水保所知识产出(1956---)知识库

Afforestation plays an important role in soil carbon storage and water balance. However, there is
a lack of information on deep soil carbon and water storage. The study investigates the effect of
returning farmland to the forest on soil carbon accumulation and soil water consumption in 20‑m deep
soil profile in the hilly and gully region of the Chinese Loess Plateau. Four sampling sites were selected:
Platycladus orientalis (Linn.) Franco forest (PO: oriental arborvitae), Pinus tabulaeformis Carr. Forest
(PT: southern Chinese pine), apple orchard (AO) and farmland (FL, as a control). Soil organic carbon
(SOC) and soil inorganic carbon (SIC) content were measured in 50‑cm sampling intervals of 20‑m
soil profiles, as well as the associated factors (e.g. soil water content). The mean SOC content of PT
was the highest in the 1–5 m layer and that of FL was the lowest (p < 0.05). Compared with FL, the
SOC storages of PO, PT and AO increased by 2.20, 6.33 and 0.90 kg m −2 (p > 0.05), respectively, in
the whole profile. The SIC content was relatively uniform throughout the profile at all land‑use types
and SIC storage was 9–10 times higher than SOC storage. The soil water storage of PO, PT and AO
was significantly different from that of FL with a decrease of 1169.32, 1161.60 and 1139.63 mm,
respectively. After the 36‑yrs implementation of the “Grain for Green” Project, SOC in 20 m soil
profiles increased as a water depletion cost compared with FL. Further investigation is still needed to
understand the deep soil water and carbon interactions regarding ecological restoration sustainability
in the Northern Loess Plateau.