Farmland Shelterbelt Changes in Soil Properties: Soil Depth-Location Dependency and General Pattern in Songnen Plain, Northeastern China

As one of the world’s largest ecological rehabilitation programs, three-north (Northern China, Northeastern and Northwestern China) shelterbelts program in China were not well evaluated on its effects multiple soil properties. This paper aims to quantify this. Seven hundred twenty soils from paired plots farmlands neighbor sampled six regions Songnen Plain northeastern China. Multivariate analysis variance regression used detect impacts shelterbelt plantations. For overall 1 m profiles, plantations had a 4.3% 7.4% decreases bulk density moisture (p = 0.000), 4.8% increase porosity 0.003). It also evidently recovered fertility with 40% total P, 4.4% K, 15.1% available K < 0.05). However, without changes SOC N > Compared farmland, produced 7.8% 20–40 cm much more minor surface (0–20 cm). younger plantation, mature tended sequestrate (from 0.11% decrease 3.31% increase) recover 2.24% decline 16.5% increase. Correlation manifested that there is significant relationship between sequestration density, porosity, moisture, pH, EC, N, alkaline hydrolyzed N. In contrast, strongest was observed (r 0.50, p 0.001). The accompanied by 1.01–1.67-fold higher deep >20 poplar forests. Our results highlight over-40-year afforestation farmland could strongly affect physics, water, nutrient P K. dependent depths, growth stages, regions. data support precise evaluation agroforestry projects black region high-latitude northern hemisphere.