Global-scale no-tillage impacts on soil aggregates and associated carbon and nitrogen concentrations in croplands: A meta-analysis

Peng Li; Duo Ying; Jing Li; Jianjun Deng; Chunkai Li; Shanyi Tian; Gen Zhao; Choufei Wu; Jiaguo Jiao; Min Jiang; Feng Hu

doi:10.1016/j.scitotenv.2023.163570

Global-scale no-tillage impacts on soil aggregates and associated carbon and nitrogen concentrations in croplands: A meta-analysis

Sci Total Environ. 2023 Jul 10:881:163570. doi: 10.1016/j.scitotenv.2023.163570. Epub 2023 Apr 17.

Authors

Peng Li¹, Duo Ying², Jing Li³, Jianjun Deng⁴, Chunkai Li⁴, Shanyi Tian⁵, Gen Zhao⁶, Choufei Wu⁷, Jiaguo Jiao⁸, Min Jiang⁹, Feng Hu⁴

Affiliations

¹ Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China; College of Resources and Environmental Sciences, Nanjing Agricultural University, Weigang, No. 1, Nanjing, Jiangsu 210095, China. Electronic address: pengli@zjhu.edu.cn.
² Institute of Maize and Featured Upland Crops, Zhejiang Academy of Agricultural Sciences, Dongyang 322100, China.
³ College of Geographical Science, Inner Mongolia Normal University, Hohhot 010022, China.
⁴ College of Resources and Environmental Sciences, Nanjing Agricultural University, Weigang, No. 1, Nanjing, Jiangsu 210095, China.
⁵ College of Resources and Environment, Southwest University, Chongqing 400716, China.
⁶ Huzhou Academy of Agricultural Sciences, Huzhou 313000, China.
⁷ Key Laboratory of Vector Biology and Pathogen Control of Zhejiang Province, College of Life Sciences, Huzhou University, Huzhou 313000, China.
⁸ College of Resources and Environmental Sciences, Nanjing Agricultural University, Weigang, No. 1, Nanjing, Jiangsu 210095, China. Electronic address: jiaguojiao@njau.edu.cn.
⁹ Changxing Natural Resources and Planning Bureau of Zhejiang, Changxing 313100, China. Electronic address: 76039318@qq.com.

PMID: 37076002
DOI: 10.1016/j.scitotenv.2023.163570

Abstract

No-tillage treatment, including no-tillage with straw retention (NTS) and without (NT), has been widely used as an efficient and sustainable alternative to conventional tillage with straw retention (CTS) and without (CT) and greatly affects soil physical quality and organic matter dynamics in cropland ecosystems. Although some studies have reported the effects of NTS on soil aggregate stability and soil organic carbon (SOC) concentration, the underlying mechanisms of how soil aggregates, aggregate-associated SOC and total nitrogen (TN) respond to no-tillage remain unclear. Through a global meta-analysis of 91 studies in cropland ecosystems, we evaluated the effects of no-tillage on soil aggregates and their associated SOC and TN concentrations. On average, no-tillage treatment significantly decreased the proportions of microaggregates (MA) by 21.4 % (95 % CI, -25.5 to -17.3 %) and silt+clay size particles (SIC) by 24.1 (95 % CI, -30.9 to -17.0 %), and increased the proportions of large macroaggregate (LA) by 49.5 % (95 % CI, 36.7-63.0 %) and small macroaggregate (SA) by 6.1 % (95 % CI, 2.0-10.9 %) compared to those in conventional tillage. The SOC concentrations for all three aggregate sizes increased significantly with no tillage: for LA by 28.2 % (95 % CI, 18.8-39.5 %), SA by 18.0 % (95 % CI, 12.8-23.3 %), and MA by 9.1 % (95 % CI, 2.6-16.8 %). TN also increased significantly for all sizes with no tillage, with LA by 13.6 % (95 % CI, 8.6-17.6 %), SA by 11.0 % (95 % CI, 5.0-17.0 %), MA by 11.7 % (95 % CI, 7.0-16.4 %), and SIC by 7.6 % (95 % CI, 2.4-13.8 %). The magnitude of the no-tillage treatment effect on soil aggregation, aggregate-associated SOC and TN varied with the environmental and experimental conditions. The positive effect on the proportions of LA occurred with initial soil organic matter (SOM) content >10 g kg^-1, whereas SOM <10 g kg^-1 did not change significantly. Additionally, the effect size of NTS compared with CTS was lower than that of NT compared with CT. These findings suggest that NTS may promote physically protective SOC accumulation through the formation of macroaggregates by reducing disturbance destruction and increasing plant-derived binding agents. The findings highlight that no-tillage may enhance the formation of soil aggregates and the associated SOC and TN concentrations in global cropland ecosystems.

Keywords: Aggregates; Meta-analysis; No-tillage; Soil carbon and nitrogen concentration; Straw retention.