Surigaoge Surigaoge, Yang Hao, Su Ye, Du Yu-He, Ren Su-Xian, Fornara Dario, Christie Peter, Zhang Wei-Ping, Li Long
Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing, China.
Davines Group-Rodale Institute European Regenerative Organic Center (EROC), Parma, Italy.
Front Plant Sci. 2023 Mar 3;14:1100842. doi: 10.3389/fpls.2023.1100842. eCollection 2023.
The 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.
Three 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).
Straw 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.
植物凋落物质量的分解是大量碳通量的来源，并且仍然是调节自然和人工管理生态系统中养分循环的关键过程。农业单作系统中已对凋落物分解进行了研究，但在间作系统中尚未涉及，间作系统会产生物种多样的凋落物质量混合物。本文旨在量化秸秆类型、土壤环境及其综合效应如何影响广泛应用的玉米/豆类间作系统中的秸秆分解。
在一个长期间作田间试验中进行了为期341天的三项分解实验，该试验包括两个氮添加水平（即不施氮和施氮）和五种种植系统（玉米、大豆和花生单作以及玉米/大豆和玉米/花生间作）。实验I用于量化凋落物质量对分解的影响；来自两种氮处理的五种秸秆类型（玉米、大豆、花生、玉米 - 大豆和玉米 - 花生）在同一玉米地块中分解。实验II研究土壤环境对根系分解的影响；大豆秸秆在不同地块（五种种植系统和两个氮水平）中分解。实验III研究“原位”分解效应，即凋落物质量（秸秆）留在原地进行分解。在实验III（“原位”地块）和I - II（“异地”地块）之间比较了凋落物和土壤效应对原位优势的贡献。
秸秆类型在相同土壤环境中影响凋落物质量损失（实验I），玉米、大豆、花生、玉米 - 大豆和玉米 - 花生秸秆的质量损失值分别为59%、77%、87%、76%和78%。秸秆类型在“原位”地块环境中也影响分解（实验III），玉米、大豆、花生、玉米 - 大豆和玉米 - 花生秸秆的质量损失值分别为66%、74%、80%、72%和76%。种植系统不影响大豆秸秆的质量损失（实验II）。施氮显著增加了实验III中秸秆的质量损失。与玉米 - 大豆秸秆混合物相比，“原位优势”效应更能促进玉米 - 花生秸秆混合物的分解。在“原位”（实验III）和“异地”地块（实验I）中，玉米 - 花生和玉米 - 大豆秸秆混合物分解均存在协同混合效应。在其“原位”地块（实验III）中，玉米 - 花生在秸秆混合物分解中表现出比玉米 - 大豆更大的协同效应。本文从这些发现对粮食生产间作系统中物种多样秸秆管理的重要意义方面进行了讨论。
