生物炭对滨海盐渍土理化性质及玉米幼苗抗氧化系统的影响

以黄河三角洲典型盐化潮土为供试土壤,设置12.5,25.0,50.0,100 g/kg 4个梯度生物炭添加量,通过盆栽试验研究不同添加量下生物炭对滨海盐渍土理化性质及玉米幼苗抗氧化系统的影响。结果表明:(1)与对照相比,随着生物炭添加量的增加,盐渍土的电导率、速效磷、速效钾、阳离子交换量及易氧化有机碳的含量呈现显著增加的趋势;不同生物炭添加量下,盐渍土的pH、碱解氮含量略有下降,但各添加量处理间差异不显著;而生物炭对盐渍土可交换态钠含量无显著影响。(2)添加适量生物炭(12.5,25.0,50.0 g/kg)可显著提高玉米幼苗叶片抗氧化酶活性和根系活力,并降低叶片超氧阴离子产生速率和过氧化氢含量,从而改善玉米幼苗的生理性状;然而,较高的生物炭添加量(100 g/kg)对幼苗抗氧化系统产生不良影响,造成植物体内活性氧的累积。因此,添加适量生物炭可以改善滨海盐渍土的理化性质,并在一定程度上有效改善盐胁迫下玉米幼苗的生理特性,但较高用量对作物抗氧化系统具有抑制作用。

Effect of Biochar on the Physicochemical Properties of Coastal Saline Soil and the Antioxidation System Activity in Maize Seedlings

The effects of biochar addition on the physicochemical properties of coastal saline soil and the activity of the antioxidation system in maize seedlings were studied by pot experiment, and the typical coastal saline soil sampled from Yellow River Delta was taken as test soil. A total of six treatments were set up in the experiment, including non-fertilizing (CK), fertilizing without biochar (CFK) and fertilizing with different addition rates of biochar (the addition rate was 12.5, 25.0, 50.0 and 100 g/kg, respectively). The results showed that:(1) Compared with CK, with the increasing of biochar-addition rate, the electrical conductivity (EC), available potassium, available phosphorus, cation exchange capacity (CEC) and easily oxidized organic carbon (EOC) of coastal saline soil increased significantly. The pH and alkali hydrolysable nitrogen content of soil treated with biochar showed decreased trends compared with CK, but there was no significant different between the biochar treatments. However, biochar addition had no significant effect on exchangeable sodium compared with CK.(2) Moderate addition rate of biochar (12.5, 25.0 and 50.0 g/kg) increased the activities of antioxidant enzymes (SOD, POD and CAT) and root activity in maize seedlings, and reduced the production rate of superoxide anion and hydrogen peroxide content of leaves, thereby improving the physiological characteristics of maize seedlings. However, the higher addition rate of biochar (100 g/kg) exhibited a negative impact on the activity of antioxidant enzyme in maize seedlings, resulting in the higher accumulation of reactive oxygen in the plants. Therefore, moderate addition rate of biochar could improve the physical and chemical properties of coastal saline soil, and to a certain extent, effectively improve the physiological characteristics of maize seedlings under salt stress, but the higher addition rate could inhibit the antioxidant system of crops.