Impact of biochar on nitrate accumulation in an alkaline soil

Abstract

The effects of biochar on alkaline soils in high-yielding agricultural fields remain poorly understood. Nitrate variation in soils due to biochar application without a change in soil pH, is a great concern relating to both crop yield and nitrate leaching. In this study, we monitored changes in dynamics of soil nitrate accumulation and effects on grain yield due to biochar application in a temperate, high-yielding region. Biochar derived from corncob was applied to an alkaline soil at biochar rates (kg ha–1) of 0 (CK), 2250 (C1), and 4500 (C2) for each of two crop seasons in 2007. A treatment with 750 kg biochar-based fertiliser ha–1 (CN) for each of two crop seasons was also included. Biochar had no significant effect on soil water content to 1 m soil depth. Biochar tended to increase the soil cation exchange capacity (CEC) in the 0–20 cm soil layer and nitrate retention to 1 m soil profile, but there was no significant difference between biochar treatments and CK. Grain yield of C1, C2, and CN was improved by 10.3%, 16.9%, and 15.5% compared with CK, respectively, but only C2 was significantly different from CK. Grain yields of winter wheat with biochar application showed a trend similar to soil CEC and average soil-nitrate retention, suggesting that the increases in grain yield were mainly attributable to improvements in soil CEC and soil nitrate retention due to biochar application in the alkaline soil. In conclusion, the effects of biochar on soil water retention, soil nitrate retention, and grain yield were very limited in alkaline soil in a high-yielding region.

Biochar and its importance on nutrient dynamics in soil and plant

“…The availability of Ca, Mg, and S increased or decreased due to incorporation of biochar in soil, as shown in Table 5. A few studies (Lu et al 2014;Zhang et al 2013) state that biochar alters the bioavailability of trace elements in soils (Beesley et al 2011). For example, woody biochar improved the availability of micronutrients (B and Mo) (Hussain et al 2017); whereas, the addition of mixed hardwood-derived biochar did not influence the Cu and Zn content (Cai and Chang 2016).…”

Effect of Organic Inputs on Strength and Stability of Soil Aggregates Associated Organic Carbon Concentration under Rice-Wheat Rotation in Indo-Gangetic Plain Zone of India

“…Lu et al, (2014) recently concluded that biochar and residue amendment could enhance the readily oxidized C (measured by KMnO 4 oxidation). Zhang et al, (2013a) found that RDN+FYM application resulted in more nitrate in the upper 1 m of soil profile. Further study about residue and RDN+FYM-induced changes in soil biota (i.e., enzyme, microbial community) regarding soil N transformation (nitrification, denitrification) is needed, because the activity of enzymes involved in the N cycle could potentially be linked to N 2 O emissions (Wu et al, 2013;Harter et al, 2013).…”

Carbon mineralization and nutrient availability in calcareous sandy soils amended with woody waste biochar

“…Particularly, biochar can modify soil functions and act as a fertilizer (by saving nutrients), enhancing the efficiency of fertilizer use by improving the physical properties of soil and reducing the amount of nutrients leaching due to charge and the surface area characteristics of biochar (Chan and Xu, 2009). Impacts of biochar on high pH soils have been studied by some researchers (Zhang et al, 2013;Lentz and Ippolito, 2012;Artiola et al, 2012). The main problematic with applying biochar to arid soils having alkaline reaction may be due to its high pH.…”