Interactions between soil amendments shape nutrient availability in boreal forests

Résumé fourni par la source

The soils of mixed boreal forests can suffer a loss of productivity after logging, particularly when soil conditions are altered. Poor vegetation recovery may further lead to nutrient loss, despite increased availability following disturbance. This study investigated the effects of amendments on chemical properties of a plantation established on a site poorly regenerated by natural regeneration. Biochar (2.6 Mg ha⁻ 1 ), wood ash (7 Mg ha⁻ 1 ), and manure (105 Mg ha⁻ 1 ) were applied alone or in combination in a randomized complete block design. After two growing seasons, soil pH, total carbon, macro- and micronutrient concentrations, and CEC were measured in the mineral soil at two depths (0–15 cm and 15–30 cm). Biochar did not change total C and N but it decreased Al and CEC (-18%) and increased Mn (+ 52%). Wood ash increased soil pH (+ 7%), C/N (+ 12%) and P (+ 30%). Co-application of biochar and manure increased Mg exch (+ 106%). Wood ash increased Al (+ 26%) and decreased total N when combined with manure (-33%). Wood ash without manure increased CEC (+ 14%), but combined with biochar and manure, it decreased CEC (-26%). Finally, manure decreased total C (-18%), N (-28%), and several macro- and micronutrients, with stronger effects when combined with ash or in the absence of biochar. However, manure increased N availability, as suggested by a higher mineral/total N (+ 53%). This study highlights the potential of amendment combinations to improve soil fertility and underscores the complex interactions between amendments and their influence on soil chemistry.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.