土壤紧实胁迫对玉米苗期生长与钙吸收的影响

为揭示玉米对不同土壤紧实胁迫的响应程度与机理,以钙素为依据,设置土壤容重分别为1.1、1.2、1.3、1.4和1.5 g/cm3等5个水平玉米盆栽试验,以探讨土壤紧实度对玉米苗期生长及对钙素吸收的影响.试验结果表明:玉米从播种到生长15d期间,其生长对土壤紧实并不敏感,而15d之后,地上部分生长速度随土壤容重增加而受到抑制;而根系生长也由于土壤的紧实胁迫而受阻,根系干物质质量下降,根系活力减小,影响钙素养分的吸收;玉米苗中全钙含量最高值(1.67％)出现在容重1.2 g/cm3处理中,土壤紧实的增加会导致根系活性减小,从而使作物根系对钙素的吸收减少、作物抗性下降,导致作物提前衰老.因此,土壤容重影响土壤中养分的有效性,土壤过松或过紧均不利于作物的生长.

Effect of Soil Compaction Stress on the Growth of Corn and Calcium Absorption at the Seedling Stage

With the aim to evaluate the influence of soil hardness to corn growth and calcium absorption, five levels of soil hardness (soil bulk density: 1.1, 1.2, 1.3, 1.4 and 1.5g/cm3) were established in the pot experiment. There was no significant influence of soil hardness to corn growth in the first 15d after seeding, however, it inhibited aboveground corn growth in the following days. Root dry mass and activity both decreased because of the high soil hardness which had a negative effect on calcium absorption. The highest calcium content (1.67%) occurred in the treatment with 1.2g/cm3 soil hardness. The increase of soil hardness caused root activity decrease which led to the decrease of calcium absorption, thus, lower crop resistance to disease and cause in senescence in advance. It was concluded that too high or too low density of soil bulk was disadvantage to the crop growth.