Biochar has Different Effects on Soil Fertility and Spring Barley Productivity in Two Boreal Soils with Contrasting Textures
摘要
This study examined the effects of wood biochar and fertilizers on the agrochemical parameters of boreal soils and the growth and development of spring barley. Short-term, 6-week pot experiments were conducted using the sandy loam Umbric Podzol and clay loam Umbric Retisol. For each soil type, a completely randomized design was applied with two fractions of biochar and two different fertilizers in triplicate. In soil samples were measured pHKCl, available P and K, N–NH4+ and N–NO3− after the completion of the experiment. The linear growth and productivity of spring barley and the raw protein content in aboveground biomass were studied. Biochar application to a sandy loam Umbric Podzol resulted in a significant increase in soil pH of 0.5 units, relieving acidity and increasing potassium content by an average of 17 mg kg−1, phosphorus by 7 mg kg−1, and nitrate nitrogen by 4 mg kg−1. Biochar enhanced linear growth, spring barley biomass yield, and raw protein content in the aboveground biomass. The fine fraction of biochar combined with NPK fertilizer exerted the most pronounced synergistic effect on almost all parameters. Applying the same experimental scheme to the clay loam Umbric Retisol slowed the growth and development of spring barley plants and reduced the average nitrate nitrogen content by 4–7 mg kg−1, creating conditions conducive to denitrification. Biochar supplemented with low-dose NPK fertilizer serves as a source of plant nutrients and an ameliorant in low-fertile coarse-textured soils. Nitrogen availability in the fine-textured soils appeared lower, potentially affecting the biochar-NPK synergy. These features can be particularly pronounced under boreal conditions with increased humidity.