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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Sustainable Agricultural Systems Laboratory » Research » Publications at this Location » Publication #405575
Research Project: Precision Integrated Weed Management in Conventional and Organic Crop Production Systems

Location: Sustainable Agricultural Systems Laboratory

Title: Does narrow row spacing suppress weeds and increase yields in corn and soybean? A meta-analysis

Author
item SINGH, MANDEEP - University Of Nebraska
item THAPA, RESHAM - Tennessee State University
item SINGH, NAVDEEP - Punjab Agricultural University
item Mirsky, Steven
item ACHARYA, BHARAT - Rodale Institute
item JHALA, AMIT - University Of Nebraska

Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/7/2023
Publication Date: 9/20/2023
Citation: Singh, M., Thapa, R., Singh, N., Mirsky, S.B., Acharya, B., Jhala, A.J. 2023. Does narrow row spacing suppress weeds and increase yields in corn and soybean? A meta-analysis. Weed Science. 71:520–535 https://doi.org/10.1017/wsc.2023.50.
DOI: https://doi.org/10.1017/wsc.2023.50

Interpretive Summary: Many individual studies have investigated the impact of the standard practice of planting corn and soybeans in narrow rows (> 76 cm wide), which could suppress weeds and improve yield. The potential for weed suppression is particularly of interest given concerns about herbicide-resistant weeds and the need for integrated weed management tools. Our objective was to conduct a meta-analysis of these studies to quantify the effect of narrow rows on crop yield and weed density, biomass, fecundity, and control in corn and soybean as compared to 76-cm rows. We compiled 1,904 pair-wise observations from 35 studies conducted across 12 US states from 1961-2018. We found that narrow rows can suppress weed density by 34%, biomass by 55%, and fecundity (i.e. seed production) by 45%, while it can improve weed control by 32% and crop yield by 11% in corn. In soybean, narrow rows suppressed weed density by 42% and biomass by 71% while improving crop yield by 12%. This study benefits farmers by further confirming the value of planting corn and soybean in narrow rows as an integrated weed management tool to improve yields and suppress weeds, which is particularly important given the on-going difficulty of preventing and controlling herbicide-resistant weeds.

Technical Abstract: arrow rows (< 76 cm) have been primarily adopted for their yield advantage in corn and soybean as compared to wide rows. Additionally, narrow rows could potentially improve crops competitiveness and suppress weeds. Many studies have been conducted in the United States to assess the impact of narrow rows on weeds in corn and soybean. However, no quantitative synthesis of these studies exists. Therefore, our objectives were to i) quantify the overall effect of narrow rows (< 76 cm) on weed density, biomass, fecundity, and control in corn and soybean as compared to 76-cm rows and ii) quantify the overall effect of narrow rows on corn and soybean yields. We compiled 1,904 pair-wise observations from 35 studies. These studies were conducted in 12 US states from 1961-2018. We found that narrow rows can suppress weed density by 34%, biomass by 55%, and fecundity or seed production by 45%, while it can improve weed control by 32% and crop yield by 11%. However, these benefits were only found in soybeans, not corn. In soybean, narrow rows suppressed weed density by 42% and biomass by 71% while improving crop yield by 12%. Our results highlight the potential of narrow rows for weed suppression and yield improvement. Therefore, narrow rows can be used as an integrated weed management tactic to help manage rapidly evolving herbicide-resistant weeds, especially in soybeans.