Evolution of Soil Carbon Storage and Morphometric Properties of Afforested Soils in the U.S. Great Plains

Abstract

The objective of this project was to use detailed soil profi le descriptions and soil carbon analyses to determine the soil C sequestration potential of tree planting across climatic gradients in the U.S. Great Plains. Tree windbreak age ranged from 19 to 70 years and age of cultivation from 22 to ~110 years. At each site, soil pits were prepared within the tree planting, the adjacent crop fi elds, and nearby undisturbed grassland. Windbreak soils had consistently thicker soil organic carbon (SOC)-enriched A or A+AB horizons when compared to the crop fi elds. The thickness of A or A+AB horizons in the windbreak soils were comparable to the undisturbed grassland soils. A linear relationship was detected between the difference in A+AB thickness of soils beneath windbreaks and undisturbed grasslands and a climate index (hydrothermal coeffi cient, HTC). These results indicate that tree windbreaks with more cool and moist climate conditions are more favorable for SOC accumulation in the surface soil. The relationship between SOC accumulation and climate factors enables the estimation of soil carbon stocks in existing windbreaks and the prediction of potential carbon sequestration of future plantings. Abstract The objective of this project was to use detailed soil profi le descriptions and soil carbon analyses to determine the soil C sequestration potential of tree planting across climatic gradients in the U.S. Great Plains. Tree windbreak age ranged from 19 to 70 years and age of cultivation from 22 to ~110 years. At each site, soil pits were prepared within the tree planting, the adjacent crop fi elds, and nearby undisturbed grassland. Windbreak soils had consistently thicker soil organic carbon (SOC)-enriched A or A+AB horizons when compared to the crop fi elds. The thickness of A or A+AB horizons in the windbreak soils were comparable to the undisturbed grassland soils. A linear relationship was detected between the difference in A+AB thickness of soils beneath windbreaks and undisturbed grasslands and a climate index (hydrothermal coeffi cient, HTC). These results indicate that tree windbreaks with more cool and moist climate conditions are more favorable for SOC accumulation in the surface soil. The relationship between SOC accumulation and climate factors enables the estimation of soil carbon stocks in existing windbreaks and the prediction of potential carbon sequestration of future plantings.

The role of soil carbon in natural climate solutions

“…Note that windbreaks and alley cropping were applied to non-African croplands to avoid double counting with farmermanaged natural regeneration. Estimates of soil carbon accumulation derive from a literature review around the soil benefits of windbreaks, or shelterbelts based [63][64][65] and alley cropping [66][67][68] . We estimate that windbreaks capture an additional 0.69 Mg C ha -1 yr -find independent estimates of soil carbon accumulation for farmer managed natural regeneration, we assumed 25% of the mitigation potential was attributable to soil accumulation, averaging together the proportion of mitigation potential for alley cropping and windbreaks.…”

Sugar Beet Harvests under Modern Climatic Conditions in the Belgorod Region (Southwest Russia)

“…The Hydrothermal Coefficient (HTC) is also an indicator of moisture content published by the Soviet climatologist G. T. Selyaninov [23]. The HTC is determined by the ratio of the precipitation amount (r) (mm) during the period with average daily air temperatures above 10 • C to the sum of temperature ( T*) during the same time-period (multiplied by 0.1), that is: The HTC is one of the indicators of agricultural growth in different parts of the world (e.g., [14] and [24][25][26]). As an important agro-climatic indicator that defines the resource and energy demands of crops, the period when the daily mean temperature greater than 10°C is a viable baseline because it describes the period of active vegetation for a majority of plants, including sugar beets.…”

“…In particular, the BCP is the ratio of the sum of the average daily temperatures over the period of active vegetation ( o C) to the analogous sum for a reference region ( o C), multiplied by the coefficient reflecting the influence of moisture (moisture index) on agricultural yield. The formulae are: The HTC is one of the indicators of agricultural growth in different parts of the world (e.g., [14,[24][25][26]). As an important agro-climatic indicator that defines the resource and energy demands of crops, the period when the daily mean temperature greater than 10 • C is a viable baseline because it describes the period of active vegetation for a majority of plants, including sugar beets.…”

“…Meteorological data were also used to calculate the two additional climatic indexes connected to agricultural productivity such as the BCP (see [14] or [24][25][26]) index and the moisture index (C p ). The moisture index is actually part of the calculation of the BCP (2a).…”

Nonlinear turnover rates of soil carbon following cultivation of native grasslands and subsequent afforestation of croplands

“…6). Conversely, loss rates of remaining prairie-C in afforested soils appeared to be mostly contextual and even site specific, likely as a function of local hydrothermal conditions (Chendev et al 2014(Chendev et al , 2015b.…”