Enhancing soil ecosystem multifunctionality through combined conservation tillage and legume-based crop rotation in the North China Plain

Abstract

Conservation agriculture (CA), based on principles of conservation tillage (CT) and crop rotations, has been adopted as a solution to global climate change. However, interactions between these principles and their cumulative effects on soil functions and crop productivity are not yet fully understood. Herein, a 4-year filed experiment was conducted to assess the impact of CA on soil ecosystem multifunctionality (EMF) in the North China Plain (NCP). The results showed that CA improved EMF by up to 532 % compared to traditional agriculture (rotary tillage under wheat and maize rotation system). This enhancement is mainly driven by a 12.3 % increase in soil organic carbon (SOC) storage, an 8.3 % reduction in soil carbon to nitrogen ratio (C: N), a 68.3 % boost in soil enzyme activities index (SEI), and a 59.7 % increase in available phosphorus (AP) under legume-based crop rotations (LBCR) compared to maize-wheat-maize-wheat (MWMW). The principle of CT improved soil physical structure, enhancing soil aggregate stability by up to 38.1 % compared to rotary tillage (RT). Although, the benefits of CT on crop yield were not always observed, positive interactions on crop yield occurred under LBCR combined with CT. For instance, the soybean-wheat-soybean-wheat (SWSW) rotation produced 40.8 % higher yields than the MWMW rotation under CT. Overall, benefits of CT in improving soil structure, along with the increased diversity crop residues, adjustments in soil nutrient stoichiometric ratios, and enhanced soil enzyme activity under LBCR, led to improved SOC sequestration, crop yield and EMF under CA. The positive interactions between the principles of CA demonstrate its ability to enhance ecosystem multifunctionality. As a result, the combination of CT and LBCR within CA is recommended to sustain the productivity in NCP and other regions with similar conditions.