不同基底处理下碱蓬种植对滨海盐渍土的改良与修复效应初探

Primary exploration of reformating and renovation on coastal saline-alkali soil under different substrate treatment

以碱蓬为材料,在天津经济技术开发区再生水景观河道8个河内中心岛上布置了不同基底处理对土壤生态修复作用的试验。在对中心岛作挖排盐暗沟、铺设排盐暗管、铺垫可降解薄膜并垫土20 cm、铺垫可降解薄膜并垫土30 cm和原土拌砂5种基底处理,并进行垫土后人工种植碱蓬。结果显示:各种措施对土壤生态修复均有效果,都提高了碱蓬生物量,降低了土壤含盐量,且土壤含盐量越低,生物量越大。各项措施中,原土拌砂效果最明显,碱蓬生物量(干重)达到对照的3.92倍;上层土壤中速效氮、速效磷、速效钾分别增加了6.89、19.98和80.0 mg.kg-1;有机质含量增加了2.57 g.kg-1。铺垫可降解膜并垫土20 cm效果最差,碱蓬生物量仅为对照的1.62倍。其他措施的效果依次为挖排盐暗沟、铺垫可降解膜并垫土30 cm、铺设排盐暗管。种植碱蓬有降低土壤盐分及改良土壤的作用,但对下层土壤没有明显的修复作用。

The effects of different substrate treatments on soil eco-restoration were studied by planting Suaeda salsa at 8 scenic river islands with reclaimed wastewater in Tianjin Development Area. Five substrate treatments were established, namely, digging desalt culverts, under-laying desalt pipes, under-laying degradable films covered with 20 cm thick soil, under-laying degradable films covered with 30 cm thick soil, and mixed sand with the soil. The results are listed as follows. There was a negative correlation between the biomass of Suaeda salsa and soil salt conents. Among the treatments, mixed sand with the soil had the best eco-restoration effect with the biomass （dry weight） of Suaeda salsa being 3.92 times higher than the control. In the treatment of mixed sand with the soil, the available N, P, K and organic matter content of topsoil were increased by 6. 89, 19.98, 80.0 mg·kg^-1 and 2. 57 g ·kg^-1 respectively. The effect of under-laying degradable films covered with 20 cm thick soil treatment was smallest among all the substrate treatments with the biomass （ dry weight） of Suaeda salsa being 1.62 times higher than the control. The effects of the other three substrate treatments were in the following order： digging desalt culverts, under-laying degradable films covered with 30 cm thick soil and under-laying desalt pipes. Planting Suaeda salsa could reduce the soil salt content, but had no obvious restoration effect on subsoil.