On the >re Frequent Growth of Barle On Heavy Land By J,B.Lav7es (Elp p. p. 7-JiU pbrarg ^orii] Carolina ^tatc fflollcgc S001 98326 T ON THE WORE FREQUENT GROWTH OF BARLEY HEAVY LAND. THIS BOOK IS DUE ON THE DATE INDICATED BELOW AND IS SUB- JECT TO AN OVERDUE FINE AS POSTED AT THE CIRCULATION DESK. J. B [Redd befo: PRINTED BY WILLI EKS IVE the 'A ON THE MOEE FREQUENT GROWTH OF BARLEY HEAVY LAND. BY J. B. LA WES, F.R.S., F.C.S. \_Read before the London Farmers' Club, February/ 1, 1875.] LONDON: PRINTED BY WILLIAM CLOWES AND SONS, STAMFORD STREET, AND OHAEING CROSS. 1875. LONDON : PRINTED BY WILLIAM CLOWES AND SONS, JTAMKORD STKEET AND CHAKING CROSS. ON THE MORE FREQUENT GROWTH OF BARLEY ON HEAVY LAND. Last summer I received a pamphlet ' On the Growth of Barlej in France,' by Mr. George Gibson Richardson. He commences bj saying that the high average price to which barley appears permanently to have attained, interferes very seriously with the profits of the brewing trade, and renders it necessary that some attempt should be made to increase the supply, where such increase could be available for the English market. He goes on to say, that the land in Great Britain suitable for the growth of the finest barley is limited, that it is already so applied as far as practicable, and that on such land the farming has long been so good that an increased produce per acre is not to be looked for, nor is the result always satisfactory when such increase is ob- tained. But, he says, there is a country within sight of our own shores possessing every requisite for the growth of barley suitable for the choicest purposes of the English brewers ; and he, pro- ceeds to explain the means he has taken to stimulate French farmers to increase the production of barley, and the success which has attended the supply to them of English-grown seed. It is quite probable that any attempt to increase the yield of barley per acre, upon the best barley soils in this country, would be attended with a diminution in the quality of the grain. If, therefore, an effort is to be made to increase the national yield of the crop, it must either be done by growing it more frequently upon barley-soils, or by extending its growth upon soils which are not generally considered to be well suited to it. I have for some time held- the opinion that we have not taken full advantage of the peculiar adaptation of our climate to the successful growth of barley ; and the appearanee of Mr. Richard- son's pamphlet has induced me to bring this subject before the members of the Farmers' Club. The present is, moreover, a very appropriate time for its discussion. Thus, after a wheat- crop not more than fairly abundant, the decline in price of the u.^wy 4i.3S4 i\. w^ State Collejre 4 On the more Frequent Growth of Barley on Heavy Land. grain has been very great. On the other hand, barley is, weight for weight, dearer than wheat. You need hardly be told that the climate of CJreat f^ritain is not so favourable for the produc- tion of good wheat as is that of many of the countries which supply us with that grain. The current prices in Mark Lane show that foreign wheats command higher rates than the produce of our own soil. The contrary is the case with barley. The best English is far superior to any foreign barley. The greater success of the British farmer, in this respect, with barley than with wheat, cannot be attributed to a greater expen- diture of skill and capital in the production of the former crop, for he devotes equal skill, and more money, to the growth of wheat than of barley. It may, therefore, be assumed that the climate of this country is very I'avourable for the production of good barley ; and we have to consider this evening whether we have taken full advantage of this natural gift, or whether the extended culti- vation of the crop on soils too heavy to be classed as " barley- soils," might not have a more prominent place in our agriculture. To argue in favour of growing several corn-crops in succession may, at first sight, appear to be advocating an old practice which has been found wanting, and which has been abandoned in favour of the more modern system of rotation, or alternation of grain with fodder crops. To grow corn-crops in succession, each one inferior to the last, until the produce does not pay the cost of labour and seed, and then to allow the land to rest for several years, is a process totally different from that which I am about to propose. Artificial manures were almost unknown to the last generation of farmers. A knowledge of their effects, and abundant and c;heap supplies of them, are essential to the system I have to advocate. In bringing the subject of the more extended growth of barley in Great Britain before you this evening, I shall trouble you with figures as little as possible. They are the less necessary as a full report of our experiments with this crop has been pub- lished quite recently, in the ' Journal of the Royal Agricultural Society of England.' From the results there recorded, and from some which have been obtained since, I shall select a few as may be needed to illustrate and support my views. I do not anticipate any difficulty in proving to your satisfaction that, upon my land, wliicli partakes much more of the character of a wheat than of a barley soil, crops of barley, good both in quantity and in quality, may be grown for many years in succession. I must leave it for you to decide whether your own soils are suitable for the trial, and to what extent it may be desirable and profitable to follow such a course in practice. On the more Frequent Groivth of Barley on Heavy Land. 5 I propose to show — First. That by the aid of artificial manures good crops of barley may be grown with profit upon heavy land, and much more frequently than according to our adopted systems of rotation. Secondly. That on such land it is more advantageous to grow barley after another corn-crop, by means of artificial manures, than after roots consmned on the land. The soil upon which my experiments have been carried on is a heavy loam, with a clay subsoil, resting upon chalk at a depth of from 8 to 12 feet from the surface. It is not artificially drained. Before commencing the continuous growth of barley, it had grown the following crops : — 1847. Swedish turnips, with dung and superphosphate ; the roots carted off; 1848. Barley, unmanured ; 1849. Clover; 1850. Wheat; 1851. Barley, manured with sulphate of ammonia. The first experimental barley-crop was in 1852 ; and the land has been under barley ever since. Thus, in 27 years, there have been grown 1 crop of clover, 1 of wheat, and 25 of barley ; the last 23 of which have been under careful experiment. Excepting on one plot, no dung, or animal manure of any kind, has been applied to the land during the whole of that period. In the following Table is given the average number of bushels of dressed corn per acre, over 23 years, 1852-74, inclusive, by several different manures. Barley groicyi for 23 Years in Succession on the same Land. Seasons 1852-1874. Eothamsted, Herts. Table I. — Dressed Corn per Acre, in Bushels. Average MANURES, PER ACRE, PER ANNUM. 23 Years, 1852-'74. Bushels. Superphosphate, alone 2-lf Superphosphate, andj^OO^Jby^'^o'ii^-^'^lts (o'' 275 lbs. nitrateji ^^ i200 lbs. ammonia salts (or 275 lbs. nitrate | soda)*, and sulphates potass, soda, and [ , 48f magnesia ) 14 tons farmyard-manure I 48^ * 400 lbs. ammonia-salts 6 years, 200 lbs. 10 years, 275 lbs. nitrate of soda 7 years. 6 On the more Frequent Growth of Barley on Heavy Land. 200 lbs. of ammonia-salts, or 275 lbs. of nitrate of soda, each contain nitrogen equal to about 50 lbs. of ammonia. Although there are certain important distinctions between the actions of these two manures, we may assume for our present purpose that in the quantities named thev are of equal manurial effect. The average produce over 23 years, by superphosphate of lime alone, is only 24| bushels per acre per annum ; showing, therefore, that there was an important deficiency of something, which was supplied in the case of each of the other experiments. The addi- tion of ammonia-salts, or nitrate of soda, to the superphosphate, raises the produce to 49 bushels per acre per annum. The addi- tion to this mixture, of sulphates of potass, soda, and magnesia, does not increase the produce further, giving only 48f bushels ; whilst 14 tons of farmyard-manure have given 48^ bushels. In fact, the last three experiments quoted give almost identical amounts of produce, and an average, over 23 years in succession, of more than 6 quarters of dressed barley per acre per annum. That small quantities of artificial manure should, over such a long period, give as much barley as 14 tons of farmyard-manure applied annually is certainly a most striking fact. It may be useful, and will serve as some explanation of it, to point out briefly some of the most important points, both of distinction and of similarity, between the mixture of superphosphate of lime and ammonia-salts or nitrate of soda on the one hand, and farm- yard manure on the other. In round numbers, there have been removed annually, 'xf\ corn and in straw, about 2f tons of produce per acre. Deducting from this the moisture it contains, there remain about 46^ cwts., or rather more than 2^ tons of dry or solid substance removed annually, and deducting from this again the mineral matter and nitrogen it contains, there remain about 44 cwts. of non-nitro- genous vegetable or combustible substance. In the dung very much more than this amount of vegetable matter has been returned to the land every year, but in the artificial manures none. Here then we have two parallel experiments, extending over a period of 23 years, in one of which much more non-nitrogenous or carbonaceous organic matter than was contained in the crop has been annually returned to the land in the manure, and in the other none, and yet the produce is equal in the two cases. Now, 1 would ask whether you think it possible that such a soil as mine could stand such a drain as this for 23 years, or for 27 if we go back to the last application of dung, without showing a marked decline in the produce, if the plant depended upon the soil for its supplies of non-nitrogenous vegetable matter, or if that contained in the dung was at all essential to the result. The conclusion is, I think, obvious, that under the On the more Frequent Groicth of Barley on Heavy Land. 7 influence of the superphosphate of lime and ammonia-salts or nitrate of soda, the growing barley was able to obtain its non- nitrogenous organic matter, amounting to between 90 and 95 per cent, of its total dry or solid substance, from the atmosphere, and not from the soil. You will not fail to see the great importance of recognising this fact when you are told that you may depend upon artificial manures to grow more frequent corn-crops. Artificial manures contain but little, and the best of them no carbonaceous organic matter. If, therefore, they were active only so long as the plant could obtain sufficient organic matter from the soil, each succeed- ing corn-crop would cause a reduction of the condition of the soil, which could only be restored by the dung-cart. If, on the other hand, the organic matter is supplied by the atmosphere, the repetition of corn-crops by means of proper artificial manures may increase rather than diminish the condition of the land. If we deduct from the 14 tons of dung, its water, its carbo- naceous organic matter, and the extraneous mineral matter (soil, sand, &c.) which it always contains, there remains scarcely half a ton of mineral and nitrogenous matter. A good deal of this mineral matter is of comparatively little value. Of nitro- gen there is from three to four times as much as in the 200 lbs. ammonia-salts, or in the 275 lbs. of nitrate of soda. But as the artificial manure and the dung have given equal crops, it is obvious that a given amount of nitrogen applied in the artificial manure is much more effective than the same amount supplied in dung. There is an essential mineral constituent of a barley-crop which is supplied in dung, but not in the mixture of super- phosphate of lime and ammonia-salts or nitrate of soda : this is potass. The -crops grown by this artificial manure must, therefore, have obtained it from the soil itself. Of potass, the average crop of corn and straw has removed from 30 to 35 lbs. annually. It is obvious that, up to the present time, my soil has been capable of yielding the quantity required. The dung has supplied about 1^ cwt. of potass annually, or about 341 cwts. in the 23 years ; and in the experiment No 3 the sulphate of potass has supplied an average of about 1 cwt. annually, or about 23 cwts. in the 23 years ; yet neither the dung nor the artificial manure containing potass has given more barley than experiment No. 2 without potass. What may be the resources of other soils in potass it is not for me to say. It is, however, not at all likely that any farmer will grow corn, and remove both the straw and the grain, for so many years in succession from the same field as in my experiments, without bringing the dung-cart into it ; and I may remark that if the 8 On the more Frequent Groxoth of Barley on Heavy Land. straw had been returned to the land, I might have taken more than 50 crops of barley in succession, without taking from the soil as much potass as I have done up to the present time. The same kind of argument is applicable, but in a higher degree, in the case of silica. The straw of a barley-crop contains about five times as much silica as the grain ; so that if the straw were periodically returned to the land in the form of dung, the exhaustion of that substance would be more gradual than that of potass. So also with other constituents. From the facts I have brought before you, it may I think be concluded, that upon heavy soils, with a subsoil of clay, full crops of barley may be grown by the use of an artificial manure containing superphosphate of lime, and nitrogen either in the form of nitrate of soda, ammonia-salts, or Peruvian guano. The next point is to show that barley may be grown not only in full quantity, but of good quality, by artificial manures used for many years in succession on the same land. The following Table (II.) shows the average weight per bushel of the barley grown by superphosphate of lime, and salts of ammonia or nitrate of soda, over the first 8 years, the second 8, the last 7, and the total period of 23 years. Barley grown for 23 Years in Succession on the same Land. Seasons 1852-74. Eothamsted, Herts. Table II. — Weight per Bushel of Dressed Corn. No. MANURES, PER ACRE, PER ANNUM. First 8 Years, 1852-'59. Second 8 Years, is&o-er. Last 7 Years, 1868-'74. Total 23 Years, 1852-'74. 2 prT.],n« anrl/^*^^ ^^■''- ammonia-salts \ Superphos., and| ^^^ 275 lbs. nitrate soda*/ lbs. 51 lbs. 54i lbs. ;55i lbs. 53^ It is seen that the average weight per bushel of the barley was higher during the second than during the first 8 years, and higher still during the last 7 years of the 23. It is probable that the increase is in great part due to more favourable ripening seasons during the later years ; but whatever may be the cause, it is clearly shown that when barley is grown by proper artificial manures, even for many years in succession on the same land, it does not deteriorate in quality. Samples of the barley grown last year by a great variety of * 400 lbs. ammonia-salts 6 years, 200 lbs. 10 years, 275 lbs. nitrate of soda 7 years. On the more Frequent Growth of Barley on Heavy Land. artificial manures were exhibited, and in Table No. III. the produce per acre, and the weight per bushel, in each case, is given. Table III. — Peoduoe, and Weight per Bushel, of Barley grown in 1874. ROTHAMSTKD, HeRTS. MANURES, PER ACRE, PER ANNUM. Dressed Corn per Acre. Weight Barley grown coatinuously, 23rd year, 1874. 1 Superphosphate, alone 2 Superphosphate, and 200 lbs. ammonia salts 3 Superphosphate, and 275 lbs. nitrate soda 4 ; Superphosphate, and 1000 lbs. rape-cake 1200 lbs. ammonia-salts, and sul- phates potass, soda, and mag- nesia !275 lbs. nitrate soda, and sul- phates potass, soda, and mag- nesia ilOOO lbs. rape-cake, and sul- phates potass, soda, and mag- nesia Barley, unmanured, after Barley, and after Clover. Barley after barley Barley after cloTcr 32| 58' 57^ 56i I took the liberty of forwarding some of the samples to Messrs. Bass for their opinion upon them. In answer, they said that all were suitable for malting. No. 1, grown by superphosphate of lime alone, they considered the best ripened, and the most kindly in appearance ; and, after that. No. 4, grown by superphosphate and rape-cake, which, it will be seen, gave more than 6 quarters of barley, with a weight per bushel of 57^ lbs. Messrs. Bass go on to say that " the barley of this country possesses so decided an advantage in size over the barley of other countries, that we have been long surprised more attention has not been paid to this cereal. We cannot but think the time will come, and that shortly, when agriculturists in this country will see the advantage in placing a greater proportion of land under barley." We now come to the important question of cost. I thought it desirable to obtain estimates from other, and independent, B 3 10 On the more Frequent Growth of Barley on Heavy Lanu. sources, of the cost of some of the ordinary tillage operations. I am indebted to a number of practical farmers, residing in various counties, for answers to the following question — What is the cost of cultivating an acre of barley, of 6 quarters per acre, the barley following a previous corn-crop ; the estimate to include every mechanical operation except hoeing, and to ex- clude rent, rates, seed, and manures? The difference in the estimates was rather wide, varying from 455. to ij6s. I propose to adopt the highest, as I should prefer that, in the matter of cost, my estimate should be above rather than below that of others : — Cost per Acre. £ s. d. £ s. d. Rent and rates 1 12 2^ bushels seed, at 40s 12 6 2i cwts. nitrate of soda, at 16s 1 16 3i cwts. superphosphate, at 6s 110 Hoeing twice 7 Ploughing, harrowing, drilling, harvesting, thrash-) 350 ing, and taking to market ) Total 8 13 6 Produce per Acre. 6 quarters of barley, at 44s 13 4 3 bushels of offal corn, at 4s 12 li ton straw, at 2O5 1 10 Total 15 6 Cost 8 13 6 6 12 6 It would be quite possible, by adding to the expenses on one side, and reducing the Belling prices on the other, to bring out a very different balance. For instance, I have valued the straw at 20a'. per ton ; which would not be too much if sold off the land ; but it will most frequently be used on the farm, in which case the consuming, or manure value only, could be adopted. Still, under the most unfavourable arrangement of the figures, there would appear to be a good profit on the operation. It is for others to consider how much it would probably be under their own particular circumstances. I will now describe briefly some results obtained in another field. It has not been under careful experiment, and I am unable, therefore, to give the amounts of produce previous to the last two years. It has, however, been cropped as follows : — On the more Frequent Growth of Barley on Heavy Land. 11 1864. Red clover. 1865. Wheat, with artificial manures. 1866; Mangolds, with dung and artificial manures ; crop re- moved from the land. 1867. Wheat, unmanured. 1868. Oats, with artificial manures. 1869. 1870, 1871, and 1872. Barley, with artificial manures. Thus, prior to 1873, it had grown 6 corn-crops in succession, the last five with artificial manures. In 1873 it was unmanured, one-half being in barley and the other half under clover, sown with the barley in the previous year. The object in sowing red clover was to ascertain whether, after a succession of corn-crops grown by artificial manures, there remained any residue suit- able for the growth of red clover. In 1874 the whole field, both barley and clover ground, was again sown with barley, and the produce was in the two years as follows : — Tablb IV. — Barley after Barley, and after Clover, all Unmanured. Produce per Acre. 1873 1874 1873 1874 Barley Barley after barley Clover-hay Barley after clover Barley after clover more than after barley 31 bushels. 32| bushels. 54 cwta. 58 bushels. 251 bushels. Thus, after 6 corn-crops since the application of dung, and the last 5 grown by artificial manures, in 1873 the produce of barley without manure was 31 bushels, and that of clover 54 cwts. of hay. In the next year, 1874, again without manure, the produce of barley was, after barley 32| bushels, and after clover 58 bushels ; or 25|- bushels more after the clover than after the barley. An outgoing tenant who had taken a wheat crop, an oat crop, and 4 barley crops in succession, with artificial manures alone, would stand a poor chance of establishing a claim for unex- hausted manures. Yet, without any further application of manure, the land so treated has yielded 2f tons of clover-hay, and 7J quarters of barley. These facts show that the current opinion as to the exhaustion of the soil by corn-cropping re- quires some modification, at any rate in the case of heavy land 12 On the more Frequent Growth of Barley on Heavy Land. on which full crops have been grown by means of suitable artificial manures. It cannot for a moment be supposed that any one cultivating a large farm could devote more than a certain limited propor- tion of the whole to the growth of barley. Even with the aid of steam-cultivation wet springs would occasionally reduce the area pre-arranged for the crop. Assuming, however, it to be concluded, that it would be profitable to extend the area under barley on heavy land, I would venture to suggest the following as a rotation worth trying. I would divide the land into twelfths, as follows : — One-twelfth mangolds ; One-twelfth beans ; One-twelfth red clover ; Two-twelfths wheat ; Seven-twelfths barley. Or, assuming a farm of 600 acres, there would be — 50 acres mangolds ; 50 acres beans ; 50 acres red clover ; 100 acres wheat ; 350 acres barley. It would certainly require great attention to the cleaning of the land, if so large a proportion as three-quarters of the farm were in corn. If this difficulty can be got over, I see no reason why such a course of cropping should not be more profitable than that fixed by the ordinary rotation. That some attempts have been made to wander from the orthodox rotation of crops is evident from the fact that I occa- sionally receive visits from farmers who come to see whether the experimental corn-corps at Rothamsted still continue to flourish ; and I find from them, on inquiry, that too much, rather than too little, success has been the occasion of their journey. Their friends and neighbours tell them it may be all plain sailing just now, but retribution is surely not far off. They dangle the spectre of exhaustion before their eyes, and terrify them with the prospect of the evil consequences which must, sooner or later, overtake them. I have reason to think, however, that an inspection of my fields tends to reassure them ; and that they return home at any rate with the consolation that, if barrenness is to follow the more frequent growth of corn, it will certainly make its appearance in the fields of Rothamsted before it does in their own. Not long ago, there was some discussion in this room as to the On the more Frequent Groivth of Barley on Heavy Land. 13 length of time successive corn-crops might be grown, and your President observed that, with deep cultivation, and the use of artificial manures, corn might be grown for 25 years. In the ex- perimental wheat-field at Rothamsted the 37th crop since the application of farmyard-manure, and the 3Gth corn-crop, is now go wing ; and in the experimental barley-field 28 crops have been taken since the application of farmyard-manure, of which 26 have been corn-crops, and 25 of them in succession. In both fields the cultivation of the land has been very superficial, being conducted according to the ordinary practice of the district 40 or 50 years ago. Doubtless subsoiling, or deeper cultivation, would in some cases largely increase our produce, and in others lessen the amount of manure required to obtain it. But to adopt either would sacrifice that which, up to the present time, has given the Rothamsted experiments a position which no other field-experiments can lay claim to, namely, that they are carried on year after year without change, either in the mechanical cul- tivation of the land, in the description of crop grown, or in the manures applied. If some important constituent is wanting, the crop must neces- sarily decline. The barley grown by superphosphate alone has shown a very marked decline in produce during the second half, compared with the first half of the period. In other cases, where the proper manures have been applied, the average produce over the second half of the period is equal to that of the first half. From this it may be concluded, that any decline in produce will take place at any rate only very gradually, and that the time when the land will no longer grow good crops of barley must be very remote. After 20 years, the plot which had received 14 tons of farmyard-manure annually during that period was divided, and the application was then stopped on the one-half, but con- tinued on the other. During the sulDsequent three years, although the produce on both portions has been large, it has been con- siderably less where the application was stopped than where it was continued. Still, it may be expected that 20, or 30, or more years will elapse, before the residue from the previous applica- tions of dung is exhausted. The subject of how long corn-crops may be grown is obviously one of great scientific interest ; but the amounts of produce shown in the Tables, and the quality of the samples exhibited, are sufficient to show that, on heavy land, and with proper arti- ficial manures, crops of barley which meet all the requirements of practice, both as to quantity, and quality, may be grown for many years in succession. It will be useful to state the course of operations which may 1 4 On the more Frequent Groicth of Barley on Heavy Land. be advantageously followed bv those who decide to grow barley more frequently after a previous corn-crop. Cultivation. The land should be ploughed up as early as practicable in the autumn, and should not be touched again until it is dry enough to sow in the spring. Time of Sowing, and Quantity of Seed per Acre. The sowing should be in the last week in February, or as soon as possible afterwards. A good tilth is essential ; it is vain to expect to grow a good crop of barley without it, especially when artificial manures are used. The quantity of seed per acre may be 2\ bushels if sown early, increasing to 3 bushels as the season advances. Manures. Nitrogen is an essential constituent in an artificial manure for barley. It can be purchased in nitrate of soda, sulphate of am- monia, or Peruvian guano. Feeling unable to recommend guano without some assurance as to its composition, I wrote to Messrs. Schroder and Co., the agents for the sale of Peruvian guano in this country, stating my difficulty, and in reply they write as follows : — " . . . . The importations of guano from the Guanape and Macabi Islands, during the time the agency has been in our hands, have averaged nearer 13 than 12 per cent, of ammonia. The quality from both islands has moreover been so even and uniform, that cargoes analysing anything below 12 per cent, of ammonia have been quite the exception." It is very satisfactory to find that the present supply of Peru- vian guano is so good and uniform in quality. If Messrs. Schroder and Co. would comply with a suggestion I have made, and state in their advertisements that they would not send out raw guano containing less than 12 per cent, of ammonia, nothing further could be desired. In my experimental field, nitrogen equal to 50 lbs. of ammonia is required to grow 6 quarters of barley over an average of seasons. About this amount of nitrogen (rather less) would be supplied in the quantities of nitrate of soda, or of sulphate of ammonia, or of Peruvian guano containing 12 per cent, of ammonia, given in the first column below, and slightly more in the mixtures of them given in other columns : — On the viore Freqnent Gro^cth of Barley on Heavy Land. 1 5 If used Separately. If used in Combination. Nitrate of soda Sulphate of ammonia Peruvian guano Cwts. If Cwts. If 1 Cwls. When nitrate of soda or sulphate of ammonia is used, without guano, about 3 cwts. of superphosphate, per acre, should also be employed. When Peruvian guano is used alone, no superphosphate need be applied. When If cwt. of nitrate and 1 cwt. of Peruvian guano, or 1|^ cwt. of each, is used, 1 cwt. of superphosphate, in addition, will be sufficient. As in all cases of ordinary farming the straw will go back to the land periodically in the form of dung, it is probable that, under such circumstances, smaller quantities of artificial manure may be required to yield the same amount of crop, than were found necessary in my experimental field. On a farm of 600 acres, under the twelve-course rotation which I have suggested, there would probably be about 2000 tons of dung made annually. This would allow 20 tons, per acre, for the 50 acres of mangold, 10 tons, per acre, for the 50 acres of beans, and 10 tons, per acre, for the 50 acres of red clover. The wheat following the beans or the clover would require no artificial manure. The grain-crop following the mangolds might require a small dressing of nitrate of soda in the spring, say 1 cwt. per acre. For the barley suc- ceeding this, or succeeding the wheat after clover or beans, \^ cwt. of nitrate of soda, with 2 cwts. of superphosphate, or 2^ cwts. guano without superphosphate, might be sufficient. For the next crop of barley (the third corn-crop) the quantities given in the foregoing Table might probably be required. A knowledge of the soil and climate, and practical experience in the use of the manures, are, however, essential to determine the exact quantities of manure required to produce full crops. But the cultivator must bear in mind, that a deficiency of produce is more likely to be due to a deficiency of nitrogen than of any other substance. Mode of Application of the Manures. In my experimental fields the artificial manures are sown broadcast by hand, and ploughed or harrowed in before the seed is sown ; and to ensure the necessary regularity of distribution. 16 On the more Frequent Groicth of Barley on Heavy Land. the quantity is divided, and the ground sown two or three times over. In the fields under ordinary farm-cultivation, the manures are mixed together and sown immediately behind the drill, once over only ; and the seed and manures are harrowed in together. A machine-distributor which will sow small quantities of arti- ficial manure with perfect regularity is much wanted, and has not yet been produced. IVeeds. I will assume that a farmer intending to grow several corn- crops in succession starts with his land clean ; aud being so, it is by no means difficult or costly to keep it clean. Each descrip- tion of soil has its own prevailing weeds, and they should be watched very closely. Charlock is the great weed of this district, and the corn-fields are yellow with it when it comes into blossom. It is, however, not difficult to keep it under. Wild oats are the most troublesome of our weeds, and their appearance in the crop should be most carefully watched. If they are only seen here and there, the farmer may think it scarcely worth while to have them taken out ; but the next year they will probably be found to have increased a hundredfold, and then pulling them out is almost impossible. They shed their seed before the barley is ripe, and will not grow by any autumn cultivation ; so that if once they have gained the ascendency, nothing remains but to cease growing corn, and to clean the land. Freedom of Croppiny. If every farmer were bound down by a stringent law not to grow two corn-crops in succession, and the law were unalterable, we should be discussing a subject this evening which could have no practical bearing. There is, I think, an impression gaining ground among landlords, land-agents, and tenants alike, that a greater latitude in cropping might be mutually beneficial. Land- lords are, however, timid : they say, we have done very well under the old customs, why should they be changed? Land- agents are also timid, as well as wise in their generation : they say, if greater latitude be granted to the tenant, and any difficulty should afterwards arise about the letting of the land, we shall be told by the landlord that this is what comes of your absurd innovations. When I addressed you nearly five years ago in this room, on the suljject of Unexhausted Improvements, I pleaded on behalf of the tenant-farmer for greater freedom of cropping. I said I thought a tenant holding a lease should be left unrestricted in his cropping, provided he gave up the land at the end of his On the more Frequent Groicth of Barley on Heavy Land. 17 term with a due proportion of corn and fallow crops. I am disposed to think, however, that little or no injury would be done to the letting-value of the land, if a considerably larger pro- portion of it were given up under corn, provided it were not a light-land or a stock-farm, provided neither roots nor straw were sold, and provided the corn-land were given up sufficiently clean to grow another corn-crop. Having said so much on behalf of the tenant, I will say this on behalf of the landlord. If he relax covenants in regard to cropping, he should make them much more stringent in regard to weeds. If the land under corn be not kept clean, the landlord should have power to clean it at the expense of the tenant while the crop is growing, or to recover damages in some way which will secure the object in view, namely : that the corn-land shall be given up in a condition as to cleanliness, such that the incoming tenant may with advantage take another corn-crop from it. If barley is to be grown more frequently, it is obvious that some other crop must either be excluded from the rotation or only be grown at longer intervals. Now, the root-crop appears to me to be somewhat out of place on heavy land. When such land is not clean enough to grow corn, a root-crop, or a summer fallow, may be advantageous. But if the land be clean, I sub- mit to your consideration whether it would not be more profit- able to grow barley by the direct application of artificial manures, than by the indirect process of manuring for the growth of a root-crop ? It would occupy too much time and space to discuss fully the exact position which a root-crop holds in a rotation ; involving as it does the question of the production of meat and manure, by the consumption of the roots and other food. I will confine myself to directing attention to the results of some experiments which have led me to place a lower value upon roots as a heavy-land crop, than mwlern practice has assigned to them. In a field devoted to the continuous growth of turnips, it was decided, after 10 crops of roots had been removed, to grow barley for the purpose of ascertaining whether, by the growth of the turnip, any residue had been accumulated within the soil which was suitable for the growth of barley. For instance, as silica is taken up in very small quantity by the turnip, but very largely by barley, it was possible that during the 10 years of the growth of the turnips it might have accumulated within the soil in a very favourable condition for being taken up by the barley, in combination with ammonia, for example. Three unmanured barley-crops were taken in succession after 18 On tlic more Frequent Growth of Barley on Heavy Land. the turnips. The average produce of the barley after 10 crops of turnips, manured during the last 8 years by a liberal mixed mineral manure, was 20 bushels per acre ; and where the turnips had received the same mineral manure, with some ammonia-salts also, the average produce was 22 bushels per acre. Over the same 3 years, the average produce of barley without manure, in the field where barley was growing continuously, was, after o preceding corn-crops, 31^ bushels, or 11^ bushels more than after the 10 crops of turnips. The amount of produce of the unmanured barley after the mineral-manured turnips did not vary more than 1 bushel per acre in the 3 years. The second of the 3 crops was grown in the very productive year of 1854, but amounted to only 19^ bushels ; whereas, in th,e same season, the produce without manure in the field where barley was growing continuously was 35 bushels, though following 4 preceding corn-crops. In the same field, the superphosphate of lime alone gave AQ^ bushels ; and several of the artifical mixtures con- taining nitrogen gave nearly 8 quarters per acre. The conclusion to be drawn from these curious results is that, independently of the excess of manure applied for the growth of the turnip, it leaves no residue suitable for the growth of barley ; but, on the contrary, it exhausts the soil of what is required for the barley far more than does the growth of barley itself. Compare this with the produce of barley after clover, already referred to, and shown in Table IV., and it will be seen how very different is the position which clover and roots hold in a rotation. It may be said that in ordinary practice the turnips are consumed on the farm, or even in the field which grew them, and hence much of what they take out of the land is restored to it. This is perfectly true. But I would ask whether, if the turnip leaves no residue suitable for the barley excepting the excess applied for the roots, and merely converts a portion of the food which would grow barley into turnip, to be consumed by animals for the reproduction of manure, would it not, in the case of heavy land, be more economical to convert such food directly into barley, without the intervention of the roots? Another field has been devoted, for nearly 28 years, to experi- ments on rotation. The course of cropping has been turnips, barley, clover or beans, and wheat. The turnips alone are manured, and on the portion to Avhich I am about to refer they are all fed on the land. The manure applied per acre, for each turnip-crop, has been a mixture of superphosphate of lime and salts of potass, soda and magnesia, with, in addition, 2000 lbs. rape-cake, 200 lbs. ammonia-salts. On the more Frequent Groioth of Barley on Heaxiy Land. 19 The average produce over 6 rotations has been Swedes, 12 tons, Barley, 47 bushels, - Beans, 24 bushels. Wheat, 83 bushels. Let us compare this result with that obtained from the same amount of manure applied directly for barley in the experi- mental barley-field. 1000 lbs. of rape-cake have given, over 20 years, an average of 45 bushels per acre per annum. This used twice gives, therefore, 90 bushels for the use of 2000 lbs. of rape-cake. Again, mixed mineral manure and 200 lbs. of ammonia-salts (as also used in the rotation experiment) has given, over 20 years, an average of 46 bushels. We have, therefore, in all 136 bushels of barley produced by the use, on 3 acres, or in three years, of 2000 lbs. of rape-cake, 200 lbs. ammonia-salts, and mixed mineral manure. In the rotation experiment, the same amount of manure grew in the first year 12 tons of swedes, for which nothing was received but the increased value of the animals consuming them. There was left, therefore, some charge for expenses, besides the cost of the manures, against the 3 succeeding crops ; which were, 47 bushels of barley, 24 bushels of beans, and 33 bushels of wheat ; whereas, when the same amount of manure was applied directly for the growth of barley, there was no extra charge against the crops as \vhen grown after the roots, and 136 bushels of barley were obtained. It may be said, that the injury done by the sheep consuming the roots on the land accounts for the comparatively small effect of the manures in the rotation experiment. No doubt they do injury, and this is one of the great objections to the growth of a large area of roots upon heavy land. This will not, how- ever, account for the following facts : — In the very hot and dry season of 1868, the root-crop in the rotation experiment entirely failed, but the succeeding barley- crop was only 42 bushels ; whilst, one-third the quantity of manure, applied directly for the barley in the experimental barley-field, gave nearly 45 bushels. In the rotation experiment, there has obviously been a much less result from a given amount of manure, than in the experi- mental barley-field. The exact explanation of the fact is not quite clear. Some of the nitrogen of the rape-cake and ammonia- salts has, no doubt, been lost by winter drainage, and some retained by the soil in such a condition of combination or distribution as to be only very slowly available for succeeding crops. At any rate, we learn that artificial manures give a much 20 On the more Frequent Groictli of Barley on Heavy Land. better result when they are applied not long before active growth commences, and that, on heavy land, they can be more profitably used directly for the growth of barley than for roots to be suc- ceeded by barley. The great value of root-crops upon light land, and even upon some of the heavier soils where the climate is comparatively moist, has led to their cultivation upon land, and under climatal conditions, which are more suitable for the growth of grain. Added to this, there is a sort of undefined opinion prevailing with many farmers, that the manure produced by animals acts in some mysterious way, quite different from artificial manures, and hence they are afraid to trust too much to the latter sub- stances. The results obtained in the experimental field at Rothamsted show conclusively to what a great extent artificial manures may be relied upon to produce full crops of barley, of good quality, under what may be considered by no means favourable conditions as to tillage. There is no reason to doubt that, with the im- proved methods of cultivation now so much practised, the results I have laid before you this evening may be exceeded ; and if the suggestions I have put forward be adopted, the brewers will not long have to complain that they are compelled to seek in other countries for the supply of barley which may be grown with profit on our own soils to a much greater extent than hitherto. W . 0. btate College LONDON: I'EINTED BV WILLIAM CLOWES AKD SONS, STAMFORD STKEET AND CHABING CROSS.