不同土壤紧实度对棉花根系生长的影响

Effect of Soil Compaction on Root Growth of Cotton

试验于1992～1995年在扬州大学农学院进行。供试棉花品种岱15,设砂、粘土不同容重盆栽。结果指出,容重1.1g/cm^3处理,根系长势“前旺后衰”,容重1.4g/cm^3和1.5g/cm^3处理根系生长始终处于劣势,而容重1.2g/cm^3和1.3g/cm^3处理主根生长率与一次侧根增长率高,主根长,一次侧根量大,根系活力强,吸收氮、磷、钾多,长势“前强后稳”,为最优处理;还发现,棉根干重随土壤容重从1.1g/cm^3到1.5g/cm^3的增加而逐渐减少,但在土壤容重为1.2～1。3g/cm^3时,根量适中,冠/根比较大,生物学产量和经济产量最高,根系生产力最强。因此,容重1.2～1.3g/cm^3是最适宜棉花根系生长和能充分发挥根系生产力的理想土壤紧实度。

Pot experiments were conducted to study the effect of soil compaction on root growth of upland cotton (Gossypium hirsutum). Two type of soils with contrasting texture (sandy loam and clayey)were used. Results showed that soil bulk density (SBD) between 1. 2 and 1.3g/cm3 favored root growth as indicated by the data of root growth rate, main root length, number of branch root, root activity and nutrient uptake of cotton plant. Although the dry weight of root decreased with the increase of SBD from 1.1 to 1. 5 g/cm3, the ratio of stem/ root, and consequently, both biological and economic yield were optimal when SBD was 1. 2-1. 3 g/cm3. It was concluded that SBD between 1. 2 and 1. 3 g/cm3 was most favorable for cotton root growth.