Physical aspects of soil fertility - the response of roots to mechanical impedance.
Physical aspects of soil fertility - the response of roots to mechanical impedance.
复制标题
土壤肥力的物理方面 - 根部对机械阻抗的响应。
DOI：
10.18174/njas.v22i4.17215
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发表时间：
1974
期刊：
影响因子：
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通讯作者：
M. Goss
中科院分区：
文献类型：
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作者：
R. Russell;M. Goss
乍一看，这篇文章的标题在一本献给A.C.Schuffelen教授的出版物中似乎不合时宜，因为它与他在土壤肥力方面做出如此杰出贡献的化学方面几乎没有关系。但这一选择是有原因的。土壤科学研究的进步在很大程度上依赖于跨学科联系的增加，这种联系通过知识的进步而成为可能，并因紧急问题而变得必要。Schuffelen教授的工作提供了极好的例证：严格且往往新颖的物理化学应用于阐明土壤固相和溶液相之间的离子平衡，极大地促进了对土壤/植物营养关系的理解；15年前，这一知识使他能够与核物理学家合作，鼓励以合乎逻辑的方法解决全球范围内的尘埃沉积在土壤上提出的新问题。农业实践中的一些最新发展现在越来越多地将注意力转向土壤肥力的另一个方面，即根系对其物理环境的反应，包括对机械胁迫的反应。在这方面，进展将在很大程度上取决于新的或加强的跨学科联系。这与Schuffelen教授自身兴趣的发展并行不悖，这鼓励了选择本专题。另一个原因是认为，综合考虑植物对土壤环境的化学和物理方面的反应，应使人们能够更广泛地了解控制肥力的因素。尽管在过去的几个世纪里，农业实践发生了相当大的变化，但直到最近十年，一个基本原则几乎没有受到质疑，那就是仔细耕种种植可耕种作物的土壤的重要性。传统上，耕作有两个主要作用，即为植物生长创造适宜的土壤条件和控制杂草。除草剂，特别是百草枯(Hood et al.，1963,1964)问世之前，没有其他的杂草控制方法。有证据表明，在没有杂草的情况下，耕作的需求可能会减少(Russell&Ken，1938；Pereira，1941)，然后变得具有实际意义，到1970年，减少耕作或直接钻探(在美国，“免耕”)在几个国家得到了成功的实践。劳动力成本的增加是这些发展的一个特别激励因素，可以预见，“能源危机”将是进一步的刺激因素。这些新的做法强调了了解土壤物理条件对根生长的影响的重要性。放弃一年一度的耕作可能会导致土壤更加紧实；但现在很明显，在许多情况下，尽管不是所有情况，作物产量可能不会受到损害。有时，与传统耕作不同，直接钻探多年来土壤条件似乎更好(Baeumer等人，1971)。不可能有足够的基础来
The title of this article may at first sight seem out of place in a publication dedicated to Professor A. C. Schuffelen as it is little related to the chemical aspects of soil fertility on which he has made such an outstanding contribution. But there are reasons for this choice. Progress in the scientific study of soil has depended largely on in creasing interdisciplinary links, made possible by advancing knowledge and made nec essary by emergent problems. Professor Schuffelen's work provides excellent illustra tions: the rigorous and often novel application of physical chemistry to elucidating ionic equilibria between the solid and solution phases of the soil much advanced the understanding of soil/plant nutritional relationships; a decade and a half ago this knowledge enabled him, in collaboration with nuclear physicists, to encourage a logical approach to new questions posed by the deposition of worldwide fallout on the soil. Some recent developments in agricultural practices now increasingly direct attention to another aspect of soil fertility, namely the response of root systems to their physical environment, including their reaction to mechanical stress. Here again progress will largely depend on new or strengthened interdisciplinary links. This parallel with the development of Professor Schuffelen's own interests encouraged the choice of the present subject. A further reason was the belief that the conjoint consideration of the response of plants to the chemical and physical facets of the soil environment should permit a broader understanding of the factors which control fertility. Despite the considerable changes in agricultural practices which have occurred over the past several centuries, one basic tenet remained virtually unquestioned until the last decade, namely the importance of the careful cultivation of the soil on which arable crops are grown. Cultivation traditionally served two main functions to produce suitable soil conditions for plant growth and to control weeds. There was no alternative method for weed control until herbicides, especially paraquat (Hood et al., 1963, 1964), became available. Evidence that the need for cultivation can be less when weeds are absent (Russell & Keen, 1938; Pereira, 1941) then became of practical importance, and by 1970 reduced cultivation or direct drilling (in USA 'no till') were being successfully practised in several countries. The increasing cost of labour was a particular incentive to these developments and it may be expected that the 'energy crisis' will be a further stimulus. These new practices emphasize the importance of understanding the effects of soil physical conditions on root growth. The abandonment of annual cultivation can result in greater compaction of the soil; yet it is now evident that in many, though by no means all, situations crop yields may not be impaired. Sometimes, indeed, soil conditions appear to be better when direct drilling, as opposed to traditional cultivation, has been practised for many years (Baeumer et al., 1971). There can be no adequate basis for