Weed Diversity Affects Soybean and Maize Yield in a Long Term Experiment in Michigan, USA

Abstract

Managing production environments in ways that promote weed community diversity may enhance both crop production and the development of a more sustainable agriculture. This study analyzed data of productivity of maize (corn) and soybean in plots in the Main Cropping System Experiment (MCSE) at the W. K. Kellogg Biological Station Long-Term Ecological Research (KBS-LTER) in Michigan, USA, from 1996 to 2011. We used models derived from population ecology to explore how weed diversity, temperature, and precipitation interact with crop yields. Using three types of models that considered internal and external (climate and weeds) factors, with additive or non-linear variants, we found that changes in weed diversity were associated with changes in rates of crop yield increase over time for both maize and soybeans. The intrinsic capacity for soybean yield increase in response to the environment was greater under more diverse weed communities. Soybean production risks were greatest in the least weed diverse systems, in which each weed species lost was associated with progressively greater crop yield losses. Managing for weed community diversity, while suppressing dominant, highly competitive weeds, may be a helpful strategy for supporting long term increases in soybean productivity. In maize, there was a negative and non-additive response of yields to the interaction between weed diversity and minimum air temperatures. When cold temperatures constrained potential maize productivity through limited resources, negative interactions with weed diversity became more pronounced. We suggest that: (1) maize was less competitive in cold years allowing higher weed diversity and the dominance of some weed species; or (2) that cold years resulted in increased weed richness and prevalence of competitive weeds, thus reducing crop yields. Therefore, we propose to control dominant weed species especially in the years of low yield and extreme minimum temperatures to improve maize yields. Results of our study indicate that through the proactive management of weed diversity, it may be possible to promote both high productivity of crops and environmental sustainability.

Weed Suppression in Only-Legume Cover Crop Mixtures

“…Additionally, in both years the plants experienced different growth conditions that may have affected weed population dynamics as a function of ecological interactions within and between plant populations, nutrient, and water limitation, rainfall, and temperature [13]. Specifically, in 2017 the low temperature (Figure 1) at the early growth stage may have increased the prevalence of competitive weed species and this effect is in agreement with [14].…”

“…First, the rapid and successful establishment of cover crops will hamper weed growth and development through niche pre-emption and competition [10,11]. However, the initial weed seedbank [12], weed response to the ambient conditions [13,14], and soil fertility [15,16] may interfere with the successful establishment of cover crops. Second, incorporated (green manures) or surface application of crop residues as mulch can effectively inhibit or retard germination and establishment of weeds [17,18].…”

Crop production structure and stability under climate change in South America

“…Specifically, we propose the logistic model as the functional form for crop yield growth analysis because of its flexibility, realism, predictability and generality. Stable and stagnant crop yield changes could be the consequence of a negative feedback structure (due to biophysical internal processes), able to persist over time in a state of dynamics equilibrium with their environment (Ferrero et al, , ). Understanding and modelling how both feedback mechanisms and climate interact in shaping the dynamics of crop yield may be fundamental to our ability to predict crop response under climate change.…”

“…Generally, when the crop has a higher yield, it also has a greater water demand and, therefore, we over‐estimate the response of the crop to climate change if we do not consider it, at least for high‐yield systems. Recently, we used models with biologically interpretable parameters, that also take into account the nonlinear crop yield growth previously discussed, to understand hydric stress in maize throughout Spain (Ferrero et al, ), and the effects of weed community diversity and climate on maize and soybean in a long‐term experiment in Michigan, USA (Ferrero et al, ). Here we consider whether general patterns exist for a more profound understanding of crop yield dynamics in order to develop wide‐ranging strategies for coping with the impacts caused by climate change.…”

Quantification of regulating ecosystem services provided by weeds in annual cropping systems using a systematic map approach

“…() and Ferrero et al . () provided results from research aimed at testing this relationship. However, they did not manipulate weed densities and simple correlation analyses were the only means with which weed diversity–crop yield relationships were tested.…”