生物炭和EM菌对黄河三角洲盐碱地田菁生长和光合特性的影响

为揭示生物炭和EM菌对黄河三角洲田菁生长和光合作用的影响,通过盆栽试验,进行不同EM菌处理(不添加EM菌,EM-;添加EM菌,EM+)和不同水平生物炭处理(0,B₀;0.5%,B₁;1.5%,B₂;3%,B₃;生物炭质量/土壤质量),测定田菁生长指标、光合光响应曲线和叶绿素荧光参数的变化。结果表明: 在生物炭和EM菌及其交互处理中,EM+B₃处理效果最好,其中田菁株高、基径和总生物量比EM-B₀分别显著增加69.5%、90.0%和141.1%。生物炭和EM菌显著改善田菁的光合作用,EM+B₃处理田菁的净光合速率、蒸腾速率、水分利用效率、气孔导度比EM-B₀分别提高93.8%、35.1%、43.4%、34.8%。生物炭和EM菌有效改善叶绿素荧光参数,EM+B₃处理的潜在光化学效率、实际光化学效率、表观光合电子传递效率和非光化学淬灭系数比EM-B₀分别显著提高25.8%、31.5%、37.2%和56.8%。田菁的生长指标、光合参数和叶绿素荧光参数在EM+处理下随着生物炭量的增加而增大,而在EM-处理下B₃出现抑制现象。添加EM菌和3%生物炭(EM+B₃)有助于提高田菁光合能力和叶绿素荧光特性,拓宽叶片的光照生态幅,增强保水抗旱性能,促进田菁的生长。

Effects of biochar and EM application on growth and photosynthetic characteristics of Sesbania cannabina in saline-alkali soil of the Yellow River Delta,China

We examined the effects of biochar and effective mircoorganisms (EM) application on growth and photosynthetic characteristics of Sesbania cannabina in the Yellow River Delta, by a pot experiment with different EM treatments (without EM addition, EM-; with EM addition, EM+) and a gradient of biochar treatments (0, B₀; 0.5%, B₁; 1.5%, B₂; 3%, B₃; biochar weight/soil weight). The growth parameters, photosynthetic light response curve and chlorophyll fluorescence characteristics of S. cannabina were measured. The results showed that the EM+B₃ treatment had the best effect among all the treatments. Compared with the EM-B₀ treatment, the EM+B₃ treatment increased height, stem diameter, and total biomass by 69.5%, 90.0% and 141.1%, respectively. Biochar and EM significantly improved photosynthetic capacity. Compared with the EM-B₀ treatment, the EM+B₃ treatment significantly enhanced the maximum light response of net photosynthetic rate, transpiration rate, water use efficiency, and stomatal conductance by 93.8%, 35.1%, 43.4%, and 34.8%, respectively. Biochar and EM improved the parameters of chlorophyll fluorescence. Compared with the EM-B₀ treatment, the EM+B₃ treatment significantly increased the potential photochemical efficiency, the actual photochemical efficiency, the apparent electron transport rate and the non-photochemical quenching coefficient by 25.8%, 31.5%, 37.2%, and 56.8%, respectively. The parameters of growth, photosynthesis and chlorophyll fluorescence increased with the increasing biochar under EM+ treatments, whereas the B₃ treatment had negative effect under EM- treatments. The co-addition of EM and 3% biochar (EM+B₃) could improve the photosynthetic capacity and chlorophyll fluorescence characteristics of S. cannabina, broaden light ecological amplitude, boost the water retention and drought resistance property, and promote the growth of S. cannabina.