Título:	Improving soil carbon in semiarid agroecosystems: reclaimed water and mulch effects in cactus-sorghum intercropping.
Autoria:	TOMAZ, A. R. LAL, R. SILVA, W. R. da INAGAKI, T. M.
Afiliação:	FEDERAL RURAL UNIVERSITY OF PERNAMBUCO; THE OHIO STATE UNIVERSITY, 2021 COFFEY ROAD, COLUMBUS, OH; FEDERAL RURAL UNIVERSITY OF PERNAMBUCO; NORWEGIAN INSTITUTE OF BIOECONOMY RESEARCH (NIBIO).
Ano de publicação:	2026
Referência:	Journal of Cleaner Production, v. 543, 147687, 2026.
Páginas:	13 p.
Conteúdo:	In semiarid regions, soil organic carbon (SOC) stocks and soil organic matter (SOM) pools are often low due to limited biomass input and inadequate management. This study evaluated SOC stocks and SOM fractions in a forage cactus–sorghum intercropping system irrigated with treated sewage water under diverse mulch in the northeastern Brazilian semiarid. The experiment followed a randomized split-plot block design with four rep licates. Main plots included four irrigation levels (0, 80, 100, and 120 % of sorghum evapotranspiration (ETc)), and split plots comprised two mulch treatments: no mulch (NM) and mulch (WM) with 8 Mg ha 1 of sabi grass, spiny burrgrass, and goosegrass. Soil samples were collected at 0–0.10, 0.10–0.20, and 0.20–0.40 m depths in three sorghum cuts to determine labile SOM fractions: hot water-extractable C (HWEO-C), potassium permanganate-oxidizable C (POX-C), and particulate organic C (POC). In addition, SOC stocks and humic sub stances (HS), including humin (HU), fulvic acid (FA), and humic acid (HA), were determined at the end of the experiment. Intercropping system productivity was also evaluated. The highest SOC, POC, POX-C, and HWEO-C stocks occurred in 80WM and 100WM treatments, especially in HS, with HU as the dominant component. SOC in the HU fraction exceeded that in native vegetation soils, with threefold increases at 0–0.10 m and six-to sevenfold increases in deeper layers. Soils without irrigation, regardless of mulch, exhibited lower C storage, underscoring the importance of water management. Combining reclaimed water irrigation and mulching enhanced SOC accumulation, particularly in stable humic fractions, boosted carbon sequestration and crop productivity, and fostered sustainable, climate-resilient agriculture in semiarid tropical regions.
Palavras-chave:	Supplemental irrigation
ISSN:	0959-6526
Digital Object Identifier:	https://doi.org/10.1016/j.jclepro.2026.147687
Tipo do material:	Artigo de periódico
Acesso:	openAccess
Aparece nas coleções:	Artigo em periódico indexado (CNPDIA)