthetically from nitrogen and oxygen or as a by-product of coking. Most widely spread are ammonium sulphate, nitrates such as urea, and liquid ammonia. Ammoniacal fertilizers are water-soluble and are well assimilated by plants, but they act more slowly than nitrates.
The initial raw material out of which phosphate fertilizers are obtained are apatites (of which there are numerous deposits in the Russia) and phosphate rock. The following kinds of phosphate fertilizers are known: superphosphate, pelletized and double, defluorized phosphate and ammophos. Phosphorites are finely ground as a result of which phosphate meal is obtained. Especially valuable is pelletized superphosphate. It is well applied with ferti-seeding, contributing greatly to germination.
Potassium-containing or potassic fertilizers are obtained from potassium rock salts, also widely occurring in the Russia. Potassium chloride, potassium sulphate, kainite are the chief commercial fertilizers derived from these salts.
But the three main elements are far from everything needed to thrive well. Plants need a number of other elements, notably: carbon, oxygen, hydrogfen, sulphur, calcium, sodium, boron, molybdenum, manganese, copper and even iron. Fertilizers containing such elements are called minor nutrients or trace fertilizers.
All kinds of fertilizers are assimilated through the root system of plants. Liming (the application of lime) is often also necessary on acid soils.
Not only must these elements be introduced into the soil, the proportion of each should be strictly calculated, and often it is best to combine several elements in one fertilizer. In this connection concentrated compound fertilizers are of high value. These not only provide all the necessary ingredients in the right proportion, but also permit of a considerable saving in bulk and weight. Thus if we use ammonium sulphate, ordinary superphosphate and sylvinite, then in order to introduce 60 kg of nitrogen, 60 kg of phosphorus and 60 kg of potassium, a ton of these fertilizers is required; at thesame time if synthetic urea, double superphosphate and potassium chloride are applied, the same amount of nutritive ingredients will be contained in 370 kg of the mixture. The compound fertilizers based on ammonium nitrate, ammonium phosphate and ammonium sulphate have great advantages. The fertilizers are a free-flowing granular product and provide considerable sayings in handling costs resulting from the higher concentration of these products cottipared with traditional superphosphate based compounds. Today there is a demand for even higher concentrations and new manufacturing processes have been developed to provide a wide range of compound fertilizers based on ammonium nitrate in place of ammonium sulphate, and containing nitrogen, phosphates and potash in any of the usually required formulations.
These formulations have the following important advantages: 1) High concentrations: giving economies in handling, bagging, transport and spreading costs. 2) Exceptionally good storage properties. The products consist of well-shaped granules substantially in the size range of 1.5-3.5 mm, completely free from dust. 3) They are suitable for all crops and all types of soil. 4) The products are so formulated as to avoid the self-sustained decomposition which has characterised some types of nitrate-based complex fertilizers. 5) The products do not show the adverse effects on germination nor the nitrogen losses which have been occasionally observed in the highest concentration products from other processes.
In certain areas, particularly tropical regions with high rainfall and acid soils, the need for highly water-soluble phosphate is not important. For such regions we can use ground phosphate rock.
But how do agriculturists know about the effect of various fertilizers? Tracer atoms come to their help. Isotopic tracers are among the most important tools of the biochemist and agriculturist, and fundamental advances of agricultural knowledge have been made with their aid.
Isotopes are now indispensable in biochemical research; primarily in establishing the basic chemical reactions which occur in normal living things.
Agriculture benefits from knowledge gained by tracer methods not only in the application and assimilation of fertilizers, but also through the control of insecticides in plants and insects.
At present in most cases fertilizers are introduced into the natural soil, but a new system of growing plants and fertilization is today also making headway. It is known as hydroponics. A bed of gravel or sand is made on a rack arid all the necessary fertilizers without exception are added. Of course, the necessary moisture content is provided. Plants thrive wonderfully on such a bed. But a further improved system has been devised. A film of synthetic rubber, able to follow the natural lay of the ground is put on the soil, whereupon sand or gravel together with the necessary fertilizers are placed. The film prevents the appearance of weed grasses and moreover impedes the formation of dunes, likely to arise as a result of wind erosion. These films are especially suitable for growing vegetables.
Сrops
By the word crop we understand every useful plant cultivated for the benefit of mankind.
Depending upon their field of application, crops can be subdivided into the following groups:
1) Food crops, comprising mainly cereals, or grain crops:
Under this head comes first and foremost wheat grown practically at all latitudes and constituting the essential primary for milling, baking bread, etc. Wheat is followed by rye grown essentially in Northern countries. Rye yields brown bread.
Next to rye in significance comes barley used for the preparation of gruels and for malting. As is well known, malt is what beer is made of. Buck wheat and millet serve principality for making gruels. It would perhaps be difficult to say whether oats belong to the group of feed crops or food crops. Porridge is made of it which is a highly nutritive food for humans, but oats are particularly widely employed for feeding domestic animals. Oats are an excellent feed for horses, milch cows, growing calves and laying hens on account of their high protein content. Oats also have a stimulating effect upon horses. Thus from the point of view of the food industry, it is a food crop, and, considered from the angle of cattle-breeding, a typical feed or kind of fodder. The same can be said of maize (corn in the USA) which is a food-stuff and a means of fattening cattle (principally hogs).
Rice. Its cultivation requires an immense quantity of moisture. It grows best in fields which can be flooded. Such rice is called lowland rice while rice grown without inundation bears the name of upland rice. Rice when not yet husked is called paddy.
Special mention should be made of crops used in the production of beverages.
Tea. The tea plant grows in China, Japan, India and the South of the Russia. It is a hardy evergreen, from three to six feet in height. The leaf is the part of the plant of which tea is made. The difference in the quality of tea is due partly to the district in which it is grown, partly to the time at which it is gathered. There are four harvests in the year - in April, May, June and August. The first gathering is confined to the choicest leaves only, andis the finest; the last gathering is the lowest quality.
Coffee. The coffee-plant grows in North Africa, the East and the West Indies, and Brazil. The seeds of the fruit, which is about the size of a small cherry, are the parts of the plant which yield coffee, and are called coffee-beans. Coffeeowesits stimulating properties to an element called caffeine, which is identical with the active principle in tea and cocoa.
Cocoa. This is the seed of the cocoa tree, which grows in the West Indies and in several parts of South America. The seed is contained in pods about five inches long, and is somewhat like a cucumber. Chocolate is simply the ground cocoa-seeds made into a paste with sugar and flavoured in various ways, but chiefly with vanilla.
Grapes grow on bushes in vineyards principally in the South. The plant itself is known as vine. The art of growing grapes is known as viticulture. Grapes are much used for making wine.
2) Feed crops are those, the main purpose of which is to supply provender to cattle. Many varieties of grasses can be listed under this head. Clover takes the first place, but timothy, alfalfa and vetch all find their useful application; many of these grasses serve at the same time the purpose of returning to the soil those particular nutritive elements which the preceding crop has extracted from the earth.
Grass-sowing is, in fact, not a minor factor in planning crop rotation. Swedes are also an important feed crop, along with mangle.
3) Industrial crops are those that provide raw materials for further processing. Sugar-beet is the main primary for the sugar industry, while various fibrous plants such as flax and hemp yield respectively linen and rough cloth, along with sacking.
Flax. The flax plant yields the fine fibres of which linen is made. It is an annual plant bearing blue flowers. It is now cultivated in nearly every country in Europe, as well as in Egypt and India. The stems, after being dried, are soaked in dew or in water, to destroy their green outer bark. The interior fibres are then dried and scutched to separate the threads completely. They are then hackled, or combed out, when they are ready to be spun, or twisted into yarn. The finer kinds of flax are made by repeated hackling.
Hemp. The hemp plant was originally a native of Persia and Northern India, but it is now extensively cultivated in the Russia, as well as in North America and Africa. The part of the plant which yields the fibres for manufacturing is the stem which is treated in much the same way as that of the flax plant.
Cotton. Perhaps the most important industrial crop for the textile industry is cotton. The cotton plant, three or four feet in height yields the cotton fibre. The commercial value of cotton depends on the length, the staple and strength of the fibre. In preparing cotton, the seeds, enclosed in bolls of down, are separated by an apparatus called a gin. The cotton is then compressed into bales and sent to a factory for making cotton fabrics. The seeds are either kept for sowing again, or are used in making oil and oil-cake for cattle. Cotton generally grows on bottom or irrigated lands.
The sunflower plant yields the best oil - sunflower oil; cotton and even flax oil are both edible, though falling of course short of the pleasant taste and flavour of olive oil, cocoa-nut oil and some other oils which rank first among salad and other seasoning preparations.
With the development of synthetic rubber, rubber-bearing trees, though partly holding their own, have to a great extent given up their former industrial significance. And although chemical technology has provided the world with new esters, essential oil bearing plants are still being grown, finding themselves a particularly vast range of application in the perfumery industry.
4) The fourth group is represented by vegetables. Though these are mostly to be seen in vegetable gardens, yet we can observe vegetables growing on vast areas of field land. The system of growing vegetables on a large scale is termed truck-farming.
Vegetables can be subdivided into the following groups: root crops comprising beetroot, carrots, turnips, radish, etc., fruit crops embracing tomatoes, water melons, musk melons,and pumpkins, as well as cucumbers; cole crops, to which cabbage belongs in first place; pulses covering peas, beans, lentils, etc. Last not least come tuber crops, principally potatoes.
Potatoes, comparatively recently introduced into Europe (they were brought from America) not only constitute an important foodstuff, but are also used for the manufacture of starch. Cauliflower, onions and swedes (used principally as a feed) also rank high in truck-farming.
Every year, new varieties of crops, cold-resistant (not subject to winter-killing), more nutritive and more tasteful are being evolved on experimental test plots.
II. HORTICULTURE
Horticulture is the art of growing, improving and propagating fruits, vegetables and flowers (floriculture). It also comprises landscape gardening.
It naturally begins with selection or breeding the best varieties of plants: fruit-trees, vegetable crops and flowers. The degree to which plants may be made to respond to the needs of man is marvelous.
Michurin and Burbank with their wonderful achievements clearly show how true this is.
Pomology
Fruit growing embraces the production of the apple, the pear, the peach, the apricot, citrus fruits (lemons, oranges and grapefruit); so-called small fruit, as the plum and the cherry; along with such berries as the strawberry, the raspberry, the gooseberry.
Choice of site, soil preparation and correct layout of orchard stand out as the main factors for longlived and high-yielding plantations.
The site should be comparatively warm, protected from cold, as well as scorching winds, so that shelter-belts are often made to surround the orchard. The best fertilizers for orchards are barnyard manure and compost, together with ammonium sulphate, superphosphate and potassic salts.
It is highly important to protect young trees from disease and insect pests. This is done by spraying with various chemicals out of sprinklers or sprayers.
Sprinkling is also effective during blossoming in spring to protect the trees against late frosts, though burning bonfires is also not unfrequently used for the purpose. During the first years after an orchard is planted truck crops are grown in the interrows, but this cannot be done when the fruits already appear in any quantity on the trees. After autumn leaf shedding the ground under the trees is ploughed under. During the whole lifetime of the orchard a persistent struggle with weeds has to be conducted: this is done by means of hoeing along with the application of herbicides.
Hand-picking of fruit has in many places given way to harvesting with the help of various machines. Most diverse types of harvesters exist at present: such as cherry harvesters, currant harvesters, orange harvesters and even pineapple harvesters.
Vegetable growing
Depending on the size of the site, vegetable-growing areas can be subdivided into kitchen gardens, vegetable gardens and truck fields.
Independently of the size of the plant, various systems of planting are used. Sometimes seedlings are planted into special holes. Just as in the case of field crops the seeds of vegetables are either thrown into the prepared beds broadcast or introduced into the ground by means of drills of which, depending on the kind of vegetable to be sown, there exist many different types; to mention just a few: carrot drills, cabbage drills, pea drills (sometimes with fertilizer placement), etc. For planting potatoes the checkrow or cluster-pocket method is sometimes applied. Very often ferti-seeding is used.
As the vegetables on the plantation grow, weeds will necessarily appear amidst them, while in many cases the plants sown will produce, too dense a growth stifling one another. Accordingly, weeding and thinning respectively become a vital necessity. These operations are at present also accomplished mechanically by weed extractors and mechanical thinners. Again, as the plant grows, it needs hilling with inthrowers, regular watering and dressing with additional fertilizers inducing better growth. If the leafage is exuberant, as in beets, top-removing is sometimes undertaken as a preliminary to taking in the crop. In the case of many truck crops, grown on a vast scale, harvesting is effected with the help of special harvesting machines, of which the potato-harvesting combine is best known.
All the aforesaid referred essentially to planting vegetables in open ground when the plant is open to the vagaries of the climate and notably to sudden frosts occurring even in springtide. But vegetables are in acute need on the market not only after the yield has been taken in, that is in summer and autumn, but also in early spring and winter. This want can be supplied by growing vegetables under glass, or even in heated premises: hothouses.
The use of glass in forcing vegetables greatly intensifies the work. Hot and cold frames are mainly used for the purpose of forcing vegetables in spring, but greenhouses (or hothouses) provided with heating batteries permit of winter cultivation even during the darkest and coldest months.
Now what vegetables are actually grown in hothouses?
Onions, parsley, celery, beetroot and cucumbers come first. These vegetables, along with heat, also receive, in the hothouses the necessary light as a potent stimulating factor, wherefore electric lighting is generally provided in greenhouses. Tomatoes are not so often cultivated in hothouses since their yield is by far less and they tend to ripen rather much later.
Hotbeds differ from coldbeds in the fact that the former are provided with a heating agent – “an organic fuel” - manure, which in decomposing liberates a definite amount of heat prevented from escaping by the glass frame.
The latest development in hothouse vegetable-growing is aeroponics - a trend which made its first appearance in the Russia. The greenhouse contains a number of racks to which reticular bags are attached; these bags contain the seedlings. The root system runs through the reticular texture of the bag and hangs out into the air. The outhanging roots are constantly humidified by nutrient solutions which are sprayed out of a pulverizer.
There is every ground to believe that aeroponics will in the near future enable automation to take care of vegetable-growing, while it may perhaps not be a dream to think of the time when spaceships sailing out into the Cosmos will have on board aeroponic conservatories to provide their pilots with fresh greenery.
III. ANIMAL HUSBANDRY
Animal husbandry or pastoral farming is no less important than field husbandry. It comprises cattle-breeding; sheep-rearing and hog-growing, to say nothing of some minor branches, as poultry-breeding, rabbit-breeding, apiculture, etc.
Cattle-breeding
Cattle can be roughly subdivided into draft cattle which has almost everywhere been replaced by various types of agricultural machinery; dairy cattle which provides dairy products (milk, butter, cream, cheese, etc.), beef cattle and dual purpose cattle.
The measure of merit of cattle is dependent upon the breed. The herds cannot be improved without the use of sires from pedigree stock.
Cattle-breeding on a scientific scale is not only aimed at improving the breed, but also at increasing the head of cattle; in stock-raising areas the herds are usually very big and the more heifers and calves are to be seen on the grazing lands, or in the corrals, the better the cattle-rearing farm is run.
One of the principal problems cattle-breeding faces is that of fodder or feeds. To choose the necessary feeds, rich enough in protein and other nutrient substances is not an easy thing.
As is well known, hay stands out as the main provender, but special crops are also grown for feeding cattle. They are mainly mangle, various leguminous plants, such as alfalfa, cow-peas, etc. Clover takes a vital part, while oilcake left over after the extraction of oil from linseed, cotton-seed and other varieties of oil-bearing seeds ranks particularly high in protein content. Most farms - both those going in for diversified (mixed) farming and those that specialize in stock-breeding - have ensilage towers where silo or ensilage is obtained through fermentation and stored. Ensilage is recognized to be an excellent feed by most cattle-breeders.
As a general rule, dairy products are processed on the farm. In the creamery milk is skimmed- and churned into butter, while some part is turned into cream or sour cream. The production of cheese and canned milk, is mostly effected at cheese factories and condenseries. After the bulk of the fat is removed from the milk, whey remains. It is still useful as a feed for domestic animals and also can be used for making curds.
Beef cattle is mostly sent to the slaughter-houses on hoof. Big meat-packing plants after the slaughter of cattle are engaged in curing, smoking, corning and especially canning the meat. Mechanization is implemented on a large scale in cattle-breeding. Particular significance belongs to it in feeding and milking. Automatic bunks (gravity belt, rationing feeder, etc.) are gradually being introduced.
Sheep-breeding
After cattle-rearing sheep-breeding ranks perhaps first among the various pursuits of pastoral farming. Sheep are ruminants and while they are fond of concentrated feeds they must also have such feeds as grass and hay. They like leguminous plants too.
The male sheep is known as the ram. The female sheep is called a ewe, and the little sheep are known as lambs.
Sheep are mainly bred for their meat (mutton) and for the wool they yield. There are accordingly two main types of sheep-breeding: for wool and for mutton. There is also a medium breed: the wool-mutton breed. But after all sheep are of course most valued for their wool. The annual clip (that is the quantity of wool sheared) of wool is a major factor in the economy of many countries. The best sheep are fine-fleece. Every effort is made to bread new and better strains: fine-fleece, semi-fine fleece and long staple. This is carried out mainly by cross-breeding. Sheep also yield milk out of which a special kind of cheese is made and mutton which contains a high percent of fats and proteins. Flocks graze not only on well-established pasturages, but also even on semi-desert or dry grazing land.
Hog-raising
What is remarkable about the next branch of animal husbandry - hog-breeding - is that it quickly yields returns. The production cycle of hogs (or swine) is much shorter than that of cattle or sheep. Another significant feature of hog-breeding is (just as dairy farming) that it gives a vast range of food stuffs derived from pork. Among them are: bacon, lard, ham, sausage, tinned (canned) pork. At the same time hog skins are sent to tanneries while hog-bristles find a vast sphere of application, down to the manufacture of toothbrushes. Even the offals of swine are used, for instance, in sausage-making.
Hogs are omnivorous. However, unlike other domestic animals the pig has a small stomach and requires its food in concentrated form. Pigs grow more rapidly than any other class of farm animals in relation to their weight. The daily ration of a pig should be composed of feeds with a definite proportion of carbohydrates, proteins, vitamins and minerals.
The male pig is called a hog and the female pig a sow, the small piglets are often called just pigs.
The fattening of pigs should, within reasonable limits, be begun from an early stage. As soon as the litter of newly-farrowed pigs is weaned (from the sow), they should be properly fed on a balanced ration.