AGRICULTURAL CHEMISTRY.

New Zealand Times, Volume XXXII, Issue 5010, 14 April 1877, Page 1 (Supplement)

AGRICULTURAL CHEMISTRY.

The Ballarat Star’s Learmonth correspondent writes ;—Another of a series of lectures given by Mr. Emerson Mclvor, on agricultural chemistry, was delivered by that gentleman on the 7th inst. in the Shire Hall, the subject being “ Soils Generally. The meeting being called under the auspices of the Ballarat Agricultural and Pastoral Society, its president, Mr. Patrick Quinlivan, occupied the chair, about sixty persons, chiefly farmers, being present. Mr. Mclvor, on opening, stated that tho present lecture was given as a key, as it were, to the next lecture he would give, namely, one on the soils of Ballaratshire. Soils are all derived from disintegrated rocks, and are of two classes—soils of disintegrations, and soils of alluvium. Soils composed of granite are, generally speaking, poor and cold, being deficient in lime, and the infertility of gx-anite soils is principally on account of the hard nature of the substratum, which does not allow of drainage, and consequently is hard and cold. On the other hand, basaltic soils are very fertile in their nature. This is due to the fact of their being more rich in the constituent parts of plant-food, the three principal component parts of plant-food being lime, potash, and phosphoric acid. Those soils of Victoria he has already examined show a very great deficiency in lime to those of France, and consequently are greatly inferior according to the proportions of vegetable matter. Soils are classified, and called vegetable when they contain a great deal of vegetable matter—say 20 per cent. ; and it used to be considered that the more vegetable matter it contained the more fertile it was. This was a fallacy, and the greater productiveness of garden soil over field was due to its better working, and not the fact of having a greater per cent, of vegetable mould. The second class of mould is clayey soil, which is colder in its nature and contains more water ; and the lecturer quoted statistics to prove the hurtful influence water exercised, although a certain amount was necessary, and cited Meohi, to show the great results from drainage on a clayey soil, and stating that one acre of uudrained land while giving £lO 10s., the drained laud gave a profit of £l7 18s.; Meohi being also a great advocate of deep ploughing. The third class of soils, viz., those of a sandy nature, is the very opposite to the clayey in character. Crops on sandy laud are very liable to be burnt up during hot weather, and after a few crops they soon give out. They are called hungry, swallowing so much manure. The fourth, calcareous soils, are those whose leading constituent is lime, and which generally has about 20 per cent. This sort of soil is well adapted for lucerne, clovers, and other cereals which contain a large perceutage of lime. The fifth being those soils of a marshy character; they consist of a mixture of lime, sand, and clay. The sixth being what is called loams, and are generally very fertile. The soil generally speaking is what the plough turns over; what is underneath is called the subsoil. From an analysis of a class of soil from a portion of Mr. Clarke’s land, a very marked difference existed between the subsoil and the top soil, and in some cases the subsoil should be partly turned up so as to increase the fertility of the land, as it contained a good portion of plant food. The lecturer cited a case where a farmer asked his opinion concerning a crop of wheat that died away after coming nearly to maturity. He told him to dig down and see what his subsoil was, as it must either be too v et or have mineral qualities of a poisonous nature. He did so and found stagnant water, showing the vast importance of paying attention to the subsoil. In some cases the subsoil has more food-feeding qualities than the top, and in those cases to turn up say two inches is productive of great good ; but great caution must always be used, as to turn up some land renders it unproductive for a season or two. He was against deep ploughing on clayey land. A good soil must contain all the necessary elements of plant food as well as a good subsoil. From a sample of fine-looking black soil from Mount Alexander, which he analysed, and which was stated to be unable to grow anything, he found that although it contained all the good qualities, it contained also as many poisonous ones. He advised, tho application of lime, with good results. One of the most important things, especially in this country, is in the soil being able to absorb moisture in hot dry weather. It also ought to be retentive, and able to hold the food it receives, and not allow the rain to wash it out. Soils are always hotter than the atmosphere ; the darker it is the more so, and warmer it will be. This is necessary for tho seed to germinate, and it is a very important principle of good land, viz., the absorpuon of heat. Mr. Gilchrist wished to know if chemistry had ever done any good for agriculture. Mr. MTvor was proud to have the opportunity to answer this question. He stated that practical experience has done more to retard real agriculture than anything else, and complained of the treatment his class received at the hands of practical men. He quoted Mechi, who once said “ Thank God I was not born a farmer, or I should have been chock full of prejudice ;” and consequently would'; never have accomplished what he has done, •and through science he has, on the poorest land in England, raised his 54 bushels of wheat. He also quoted Lawes and Gilbert as men who have distinguished themselves as scientific farmers. He claimed oil cake as a scientific food, also he stated that while in England only 15 bushels of wheat per acre could be obtained, Scotland, with an inferior climate,. could obtain 45 with a judicious system of scientific farming, and wanted only to be better known to be better appreciated. It was a question of importance, and he could dwell for hours on it. Mr. Gilchrist, in conclusion, moved a vote of thanks to the lecturer for the very able and interesting lecture given. This was seconded by Mr. James Baird, who believed to a certain extent in being a good practical fanner himself, and quoted Lawes and Gilbert, who lost a large sum of money, which they would not have lost had they been practical men. Mr. Mclvor, in reply, defended science even in the case of Lawes and Gilbert. A vote of thanks to the chairman terminated the meeting. _____________