Effects of fertility amendments on weed growth and weed–crop competition: a review

Abstract Macronutrient inputs to annual cropping systems can benefit weeds as well crops, sometimes decreasing or eliminating the benefits of fertilization. This interaction between fertility management and integrated weed is becoming increasingly important these fields increase their focus on efficiency prevention, respectively. The risk increased competition reflects fact that biomass height may be highly responsive nitrogen, phosphorus, and/or potassium. generalization supported by monoculture studies species such redroot pigweed ( Amaranthus retroflexus L.), common lambsquarters Chenopodium album barnyardgrass [ Echinochloa crus-galli (L.) P. Beauv.] ecological theory. However, field indicate variation in effects macronutrients weed–crop crop yield, even within groups. To address challenges interpreting, comparing, extrapolating from diverse reports, we propose a conceptual framework summarizes mechanisms underlying observed studies. highlights functional traits trends help predict yield outcomes binary interactions. Important factors include timing emergence, maximum heights crop, relative responsiveness added nutrient. We also survey recent work nutrient source (e.g., composition organic amendments) competition. Because different sources vary release dynamics supplied ratios, they have dramatically yield. Finally, offer guide best practices for Although this review several topics requiring further research, including multispecies interactions with other environmental factors, emerging methods considerable promise. Ultimately, an improved understanding will contribute efficient effective systems.