Impact of land use reformation on soil hydraulic properties and recovery potential of conservation tillage in India's North-West Himalayan region

Degradation of soil hydro-physical properties resulted from inappropriate land management, require a resilient management system to check further degradation. Hence, understanding soil hydraulic properties (SHPs) of various land-use regimes may aid in the long-term management of ecologically sensitive and vulnerable agroecosystems. The study looked at influence of land-use conversion from native forest land to subsequent agricultural practices on SHPs in India's N-W Himalayan area, one of the world's most susceptible agroecosystems. Moreover, the water-conducting porosity at different pressure heads and the contribution of macro and mesopores to saturation flow were quantified. For this purpose, the infiltration rate and soil hydraulic conductivity of surface soil were investigated for sal forest, conventional tillage (CT), reduced tillage (RT), and zero tillage (ZT) using the hood infiltrometer at three pressure heads. The forest land use showed the highest value followed by ZT, RT, and CT respectively for soil hydraulic conductivity, tension and residual flux potential, flow-weighted mean pore radius, and hydraulically active porosity. Additionally, the macropores contributed 61.99–73.44 % of total water flow, while the meso-micropores contributed 26.56-38.01 % of total flow across the land uses. In the water-conducting process in all land use systems, macropore's contribution was relatively higher, which comprised only small space of total soil volume, signifies its importance. Further, scatter plot matrix depicted that, mean weighted diameter (MWD), and soil organic carbon (SOC) are dominating factors controlling hydraulic conductivity. The findings strongly suggest that, while conversion of native forest land to conventional agriculture degrades soil hydraulic characteristics, SHPs may be progressively recovered in the Himalayan region by adopting conservation agriculture strategies.