XV.-Report of Experiments upon Wheat, Barley, and Swedes, undertaken by Members of the Cirencester Chamber of Agriculture. By JOHN WRIGHTSON, F.C.S., Professor of Agriculture in the Royal Agricultural College, Cirencester. INTRODUCTION. IN conducting agricultural experiments the investigator is beset with many difficulties, which tend to render his results indistinct, and to detract from the value of his work. Among these difficulties may be named the following:-(1) Inequalities in the condition or in the natural fertility of the soil; (2) inequalities in the vigour of the plant; (3) peculiarities of season; and (4) attacks of insects. A number of plots may be measured off and treated with care, but, as the crop advances towards maturity, one or other of the above-named sources of error appears, causing differences not attributable to methods of cultivation, or special dressings of manure. Hence the importance of repetition and control: for although a single series of experiments may yield results of comparatively small value, several series, designed with a view to confirm or control each other, will probably elicit evidence of almost irresistible strength. The Cirencester Chamber of Agriculture, in undertaking the work of conducting field experiments, kept this truth steadily in view; and it will be observed that the variety of manures or methods of cultivation used was restricted. The treatment decided upon was repeated sufficiently often to justify some useful conclusions being drawn; but, in spite of the precautions taken, contradictory results were occasionally obtained. Such disagreements are not uninstructive. They teach the importance of each farmer conducting experiments upon his own land in order to find its peculiarities. When a general concurrence of evidence is obtained, an important point is gained; when dissimilar answers are the result, some special reason for the want of conformity must be looked for in the soil and surrounding conditions. In the autumn of 1868, the Committee of the Cirencester Chamber decided to carry out a series of wheat-experiments. In planning this series it was resolved (1) that the trials should be of a simple character; (2) that the same series should be simultaneously carried out upon as many farms as possible; (3) that duplicate plots should in every case be used. It was also determined that the experiments should consist of two series— one a comparative trial between manurial substances, and the other between two or more methods of cultivation. Subsequently, experiments upon barley and roots were instituted. The fol VOL. VI.-S.S. Y lowing gentlemen undertook to carry out the suggestions of the Committee:-The Right Hon. Earl Bathurst, the Royal Agricultural College, Mr. E. Ruck, Mr. W. J. Edmonds, Mr. William Smith, Mr. Plumbe, and Mr. T. Little. The College undertook to send out weighed quantities of the required manures, and to provide analyses, the Chamber paying for the manure and other expenses. WIDE DRILLING AND TILLAGE EXPERIMENTS UPON WHEAT. The usual width of drilling wheat being about 9 inches, it was resolved-(1) to omit every alternate row, leaving a space of 18 inches between the rows; (2) to omit two drills, and leave two, making a space of 27 inches between double rows 9 inches apart; (3) to omit two drills and leave two, forking the interspaces during the summer; (4) to attempt the cultivation of carrots or potatoes between wheat-rows arranged as just described; (5) to try the effect of firmly pressing land with the foot in winter and spring. In carrying out these experiments the wheat was in some cases sown with the drill in the usual manner, and the surplus rows were obliterated by the hand-hoe soon after the blades of corn appeared above ground. In other cases the drill was set so as to deposit the seed at the required width. The objects of these experiments were as follows:-To show (1) how far a free admission of air and light influences the growth of the wheat-plant; (2) how far interculture is beneficial or the reverse; (3) the effect of thin seeding. Similar experiments upon barley were also undertaken with interesting results. The following is a list of the plots required for carrying out these trials: 2 plots in which 2 rows were alternately omitted and left. 2 in which 2 rows were alternately omitted and left, the interspaces being forked twice through the summer. the same as the last, but with carrots or potatoes planted in the interspaces. 2 2 22 2 firmly pressed with the foot. untouched for comparison. Wide Drilling and Interculture." In wide intervals," says Tull, "we can raise a good crop with less labour, less seed, no dung, no fallow; but not without a competent quantity of earth, which is the least expensive of anything given to corn." Tull has had a few ardent followers, among whom the late Mr. Smith, of Lois Weedon, may be mentioned as a faithful disciple. Some encouraging results, obtained by Mr. J. A. Clarke from a field cultivated upon modified Tullian principles, were published in vol. xxv. of the Royal Agricultural Society's Journal, and were the immediate cause of a series of wide-drilled plots upon the College Experimental Farm in 1865. A piece of winter-drilled wheat was selected, and alternate rows were cut out with the hoe, leaving the wheat rows 18 inches apart. In like manner three rows were removed, and three left, forming triple rows with 40-inch interspaces. Of these plots some were forked, and others merely hand-hoed. As the experiment was only commenced on April 18th, the result, as might have been expected, was not favourable to wide intervals. It was, however, worthy of notice that although half the wheat was removed, the produce from the wide-spaced plots was, in spite of the unfavourable conditions of the experiment, equal to 27 bushels per acre, while the ordinary untouched wheat yielded 32 bushels per acre. These experiments were repeated on a more extended scale in 1868, a season in which wide-drilling and forking could hardly be thought advantageous. Both wheat and barley were subjected to the trial, care being taken that the superfluous rows should be removed before they could interfere with the future prospects of the remaining rows. Some of the wide-spaced plots were twice forked during the summer, while others were kept free from weeds by means of the hand-hoe. The results are embodied in the following table : TABLE I.—Results of Wheat EXPERIMENTS, 1868. Inspection of this table shows: 1st. That in no case was the crop so good as in the case of the wheat cultivated in the usual way. 2nd. Plots in which the alternate wheat rows were obliterated were so nearly equal to those of ordinary wheat that, since half the seed might have been saved by sowing at once with a wide drill, the advantage is pretty equal in both methods. 3rd. The forked wheat was generally worse than the corre sponding unforked, a result borne out by the experiments of 1865. 4th. Since 25 and 26 bushels per acre were obtained from half the land under crop in the cases of Plots 4 and 7, the question whether the interspaces would have borne as large a crop of wheat the succeeding year, as at Lois Weedon, is worthy of attention. The experiments made upon barley during the same droughty season point to a clear advantage from wide-drilling and interculture, as will be seen upon inspecting Table II. TABLE II.-BARLEY EXPERIMENTS ON THE ROYAL AGRICULTURAL COLLEGE EXPERIMENTAL FARM, 1868. |