Landscape perspectives for agroecological weed management. A review

Abstract

Faced with the biodiversity extinction crisis and climate change, alternative approaches to food production are urgently needed. Decades of chemical-based weed control have resulted in a dramatic decline in weed diversity, with negative repercussions for agroecosystem biodiversity. The simplification of cropping systems and the evolution of herbicide resistance have led to the dominance of a small number of competitive weed species, calling for a more sustainable approach that considers not only weed abundance but also community diversity and composition. Agroecological weed management involves harnessing ecological processes to minimize the negative impacts of weeds on productivity and maximize biodiversity. However, the current research effort on agroecological weed management is largely rooted in agronomy and field-scale farming practices. In contrast, the contributions of landscape-scale interventions on agroecological weed management are largely unexplored (e.g., interventions to promote pollinators and natural enemies or carbon sequestration). Here, we review current knowledge of landscape effects on weed community properties (abundance, diversity, and composition) and seed predation (a key factor in agroecological weed management). Furthermore, we discuss the ecological processes underlying landscape effects, their interaction with in-field approaches, and the implications of landscape-scale change for agroecological weed management. Notably, we found that (1) landscape context rarely affects total weed abundance; (2) configurational more than compositional heterogeneity of landscapes is associated with higher alpha, beta, and gamma weed diversity; (3) evidence for landscape effects on weed seed predation is currently limited; and (4) plant spillover from neighboring habitats is the most common interpretation of landscape effects on weed community properties, whereas many other ecological processes are overlooked. Strikingly, the drivers of weed community properties and biological regulation at the landscape scale remain poorly understood. We recommend addressing these issues to better integrate agroecological weed management into landscape-scale management, which could inform the movement towards managing farms at wider spatiotemporal scales than single fields in a single season.

Agricultural Practices for Biodiversity Enhancement: Evidence and Recommendations for the Viticultural Sector

“…The diversity of non-crop plant species, such as resident vegetation [37], cover crops, and hedgerows, also provides important ecological services. It has been recognized that the abundance of different resident/weed plant species, whether temporary or permanent, natural or sown, supports pollination and can improve soil fertility [38], as well as enhance microbial, nematode, and earthworm biomass and diversity [39]. Vegetal diversification has the advantage of restoring natural control of crop pests, replacing, at least partially, the use of pesticides [25].…”

“…Vegetal diversification has the advantage of restoring natural control of crop pests, replacing, at least partially, the use of pesticides [25]. Additionally, the prevalence of weed species in a field is associated with significant yield loss, due to competition for water and nutrients with crop plants [38]. It is expected that, given constant weed abundance, a weed community with increased diversity and evenness will be less competitive, and therefore more agronomically beneficial [38].…”

“…The combustion of organic matter and volatilization of some nutrients also occurs. • The diversification of crops and farming practices, such as tillage, sowing date, and fertilization, can increase biotic environmental heterogeneity and prevent the dominance of most competitive weeds [38]. • The use of mulches contributes to light exclusion, the creation of physical barriers to seed emergence, and allelopathy, acting as an effective mechanism for weed control [35].…”

Integrated Weed Management: A Comprehensive Review of Conventional, Non-Conventional, and Emerging Strategies for Sustainable Agriculture

“…Farmers have always prioritized controlling weeds since the beginning of time [40]. Almost one third of the entire cost of producing field crops goes towards weed management [41].…”

¿Malezas o arvenses? Una propuesta conceptual para su manejo agroecológico

“…ISSN 2215-3608 https://doi.org/10.15517/am.2024.56900 Gómez-Gómez: ¿Malezas o arvenses? M a n u s c r i t o a c e p t a d o de colonización, establecimiento y crecimiento de las malezas más problemáticas, lo que favorece la presencia de comunidades de plantas más diversas y menos competitivas con el cultivo en un sitio y momento dado (Adeux et al, 2019;Boinot et al, 2024;Petit et al, 2018).…”