Does Straw Return Strategy Influence Soil Carbon Sequestration and Labile Fractions?

Abstract

Core Ideas Returning crop residues increased maize and wheat yields. Returning crop residues increase soil organic carbon in the surface 20 cm. Returning crop residues increase several soil labile organic C fractions. The adoption of wheat straw return including stubbles 25–30 cm in height and maize straw return in combination with sub‐soiling is an optimal straw–return strategies for sustainable crop production. Returning the crop residues has been documented to increase soil carbon storage. However, the impacts of different straw return strategies on soil C fractions and sustainable crop productivity are not fully understood. Here, we investigated the impact of different residue management systems on grain yields, SOC sequestration, and soil C fractions in a wheat (Triticum aestivum L.)–maize (Zea mays L.) double cropping system over 6 yr. The straw return strategies included no straw return (CK), conventional wheat straw return (WC), modified wheat straw return (WM), conventional maize straw return (MC), modified maize straw return (MM), conventional straw return for both wheat and maize (WC+MC), and modified straw return for both wheat and maize (WM+MM). The annual average grain yields of maize and wheat when compared to crop residue removal were increased by 32.5 and 50.5% than when the wheat straw and corn stover was not harvested, respectively. Compared to the initial value, the SOC stock increased over a 6 yr by 16.4% period when the wheat straw and corn stover was not harvested. The concentrations of microbial biomass C, very labile C, labile C, KMnO4–oxidizable C, and C management index were increased by returning the crop residue. Overall, the results suggested that the integrated and modified return strategy of both wheat and maize straw is an optimal way of sustainable crop production under the intensive wheat–maize double cropping rotation in the North–central Plain of China.

Organic mulching promotes soil organic carbon accumulation to deep soil layer in an urban plantation forest

“…This result agrees with other studies, which demonstrated that straw mulch has no obvious effect on the labile SOC fractions over different periods of time and that the SOC content does not change with management practice over the short term because of a high background carbon concentration and spatial variability (Gu et al 2016;Zhang et al 2018). However, other studies have shown that both labile SOC fractions and carbon pool activity increase significantly after straw return under an annual wheat/maize rotation system (Dong et al 2018;Li et al 2019). The continuous application of straw mulch over time can increase soil carbon sequestration by increasing stable carbon fractions Fig.…”

The broad impacts of corn stover and wheat straw removal for biofuel production on crop productivity, soil health and greenhouse gas emissions: A review

“…Among environmental considerations for biomass harvest systems, one of the most important is the effect on soil quality parameters such as soil organic matter (SOM) and SOC, nutrient balances, soil pH, aggregate stability and water holding capacity (Chen et al., 2020; Guan et al., 2020; Kan et al., 2020; Li et al., 2019; Su et al., 2020; Susser et al., 2020).…”

Increasing soil organic carbon sequestration and yield stability simultaneously through combined no-tillage and straw return in wheat-maize rotation

“…The growth periods for wheat from mid-October to early June of next year, and for maize were from mid-June to early October. The high intensity with short time interval between wheat and maize growth periods in this agricultural system have been widely reported (Li et al, 2019). To achieve high grain yields, the excessive uses of mineral fertilizers and tillage, especially the plowing and rotary tillage, are indispensable (Yang et al, 2017;Xu et al, 2019).…”

“…On the one hand, frequent adoption of conventional tillage destroys soil structural stability, decreases the water holding capacity of soils, worsens the biological characteristics, and nutrient reserve and supply (Wang et al, 2011;Xu et al, 2019;Nouri et al, 2019). However, increasing evidences from manipulative experiments (Zhao et al, 2019a;Li et al, 2019) and meta-analyses (Zhao et al, 2019b;Jat et al, 2020) have showed that adopting conservation agriculture (CA) could improve soil quality and agricultural sustainability. The CA mainly consists of various reduced and even no-tillage techniques with more than 30% of crop residue retained on soil surface, providing effective strategies for combating soil degradation (Liu et al, 2020).…”

“…Under favorable conditions of water and fertilizer, the intensive field managements stimulate the degradation of plant residues and SOM, and thus result in SOC loss (Liu et al, 2014;Guan et al, 2020). For a long time, straw burning was adopted by farmers after crop harvest, which did not only lead to a waste of biomass resources, but also gave rise to an excessive emissions of greenhouse gases, and even left these regions in a thick haze (Hou et al, 2019;Li et al, 2019). As such, adopting sustainable, cleaner field management practices (i.e., conservation tillage and straw return) is essential to promote SOC sequestration and grain yields, thus attaining economic and environmental sustainability in grain production (Zhao et al, 2018a).…”