ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00218.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Range research and its application in the United States have been primarily in the area of ecology. The guiding principle developed is that the natural plant communities (the climax vegetation) provide the best guides to forage production potential.A careful study of man's history from the Ice Ages to the present reveals the fact that man has progressed by modifying his environment. In fact, the ability to do so is one of the significant differences between man and other animals. During the last 10,000 years man has been in turn a collector and hunter, a cultivator and domesticator, and finally an industrial agriculturist. The transition has been a slow, laborious process.The mixed‐oak forests of the Mediterranean and Europe were cleared by felling and burning the trees and cultivating the cleared ground by crude flint hoes. In his migrations man learned of differences in soils and adaptations of cultivated plants. He learned to work with nature, but he also learned how to overcome some of nature's limitations.Agriculture, then, is man's attempts to overcome nature's limitations so that a desired crop can be grown and harvested. By this modification of the environment the crop supersedes the pattern of natural vegetation. There is no intrinsic difference between range and intensive agriculture, since both involve factors inherent in climate, soil, plants and harvesting.Ecologists working in the field of range management must be willing to accept ideas and principles that have put more science in the “science and art” of farming, if the “science and art” of range management is to progress suffiientiy to make possible the realization of the vast potential of our ranges and w

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00219.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

A study was made of the effect of sheep urine and some of its components on herbage production. The return of urine to the sward increased production from the grass species; the clover content of the sward was reduced.The application of nitrogen or potassium fertilizer equivalent to the normal return of nitrogen and potassium in urine increased production, but not as much as urine. The return of nitrogen and potassium fertilizer together increased production and altered botanical composition in much the same way as did urine.On a grass‐dominant urine‐treated sward the application of nitrogen fertilizer increased the “efficiency” of urine.The effect of urine on a grass/clover sward was almost entirely due to its nitrogen and potassium content. The water and indole acetic acid content of urine had no effect on pasture production or comp

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00220.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Results are given showing the effects of applying nitrogen, phosphorus, potassium, sodium and magnesium on the yield and mitieral composition of herbage cut repeatedly at the silage stage over a 3‐year period. Grasses and clovers were separated before analysis. A combination of nitrogen and potassium was essential for the maintenance of high yields. Superphosphate did not increase dry‐matter yields. 4 cwt. of common salt was ineffective, even under conditions of acute potassium deficiency; it reduced responses to potash and decreased yields when given with potash.Ammonium sulphate and common salt greatly increased sodium uptakes and muriate of potash depressed them. Potassium contents were greatly reduced by repeated nitrogen applications and muriate of potash gave consistent and significant increases. Potassium‐deficient grasses contained more sodium than potassium.Ammonium sulphate increased magnesium contents and muriate of potash reduced them. There was a marked tendency for both effects to be more significant in late‐season cuts. In late May the effects were small. 22 and 44 Ib. Mg/acre as magnesium sulphate had variable effects on herbage magnesium. These changes are discussed in relation to hypomagnesaemia.None of the fertilizer treatments altered the calcium contents of either grass or

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00221.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

A study was made of the responses of four upland soil‐ and vegetation‐types to applied lime and phosphate in the north of Scotland. Light and heavy dressings were used, the former at a rate which might be economically considered for aircraft application. Two experiments were laid down on graminaceous communities and two on contrasting types of Callunetum. The low rate of lime produced little measurable soil response, whereas the high rate induced marked and persistent effects. In terms of botanical response, however, the high rate of liming showed little advantage over the low rate in the presence of phosphate at the two grassland sites. Only very minor vegetation effects were observed at theCallunacentres, particularly where the community was in the mature stage. The results emphasize the importance of an ecological approach to upland pasture improvement, involving a knowledge of the specific responses of different plant communities to fertilizer application, combined with an appropriate measure of stock cont

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00222.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00223.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

It has been found for pasture purposes that the numerous varieties belonging to the speciesEragrostis curvulacan be grouped into types for which the names curvula, robusta blue, robusta green, robusta intermediate and chloromelas are proposed.The relative palatability of 20 varieties ofE. curvula, and 1 variety ofE. plana, Chloris gayanaandDigitaria smutsiiwere compared with one another.ChlorisandDigitariawere found to be the most palatable. Of theEragrostisvarieties studied, the robusta green, robusta intermediate and robusta blue were the most palatable, chloromelas varieties andE. planabeing intermediate and the curvula varieties the least palatable.The grasses with the highest phosphate and potash contents were also those most acceptable to livestock. Results obtained from analyses suggested that crude fibre had little bearing on palatability.The more acceptable grasses were also the more succulent.No relationship between leaf structure and livestock preference could be demonstrated.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00224.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

The response of single plants of Aberystwyth S48 timothy (Phleum pratenseL.) to increasing rates of ammonium nitrate applied in the spring and autumn is described.All spring treatments markedly increased the number of heads, as well as the total head‐length per plant, but autumn dressings had no significant effect. Percentage head‐length distribution was also greatly influenced by applications of nitrogenous fertilizer in the spring. Each higher rate of application gave a proportionate increase in the number of heads over 9 cm. in length, and a corresponding reduction in the frequency of those of 4 cm. or less. There was a positive correlation between head‐length and number of florets per unit length.The results are discussed in terms of their relationship to current practices in managing timothy crops for

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00225.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

The effects of autumn management and nitrogenous manuring on the production of early spring grass were studied from 1954 to 1957 on farms throughout England and Wales.The most important management factor influencing spring yields was the application of spring nitrogen. In the early spring 6 to 10 lb. of dry matter were produced per lb. of nitrogen applied. Autumn nitrogen increased herbage yields in the auttimn by 8 to 17 lb. of dry matter per lb. of nitrogen applied.Italian and perennial ryegrass responded well to autumn nitrogen but it was important to graze off the extra growth fairly quickly to prevent the sward becoming too open. The yield of ryegrass swards which received spring nitrogen were very much higher if they were grazed during the previous September and October than if they had been rested during those months.In two years neither the autumn management nor alumni fertilizer appeared to influence the spring yields of cocksfoot, timothy or meadow fescue swards, in one year, however, when autumn growth was poor, autumn nitrogen and resting resulted in slightly better yields on these swards in the following spring.It is suggested that resting swards during September and October to build up “reserves” is relatively unimportant in relation to the yields of grass in the following spr

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00226.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00227.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY