SCIENCE OF AGRICULTURE.

Waikato Times, Volume XXXIV, Issue 2756, 13 March 1890, Page 2

SCIENCE OF AGRICULTURE.

The Lecture at Hamilton

Propkbsoii Thomas delivered the third of his s tries of lectures on agricultural science as tvphed to agriculture, in the Volunteer Hall; Hamiltui), on Thursday evening, the (ith infit. Thero waa a Rood attendance of farmer*, and amongst those present we noticed Messrs Barugh (2) Fisher (2) Forresv W»y, Pickering, Patmi. Parr, D.ivis, Selby, Pumriae, \ViUy, Whoeler, Furze Saie, Ridlar, Edgcciithhe, llowie, Clarke, All right, Storey. ' Rnuchnsiii (2), Jolly, Mason, Hay, and Sander Amongst the audience there wero a number of ladiee, who seemed to take a great interest in the (leicturc. Professor Thnnma.jliad on the walls, tables showing the average composicertain crops, wheat, oats, clover hay "rod, meadow hay, turnips, mangolds, potatoes, beans, in pounds, per acre. ■ • Oh the motion of Mr Barugh, Mr Primrose was voted to the chair. On taking the chair, Mr Primrose briefly introduced Professor Thomas to the meeting, and-said no. doubt that all would benefit greatly by tio lecture. r Professor Thomas, on rising .to speak, was received with loud applause. He said : This will bathe third lecture I have delivered at the invitation of the Waikato Farmers' Club, who have recognised tho necessity that all light and knowledge, that science can throw on ngrieulmre should be made the most of by the farmer. Great changes have been made in agriculture by science. It is only within the last hundred years or so that science has been applied to agriculture, and now in most civilised countries, there are hundreds of men who study agriculture under the light thrown on .it by science, and it has been found possihle to make agriculture successful by the means shown to us by those who devote themselves to the science. In New Zealand there is great need of science for although it may havo many advantages the farmer.looks outside New Zealand for a market, and there has to compete against farmers who have all the advantages of science. Therefore, if he disregards these advantages he cannot compete successfully. In New Zealand labour is costly, as are also fertilizers, and were it not for the splendid climate and fertile soils, farming could not be made to ,pay. Many havo said that farming does 'not pay, but these were not' the best farmers nor those who looked to scientific agriculture in tho employment of their labour and capital. He proposed to show how a knowledge of scientific principles bears ou agriculture. Tn his first lecture he dealt with plant life and plant food, in tho second with soils, and that evening he jn tended to treat on fertilisers—a very Important subject, and to understand which a good deal must be kn"wn about plant life, and food and soils. Professor Thomas here briefly gave the substance of his two previous lectures, shewing tho lift of elements without which no crop can grow, and which are carbon, hydrogen, oxygen/ nitrogen, sulphur, phosphorus, potassium, calcium, lime, magnesium and iron, tho first six of whji:h are called the organic p*rt, or that part which may be destroyed by fire, and the latter four which are called.,- the inorganic part, which are indestructible by fire and remain after a plant has been burnt in the shape of ashes. Soil is chiefly derived from the decay of Tocks. hut in addition to that obtained from this source, there-is a quantity in all soils, of what is called " nonius," which is derived from the decay of animal or vogctable matter, according to the different variety of rock from which the soil is formed, there is iior difference in the character of the soil.- 'Certain substances may be largely present in the soil, but not those necessary for plant life. In good soils there is only about 1-10 percent of phosphoric acid, in which form phosuhnnis is supplied, and from one-tenth to twotenth percent, of nitrogen and often less than this. Potash, which contains potassium, sometimes is very plentiful, being about one per cent, of the soil, but, is generally much less, this high percentage only being in rich heavy clay soils. The substances most often absent in soils are nitrogen, phosphorus, and potassium, but although the proportion is so small the weight in an acre is considerable. For instance, an acre of "oil nine inches deep weighs about 300.0001k5, and at one-tenth per cent, there would be yOOOlbs of phosphoric acid. Soil may contain this quantity of phosphoric acid and yet the crops would not thrive, but if a manure containing lOOlbs of this acid were added it would make an appreciable difference; This difference is not cawed by the 1001ns of acid but by the way in which it is applied, too much of any substance may be present in the soil, but not in a form available for plant food, which exists in soil in two forms, active and dormant. Pl-mt. food is said to bo active, which is available, and dormant when in a form which the plants cannot dissolve out of the soil, and supposing the soil contains a large amount of food in a dormant condition we must try and brin? it into an active condition. I may define fertilisers as substances that not only add plant food to the soil, but which also render dormant food active and make it available for plant food. I will touch only ou potassium, nitrogen, phosphorus, and also lime. Lime is a plant food in itself, and is generally present iu sufficient quantities, but a greater amount is valuable in rendering dormant food active. In considering fertilisers wo must first consider the substances removed by crops, all crops, as I said before, require the elements I haye mentioned for their growth, but they require them in different proportions. The quantity required in the soil depends on the vital quantity they need for their growth. It is not to be expected that we can go on year after year growing t ho same crops unless some return is made to thesoil for the substances taken out of it. This may go on for some time, but in the end tho cround will become impoverished and the crops will be worthless. If, instead of growing tho same crops every year, the farmer wora to alternate or take a succession of crops, he would do much better. This is evident, from tho composition of the crops, that each crop requires different substances in different quantities, and if you alternate tho crops the heavy demand only comes at, intervals. But the crops requiro all the elemeuts in a certain proportion, and if these are returned back to the land iu the shape of the waste products of animals, there i.-, no Joss of fertility, but the methods of modern civilised life however render this impracticable, and large quantities of the products, etc., are exported, thus depriving the land of some of these elements. For instance, wheat requires a large amount of phosphoric acid, wool a large quantity of nitrogon, and meat a large quantity of phosphoric acid and nitrogen, and in exporting these articles mineral substances are removed and the land is impoverished. If this is to go on something must be done to I replace this material which is exported. (Applause). There are certain product! which do not carry away mineral substancos from tho soil, and where fertilisers are dear these should ba cultivated. In the first | place butter contains chiefly carbon, oxygen | and nitrogen (cheese takes a : good-deal of mineral out of the soil); oil, such as colza and olive oil, and beetroot remove little or no mineral substances, deriving their constituents chiefly from the air. With reference I to the four substances, phosphorus, nitrogen, potassium and lime, which are the constituents I will touch on, we will first take phosphorus, which is one of the most important. Tho professor then showed the formation of phorphoric acid which occurs ou phosphorus coming in contact with tho oxygou of the air, and in which way phosphorus is conveyed to the plant. Phosphoric acid, he said, is a white powder solublo in water, and which combines with lime, forming phosphate of lime. He then showed the formation of superphosphates or monocalcinm phosphate, dicalcium phosphate, and tricalciuin phosphate, the two latter of which coutaiu greater proportions of lime, and also superphosphates, us made by tho manure merchants, by; adding sulphuric acid to bonedust, which converts tho tricalcium phosphate iu tho bonus into monocalcium phosphate, or superphosphates. He then continued, superphosphates aro largely used, because they are easily soluble aud readily diffused evenly through the soil. When bones were first used as a manure they were crushed to half an inch, and it was then found that it took 15 cwt to an acre, the size of thu bones was reduced, and a smaller quantity was found to produce the same result. If large lumps wero used a large quantity would have to be used, so that the roots would meet with piece ready for them, therefore it is of importance that mauure should be evenly distributed through the soil. Lieberg iu. troduced the idea of dissolving un bones, and then it was found that one-third of the quantity of bones acted more quickly. It is well known that superphosphates which are soluble when added to tho soil are soon rendered insoluble; when the superphosphate is applied it is diffused by water, and comes in contact with certain particles which precipitate it iu an insoluble form. Carbonate of lime will do this also, so will oxide of iron, aad in most scilij the precipitation oocura in

few days. In sandy soils tho superphosphate is not precipitated. When the rain comes it is washed down helow the roots of the plants, and gradually drains away underneath. It is important, therefore, not to add too much soluble superphosphate to a soil which cannot i.e trusted with it in that form. We must know the property of tho soil »nd the property of the manure, and wa will then know if the soil is to be trusted with that manure. In light sandy soilo, it Is no «8» to apply superphosphate unless the soil has received a treatment of lime. On these it is better to employ phosphoric acid manure in an insoluble form, such as oonedust or precipitated phosphatos, which can be obtained in England. Then there are phosphatic guanos, which contain phosphate of lime, in a finely divided but insoluble condition. Almost all tho Pacifio Islands have guano of this description. On heavy soils and those rich in lime there is little or no danger of adding phosphoric acid in a soluble form, and, provided it can be done, it pays best, as a smaller quantity may be used with an equally good result, but if you use insoluble phosphate, the quantity used will be much „'er, and a large part will not be Wen up by the plants, but will remain in *the ground, and perhaps a little . will be taken up next year. It is always better to add only enough manure for one year, as manure lying in the ground is the same as money out without interest, which we all know does noc pay. If you can, always uso a quicker acting manure—the professor here tested somo Hamilton soil, and found it to contain phosphoric acid. He continued : Potash manures supply the important element potassium, which is in some soils very deficient; in clay soils, however, it is often present in large quantities, as they arrest it from goiuft to waste. A clay soil or an averago loam may safely be trustod with potash. Potassium combines toadily with tho oxygen c( tne air, but more readily with the oxygen in the water, and driving off the nitroeen from tho water, »nd potash.is formed.- When potash is put into wiilthe potassium is retained 'by tho soil aad lime takes its place. Certain substances in the soil, called double silicates, act in this way as guardians of the potash. Somo soils contain plenty of potash and other? are detieiont.imit,-anthifc-w always well to enquire if potash is present. _ Waikato soils ought not to be deficient in potash. If you want to add potash to the soil you can get it from farmyard r mr.nt.re and also from ashes, and I am surprised this latter source of potash is not in New Zealand taken greater advantage of. Thero is also a substance called kainite which is found in ' !ermany and which contains about 25 per cent of potash. In England this is sold at i' 2 per ton, and it would bo cheap here up to kl per ton, as it is a ready way to add potash to the soil and in England a very cheap way, Nitrogen is the most important substance in applying fertilizers. It is present in the soil chiefly in the humus, which is formed by tho decay of animal and vegetable matter, some S'dls are extremely rich in humus, and although some soils contain nitrogen in large quantities yet it is often one of the substances most deficient. When air is properly admitted to the soil, the bncteriai which are present in myriads in the soil change the nitrogen into nitric acid which contains a good deal of oxygen. Nitrogen is very dear to buy but a lot is converted into nitric acid in the soil. In order that this may g« on carbonate of lime must be present to act on the nitric aci), this i- why lim? is important as a fertilizer rendering the dormant food nitric acid into active food. The sources of nitrogen are \mt animal and vegetable waste, and then such cuano as may be rich in nitrogen, and which is only found in the rainless regions of the world, such as_ Peru. There is however, also found in the same regions another valuable sibstsmre. nitrate of soda, more commonly called Chili saltpetre, a most valuable manure, as most pi mts prefer to havo their nitrogen supplied in this form. In distilling coal ga*, an ammoniac d liquor is formed, which, on tie..tmenc with sulphur acid, forms sulphate of ammonia a substance, which is supplied to the farmer as a fertilizer. This substance contains 20 per cent, of nitrogeu, and nitrate of soda contains onh 15 per cent., yet, if this latter can ho obtained, it is better to use. These cannot be trusted to ordinary soils, as they will run through, and must, therefore, be added when tho heaviest rains are over, and when there is no danger of too great rainfall before the manure is used by the soili They aro not made proper use of un-. less tho soil contains a sufficient quantity of water, and in a dry season may fail altogether. Quicklime, added to any ammonia compound, drives off ammonia : this is a valuable gas very often lost. Nitrate of soda is so valuable a manure that I should like t" seo it used more in New Zealand. In Liverpool this manure could be boughl for £7 10a per ton, -whereas in Auckland it costs £20. The freight should not raise the cost more than £7.per. ton, and at £14 it would be a valuable manure. New Zealand is as near the deposits as England and it should b« brought here as cheaply as to England. Limn acts as a fertilizer in various vvr.ys. It serves to retain plant food as phosphoric acid and potash, and it also has advantages mechanically, both on heavy and ; light soils. Lime on heavy clay lands makes them more porous and freer to work, and on light soils such as in Waikato, it has tho opposite effect, rendering thotu less porous aud les< likely to sulfur from drought. Lime is also valuable on, soils containing too large quantities of organic matter, as it neutralises the acid and destroys the sourness of land ton rich I inSliunius, too much of which is injurious. There are several points to be attendodto in choosing manures. Ist. the composition of the crop, that is, what substances the crop requires, and which of them it can obtain readily, and which it will have a difficulty in getting. , 2nd. Composition of the soil : What substance it contains. If, for instance, the soil is deficient in nitrogen alone, it will be sufficient to manure for nitroeen, but if it is deficient iu nitrogen and phosphorus, it is no use manuring for .nitrogen alone. 3. In what foi?m tho food exists in the land,-'science can tell us this, but cannot tell us what the plant thinks of tho food. 4. Provious history of the land, thus, for. instanco, if a crop of turnips has been fod oil" on the land, it will not require tho same treatment as if a crop of wheat had been taken off. .">, What sort of maunrc in to be used, and in what form the substance required is present, as some manures are on only suitable for ono particular crop. All these points must be considered if favourable results are expected. Tho best thing for the farmer to do is to conduct a series pi small experiments before investing his' capital in a, large experiment, which may fail. ' I liave not exhausted mv subject in those three.lectures, nor could I do so were I to give throe dozen, but I hope if hive interested you in- the application of scientific principles to agriculture, as I think it is very necessary to New Zealand. In a now country like, this we.have not tried our soils, and we do not know our resources, and it will be some time before we know how to treat the soil to the best advantage, and we must applv all possible knowledge to make the most of our resources. We have a large area of virgin land, a good proportion of which is rich soil, and we have a good climate, and now we have got to bring as much knowledge as we can to boar on these to build up as happy and prosperous a nation as possible. Professor Thomas took his seat amid loud cheering; Mr Barugh said that all who had heard the lecture no doubt felt grateful to Professor Thomas, and many would henefit by the instruction given by him. He proposed a vote of thanks to Professor Thomas, which was carried by acclamation. In conveying tho vote of thanks to Professor Thomas, the Chairman, on behalf of tho audience, thanked the Waikato Farmer's Club for their action in getting Professor Thomas to deliver these lectures.

In responding, Professor Thomas said that it had ctiven him (treat pleasure to deliver these lectures, and he asked all present to interest themselves in a subject hr had deeply at heart, and that was science a* applied to agriculture He was surprised at tho ignorance displayed by tnnny of tho farmers in the scientific part of agriculture, many considering that the names of tho siinplo elements of the plants connected with their every day life were buorish and new. He had asked the Board of Education to give prizes for agricultural Hcience, and he hoped in that way to get some interest taken in a subject which will be of use to the colony, Mr Cf, E. Clark, chairman of tie Waikato Farmers' Ulub, in responding on behalf of that body for tho vote of thanks passed to them for their action in getting Professor Thomas to deliver these lectures, said that the Club had felt that it was important that farmers should get better acquainted with their business, and they must feel the little knowledge they possess and their inability to keep up with the competition around them unless posted tip in agricultural chemistry. In order to do this. Professor Thomas had been requested to deliver theße" lectures, but he thought that had the Club known the extent of the undertaking they would have hesitated before aiWofr, »» *he strain of delivering three

consecutive lectures must havo been groat, nnt taking into consideration the care required in taking about the quantity of chemical apparatus needed tor the Ultratrutinns. He Mpoke with reference to the establishment of a branch of the Farmers' Club in Hamilton, and said that as a body the agriculturalists should be most impottant, but as they were at present they had, no power at all, and the starting oft branches of the Club at Hamilton and To Awamutu would be a great strength to the parent Club. Hamilton is recognised as the centre of the railway system for Waikato, and therefore, as the place for holding agricultural shows, but the veto was put on shows in Waikato as long as there was no Club in Hamilton, but if a blanch was established in Hamilton, Waikato twould have a show in 1891, or perhaps 1890. He hoped soon to seo a branch in Hamilton, which would give tho parent Club double strength and enable thorn to help one another. (Cheers). A vote of thanks to the chairman closed the meeting. Professor Thomas recommends those who atttended his lectures and desire to study the subject to obtain, to begin with, a little book called Agricultural Science, published by Blackio and Co., price Is ; and after they have mastered this, to go on with Warrington's Chemistry of the I arm, pi ice 2s Gd ; al*o cret Griffiths on «Jses of Manures, price 2s 6d.