摘要:

A study of plant establishment showed that a considerable depletion in the size of the grass poptilation occurred during the first few months after sowing. In this experiment, two months after reseeding, the surviving grass seedlings amounted to about 20% of the viable seed sown; this figure was further reduced to about 10% before the swards were twelve months old.In swards based on several cultivars within a species the casualty rate varied from cultivar to cultivar, and may be further modifted by manuring and management.Evidence from older swards indicated that within a period of six years one cultivar could suppress another almost completely.The data suggest that not only is there a strong selection pressure within a sward during its early life, but also that the environment (produced in this case by manuring and management) eternities the relative persistency and aggressiveness of the individual cultivars. This illustrates how a sward originally composed of several plant types eventually settles to a narrow range, provided the management is not varied.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00214.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Data from 291 digestion trials have been used to derive regression equations relating the organic‐matter digestibility of herbage to the nitrogen percentage of its dry matter and to the nitrogen percentage in the organic matter of the resulting faces.The residual errors are very high and it is shown that the deviations from the lines are not randomly distributed but have a seasonal trend. The seasonal biases have been calculated, and the inclusion of month of cutting as a factor is found to improve the two regressions to some extent. Monthly regressions have also been calculated. Even with these, however, the errors are still too high for many practical purpose

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00215.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.tb00216.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY

摘要:

Book reviews in this article:WHYTE, R. O.Crop production and environment.IVINS, J. D. [Editor].The measurement of grassland productivity.VOISIN, A.Better grassland sward.MOORE, I.Winter keep on the farm.

ISSN:0142-5242    

DOI:10.1111/j.1365-2494.1961.tb00217.x

出版商:Blackwell Publishing Ltd    

年代:1961

数据来源: WILEY