THE IRRIGATION AGE. 



647 



Notes on Practical 

 Irrigation 



D. H. Anderson 



Plant Foods Cereals Forage Plants Fruits Vegetables 

 Root Crops. 



Plants of every variety are very hearty feeders as a 

 rule; in fact, if a plant be furnished with unlimited quan- 

 tities of its proper food, and the environments of soil and 

 climate are favorable, it will increase its bulk to enormous 

 dimensions; the case is the same with fruits. 



Sir Humphrey Davy introduced plants of miht into 

 weak solutions of sugar, gum, jelly, etc., and found that 

 they grew vigorously in all of them. He then watered 

 separate spots of grass with the same several solutions, 

 and with common water, and found that those watered 

 with the solutions throve more luxuriantly than those 

 treated \vith ordinary water. From this it may be rea- 

 sonably inferred that different organic substances are 

 taken into the circulation of plants and then converted by 

 them into its own substance, or acts as food and nourishes 

 the plant. Of course, it will be understood that by "plant 

 foods" are meant whatever material tends to make the 

 plant grow to maturity. 



We have learned that plants absorb carbon in the 

 shape of carbonic acid, and the part ammonia plays in 

 the plant economy. Indeed, ammonia is actually present 

 in the juices of many plants, for example: in beet roots, 

 birch and maple trees, etc. In tobacco leaves and elder 

 flowers it is combined with acid substances. It is also 

 an element in the perfume of flowers, whence the value of 

 barnyard manure to supply that element. 



Nitric acid is invariably present in common, well known 

 plants, in combination with potash, soda, lime, and mag- 

 nesia (nitrates). It is always contained in the juicr- of 

 the tobacco plant and the sunflower. The common nettle 

 contains it, and it is present in barley in the form of 

 nitrate of soda. 



Like ammonia, nitric acid exerts a powerful influence 

 on growing crops, whether of corn or grass. Applied to 

 young grass or sprouting shoots of grain, it hastens and 

 increases their growth and occasions a larger production 

 of grain, and this grain is richer in g-luten, and therefore 

 more nutritious in quality. 



As showing the power of a plant to select its own 

 food: if a bean and a grain of wheat be grown side by 

 side, the stalk of the wheat plant will contain silica and 

 that of the bean none. The plant intelligence, or instinct, 

 so to speak, knows what it wants or needs, and it takes 

 what it requires, rejecting everything else. Plants have 

 also the power to reject through their roots such sub- 

 stances as are unfit to contribute to their support, or 

 which would be hurtful to them if retained in their system. 

 Knobs, excrescences and exudations may often be seen on 

 the roots, stems and even the leaves of plants, which 

 many think are due to the ravages of some insect, but 

 which are nothing more than the natural effort of the 

 plant to get rid of some obnoxious or harmful substance 

 in its system. When the plant's blood is out of order its 

 nature attempts to cure it by forcing the dangerous sub- 

 stance or matter to the surface, as does the animal sys- 

 tem under like circumstances. 



Even the germinating seed is a chemical laboratory, 

 inasmuch as it gives off acetic acid, or vinegar, which dis- 

 solves the inorganic material in its vicinity and returns 

 with it in a condition to build up and nourish the plant. 



The chemical compounds nroduced by the juices of 

 all plants may be said to be innumerable. Most of them 

 are in such small quantities that it would scarcely be 

 worth while to consider them, but some are of a highly 

 remedial quality, as quinine from Peruvian bark, morphine 

 from the opium of the poppy, salicine from the willow, 

 etc. All the cultivated grains and roots contain starch in 

 large quantities, and the juices of trees, grasses and roots 

 contain sugar in surprising quantities. The flour of grain 

 contains sugar and two other substances in small quan- 



tities, namely: gluten and vegetable albumen, which are 

 important nutritive substances. Sugar is also present in 

 the juices of fruits, but is associated with various acids 

 (sour) substances, which disappear altogether or are 

 changed into sugar as the fruit ripens. 



Woody Fiber, or Lignin. 



To manufacture the foregoing chemical compounds 

 nature requires a huge structure, an enormous space when 

 compared with the product turned out. More than one 

 has wondered why a monstrous oak should produce so 

 ridiculously small a fruit as an acorn, and a weak pumpkin 

 vine one so enormous. The philosopher in the fable 

 complained of this irregularity of nature as he lay under 

 an oak. But when a small acorn fell upon his head he 

 changed his mind. Now, all this huge structure, the body 

 of the plant, is as carefully manufactured as the delicate 

 savory fruit, and out of the same ingredients, practically. 

 The bulk}' part of the plant, the bone and sinew, so to 

 speak, is the woody fiber, or lignin. 



When a piece of wood is cut in small portions and 

 cooked in water and alcohol until nothing more can be 

 dissolved out of it, there remains a white, fibrous mass 

 to which is given the name woody fiber, or lignin. It has 

 neither taste nor smell, and it is insoluble. Strange to 

 say, two of its chemical constituents are the same as 

 water, being oxygen and hydrogen, with an equal quantity 

 of carbon added. 



Under the microscope this woody fiber appears to 

 consist of what is called "cellular" matter, the true woody 

 fiber, and a coating for strengthening purposes, called "in- 

 crusting" matter. This cellular matter is composed of 

 oxygen and hydrogen in the proportions to form water, 

 but it is difficult to separate them to determine the ele- 

 mentary construction, but we shall see that they demand 

 a certain food and are intended for an important purpose. 

 The woody fiber sometimes constitutes a large pro- 

 portion of the plant, and sometimes it is very small. In 

 grasses and corn growing plants, it forms nearly one-half 

 of the weight, but in roots and in plants used for food it 

 is very small in the first stages of their" growth. The 

 following table gives the percentage of woody fiber in a 

 few common plants while in a green state: 



Name of plant. Percent of woody fiber. Water. 



Pea stalks 10.33 80.0 



White turnips 3.0 92.0 



Common beet 3.0 86.0 



Red clover 7.0 79.0 



White clover 4.5 81.0 



Alfalfa in flower 9.0 73.0 



Rye 1.0 68.0 



Starch. 



Next to woody fiber, starch is the most abundant 

 product of vegetation. By whatever names the various 

 kinds of starch are called: wheat starch, sago, potato 

 starch, arrow root, tapioca, cassava, etc., they are ail alike 

 in their chemical constitution. They will keep for any 

 length of time when dry and in a dry place, without any 

 change. They are insoluble in cold water or alcohol, but 

 dissolve readily in boiling water, giving a solution which 

 "Becomes a jel'y when cold. In a cold solution of iodine 

 they assume a blue color. 



The constituents of starch are carbon, oxygen and 

 hydrogen, with less carbon and more oxygen than woody 

 fiber and about the same quantity of hydrogen. 



That starch constitutes a large portion of the weight 

 of grains and roots usually grown for food the following 

 table will show, one hundred pounds being the quantity 

 upon which to base the percentage' 



Name of plant Percentage of starch. 



Wheat flour 39.77 



Rye flour 50.61 



Barley flour : 67.70 



Oatmeal 70.80 



Rice 84.85 



Corn 77.80 



Buckwheat 52.0 



Pea and bean meal 43.0 



Potatoes 15.0 



In roots abounding in sugar, as the beet, turnip and 

 carrot, only two or three per centum of starch can be 

 detected. It is found deposited among the woody fiber 

 of certain trees, as in that of the willow and in the inner 



