Root decomposition in Urochloa decumbens pastures fertilized with increasing nitrogen doses or intercropped with Calopogonium mucunoides (Apr, 10.1038/s41598-025-091796-01, 2025)

Cropping systems may affect root decomposition and our objective was to evaluate chemical characteristics and root decomposition in signal grass 'Basilisk' [Urochloa decumbens (Stapf) R.D. Webster] pastures under different cropping systems. A split-split plot scheme, with four cropping systems (0, 50, 100 kg<middle dot>ha(-1) of N, and intercropping with calopo (Calopogonium mucunoides Desv.) in the plots (paddocks), two experimental periods (2019/2020 and 2020/2021) in the split-plots, and nine incubation times (4, 8, 16, 32, 64, 128, 256, and 512 days) in the split-split plots, in a randomized block design with two replications was used. Root biomass was not affected (p > 0.05) by cropping systems (7.4 t ha(-1) on average). Before incubation, ADIN-TN (acid detergent insoluble nitrogen in total nitrogen) concentration was affected by cropping systems and C concentration was affected by interaction cropping systems x period. The remaining biomass had a loss total of 28% (1st ) and 30% (2nd ) after 512 d. N concentration was higher in the 1st period, resulting in a lower carbon: nitrogen ratio. Higher lignin concentration was observed for 0 kg<middle dot>ha(-1) of N (1st ) and 50 kg<middle dot>ha(-1) of N (2nd ). The ADIN concentration was higher in 100 kg<middle dot>ha(-1) of N than others systems. The lignin: N and lignin: ADIN ratios decreased over time. Although the root litter decomposition was not affected by the cropping systems, a potential average input of 18.6 kg<middle dot>ha(-1) of N was observed after 512 days.