Weed Control Using Conventional Tillage, Reduced Tillage, No-Tillage, and Cover Crops in Organic Soybean

Jonas Weber,Gerassimos Peteinatos,Christoph Kunz,Roland Gerhards,Sabine Zikeli

doi:10.3390/agriculture7050043

Abstract

Soybean field experiments were performed to investigate the weed-suppressing effects of different tillage systems and cover crop mulches at two locations in southwest Germany during 2014 and 2015. The influence of three different tillage systems on weed control efficacy, soybean plant density, and crop yield was determined. In the no-till system (NT), two different cover crops, (rye and barley), were treated by a roller-crimper before soybean sowing. For the reduced tillage system (RT), shallow soil cultivation (7.5 cm depth) using a cultivator after cover crop harvest was performed. The third system was conventional tillage (CT), which used a plow (25 cm depth) without any previous cover crop treatment. Finally, a CT system without weed control was used as a control treatment (C). Weed densities in the field experiments ranged from 1 to 164 plants m−2 with Chenopodium album (L.), Echinochloa crus-galli (L.) P. Beauv., and Sonchus arvensis (L.) as the predominant weed species. No difference in weed suppression was found between the two cover crops. The highest cover crop soil coverage was measured in the NT treatment. The greatest weed density (164 plants m−2) was measured in the untreated control. CT, RT and NT reduced weed density up to 71%, 85%, and 61%, respectively, to C, across both locations and years. Soybean plant density was reduced in NT (−36%) and CT (−18%) based on aimed sown plant density. Highest crop yields up to 2.4 t ha−1 were observed in RT, while NT resulted in lower yields (1.1 t ha−1). Our work reveals the importance of cover crops for weed suppression in soybean cropping systems without herbicide application.

Highlights

IntroductionDuring the last few decades, various cultivation methods have been examined for improving the yield potential of different crops [1] which, at the same time, have the ability to enhance ecosystem services (e.g., increases in soil organic matter, soil water retention capacity and soil biodiversity) [2]
During the last few decades, various cultivation methods have been examined for improving the yield potential of different crops [1] which, at the same time, have the ability to enhance ecosystem services [2].In this context, soil tillage plays a crucial role, as it determines both the productivity of the cropping system in terms of yield as well as its environmental impacts, such as soil erosion or carbon sequestration
One day after seeding (DAS), treatments C and conventional tillage (CT) resulted in similar bare soil proportions in 2014 (Figure 2)

Summary

Introduction

During the last few decades, various cultivation methods have been examined for improving the yield potential of different crops [1] which, at the same time, have the ability to enhance ecosystem services (e.g., increases in soil organic matter, soil water retention capacity and soil biodiversity) [2]. In this context, soil tillage plays a crucial role, as it determines both the productivity of the cropping system in terms of yield as well as its environmental impacts, such as soil erosion or carbon sequestration. Scop.) will become more prevalent than under CT systems [10,11]

Methods

Results

Conclusion