水保所知识产出(1956---)知识库

Purpose Organic amendment applications have been proposed as important agricultural management practices for the
maintenance of soil health. Weathered coal (WC), biochar (BC), and grass peat (GP) have been used widely and globally for
a long time. However, the differences in soil physical properties following the application of these amendments have rarely
been evaluated under the same field conditions.
Methods In this study, the changes in the physical properties of loamy clay soil after applying WC, BC, and GP (3%, w:w)
were investigated under field conditions after 375 days.
Results Relative to unamended soil, the WC, BC, and GP applications increased the total porosity and decreased the bulk
density of amended soils (P < 0.05). The soil water content increased by 23.8% following the BC application, whereas it was
decreased by 10.5% following the GP application (P < 0.05). The application of all the amendments increased the soil average
temperature by 0.71 °C (GP), 0.41 °C (WC), and 0.18 °C (BC) (P < 0.05). Additionally, the WC application increased the
fraction of aggregates of 1–2 mm in size (by 47.6%) and of 2–5 mm in size (by 65.8%), and the stability of soil aggregates
(P < 0.05). All the amendments increased the soil pores (> 300 and 30–300 µm) of amended soils, but the saturated hydraulic
conductivity of these soils was not significantly improved.
Conclusion The application of WC can improve the formation and stability of soil aggregates to reduce the risk of soil
erosion. BC is suitable for use in drought-prone areas with low rainfall and strong evaporation because it can increase the
retention capacity of soil water. GP should be applied with caution, considering that its decomposition after extraction leads
to the severe loss of organic carbon to the atmosphere. Overall, the selection of organic amendments in agricultural manage-
ment practices should take into account the local environmental conditions.