Short Term Effects of Revegetation on Labile Carbon and Available Nutrients of Sodic Soils in Northeast China

Abstract

In response to land degradation and the decline of farmers’ income, some low quality croplands were converted to forage or grassland in Northeast China. However, it is unclear how such land use conversions influence soil nutrients. The primary objective of this study was to investigate the influences of short term conversion of cropland to alfalfa forage, monoculture Leymus chinensis grassland, monoculture Leymus chinensis grassland for hay, and successional regrowth grassland on the labile carbon and available nutrients of saline sodic soils in northeastern China. Soil labile oxidizable carbon and three soil available nutrients (available nitrogen, available phosphorus, and available potassium) were determined at the 0–50 cm depth in the five land uses. Results showed that the treatments of alfalfa forage, monoculture grassland, monoculture grassland for hay, and successional regrowth grassland increased the soil labile oxidizable carbon contents (by 32%, 28%, 15%, and 32%, respectively) and decreased the available nitrogen contents (by 15%, 19%, 34%, and 27%, respectively) in the 0–50 cm depth compared with cropland, while the differences in the contents of available phosphorus and available potassium were less pronounced. No significant differences in stratification ratios of soil labile carbon and available nutrients, the geometric means of soil labile carbon and available nutrients, and the sum scores of soil labile carbon and available nutrients were observed among the five land use treatments except the stratification ratio of 0–10/20–30 cm for available phosphorus and the values of the sum scores of soil labile carbon and available nutrients in the 0–10 cm depth. These findings suggest that short term conversions of cropland to revegetation have limited influences on the soil labile carbon and available nutrients of sodic soils in northeastern China.

Soil organic matter fractions and carbon distribution under different management in Lesotho, southern Africa

“…The variability in SOC and STN among the depths studied could be related to crop residue accumulation on the soil surface and crop roots exudates (Brar et al., 2013; Kaur et al., 2008). Improvements in agronomic practices such as, but not limited to, increasing cropping intensity, enhancing land sustainability, increasing chemical fertilizer addition, and improving crop residue management, contributed to increased C and N inputs and enhanced SOC and STN levels (Amanuel et al., 2018; Li et al., 2020; Yu et al., 2020). The data generated from this study supported our hypothesis that the high N rate with NT contributes to the enhancement of SOC and STN, but not with MP practice and with low N addition rate.…”

Changes in Storage and the Stratification Ratio of Soil Organic Carbon under Different Vegetation Types in Northeastern China

“…Therefore, the dominant native species Leymus chinensis (Trin.) Tzvel covered the whole area, and other vegetation communities were very limited in the study area before the 1960s [16]. Due to the influences of grazing, trampling, and mowing, the vegetation cover decreased in the study area after the 1960s, which then substantially accelerated land salinization in the surface soil.…”

“…After removing the visible plant materials, these disturbed soil samples were sieved through a 0.25-mm mesh for determining the SOC concentration. The SOC concentration was determined using the K 2 Cr 2 O 7 -H 2 SO 4 oxidation method [16]. Soil bulk density (BD) at each depth in each sampling plot was measured using the core method described by Blake and Hartage [28].…”

“…Soil bulk density was measured using soil cores (volume, 100 cm 3 ) with five replicates for each vegetation type. Soil pH was measured using a PHS-3C instrument (INESAS Scientific Instrument Co., Ltd., Shanghai, China), and electrical conductivity (EC) was measured using a DDS-307 instrument (INESAS Scientific Instrument Co., Ltd., Shanghai, China) in a 1:5 soil/water solution [16].…”

Long-term warming does not affect soil ecoenzyme activity and original microbial nutrient limitation on the Qinghai—Tibet Plateau

“…generally show stratification at different depths and consequently, the soil stratification ratio (SR) is used widely as a key indicator of soil conditions (Yu et al, 2020). Temperature changes affect the surface soil first and then gradually affect the deeper soil, although the effect of warming on the soil is weakened with soil depth because of the soil buffer and barrier effect (Fierer et al, 2003;Bai et al, 2019).…”