紧实胁迫对土壤呼吸强度及黄瓜生长和品质的影响

EFFECT OF SOIL COMPACTION ON SOIL RESPIRATION INTENSITY,PLANTS GROWTH AND FRUIT QUALITY OF CUCUMBER

用容重为1.2和1.5 g cm-3的土壤进行盆栽试验,研究了紧实胁迫对土壤剖面各层中呼吸强度及CO2浓度的影响,调查了黄瓜植株及果实品质对土壤紧实胁迫的反应。结果表明:紧实土壤(高容重)土面下CO2浓度及呼吸强度均大于疏松土壤(低容重)。紧实土壤中黄瓜根系伸长生长受到抑制,根系重量显著减小,根冠比(地下部干重/地上部干重)降低;地上部的鲜重及干重也减小,但干物质含量却有一定程度增加;展开的叶片数减小,黄叶数增加,植株衰老提早。果实增大速度受到抑制,糖/酸比大幅度下降,风味变差。

a pot experiment was carried out using soils, 1.2 and 1.5 gcm-3in bulk density, was experimented to study effects of soil compaction on soil respiration intensity and CO2concentration in various soil layers, and responses of cucumber to soil compaction in plant growth and fruit quality. Results show that CO2concentration and respiration intensity in the soil layers below the surface in the compacted soil （CS） were higher than in the loose soil （LS）. The extension of roots was hindered in CS, leading to significantly lower dry weight of the roots, decreased root/shoot ratio, and lower fresh weight and dry weight of shoots, too, but certain increase in dry matter content. Fewer extended leaves, more yellow leaves and earlier senescence were found of the plants in CS that in LS. And further more, fruit expansion rate suppressed, soluble sugar content in fruit lowered, contents of soluble protein and organic acid significantly increased, sugar/acid ratio declined sharply, and fruit flavor worsened.