不同改良措施对盐渍化土壤水热碳与葵花产量的影响

Effects of Different Improvement Measures on Hydrothermal Carbon and Sunflower Yield in Salinized Soil

为探明不同改良措施对盐渍化土壤水热碳及葵花产量的影响,设置了施加生物炭(C,22.5 t/hm^2)、脱硫石膏(S,37.5 t/hm^2)、秸秆还田(J,20.625 t/hm^2)和对照(CK)4个处理,进行大田试验。结果表明:3种改良措施均能改善土壤水热环境,其中生物炭更具优势。3种改良处理在整个生育期内0~20 cm和20~40 cm土层的土壤含水率显著高于对照;在垂直分布上表现出0~40 cm土层各改良措施保水、蓄水作用的效果优于40 cm以下土层,各处理剖面土壤水分空间分布格局均表现出下湿、上干的特点。与CK相比,各改良处理体现出良好的增温、保温效果,均表现出低温时具有“增温效应”、高温时具有“降温效应”,且对温度的调控作用主要集中在5~25 cm土层,从35 cm处开始影响减弱。采取3种改良措施均能增加土壤有机碳含量和有机碳密度,其中施加生物炭效果最显著,有机碳密度较对照增加了17.46%。与对照相比,C处理的葵花产量增产率最高,达32.28%,J、S处理产量分别增加21.94%、30.68%,三者差异不显著。综合分析得出,施加生物炭22.5 t/hm^2为适宜于河套灌区盐渍化农田种植葵花过程中的土壤改良处理。

Aiming to explore the effects of different improvement measures on hydrothermal carbon and sunflower yield in salinized soil,experiment was carried out by applying biochar(C,22.5 t/hm^2),desulfurization gypsum(S,37.5 t/hm^2),straw returning(J,20.625 t/hm^2)and control(CK)in field.The results showed that three improvement measures can improve the soil hydrothermal environment,of which biochar had advantages.The soil moisture content of the soil layers of 0~20 cm and 20~40 cm during the whole growth period was significantly higher than that of the control.In the vertical distribution,the improvement effect of water conservation and water storage of 0~40 cm soil layer was better than that of soil layer below 40 cm.The spatial distribution pattern of soil moisture in each treatment section showed the characteristics of wet and dry.Compared with CK,each improved treatment had good temperature increase and heat preservation effect,both of which had“warming effect”at low temperatures,and“cooling effect”at high temperatures,and the regulation of temperature was mainly concentrated at 5~25 cm soil layer,and weakened from 35 cm.The application of three improvement measures can increase the soil organic carbon content and organic carbon density,among which the biochar effect was the most significant,and the organic carbon content was increased by 17.46%compared with the control.Compared with the control,the yield of C treatment was the highest,reached 32.28%,and the yield of J and S treatment was increased by 21.94%and 30.68%,respectively.The difference between the three was not significant.According to comprehensive analysis,the application of biochar of 22.5 t/hm^2 was more suitable for soil improvement in the process of planting sunflower in salinized farmland in Hetao Irrigation District.