Long‐term cultivation of Miscanthus and switchgrass accelerates soil organic carbon accumulation by decreasing carbon mineralization in infertile red soil

Abstract

Perennial energy crops (PECs) such as Miscanthus spp. and switchgrass (Panicum virgatum L.) may have particular influence on microbial communities and their functions in soil organic carbon (C) utilization and mineralization (Cm). In this study, long‐term effects of PECs on Cm and soil hydrolase activities were examined in bulk and rhizosphere soils of Miscanthus and switchgrass grown on a red soil in South China. Long‐term cultivation (10 years) of PECs led to increases in soil organic C (SOC) and the absolute Cm of bulk and rhizosphere soils. Total Cm was correlated with dissolved organic C and dissolved organic nitrogen (N) in red soils. The specific Cm in bulk soils of switchgrass and Miscanthus were decreased by 11.73% and 20.67% comparing with the control group, respectively. Cultivation of PECs led to a relatively high C/N ratio. There was a difference in priming effect on activities of β‐glucosidase (BG), leucine amin peptidase, N‐acetyl‐β‐glucosaminidase (NAG), and phosphatase between rhizosphere and bulk soils. Compared with the control without PECs, BG activity did not change significantly in bulk soils of PECs, whereas NAG activity decreased significantly. Soil microorganisms were generally limited by soil C and phosphorus (P) in the red soil. The C and P limitations were significantly linearly related with relative Cm (p < 0.05). Phosphorus limitations in microbial communities were lower with PECs than in the control, indicating that cultivation of PECs could provide an optimal nutrient environment for both plants and microorganisms. Thus, long‐term cultivation of PECs increased SOC content but decreased specific Cm rates. However, because C and P limitations remain for plants and soil microbial communities, optimum fertilization is also necessary for sustainable growth of PECs on red soils.

Early production of switchgrass (Panicum virgatum L.) and willow (Salix spp.) indicates carbon accumulation potential in Appalachian reclaimed mine and agriculture soil

“…Our research provides evidence that net soil C sequestration may be possible in the early establishment years on especially degraded land like reclaimed mine soil. Looking toward stand maturation, which often occurs after three to four growing seasons (Kopp et al., 2001; Skousen et al., 2014), our regression results suggest that the stable C pool in the soil (MAOM) will increase if certain soil chemical and biological properties measured here (i.e., BG, POXC, microbial respiration, and MAOM C:N) continue to increase as demonstrated in previous research (Ferrarini et al., 2021; Fu et al., 2022; Kantola et al., 2017). It is likely that longer term bioproduct crop production can result in C sequestration (Blanco‐Canqui, 2016; Ma et al., 2000; Rytter et al., 2015) with higher potential in mine soils.…”

Effects of soil physics, chemistry, and microbiology on soil carbon sequestration in infertile red soils after long‐term cultivation of perennial grasses

“…Our results suggest that the cultivation of PECs may be a promising managerial strategy to facilitate the enhancement of SOC stock in acidic infertile soils (Fu, Xu, Hou, et al, 2022; Xu et al, 2021). The following underlying mechanisms may explain our findings.…”

“…The 0–20 cm topsoil samples for MS, SG, SA, and CK were collected in January 2021, corresponding to 10 years of cultivation. Soil samples of SG and SA were obtained as follows: eight soil cores (0–20 cm) of each plant were collected from the plant center using a soil auger (5‐cm diameter) at 10 and 50 cm in each direction (east, west, south, and north), which were then mixed to obtain a composite sample (Fu, Xu, Hou, et al, 2022; Martani et al, 2021). Soil samples of MS were collected from five plants within a plot, randomly selected in an “S” pattern.…”

“…The mitigation of greenhouse gas (GHG) emissions is considered a global issue of the 21st century (IPCC, 2002). An increase in global GHGs is predicted to increase future atmospheric temperatures, with current research focusing on reducing GHG emissions and thereby increasing carbon sequestration in terrestrial ecosystems (Fu, Xu, Hou, et al, 2022; Xu et al, 2021). Agriculture is one of the most important sectors that contribute to the global carbon (C) pool and accounts for a substantial fraction of food production (Rumpel et al, 2018; Smith et al, 2016).…”

Nitrogen acquisition and retention pathways in sustainable perennial bioenergy grass cropping systems

“…However, it is important to note that high mineralization rate leads to the active mining of SOM reserves, posing a sustainability issue for long‐term cultivation. Intriguingly, however, research also suggests that perennial tall grasses can delay N depletion in soil by counterbalancing the enhanced mineralization rates through increased SOM stocks (Fu et al., 2022; Schittenhelm et al., 2021), which can be further facilitated by biological N fixation.…”