No-tillage improves summer rocket yields by reducing soil temperature and weed density and increasing soil potassium contents

Introducing a grass cover crop into the rocket production system is an option to increase diversity and sustainability. The objective of this study was to evaluate the effectiveness of no-tillage system for growing rocket (Eruca sativa) cultivars in two successive crops (cover crop – rocket first crop – rocket second crop) in the summer, using ruzigrass (Urochloa ruziziensis) as cover crop, and its effects on weed management and soil fertility and temperature. A randomized block experimental design with four replications was used, in a 2×3 split-plot arrangement consisting of two soil management systems (1 - no-tillage – NT; 2 - conventional tillage - CT) in the plots and three rocket cultivars (Cultivada, Folha Larga, and Selecta) in the subplots. The dry and fresh weight of rocket and soil temperature and macronutrient contents were evaluated and weed species were identified and counted. The results showed that the cultivars exhibited similar adaptability to NT. However, rocket yield increased in the second crop in NT system. Soil temperature during the hottest times of the day decreased by up to 3.8 °C due to the introduction of the grass cover crop into the system. Weed infestation in the first crop decreased by 74.8% in NT (135.2 plants m-2) compared to CT (536.1 plants m-2). Digitaria horizontalis was the weed species that presented the highest density in both soil management systems. Soil K contents increased after the two rocket crops in NT system. The results indicate that the rocket cultivars can be successfully grown under no-tillage system, contributing to the sustainability of the crop production system.