土壤中的玉米根系生长及其研究应注意的问题

土壤中的根系如何生长？由于根系生长在土壤中无法直接观察和研究，使得对土壤中的根系生长和发育规律、空间分布规律及其对养分的吸收了解很少。已知的关于土壤中根系生长的研究结果与室内控制条件下所获得的短期试验结果有很大不同。本文针对田间条件下生长的玉米根系发育规律、根系的更新和衰老、根长与根重的关系、根鞘形成、根系生长与氮素利用效率以及土壤Nmin与取样方法，特别是在研究土壤中生长的根系时需要注意的问题进行讨论，希望对田间条件下玉米根系的生长发育有更多了解，并对目前国内进行的众多田间条件下的作物根系研究有所借鉴。

Real maize roots in the soil and issues should be considered by study

How do real roots grow and work in the soil? Because soil is opaque growing environment, it is not possible to observe or study roots grown in the soil directly. Therefore, less is known about the real root growth and development, its spatial distribution as well as its nutrient uptake in the soil. In this paper, the following issues were discussed with maize as an example: the growth and development, and renewal and senescence of real roots in the soil during the whole growth period; the relationship between root length and dry weight; the formation of rhizosheath; root growth and nitrogen use efficiency; soil Nmin, and especially the attention should be paid during the study of real roots in the soil. The aim of this paper is to let a better understanding of the growth and development of real maize roots in the soil though the discussion mentioned above, and to use for reference for the investigation of crop roots grown in the soil.