保水剂对煤矸石基质上高羊茅生长及营养吸收的影响

为探索保水剂对煤矸石废弃地上高羊茅生长及营养特征的影响,按煤矸石与土壤质量比设3种基质梯度,每种基质分别添加3种质量的保水剂,设对照(CK),共10种处理。观测和分析不同处理下高羊茅的生长高度、生物量、营养特征及SPAD值(相对叶绿素含量),结果显示:保水剂主要影响高羊茅地上部分的生物量,而煤矸石与土壤的质量比主要影响地下部分的生物量;煤矸石与土壤质量比相同条件下,添加1 g/kg的保水剂即可促进高羊茅的生长,添加2 g/kg保水剂能使高羊茅尽快适应基质环境,使其日均生长率在出苗后第2周达到峰值。煤矸石基质中添加保水剂能促使高羊茅将煤矸石基质中的营养元素从植株地下部分向地上部分转移,供植株生长需要,基质中添加1 g/kg保水剂时高羊茅对磷的吸收效果最好。此外,添加保水剂能使叶片的SPAD值增加。综合比较不同处理下高羊茅的株高、生物量、营养特征及叶片的SPAD值认为,处理6(煤矸石与土壤质量比为750:250、基质中添加2 g保水剂)与处理8(煤矸石与土壤质量比为500:500、基质中添加1 g保水剂)是适合煤矸石废弃地上高羊茅生长的较好配比。

The effect of super absorbent polymer on the growth and nutrition absorption of Festuca arundinacea L. on an improved gangue matrix

Super absorbent polymers (SAPs) can absorb water up to a few hundred or even a few thousand times their own mass. Their special physical structure, unique chemical composition, and characteristics of high water absorption capacity allow super absorbent polymers to be widely used in agriculture, horticulture, forestry and other industries to relieve drought and reserve water for farmland, seedling protection, and crop yield improvement. However, the amount of super absorbent polymers applied is an important parameter to evaluate. Applying the incorrect amount can result in either no effect, or soil permeability may be compromised if excess amounts are used. This can cause plant roots to have difficulty breathing or to have root rot. To explore the influence of super absorbent polymers on the growth and nutritional characteristics of Festuca arundinacea L. on gangue waste, three matrix gradients were set up with different weight ratios of gangue/soil. The matrix of each gradient was added into the super absorbent polymer in three different qualities. Ten treatments in total, including CK, were set up in this paper. The height growth, biomass, nutritional characteristics and SPAD (Soil and Plant Analyzer Development) value of Festuca arundinacea L. under different treatments were observed. The effects of different treatments on the gangue matrix and on Festuca arundinacea L. growth were analyzed to determine the reasonable dosage of super absorbent polymer to be added to the gangue wasteland for vegetation recovery. This provides a theoretical basis and technical support for this practical application. The results show that adding super absorbent polymers helps strengthen the gangue matrix''s ability to hold water, increasing the water available to the plants, which promotes plant growth and biomass increase. The super absorbent polymer mainly impacts aboveground biomass, while the underground biomass is mainly affected by the weight ratio of the gangue/soil; for treatments where the weight ratio of gangue/soil is the same, adding 1 g/kg super absorbent polymer accelerates Festuca arundinacea L. growth; adding 2 g/kg super absorbent polymer to the matrix helps Festuca arundinacea L. quickly adapt to the matrix environment and the daily average growth rate reaches peak value 2 weeks after the seedling emergence. Adding super absorbent polymer to a gangue matrix enhances the gangue''s ability to hold fertilizer and to supply nutrients to plants. Festuca arundinacea L. can promote growth by transferring nutrients in the gangue matrix from underground plant parts to aerial parts. Phosphorus absorption was most efficient when 1 g/kg super absorbent polymer was added. Super absorbent polymers affect photosynthesis parameters of blade leaves by imposing impact on plant water use efficiency. Therefore, adding super absorbent polymers can increase the SPAD value of the blade leaf. From comprehensive comparisons of plant height, biomass, nutrition characteristics and leaf SPAD values of Festuca arundinacea L. under different treatments, treatment No. 6 (weight ratio of gangue/soil is 750:250, with 2 g super absorbent polymer) and treatment No. 8 (weight ratio of gangue/soil is 500:500, with 1 g super absorbent polymer) were the optimal conditions found to help Festuca arundinacea L. grow on gangue waste.