立式深旋耕作对马铃薯农田土壤温室气体排放的影响

Effects of Vertical Deep Rotary Tillage on Soil Greenhouse Gas Emissions from Potato Farmland

为明确立式深旋耕作(VRT)技术对马铃薯全生育期农田温室气体(CO2和N2O)排放的影响,采用静态暗箱-气相色谱法,设置立式深旋松覆膜种植马铃薯(VRT-P)、旋耕覆膜种植马铃薯(TT-P)、立式深旋松露地无作物(VRT-FL)和旋耕露地无作物(TT-FL)4个处理,测定土壤含水量、温度和温室气体排放通量等,研究VRT对温室气体排放的影响及其机制。结果表明,VRT能显著提高0~30cm土层的土壤含水量,在现蕾期、始花期、盛花期和淀粉累积期,VRT-P处理较TT-P处理分别增加了9.8%、8.4%、14.6%和18.9%,VRT-FL处理较TT-FL处理分别增加了12.3%、9.1%、10.7%和26.8%;0~25cm土层土壤温度在现蕾期显著增加。农田土壤温室气体N2O和CO2排放通量呈现夏秋高而冬春低的季节性分布规律,在马铃薯生育期内VRT-P处理的N2O和CO2排放通量较TT-P处理分别提高39.9%和26.1%,在休闲季节分别提高11.2%和35.9%;VRT-FL处理的N2O和CO2排放通量较TT-P处理分别增加62.8%和4.4%,在休闲季节分别增加了41.5%和4.8%。种植作物对温室气体排放有显著影响,VRT-P处理的N2O和CO2排放通量较VRT-FL处理分别提高了78.2%和41.9%,TT-P处理的N2O和CO2排放通量较TT-FL处理分别提高了107.3%和24.1%,均达到显著差异。VRT提高了土壤温度和湿度,可显著提高土壤温室气体(N2O和CO2)排放通量。

In order to study the effects of vertical deep rotary tillage(VRT) technology on greenhouse gas(CO2 and N2O) emissions in the whole growth period of potato farmland was analyzed. Static box-gas chromatography was used in the experiment to design four treatments: vertical deep rotary mulch planting potato(VRT-P), rotary tillage mulch planting potato(TT-P), vertical deep rotary mulch without crop(VRT-FL) and rotary tillage without crop(TT-FL). Soil water content, temperature and greenhouse gas emission flux were measured to study the effect of vertical deep rotary tillage on greenhouse gas emissions and its mechanism. The results showed that VRT treatment could significantly increase the soil water content of the 0-30 cm soil layer. At buding stage, early flowering stage, full flowering stage and starch accumulation stage, VRT-P increased by 9.8%, 8.4%, 14.6% and 18.9% respectively compared with TTP, while VRT-FL increased by 12.3%, 9.1%, 10.7% and 26.8% respectively compared with TT-FL. Soil temperature in 0-25 cm soil layer increased significantly at budding stage. The emission fluxes of greenhouse gases(N2O and CO2) from farmland soil showed a seasonal distribution pattern of high in summer and autumn and low in winter and spring. During the potato growth period, the N2O and CO2 emission fluxes of VRT-P increased by 39.9% and 26.1% respectively compared with TT-P, and increased by 11.2% and 35.9% respectively in leisure season. Compared with TT-P, the N2O and CO2 emission fluxes of VRT-RL increased by 62.8% and 4.4% respectively, and increased by 41.5% and 4.8% in leisure season respectively. Planting crop had a significant effect on greenhouse gas emissions. The N2O and CO2 emission fluxes of VRT-P increased by 78.2% and 41.9% respectively compared with VRT-FL, and TT-P significantly increased by 107.3% and 24.1% respectively compared with TT-FL. Therefore, vertical deep rotation tillage significantly increases the emission flux of soil greenhouse gases(N2O and CO2) due to the increase of soil temperature, humidity and the change of soil physical structure.