Biochar amendment improves alpine meadows growth and soil health in Tibetan plateau over a three year period

Abstract

Previous biochar research has primarily focused on agricultural annual cropping systems with very little attention given to highly fragile, complex and diverse natural alpine grassland ecosystems. The present study investigated the effect of biochar on the growth of alpine meadows and soil health. This study was conducted in the Qinghai Tibetan Plateau over a three year period to investigate the effect of three rice husk biochar application rates alone and combination with high and low NPK fertilizer dosages on alpine meadow productivity, soil microbial diversity as well as pH, carbon and nitrogen content at 0-10 cm and 10-20 cm depth. At the end of the 3 rd year soil samples were analysed and assessed by combined analysis of variance. The results showed that biochar application in combination with nitrogen (N), phosphorus (P) and potassium (K) fertilizer had a significant increase in fresh and dry biomass during the second and third year of the study as compared to control and alone biochar application (p≤0.05). Biochar alone and in combination with NPK fertilizer resulted in a significant increase in the soil pH and carbon contents of the soil. XPS results, the SEM imaging and EDS analysis of aged biochar demonstrated that the biochar has undergone complex changes over the 3 years as compared to fresh biochar. This research suggests that biochar has positive effect on alpine meadow growth and soil health and may be an effective tool for alpine meadow restoration.

How biochar works, and when it doesn't: A review of mechanisms controlling soil and plant responses to biochar

“…Two studies identified the formation of porous organo‐mineral heterogeneous microagglomerates with mineral phases consisting of Fe, Al, Si oxides, phosphates (Ca/Fe/Al), carbonates (Ca/Mg), and chlorides (K, Na), and dimensions from 1 to 50 nm, bound together by organic compounds and bonded to the biochar surface (Archanjo et al, 2017; Rafiq et al, 2020). Simultaneous occurrence of Fe(II) and Fe(III) present as magnetite and hematite could make N and P more available through redox cycling of Fe (Haider et al, 2020).…”

“…In their meta‐analysis, Ye et al (2020) reported an increase in crop yield over multiple years after a single biochar application, where fertilizer was applied. Rafiq et al (2020) found that moderate rates (2–6 Mg ha −1 ) of rice husk (high ash) biochar applied with fertilizer gave a residual benefit for pasture yield, lasting at least 3 years, associated with enhanced microbial activity and diversity. Kumar, Elad, et al (2018) observed increased fruit yield and quality, and resistance to the pathogen causing powdery mildew and the arthropod pest broad mite, over three seasons in fertilized, irrigated peppers after application of greenwaste and woody biochars.…”

Biochar Aging: Mechanisms, Physicochemical Changes, Assessment, And Implications for Field Applications

“…Scanning electron microscopy (SEM) images revealing the surface morphology of fresh and aged biochars subjected to various aging methods. (a) Rice husk biochar, naturally aged for 3 years in the field . (b) Pine wood biochar formed during a wildfire event, naturally aged outdoors for 10 years without any contact with soil .…”

“…The blockage or fragmentation of the biochar structure will affect properties such as the surface area, pore volume and the pore diameter. It has been reported that 3 years of natural field aging in the Qinghai Tibetan Plateau caused the surface morphology of rice husk biochar to become much rougher and show signs of collapse (Figure a) . Even when biochar is not applied to soil, atmospheric oxidation can lead to much more irregular structures (Figure b) .…”

Sustainable soil use and management: An interdisciplinary and systematic approach

“…Because of its carbon negativity and beneficial properties for soil management, biochar has been proposed as a possible technology to help mitigate climate change (Woolf et al, 2010). Numerous studies have explored the usage of biochar in croplands (Laird et al, 2010b), while recent studies have also examined its application in other systems, such as alpine grassland (Rafiq et al, 2019).…”