1. Nitrogen Residual Effect of Winter Cover Crops on Maize in Uruguay: Conventional and Isotopic Evaluation.
- Author
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Mori Alvez, Cristina, Perdomo Varela, Carlos, and del Pino Machado, Amabelia
- Subjects
SUSTAINABLE agriculture ,CORN ,WEEDS ,LUPINES ,OATS ,COVER crops ,MONOCULTURE agriculture - Abstract
This study aimed to evaluate the nitrogen (N) residual effects of winter cover crops (CCs) on soil N availability and corn (Zea mays L.) performance over two growing seasons and at two sites in Uruguay. Both conventional and isotopic methods were used to assess the N residual effects of two legume monocultures, a legume–grass mixture, an oat monoculture, and a control without CCs. The experimental design was a randomized block with split plots, where CCs were applied to main plots and N rates (0 and 100 kg ha⁻
1 ) to subplots. An isotopic trial with15 N was included to measure fertilizer N use efficiency (NUE). Results varied between sites: at Site 1, legume monocultures enhanced soil N availability and, along with N rate, significantly increased corn yield and N uptake. At Site 2, only the N rate affected these variables. Site 1 had a low crop15 N recovery, averaging 9.5% due to weeds and heavy rainfall, while Site 2 showed higher recovery, notably when corn succeeded lupine (35%) and mixture CCs (40%). The soil's top layer and corn grain showed the highest15 N concentration. The study suggests that specific CC combinations tailored to site conditions may optimize corn yield and NUE. [ABSTRACT FROM AUTHOR]- Published
- 2024
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