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1998年7月,利用非称重式蒸渗池种植单一种源的一年生黄檀种苗,研究在印度沙漠地区培养黄檀种苗的合理灌水技术参数。当各处理(W1、W2、W3、W4)的土壤水分含量分别降低到7.56%、5.79%、4.44%和3.23%时,通过灌溉使苗木生长保持在一定的土壤的水分状况,如36.2mm(W1)、26.5mm(W2)、20.2mm(W3)和18.1mm(W4)。结果表明,在36.2mm(W1)水平时,种苗的株高、冠径、叶数和叶面积达到最大值(p<0.01)。在W1和W2处理中,虽然上述参数没有明显差异,但在W2处理中,种苗的每升水分利用率的生物量最大。在W3、W4和W5灌溉水平下,不利于提高种苗的株高、生物量和营养积累。在W2水平以下(5.79%),土壤水分有效率能提高根系生物量占总生物量的百分比。但在W3和W4处理中,叶干生物量百分比下降,同时在W5处理中,茎干生物量百分比下降。在W5处理中,土壤水势达到-196Mpa,种苗才可以成活。在W3和W4处理中,土壤水分有效率的限额影响黄檀种苗的生长和生物量。在W2处理中,土壤水分有效利用率最高,种苗的生长和生物量达到最高值。因此,在壤砂土条件下,通过灌溉维持幼苗土壤水分含量在5.79%以上时,可获得较好的黄檀种苗的生长和生物量产量。
In July 1998, annual monocotyledonous sandalwood seedlings were planted in a non-weighted steaming cell to study the reasonable irrigation parameters for cultivating sandalwood seedlings in desert areas of India. When the soil water content of each treatment (W1, W2, W3, W4) decreased to 7.56%, 5.79%, 4.44% and 3.23% respectively, the growth of seedlings was maintained at a certain soil moisture condition by irrigation, W1), 26.5 mm (W2), 20.2 mm (W3) and 18.1 mm (W4). The results showed that the plant height, crown diameter, leaf number and leaf area reached the maximum (p <0.01) at the 36.2mm (W1) level. In the W1 and W2 treatments, although there was no significant difference in the above parameters, in the W2 treatment, the seedlings had the highest biomass per liter of water use efficiency. Under the irrigation level of W3, W4 and W5, it is not conducive to increase plant height, biomass and nutrient accumulation. Below W2 (5.79%), soil moisture efficiency increased the percentage of root biomass to total biomass. However, in the W3 and W4 treatments, the percentage of leaf biomass decreased, while the percentage of stem biomass decreased in W5 treatment. In the W5 treatment, soil water potential reached -196Mpa, seedlings can survive. In W3 and W4 treatments, the limits of soil moisture efficiency affected the growth and biomass of Dalbergia seedlings. In W2 treatment, the highest effective utilization of soil moisture, seedling growth and biomass reached the highest value. Therefore, under the conditions of loamy soil, the growth and biomass yield of Dalbergia seedlings could be better maintained when the soil moisture content of seedling was above 5.79% by irrigation.