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引言 为使作物正常生长与获得经济产量,植株必须维持一定的养分水平,这已成为科学的概念。如果养分浓度低于或高于适宜水平,这种胁迫必然导致可见症状并降低产量。作物生育阶段中可能遇到缺素的胁迫,然而只有定期地采样并加以分析才有可能确定这种胁迫出现的时期。 随着植株分析逐渐成为确定作物营养状况更有用的手段,认真评价植株叶片养分含量的变化规律,对于建立最好的采样时间提供很有用的资料。
INTRODUCTION Plants have to maintain a certain nutrient level for proper crop growth and economic yield, which has become a scientific concept. If the nutrient concentration is below or above a suitable level, such stress will necessarily result in visible symptoms and reduce yield. It is possible that crop stress may be encountered during the fertility stage, but only regular sampling and analysis will make it possible to determine the period of such stress. Plant analysis has become a more useful means of determining the nutritional status of crops. The changes of nutrient content in plant leaves are carefully evaluated, providing useful information for establishing the best sampling time.