“AGRICULTURE.”

Thames Star, Volume LXII, Issue 17410, 6 July 1928, Page 5

“AGRICULTURE.”

PAPER READ AT ROTARY. BY HUGH CRAWFORD, A.O.S.M INFORMATION FOR FARMERS. [The following very interesting and most instructive paper on “Agriculture” was read recently to the Thames Rotary Club. It is printed here for the perusal of our farmer readers, and will be continued daily.] I.

Agriculture. The word agriculture is made up oi two Latin words; agor. a field, and cultura, cultivation, and the both words together mean the cultivation of the soil. AGRICULTURE is the art of cultivating the soil so as to make it yield its greatest quantity and best quality with the least expenditure ol labour and money. THE COUNTRIES that devote the most attention to the teaching of agriculture produce the best and heaviest crops, and consequently enjoy a greater amount of prosperity than those that pay less attention to the science and are of agriculture. Plants. A plant is a living thing and requires to be fed just the same as the stock on the farm. Parts of a Plant. 1. The ROOT, or the portion- underground which supports the, plant in the soil, and provides it with a portion of its food. 2. The STE-M, or the portion above the ground, which forms the main body of the plant, add from which spring the leaves, etc. 3. The LEAVES are the breathing organs of the plant- and is also one of its feeding organs. The FLOWER is the organ engaged in producing the fruit, or seed, from which new plants spring. SOIL is that portion of the earth's surface in which plants may be grown. Nearly all soils have been originally formed by the gradual breaking up and weathering away of rocks. The gasses of the air and in water combine with portions of rocks and cat their way into them.

Take the andesite rock in our district; it is composed of (this sample was taken from the mouth of thh Moanataiari level): —Silica, 57.15 per cent.; alumina, 19.20 p.c.; ferric oxide, 1.36'p.c.; ferrous oxide, 4.17 p.c.; manganous oxide, 0.42 p.c.; lime (Ca-O), 7.13 p.c.; magnesia (MgO), 3.58 p.c.; potash (K2O), 1.10 p.c.; soda (Na2o), 2.88 p.c.; titanium dL. oxide, 0.84 p.c.; sulphuric anhydride, 0.12 pic.; phosphoric anhydride (P 205) 0.10 p.c.; water (at lOOdeg. Cent.), 0.68 p.c.; combined water and organic matter, 1.41 p.c.; total, 100.20 p.c. Out of .seven analyses this is the only one containing phosphoric anhydride. The soil,,- therefore, formed from an andesite, will contain all these kinds of foods.

The soil itself is divided into two very distinct layers, the surface soil and the subsoil. The former is dark in colour owing to the decomposition of the vegetation growing n the surface. The subsoil on the other hand is lighter in colour and not as friable as the surface soil.

Soils derived from rhyolite yield' on decomposition (with an admixture oi organic matter), a. loam. However, it decomposition is incomplete, the particles of rock which are unaffected act as sand which explains how some of these soils are so friable. The Twin Peak (Puriri) soil is composed of an rhyolite of the .following composition:—Silica, 72.40 per cent.; alumina, 14.09 p.c.; ferric oxide, 0.48 p.c.; ferrous oxide, 2.52 p.c.; manganous.. oxide (MnO), , 0.42 p.c.,; lime (Gab), 1.15 p.c.; magnesia oxide (MgO), 0.20 p.c.; potassium oxide (K2O), 4.09 p.c.; sodium oxide (Nu2o), 2.97 p.c.; titanium oxide TI02), 0.15 p.c.; carbonic anhydride (CO2), 0.82 p.c.; water and organicmatter, 0.8(5 p.c. ;•• total, 100.15 p.c. The andesite and rhyolite are the two principal rocks from which our soil is derived, and as they are both low in phosphoric acid, phosphatie manures will give splendid results. The state in which the soil grains exist has a marked bearing on the general fertility. In a well-tilled soil having a fair proportion of humus and lime, the soil grains are not present as individual particles, but are grouped together in the form of granules. When a soil of a clay nature is puddled any granules which may have been present in its natural state are destroyed, the soil becoming very plastic and on drying sets into a hal’d lump. This .property is reduced to a minimum when the soil becomes granu la ted, either by. the presence of lime and of humus, or by careful and proper methods of cultivation. . - On the clay lands of the Hauraki Plains between the two rivers it is suicidal to allow the cattle to poach the ground. If the rainfall cannot be deiflt with by the present drains, find out the lowest part of the paddock and sink a well. Plough a number of small surface drains to this spot and pump out the acciunulated water to the existing drains. It is better to go to this extra troublo than have twothirds of the grazing area spoilt by the cattle, or better still if the cattle can be taken off the farm during the wet season, or as an alternative, house them in the winter time. The recent- dry spell during last summer has lieen of inestimable value to these clay lands (providing drainage down to a depth of at least t-hiee f.eet)„ as nature has, supplied this gift, do not undo the good work -bv allowing poaching to take place again. Fertilisers. We manure to supply plants with foods which are not immediately avail able in the soil. Consider the ton nine inches; we have to deal with 32,070 cubic feet of soil per acre, and as each cubic foot of soil weighs about 751 b. tli© ton nine inches of soil works out at 2,450,2501 b per acre. An average soil contains .1 per cent, nitrogen. .15 per cent, phosphoric acid, and .4 per cent, of potash, and on these figures an average _ soil would contain 24501 b nitrogen, 36751 b of phosphoric acid, and 98001 b of potash, but this plant food is for the most part not immeidately available for the use of the crop, whereas the material supplied in a manure is capable of being readily used.