氮肥与有机肥配施对设施土壤呼吸的影响

Effect of Combined Application of Nitrogen Fertilizer and Manure on soil Respiration in Greenhouse Cultivation

依托设施番茄栽培连续3年田间施肥定位试验,利用田间原位土壤呼吸测定法,研究了施氮量0、187.5、375.0、562.5 kg hm^(-2)(N0、N1、N2、N3)及氮肥与有机肥(M:75000 kg hm^(-2))配施(MN0、MN1、MN2、MN3)对土壤日呼吸速率的动态变化和累积呼吸量的影响,并分析了影响土壤呼吸的因素。结果表明:在番茄生长期内,各处理土壤日呼吸速率的动态变化趋势基本一致,番茄生长前期,各施肥处理土壤日呼吸速率较小且变动较小,生长64 d后,各施肥处理土壤日呼吸速率随生长天数的延长呈快速增加趋势,82 d时达最大峰值,之后则呈现下降趋势,但仍维持较高的数值;与单施氮肥处理相比,氮肥与有机肥配施可提高土壤日呼吸速率,并极显著提高土壤呼吸累积量(P<0.01),在施氮处理中,N1处理土壤呼吸累积量显著高于其它4个处理,而氮肥与有机肥配施处理中,施氮量对土壤呼吸累积量影响不显著。各处理5 cm、10 cm、15 cm处土壤温度与土壤日呼吸速率之间均呈显著指数相关性(P<0.05或P<0.01),敏感系数Q10值均随土层深度的增加呈增大趋势,其中,N1(187.5 kg hm^(-2))和MN1处理土壤日呼吸速率对温度的敏感性较强;表层(0~10 cm)土壤容重、pH值和有机碳含量与土壤呼吸累积量之间均有显著线性关系(P<0.05)。本试验条件下,连续有机肥与氮肥配施,可显著提高土壤呼吸,促进CO2排放。

This study used the field fertilization experiment facilities growing tomato for three consecutive years. Eight treatments were set up according to nitrogen application rates 0, 187.5, 375.0, and 562.5 kg hm-2 （NO , N1 , N2 , N3） and combinations of nitrogen and organic manure fertilizers （M： 75000 kg hm^-2） （MN0, MN1, MN2, MN3）. We studied the dynamic changes of soil respiration rate under different fertilization treatments in the tomato growth period using the alkili absorption method, The results showed as follows： In the tomato growth period, the trend of dynamic change of soil respiration rates were basically the same in different fertilization treatments. In the early growth stage, soil respiration rate for each treatment was smaller than in the later stages. After 64 d, the diurnal soil respiration rate of each treatment increased with the lengthening of growing days. It reached a maximum peak on day 82 and then showed a downward trend. Compared to nitrogen manure improved diurnal soil respiration rates, and 0.01）. In mere nitrogen application treatments, the treatments, the combinations of nitrogen fertilizer and organic increased soil respiration cumulative amount significantly （P 〈 cumulative soil respiration amount of N1 （187.5 kg hm^-2） was significantly higher than the other four treatments, while in the combined treatments, nitrogen application rates had no effect on cumulative soil respiration amount. There was a significant exponential correlation between temperature in 5 cm, 10 cm, and 15 cm soil layers and daily respiration rate （P 〈 0.05 or P 〈 0.01）. The Q10 values increased with increasing soil depth. There were significant linear relationships （P 〈 0.05） between soil bulk density in the surface layer （0 - 10 cm）, pH, and organic carbon content and soil respiration. In conclusion, continuous application of organic fertilizer and nitrogen fertilizer could significantly increase soil respiration and promote CO2 emission.