After-Effects of Hydrochar Amendment on Water Spinach Production, N Leaching, and N₂O Emission from a Vegetable Soil under Varying N-Inputs

Abstract

Biochar use in agriculture brings significant agronomic and environmental co-benefits, which are a function of biochar and crop types and nitrogen (N) rates. We here conducted a soil column experiment to evaluate the after-effects of hydrochar amendment at 0.5 and 2.0 wt% on vegetable production, N recovery and losses via leaching and nitrous oxide (N2O) emission from water-spinach (Ipomoea aquatica Forsk)-planted vegetable soil receiving three N inputs (120, 160, and 200 kg/ha). The results showed that hydrochar with 2.0 wt% significantly (p 4+, NO3− and total N concentrations in leachate. When applied at 2.0 wt%, hydrochar significantly (p 2O emissions by 109–133% under 200 kg N/ha but decreased them by 46–67% under 160 kg N/ha. Therefore, after three years of application, hydrochar still improves the production of leafy vegetable, but the impacts on N leaching and N2O emission vary, depending on inorganic N and hydrochar application rates.

Keywords

• biochar
• leachate
• N losses
• nitrous oxide
• vegetable production