基质和水氮处理对假茉莉水分利用率及生物量的影响

Effects of matrix and water-nitrogen treatments on water use efficiency and biomass of Clerodendrum inerme

假茉莉(Clerodendrum inerme)是一种重要的半红树植物,是海岛及沿海防护林的重要组成部分,淡水、土壤是海岛植被恢复的重要生态因子。为了总结出最适合假茉莉生长发育的土壤及水肥条件,该文设置了不同基质、浇水频率及氮素处理,对不同处理下假茉莉的生物量及水分利用率进行了研究。结果表明:(1)在不同的基质中,含泥炭的混合基质对于假茉莉生物量的积累具有突出作用,S 4基质(珊瑚砂∶泥炭∶红壤土∶椰糠=12∶2∶3∶3)地下生物量(平方根)为1.66 g,极显著高于不含泥炭的基质,S 1基质(珊瑚砂∶泥炭=3∶2)总生物量(平方根)为4.54 g,极显著高于其他基质。(2)中、低浇水频率下的总生物量分别为4.02、4.23 g,极显著高于高浇水频率下的3.46 g,而不同氮素处理间生物量的差异并不显著,这表明假茉莉在中、低浇水频率,少施氮肥或不施氮肥的条件下仍然能够获得较高的生物量。(3)对于水分利用率而言,原珊瑚砂基质保水性较差,水分利用率较低,而混合基质在中、低浇水频率下水分利用率均有不同显著程度的提高。综上结果显示,假茉莉在含泥炭基质,中、低浇水频率,无氮或低氮条件下能够较好生长。

Clerodendrum inerme is a semi-mangrove plant that is an important part of island and coastal shelter forests.Fresh water and soil are important ecological factors for island vegetation restoration.In order to summarize the most suitable soil,water and fertilizer treatment for C.inerme,we set different matrices,irrigation frequencies and nitrogen treatments,and studied the biomass and water use efficiency of C.inerme under the different treatments.The results were as follows:(1)Peat-containing mixed matrix had a prominent effect on the biomass accumulation of C.inerme.The underground biomass(Square Root Calculations)of S 4 matrix(coral sand∶peat∶red soil∶coco peat=12∶2∶3∶3)was 1.66 g,which was significantly higher than that of peat-free matrix,and the total biomass(Square Root Calculations)of S 1 matrix(coral sand∶peat=3∶2)was 4.54 g,which was significantly higher than other matrices.(2)In addition,the total biomasses treated at medium and low irrigation frequencies were 4.02 and 4.23 g,respectively,which were significantly higher than 3.46 g at high irrigation frequency.But the biomass between different nitrogen treatments was not significant,indicating that C.inerme could obtain high biomass under medium and low irrigation frequencies,with less or no nitrogen fertilizer.(3)For water use efficiency,the original coral sand matrix was kept at a low level,and the mixed matrix has been significantly improved,especially at medium and low irrigation frequencies.Therefore,C.inerme can grow well under peat-containing matrix,medium and low irrigation frequencies,with low nitrogen or no nitrogen.