Effect of Crop Residues on Weed Emergence

Nebojša Nikolić,Roberta Masin,Donato Loddo

doi:10.3390/agronomy11010163

Abstract

Weed behaviour in crop fields has been extensively studied; nevertheless, limited knowledge is available for particular cropping systems, such as no-till systems. Improving weed management under no-till conditions requires an understanding of the interaction between crop residues and the seedling emergence process. This study aimed to evaluate the influence of maize and wheat residues, applied in three different quantities (1, the field quantity, 0.5, and 1.5-fold amounts of the field quantity), on the emergence of eight weed species: Abutilon theophrasti, Amaranthus retroflexus, Chenopodium album, Digitaria sanguinalis, Echinochloa crus-galli, Setaria pumila, Sonchus oleraceus, and Sorghum halepense. The experiment was conducted over two consecutive years. The results showed that the quantities 1 and 1.5 could suppress seedling emergence by 20 and 44%, respectively, while the quantity 0.5 seems to promote emergence by 22% compared with the control without residues. Weed species showed different responses to crop residues, from C. album showing 56% less emergence to S. halepense showing a 44% higher emergence than the control without residues. Different meteorological conditions in the two-year experiment also exhibited a significant influence on weed species emergence.

Highlights

Weeds, being superior competitors than crops in contention for available resources, have become one of the major agricultural problems worldwide [1]
This study aimed to evaluate the influence of maize and wheat residues, applied in three different quantities (1, the field quantity, 0.5, and 1.5-fold amounts of the field quantity), on the emergence of eight weed species: Abutilon theophrasti, Amaranthus retroflexus, Chenopodium album, Digitaria sanguinalis, Echinochloa crus-galli, Setaria pumila, Sonchus oleraceus, and Sorghum halepense
Given the rise of agricultural land under conservation management and the increasing use of different mulches containing crop residues as part of integrated weed management, it becomes even more important to understand the behaviour of weed species under these conditions

Summary

Introduction

Weeds, being superior competitors than crops in contention for available resources, have become one of the major agricultural problems worldwide [1]. Besides being used to suppress weed emergence, crop residues, coupled with good agricultural management practices, can have many positive impacts on soil quality. They are considered an effective anti-erosion measure; they can improve soil structure, increase organic content in the soil, reduce evaporation, and help fix carbon dioxide (CO2). Crop residues can inhibit light transmittance to the seeds underneath, which may inhibit germination [10] These findings confirm that crop residues can act as an obstacle for water and light penetration and can reduce temperature fluctuations, which can lead to a deceleration, reduction, or a complete absence of seed germination and plant emergence [5,11]. The uniformity of residue distribution may be critical, regardless of the amount used

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Discussion

Conclusion