Higher lime rates for greater nitrogen recovery: A long-term no-till experiment labeled with 15N

• Autor(a) principal: Bossolani, João William [UNESP]
• Data de Publicação: 2023
• Outros Autores: Crusciol, Carlos Alexandre Costa [UNESP], Mariano, Eduardo [UNESP], Moretti, Luiz Gustavo [UNESP], Portugal, José Roberto [UNESP], Fonseca, Mariley [UNESP], Momesso, Letusa [UNESP], Côrt, Andressa Selestina Dalla [UNESP], Costa, Vladimir Eliodoro [UNESP], Cantarella, Heitor
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.fcr.2023.108971; http://hdl.handle.net/11449/248874
• topic: 15N-labeled fertilizer; Liming; Maize/soybean rotation; Nitrogen losses

Context or problem: Soil acidity limits crop growth and yield all over the world. Low grain yields is usually associated with poor soil fertility; however, little attention has been given to the nitrogen-based fertilizer use efficiency in soils managed with lime. Objective: Given the current scenario of uncertainties regarding the availability and prices of fertilizers, our study aimed to understand how maize intercropped with ruzigrass and soybean plants develop in long-term soils managed with lime rates, and what the fate of the 15N–labeled ammonium sulfate [(15NH4)2SO4] applied in the soil-plant system. Methods: The treatments consisted of four dolomitic lime rates applied to the soil surface [control, half the recommended lime rate (½ RLR), full recommended lime rate (1 RLR) and double the recommended lime rate (2 RLR)]. Results: The higher lime rate (2 RLR) improved fertility, carbon and nitrogen stocks in the soil profile, and grain and/or stover production of maize, ruzigrass and soybean. As a consequence, maize and ruzigrass recovered a high amount of 15N-fertilizer. On the other hand, soybean recovered less 15N-fertilizer, regardless of treatment, but a greater amount was found in acidic soils. At the end of the maize and soybean growth cycles, our results showed that in 2 RLR-amended soil, the 15N unrecovered was 71% lower than control. Finally, our results suggested that the use of low lime rates (½ RLR) may increase the 15N losses potential to deep layers, whereas low amounts of 15N were found in the subsoil when higher lime rates were applied. Conclusions and implications: Soil acidity management through higher lime rates leads, over time, to increased soil fertility, resulting in a favorable environment for plant growth and the use of nitrogen fertilizers. In this way, it is possible to obtain a more productive and less costly agricultural system, and with less potential to pollute the environment.