Technology to utilise and suppress weeds for sustainable maize production

Abstract

Throughout agricultural history, controlling weeds to prevent yield loss has been a longstanding focus. However, a practical technology that leverages weeds as a beneficial biological resource without compromising crop yields has remained elusive. Our study proposes and evaluates an innovative integrated technology to utilise and suppress weeds (ITUSW) for sustainable maize cultivation. In brief, maize was planted in ultrawide rows (100 cm apart) with two plants per hill on strip-tillage beds. Interrow weeds were allowed to grow naturally. These weeds were mowed during the seedling, tillering, and flowering stages. The mowed material, combined with the previous year's maize stover that was laid on the interrows, was then used as mulch over the maize rows and eventually returned to the soil through the practice of strip-tillage. Our five-year field study suggest that maize yields under the ITUSW treatment did not differ from those achieved by the plastic film mulching for weeding (MFW), chemical weeding (CW), chemical weeding plus straw return (CWSR), and mechanical weeding by hand hoeing (MHW)(p ​> ​0.05) treatments, yet they significantly surpassed those of the chemical weeding combined with straw mulching (CWSM)(p ​< ​0.05) treatment. Importantly, the above-ground intra-row weed biomass under the ITUSW was notably reduced compared to the MFW treatment, resembling the levels observed in other treatments. Conversely, the inter-row weed biomass experienced substantial increases of up to 448 g/m² through maize growth season, specifically by 9.89-, 5.14-, 4.36-, and 3.51-fold in contrast to the SWSM, CW, MHW, and MFW, treatments respectively (p ​< ​0.05). Our series of supplementary experiments confirmed that weeds beyond a 25 cm radius do not induce yield loss (p ​< ​0.05). Moreover, ITUSW designed with a wide row layout, strip tillage, inter-row weed mowing, and intra-row weed mulching eliminated competition from inter-row weeds and achieved the resource utilisation of inter-row weeds, such as soil improvement and biomass mulching. Besides, ITUSW is compatible with winter crops such as wheat. Consequently, ITUSW shows potential to replace chemical herbicides in maize production, and weeds are redefined from foes to allies, propelling agriculture towards enhanced sustainability.