生物腐植酸对露天矿排土场黑麦草生长的影响

目的]研究生物腐植酸对露天矿排土场土壤改良效果的影响,为进一步提高露天矿排土场的土壤质量提供科学参考。方法]通过盆栽试验,研究不同生物腐植酸含量(0~400kg/hm2)对露天矿排土场不同土地利用类型〔(刺槐(Robinia pseudoacacia)林、榆树(Ulmus pumila)林、荆条(Vitex negundo)林、农田、未复垦土地〕下黑麦草(Lolium multiflorum)生长状况的影响。结果]刺槐土、榆树土、荆条土、农田土、未复垦土出苗率最大值分别出现在加入生物腐植酸量为200,200,300,300,200kg/hm2的试验盆;5种土壤黑麦草幼苗株高所需生物腐植酸最大量值分别为200,200,200,300,300kg/hm2;5种土壤黑麦草根系长度最大值分别出现在300,100,300,300,300kg/hm2的试验盆;而生物量最大值分别出现在加入生物腐植酸量为200,100,200,300,300kg/hm2的试验盆。随着生物腐植酸量的增加,各土地利用类型条件下种植的黑麦草出苗率、株高、根系长度、生物量均表现出先增加后减小的趋势。结论]生物腐植酸对露天矿排土场不同土壤植物更新与生长具有剂量效应,表现为"单峰型"变化规律,体现出适量的生物腐植酸对露天矿排土场植被恢复具有促进作用。

Effects of Biological Humic Acid on Growth of Lolium Multiflorum in Open-pit Mine Dump

Objective] The effect of biological humic acid on soil improvement in open-pit mine dump was studied, in order to provide scientific references for the improvement of soil quality.Methods] Biological humic acid with different contents(0-400 kg/hm²) were added in five different kinds of soil which were derived from five land use types(Robinia pseudoacacia forest, Ulmus pumila forest, Vitex negundo forest, farming land and unutilized land). Pot experiments were conducted by planting Lolium multiflorum species. The effects of biological humic acid on soil improvement were investigated.Results] The maximum emergence rate for the soil from R. pseudoacacia, U. pumila, V. negundo, farming and unutilized land occurred when the amounts of biological humic acid were 200, 200, 300, 300 and 200 kg/hm², respectively. The maximum amount of biological humic acid required by Lolium multiflorum seedling for five different kinds of soil were 200, 200, 200, 300 and 300 kg/hm². The maximum root length occurred when the amounts of biological humic acid were 300, 100, 300, 300 and 300 kg/hm², respectively, and the maximum biomass occurred when the amount were 200, 100, 200, 300 and 300 kg/hm², respectively. As the biological humic acid increases, all the seedling emergence, seedling height, root length and seedling biomass showed a downward trend before an increase.Conclusion] There was a dose effect of the biological humic acid on the plant regeneration and growth in different soil of open-pit mine dump. The change curves of the relations for the plant regeneration and growth and the biological humic acid appeared as a "single-peak" shape, which indicate that a balanced amount of biological humic acid could improve the vegetation recovery in open-pit mine dump.