Studies in the producton and conservation of Gramineae and Leguminosae, with special reference to the intensive production of herbage for crop-drying

Holmes, William (1948) Studies in the producton and conservation of Gramineae and Leguminosae, with special reference to the intensive production of herbage for crop-drying. PhD thesis, University of Glasgow.

Abstract

In Part 1, the development of crop-drying has been briefly reviewed and the important contribution the process can male to the nation's food supplies has been pointed out. It has been stressed that a high yield of herbage, produced at a low cost and evenly distributed over the season, is necessary to minimise the overall costs of production of dried grass. Evidence has been quoted which indicates that the greatest yield of material of high nutritive value is Obtained, when the herbage is cut before flowering, and the possibility of increasing yields and levelling their seasonal distribution by the use of chemical fertilisers has been suggested. In Part II, a two year experiment has been described in which the yields, seasonal productivity and chemical composition of four crops under four Manurial treatments were studied. The crops were vetches, barley, a ryearass by and a eocksfoot ley. The manorial treatments included a control and three treatments in which 33/4 cwt. of Nltrochalk (61 1b. of nitrogen) were applied in one, two, or three dressing during the season. The statistical layout, which involved 4 replications of 16 crop-treatments, was found to be satisfactory and significant differences in yields and percentages of dry matter and crude protein were shown between crop-treatments. The results from the annual crops were comparable in 1945 and 1946, but the yield from the lays was slightly higher in the second year. In the first year, production did, not however begin until July, while in the second year, it was spread over a full six months i.e. May - October. When treated with nitrogenous manures, significant responses in yield and in crude protein percentage were shown by all crops except vetches. Differences in, yield and composition were found to be associated with the method of distributing the nitrogenous fertilisers, This also affected the seasonal distribution of the yields. The yields attained ranged from 22 - 56 cwt. per acre of dry matter or 420 - 1,100 1b., per acre of crude protein. The crude protein percentage reached 30% with vetches and barley and 25% with the leys. By encouraging the grass species at the expense of the clovers, the nitrogenous manures affected the botanical composition of the swards. The cost of producing dried herbage under the different treatments was estimated and the value, based on the nutrient content of such crops, was assessed. Comparison of costs with food values showed that barley would be unprofitable unless only one out was taken and then the crop allowed to ripen for harvest. Vetches were shown to be on the margin of profitability while it was estimated that the lays under the best treatments would give an appreciable profit. A note on the validity of small samples as estimates of yield showed these to be fairly reliable Tor grass leys but quite unsatisfactory for the annual crops used in the experiment. In Part III, the effects of nine different manurial treatments on two separate grass swards have been described. Up to 18 cwt. Of Nirochalk (312 lb. of nitrogen) Wore applied per acre and various methods of distributing the application over the season were adopted. The simplified statistical layout adopted was found to be satisfactory. The results obtained from the two grass swards were comparable, but the old and well established long ley was shown to be superior in yield to the Italian ryegrass sward. Conclusion: Consideration of the results suggests that, provided climatic conditions in respect of rainfall and temperature are favourable, herbage for crop-drying can be produced in fairly level quantities over an extended season of six months. Production in the first three months could be obtained from established grass swards - of a predominantly ryegrass type. A leguminous crop such as vetches or red clover, supplemented perhaps by a cereal cut, would maintain production in late June and July. In the latter part of the Season established lays would again yield economic crops and at this time those containing an appreciable proportion of cocksfoot would show to advantage. Moreover, the produce from grass leys sown in spring would by then be available, and from July onwards heavy nitrogenous applications would again prove effective in increasing production. The methods described could be readily applied within a system of alternate husbandry. As a result of the adoption of such methods, while the fertility of the soil would be maintained, food production would ho increased, and the health of the country's stock Improved. (Abstract shortened by ProQuest.).

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: N C Wright
• Keywords: Agronomy
• Date of Award: 1948
• Depositing User: Enlighten Team
• Unique ID: glathesis:1948-73871
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 14 Jun 2019 08:56
• URI: https://theses.gla.ac.uk/id/eprint/73871