Maize/peanut intercropping has greater synergistic effects and home-field advantages than maize/soybean on straw decomposition

Abstract

IntroductionThe decomposition of plant litter mass is responsible for substantial carbon fluxes and remains a key process regulating nutrient cycling in natural and managed ecosystems. Litter decomposition has been addressed in agricultural monoculture systems, but not in intercropping systems, which produce species-diverse litter mass mixtures. The aim here is to quantify how straw type, the soil environment and their combined effects may influence straw decomposition in widely practiced maize/legume intercropping systems.MethodsThree decomposition experiments were conducted over 341 days within a long-term intercropping field experiment which included two nitrogen (N) addition levels (i.e. no-N and N-addition) and five cropping systems (maize, soybean and peanut monocultures and maize/soybean and maize/peanut intercropping). Experiment I was used to quantify litter quality effects on decomposition; five types of straw (maize, soybean, peanut, maize-soybean and maize-peanut) from two N treatments decomposed in the same maize plot. Experiment II addressed soil environment effects on root decomposition; soybean straw decomposed in different plots (five cropping systems and two N levels). Experiment III addressed ‘home’ decomposition effects whereby litter mass (straw) was remained to decompose in the plot of origin. The contribution of litter and soil effects to the home-field advantages was compared between experiment III (‘home’ plot) and I-II (‘away’ plot).Results and discussionsStraw type affected litter mass loss in the same soil environment (experiment I) and the mass loss values of maize, soybean, peanut, maize-soybean, and maize-peanut straw were 59, 77, 87, 76, and 78%, respectively. Straw type also affected decomposition in the ‘home’ plot environment (experiment III), with mass loss values of maize, soybean, peanut, maize-soybean and maize-peanut straw of 66, 74, 80, 72, and 76%, respectively. Cropping system did not affect the mass loss of soybean straw (experiment II). Nitrogen-addition significantly increased straw mass loss in experiment III. Decomposition of maize-peanut straw mixtures was enhanced more by ‘home-field advantage’ effects than that of maize-soybean straw mixtures. There was a synergistic mixing effect of maize-peanut and maize-soybean straw mixture decomposition in both 'home' (experiment III) and ‘away’ plots (experiment I). Maize-peanut showed greater synergistic effects than maize-soybean in straw mixture decomposition in their 'home' plot (experiment III). These findings are discussed in terms of their important implications for the management of species-diverse straw in food-production intercropping systems.

Effects of Fertilization Practices on the Metabolic Functions of Soil Microbial Communities under Subsurface Irrigation with Stalk Composite Pipe

“…It is also possible that this is because when straw quality was low (e.g., high lignin content), N addition inhibited straw decomposition. Conversely, when straw quality was high, N addition enhanced straw decomposition [50].…”

Promotion of Maize Straw Degradation Rate by Altering Microbial Community Structure through the Addition of Soybean Straw

“…The organic carbon in the straw breaks down into readily degradable components (such as starch and glucose) and more resistant components (such as lignin). Soybean straw contains more easily degradable parts, whereas maize straw has more resistant components (Surigaoge et al, 2023). During the early stages of incubation, readily decomposable crop residues were broken down rst, boosting soil microbial growth, releasing substantial nutrients, and signi cantly enhancing CO 2 emission (Gezahegn et al, 2019).…”

An optimal combined slow-release nitrogen fertilizer and urea can enhance the decomposition rate of straw and the yield of maize by improving soil bacterial community and structure under full straw returning system

“…To address these issues, nitrogen fertilizer can be used to effectively regulate the C/N ratio after straw is returned to a field. This helps improve microbial activity ( Zhang et al, 2022 ; Surigaoge et al, 2023 ), promote straw decomposition, and provide sufficient nitrogen fertilizer for crops. Previous studies have primarily focused on the effect of common urea fertilizer on straw decomposition ( Liu et al, 2021 ; Mühlbachová et al, 2021 ).…”