Spatial and Temporal Variability of Soil Respiration between Soybean Crop Rows as Measured Continuously over a Growing Season

Abstract

An improved understanding of temporal and spatial variations in soil respiration is essential for measuring soil CO 2 effluxes accurately. In this study, a field experiment was conducted to investigate the spatial and temporal variability of soil respiration between adjacent crop rows in a soybean (Glycine max L.) field. Soil CO 2 concentration, water content, and temperature at a 7.5 cm depth were recorded continuously at 0 cm, 12 cm, 24 cm, and 35 cm from the plant row during the growing season. Root biomass at the corresponding locations was collected from the 0 to 10 cm and 10 to 20 cm soil layers at three growth stages. Seasonal CO 2 efflux data showed that the minimum value appeared at the seeding stage, increased gradually, reached the maximum at the flowering and grain-filling stages, and then dropped steadily at the mature stage. Within a growth stage, CO 2 effluxes related positively to soil temperature, but negatively to soil water content. In the early and vigorous growing stages of soybean crop, soil respiration showed apparent diurnal variations, and was most significant at the crop row location. Except for the seeding stage, CO 2 effluxes at the crop row were larger than that of other locations, and effluxes at 35 cm from the row were representative of the mean CO 2 efflux between adjacent rows. We concluded that the spatial heterogeneity of CO 2 efflux between crop rows should be taken into consideration when measuring soil respiration in agricultural ecosystems.

Stylo grass affecting soil respiration in latosol guava orchard of southern subtropical region of China

“…(2016) and Gu, Zhou, Zhou, Smaill, and Clinton (2020) found that soil temperature, rather than soil moisture, mainly control the soil respiration. Wang and Ren (2017) found that CO 2 effluxes related positively to soil temperature, but negatively to soil water content within a growth stage in a soybean ( Glycine max L.) field. Zhang, Zhao, Fu, Zhao, and Jia (2020) reported that soil respiration was sensitive to a single factor, soil temperature, in the wetland and desert shrubland of Northwest China.…”

Soil carbon dioxide emissions in a sorghum field: Row position and growth stage effects

“…Such hysteresis was associated with microbial population dynamics and/or litter input (Jia et al., 2013). Few, if any, reports of growth stage effect on SCE exists for crops (Dhadli, Brar, & Black, 2015; Wang & Ren, 2017; Wang et al., 2019). The growth stage effect in sweet sorghum in this study (northern Alabama) was not observed in corn in the midwestern United States (Iowa; Sauer, unpublished data, 2008–2009).…”