Lu Ze-Rang, Li Yong-Mei, Yang Chun-Huai, Xia Zi-Tai, Cheng Wei-Wei, Wang Zi-Lin, Zhao Ji-Xia, Fan Mao-Pan
1. College of Resources and Environment, Yunnan Agricultural University, Kunming 650201, China.
Huan Jing Ke Xue. 2024 Mar 8;45(3):1644-1654. doi: 10.13227/j.hjkx.202304166.
In order to explore the effects of continuous annual crop rotation and fallow on aggregate stability and organic carbon content in red soil, the red soil in sloping farmland was taken as the research object, and the water-stable aggregates and organic carbon content were determined using the wet sieve method and potassium dichromate-concentrated sulfuric acid external heating method, respectively. The changes in soil aggregate stability and organic carbon content under the four treatments of maize-vetch-maize rotation (M-V-M), maize-pea-maize rotation (M-P-M), maize-fallow-maize (M-F-M), and annual fallow (F-F-F) from 2020 to 2022 and the relationships between them were analyzed. The results showed that in 2021 and 2022, the contents of > 2 mm aggregates treated with F-F-F, M-V-M, and M-P-M were significantly increased by 67.01%-100.92%, 29.71%-33.67%, and 29.68%-38.07%, respectively, compared with that treated with M-F-M. In 2021 and 2022, the stability parameters of F-F-F and M-V-M were significantly higher than those of M-F-M ( < 0.05). The content of > 2 mm aggregates, geometric mean diameter (GMD), and mean weight diameter (MWD) under the M-V-M treatment and (> 0.25 mm aggregate contents), MWD and > 2 mm aggregate contents under the F-F-F treatment increased with the increase in fallow years, whereas the content of 1-2 mm and < 0.25 mm under the F-F-F treatment decreased with the increase in fallow years. Both green manure rotation and fallow treatment could increase the SOC content, and the SOC content of F-F-F and M-V-M treatment increased with the extension in age. Correlation analysis showed that SOC content was significantly positively correlated with and GMD under all treatments. and GMD under the F-F-F treatment and GMD and MWD under M-V-M were significantly positively correlated with SOC content. The results showed that continuous annual crop rotation and fallow was beneficial to improve the content of soil macro-aggregates, aggregate stability, and SOC content, which could provide theoretical basis for the implementation of reasonable continuous annual crop rotation and fallow patterns and soil erosion control in red soil areas of sloping farmland in southern China.
为探究连年作物轮作和休耕对红壤团聚体稳定性及有机碳含量的影响，以坡耕地红壤为研究对象，分别采用湿筛法和重铬酸钾 - 浓硫酸外加热法测定水稳性团聚体和有机碳含量。分析了2020 - 2022年玉米 - 紫云英 - 玉米轮作（M - V - M）、玉米 - 豌豆 - 玉米轮作（M - P - M）、玉米 - 休耕 - 玉米（M - F - M）和连年休耕（F - F - F）4种处理下土壤团聚体稳定性和有机碳含量的变化及其相互关系。结果表明，2021年和2022年，F - F - F、M - V - M和M - P - M处理的>2 mm团聚体含量分别比M - F - M处理显著增加67.01% - 100.92%、29.71% - 33.67%和29.68% - 38.07%。2021年和2022年，F - F - F和M - V - M处理的稳定性参数显著高于M - F - M处理（<0.05）。M - V - M处理下>2 mm团聚体含量、几何平均直径（GMD）和平均重量直径（MWD）以及F - F - F处理下（>0.25 mm团聚体含量）、MWD和>2 mm团聚体含量随休耕年限增加而增加，而F - F - F处理下1 - 2 mm和<0.25 mm的含量随休耕年限增加而降低。绿肥轮作和休耕处理均能增加土壤有机碳含量，F - F - F和M - V - M处理的土壤有机碳含量随年限延长而增加。相关性分析表明，各处理下土壤有机碳含量与和GMD均呈显著正相关。F - F - F处理下和GMD以及M - V - M处理下GMD和MWD与土壤有机碳含量显著正相关。结果表明，连年作物轮作和休耕有利于提高土壤大团聚体含量、团聚体稳定性和土壤有机碳含量，可为中国南方坡耕地红壤区实施合理的连年作物轮作和休耕模式及控制土壤侵蚀提供理论依据。
