Impact of sole and combined application of biochar, organic and chemical fertilizers on wheat crop yield and water productivity in a dry tropical agro-ecosystem

Abstract

Agriculture under changing climate scenario is facing major challenges of water scarcity and resource imbalances. Crop water productivity (WP) may act as an indicator of crop responses to water limitation. Organic amendments such as biochar and manure application to soil are suggested for improving soil quality and reducing water requirements from agricultural sector. However, studies exploring the impact of biochar as sole or in combination with organic and/or chemical fertilizers on WP in dry tropical agro-ecosystems are limited. In this study, we observed the effect of rice-husk ash (RHA, biochar) along with farmyard manure (FYM) and chemical fertilizers (CF) under varying water conditions on soil hydro-physical properties, yield and WP of wheat crop. Water-filled pore space (WFPS), grain and straw yield, irrigation and total water productivity varied significantly (at P < 0.001) at treatment level. Grain and straw yield were found higher under sole and combined CF applied treatments. Sole and combined RHA and FYM amendment improved water holding capacity (WHC) and WFPS, whereas a decrease in crop yield was observed as compared to the control. Irrigation and total water productivity were found higher under combined RHA + FYM and sole CF treatments with reduced water supply (except sole CF) as compared to control and sole RHA treatments with full water irrigation. Crop water productivity was found positively correlated with grain and straw yields, however, significant correlations were not observed with WHC and WFPS. Results indicate that increasing soil hydro-physical properties in silty-loam soil may hinder crop yield and WP under sole biochar applied soils. Overall, the implications of the study would help in devising agro-management practices based on combined application of RHA and FYM with reduced chemical fertilizer and water inputs to mitigate the impacts of climate change without compromising crop yield in the highly vulnerable dry tropical agro-ecosystem of India. Moreover, long-term studies are needed in these ecosystems to identify the appropriate agricultural package for mitigating the forthcoming water scarcity conditions.

Application of biochar-based materials in environmental remediation: from multi-level structures to specific devices

“…The surface functional groups, which include aliphatic, aromatic, hydroxyl, carboxyl, carbonyl, amido, and azyl groups, could be determined by FT-IR (Uchimiya et al 2013), X-ray photoelectron spectroscopy (XPS) (Singh et al 2019), and NMR (Cao et al 2011). Some studies have investigated surface functional groups on biochars, such as carboxyl, carbonyl, phenolic -OH, and ester groups (Mao et al 2012;Rao et al 2011).…”

“…Biochar is a stable carbon-rich solid product obtained by pyrolysis of biomass under an oxygen-limited environment (Chen et al 2008;Lehmann 2007;Xiao et al 2018). Due to its inert carbon matrix, rich surface oxygen-containing functional groups, high surface area, and developed pore structure, biochar has shown great potential in carbon sequestration, greenhouse gas (CO 2 , N 2 O, and CH 4 ) emission reduction (Woolf et al 2010;Wang et al 2019b), soil improvement (Lehmann et al 2011;Weng et al 2017;Palansooriya et al 2019) and crop yield increase (Khan et al 2013;Singh et al 2019), which received increasing attention from scientists and policy makers around the world. In the terms of environmental remediation, Chen et al (2008) systemically investigated the sorption of organic pollutants by biochar pyrolysis at different temperatures, and they found that the adsorption mechanisms of biochars were evolved from partitioning-dominant at low pyrolytic temperatures to adsorption-dominant at higher pyrolytic temperatures.…”

Maize Growth and Yield Modelling Using AquaCrop Under Deficit Irrigation with Sole and Combined Application of Biochar and Inorganic Fertiliser

“…In this way, we could clearly delineate and provide clearer information of the contribution of each of the factors (biochar and fertiliser) to maize growth and yield. This becomes imperatives since the modelling approach is lagging in the growing body of knowledge on the roles of individual and combined application of biochar and inorganic fertiliser in improving crop growth and yield under water limiting conditions (Akhtar et al 2014;Agbna et al 2017;Singh et al 2019) and salinity stress (Kazemi et al 2019). In all irrigation treatments, the canopy cover (CC) was well predicted in the biochar-treated plots during the calibration and validation.…”

“…This has intensified the study of crop (maize) water productivity under deficit irrigation (Oktem 2008; El-Hendawy and Schmidhalter 2010; Karimi and Gomrokchi 2011;Talaat 2020). Moreover, soil amendments such as manure and inorganic fertiliser are being used to complementarily improve crop productivity in deficit irrigation practice (Reddy et al 2009;Singh et al 2019). But organic manure and inorganic fertiliser easily mineralise in soils.…”

“…It has the potential to sequester carbon in the soil and consequently mitigate climate change (Major et al 2010;Woolf et al 2010;Sohi et al 2010). Moreover, the use of biochar as a soil amendment has been reported to enhance soil water retention capacity (Gaskin et al 2010;Sohi et al 2010), which would invariably increase crop yield and water productivity, particularly in drought prone areas (Singh et al 2019). Due to the numerous advantages, the use of biochar offers in agriculture, particularly in 'degraded' and coarsetextured soils, studies on the effect of biochar on crop productivity, is also on the increase in the tropics, particularly in Nigeria (Ndor et al 2015;Fagbenro et al 2018;Adekiya et al 2019;Oladele et al 2019;Ullah et al 2019).…”