不同配方生物炭改良盐渍土对小白菜和棉花生长及光合作用的影响

针对盐渍土壤理化性质差、肥料利用率低和作物长势弱的问题,利用不同配方生物炭进行土壤改良。采用盆栽试验的方法,以小白菜和棉花为研究对象,设置5个不同的处理:不施肥(对照CK0)、常规施肥(CK)、常规施肥+生物炭(C1)、常规施肥+生物炭+硝化抑制剂(C2)和常规施肥+生物炭+硫酸钙(C3),研究不同配方的生物炭处理对小白菜和棉花生长及光合作用的影响。结果表明,与常规施肥比较,C3处理效果更明显。小白菜的株高和株重分别增加32.7%和112.0%,叶绿素含量与净光合速率分别提高45.5%与32.9%;胞间CO_2浓度和蒸腾速率分别下降15.0%和59.2%。光谱分析表明,C3处理反射率更高,叶片组织更完好。与CK比较,生物炭处理同样促进棉花生长,显著提高叶绿素含量,降低叶片中丙二醛含量和过氧化氢酶活性,增强抗逆性,减少棉花损伤。同时,降低了棉花叶片中胞间CO_2浓度,提高水分利用率。土壤分析表明,生物炭配施改良剂能显著改善土壤理化性质,与常规施肥相比,C2处理的土壤有机质、速效磷和碱解氮含量分别提高57.3%,22.9%和40.8%,而对土壤速效钾和pH影响较小,C3处理对土壤电导率有较大提高。因此,实践中在改良盐渍土壤时,需注意改良剂的合理施用,防止土壤盐分的进一步积累。

Amelioration of Saline Soil with Different Biochar Fertilization Formulas and Its Effects on Growth and Photosynthesis of Brassica Chinensis and Cotton

Aiming at the poor physicochemical properties, the low fertilizer use efficiency and the weak crop growth in saline soils, a saline soil was ameliorated with different biochar fertilizers in this study. Brassica chinensis and cotton were used as research materials in this pot experiment. Five different treatments were conducted, i.e., non-fertilized control group (CK0), conventional fertilization (CK), conventional fertilization+biochar (C1), conventional fertilization + biochar + nitrification inhibitor (C2), conventional fertilization + biochar + Calcium sulphate (C3). The growth and photosynthesis of Brassica chinensis and cotton were measured. The results showed that C3 treatment was more effective in crop growth than that of CK. The plant height and weight of Brassica chinensis were increased by 32.7% and 112.0%, respectively, and the chlorophyll content and net photosynthetic rate were increased by 45.5% and 32.9%, respectively. The intercellular CO₂ concentration and transpiration rate were decreased by 15.0% and 59.2%, respectively. Spectral analysis indicated that the C3 treatment had higher reflectance and better leaf tissue. The experimental results also indicated that, compared to CK, biochar treatments promoted cotton growth, expressed as increase in chlorophyll content significantly, decreasing malon dialdehyde content and catalase activity in leaves, leading to the enhanced stress resistance and the reduced plant damage. At the same time, the intercellular CO₂ concentration in cotton leaves was reduced, and the water use efficiency was improved. Soil analysis suggested that the application of biochar significantly improved the physical and chemical properties of soil. Compared with CK, the organic matter content, available phosphorus content and alkali nitrogen content in C2 treated soil were increased by 57.3%, 22.9% and 40.8%, respectively. However, the influence on soil available potassium content and pH value was not obviously, and C3 treatment had an obvious increase in soil electrical conductivity. Therefore, when ameliorating the saline soil, it is necessary to pay attention to the reasonable application amount of the modifiers to prevent further accumulation of soil salinity.