Potential benefits of liming to acid soils on climate change mitigation and food security

Abstract

Globally, about 50% of all arable soils are classified as acidic. As crop and plant growth are significantly hampered under acidic soil conditions, many farmers, but increasingly as well forest managers, apply lime to raise the soil pH. Besides its direct effect on soil pH, liming also affects soil C and nutrient cycles and associated greenhouse gas (GHG) fluxes. In this meta-analysis, we reviewed 1570 observations reported in 121 field-based studies worldwide, to assess liming effects on soil GHG fluxes and plant productivity. We found that liming significantly increases crop yield by 36.3%. Also, soil organic C (SOC) stocks were found to increase by 4.51% annually, though soil respiration is stimulated too (7.57%). Moreover, liming was found to reduce soil N 2 O emission by 21.3%, yield-scaled N 2 O emission by 21.5%, and CH 4 emission and yieldscaled CH 4 emission from rice paddies by 19.0% and 12.4%, respectively. Assuming that all acid agricultural soils are limed periodically, liming results in a total GHG balance benefit of 633−749 Tg CO 2 -eq year −1 due to reductions in soil N 2 O emissions (0.60−0.67 Tg N 2 O-N year −1 ) and paddy soil CH 4 emissions (1.75−2.21 Tg CH 4 year −1 ) and increases in SOC stocks (65.7-110 Tg C year −1 ). However, this comes at the cost of an additional CO 2 release (c. 624-656 Tg CO 2 year −1 ) deriving from lime mining, transport and application, and lime dissolution, so that the overall GHG balance is likely neutral. Nevertheless, liming of acid agricultural soils will increase yields by at least 6.64 × 10 8 Mg year −1 , covering the food supply of 876 million people. Overall, our study shows for the first time that a general strategy of liming of acid agricultural soils is likely to result in an increasing sustainability of global agricultural production, indicating the potential benefit of liming acid soils for climate change mitigation and food security.

Responses of soil pH to no‐till and the factors affecting it: A global meta‐analysis

“…Significant negative effects of acidification on soil nutrients under NT are highlighted in this meta-analysis. This observation also provides evidence in support of the hypothesis that accelerated soil acidification could degrade soil quality and undermine agronomic productivity (Deng et al, 2017;Donaldson et al, 2014;Meng et al, 2019;Wang et al, 2021). However, none of the obvious differences or relationships in changes of other indicators (i.e., crop yield and SOC) was observed with the change of soil pH in this meta-analysis.…”

“…As an effective and widely used solution to amend soil acidification, liming also offers potential benefits on mitigating climate change and sustaining food security (Wang et al, 2021). Indeed, the results presented herein indicate that adopted liming in NT and CT could increase soil pH by 0.17 and 0.22 units compared to the initial soil, respectively (Table S1).…”

Isotopic responses of magnesium to two types of dissolution-reprecipitation processes for the growth of the double-carbonate mineral norsethite

“…Carbonate is a ubiquitous material and plays an essential role in human society, such as construction, agriculture, and mechanical engineering (e.g., Børja and Nilsen, 2009;De Muynck et al, 2008;Gu et al, 2008;Jin and Yue, 2008;Wang et al, 2021). For a better interpretation of carbonate geochemical records and industrial applications, it is important to understand the mechanism that controls carbonate nucleation and growth.…”

Maintaining grass coverage increases methane uptake in Amazonian pasture soils

“…The effect of soil liming on methane fluxes is still poorly understood, and studies of temperate forests show that liming can lead to both an increase and a decrease of methane consumption (Wang et al 2021;Borken and Brumme, 1997;Butterbach-Bahl et al, 2002). In wheat-focused agriculture liming has led to an increased consumption of methane in soil (Hütsch et al, 1994).…”