灌水周期和保水剂用法对小桐子水分利用的影响

为探明小桐子幼树水分高效利用管理模式,通过盆栽试验,研究了3种灌水周期(5,10,15 d)和3种保水剂用法(环施、半环施、穴施)对小桐子幼树生长和水分利用效率的影响.结果表明:灌水周期相同时,保水剂环施的水分利用效率最大,半环施的次之,穴施的最小;保水剂用法相同时,灌水周期为10 d的水分利用效率最大,5 d的次之,15 d的最小.保水剂环施时,与灌溉周期为5 d和15 d相比,灌溉周期为10 d能明显降低蒸散量,增加根区土壤含水量,同时显著促进植株生长,增加总干物质累积量分别为12.89%和51.83%,同时提高总水分利用效率分别为51.81%和58.28%.因此,在本试验条件下保水剂环施和灌水周期为10 d组合具有促进小桐子幼树生长和提高水分利用的作用.

Effects of irrigation frequency and super absorbent polymer usage on water use of young Jatropha curcas L. tree

A pot-grown experiment was conducted to investigate water efficient use mode of Jatropha curcas L. tree, using three irrigation frequency(5 d, 10 d and 15 d)and three SAP usage(ring, half ring and hole), the effects of irrigation frequency and SAP usage on growth and water use efficiency(WUE)of young Jatropha curcas L. tree was studied. Results showed that the WUE sequence of three SAP usage was ring>half ring>hole under same irrigation frequency, and the WUE sequence of three irrigation frequency was 10 d>5 d>15 d under the same SAP usage. When SAP ring application, irrigation frequency of 10 d reduced evapotranspiration obviously, increased soil water content and promoted plant growth significantly, increased total dry mass by 12.89% and 51.83%, and increased total WUE by 51.81% and 58.28% respectively compared irrigation frequency of 5 d and 15 d. Thus the combination of ring SAP usage and irrigation frequency of 10 d could promote young Jatropha curcas L. tree growth and increase WUE under the experiment condition.