Effect of Land Use History and Pattern on Soil Carbon Storage in Arid Region of Central Asia

Abstract

The purpose of this study is to investigate variations in soil organic carbon (SOC) in arid areas due to differences in the cultivation history, land use, and soil salinization. The study area is the lower Sangong River basin on the piedmont of the northern TianShan mountains, which experiences heavy land-use activities. In 1982 and 2005,127(152) and 74 (161) samples in old (new) oasis were collected from each site at the surface soil (i.e., 0–20 cm). The data reveal that the mean value of the surface soil organic carbon content of the old oasis was higher than that of the new oasis by 4.01 g/kg in 1982 and 3.79 g/kg in 2005. Additionally, the soil organic carbon content decreased more rapidly in the newly reclaimed oasis than in the old oasis from 1982 to 2005. The spatial pattern of the SOC content was correlated with the exploitation time in the new oasis, the agricultural land use history, and the SOC content. The decreasing trend is clearer in the high SOC content area than in the low SOC content area. Farmland is the largest carbon pool in both the new and old oases. The carbon density of the old oasis was higher than that of the new oasis by 4.01 and 3.79 g/kg in 1982 and 2005 respectively. The loss of SOC in the agricultural watershed of the arid region in NW China is obvious. Improvements of land management practices, such as no tillage, straw returning to soil, and balanced fertilization techniques, should be adopted to increase the SOC content.

Factors Governing Total and Permanganate Oxidizable C Pools in Agricultural Soils from Southern Italy

“…Citrus cultivation provided values (46.9 Mg C ha −1 ) similar to those by Chiti et al [37] (44.1 Mg C ha −1 ), while Mediterranean natural land cover, consisting of scrub and garrigue, showed an intermediate C stock compared to arable and woody crops (44.3 Mg C ha −1 ) with lower values than Novara et al [44] (112 Mg ha −1 ), but similar to Alberti et al [50] (47.6 Mg ha −1 ) and Francaviglia et al [42] (40.6 Mg ha −1 in the 0-25 cm soil layer) falling within the range reported by Muñoz-Rojas et al [10] for this land use. As observed by Li et al [51], natural land cover showed higher TOC concentration than cropland. The higher TOC in natural areas can be associated with the larger annual addition of leaf litter combined with the absence of any soil disturbance such as tillage [52,53].…”

Humusica 1, article 2: Essential bases—Functional considerations

“…NIT-humus, naturally, seems always to be induced to grow, fast in temperate regions and more slowly under harsher climatic conditions. Soils submitted to traditional agriculture have lost 50 to 75% of their historical pool of organic matter in less than a century (Lal, 2007;Chan, 2008;Li et al, 2013;Schwartz, 2014). To stop this destructive process would be in negative contrast to this reported longterm trend.…”

Response of Carbon Dynamics to Climate Change Varied among Different Vegetation Types in Central Asia

“…Han et al [53] conducted an experimental study on fencing effects in a meadow steppe in Central Asia, however, their research is limited to only a few sites. Lee et al [54] and Li et al [55] examined the effects of environmental factors on soil organic carbon in Central Asia, without considering the above ground carbon dynamics. This study, focusing on the differences between the dominant vegetation types, could give guidance to stakeholders and decision makers in increasing the regional adaptive capacity to climate change.…”