What is the applicability of clean production technologies for maize as a countermeasure to reduce on-farm CO2 emissions and increase crop productivity?

Abstract

Agricultural production activities are the second-largest source of greenhouse gas emissions and one of the most significant sources of carbon emissions. The development of cleaner production in agriculture has become inevitable, focusing on the conservation of the ecological environment quality of the agroecological regions while maintaining sustained, stable, high productivity. Most previous studies failed to examine the quantitative effects of cleaner production methods on agricultural yields and CO2 emissions, focusing instead on the development of standardized technical frameworks and systems for cleaner production. Herein, a meta-analysis was used to evaluate the effects of fertilizer reduction and replacement, integrated straw usage, and water-saving irrigation methods on CO2 emissions and productivity of maize fields. We studied the practical applicability of cleaner production technologies in various regions of China to examine new models of cleaner production for maize cultivation. Our results show that the relationship between the adoption of maize cleaner production technologies and carbon reduction and yield increase is non-linear and influenced by many factors. Fertilizer reduction and substitution technology had the greatest effect on suppressing CO2 emissions from maize fields (−356%), while integrated straw usage technology brought about higher CO2 emissions from fields (434%) due to the return method and soil temperature. The adoption of both integrated straw usage technology (132%) and water-saving irrigation technology significantly increased maize productivity, with water-saving irrigation technology differentiating between the specific environment in which the technology was applied (90% for traditional irrigation and 229% for rainfed planting), and fertilizer reduction and substitution technology having no significant effect on changes in maize productivity. Combined with the practical applicability of cleaner production sub-technologies in maize cultivation, we identified the optimal maize cleaner production model as organic fertilizer substitution technology (proportion <50%) + straw charcoal return technology + sub-film drip irrigation technology (rainfed)/subsurface drip irrigation technology (traditional irrigation).