Weed Communities in Semiarid Rainfed Croplands of Central Argentina: Comparison between Corn (Zea mays) and Soybean (Glycine max) Crops

Abstract

The semiarid Espinal in central Argentina, being recently transformed from natural semiarid grasslands into agriculture, represents an interesting scenario to understand the early stages of weed community assembly and its relationship with crop identity and management. Our aim was to characterize the weed communities in corn (Zea maysL.) and soybean [Glycine max(L.) Merr.], the main crops of the Espinal region, under the dominant rainfed conditions. Weed surveys were carried out in 53 fields, and farmers were interviewed to collect information about crop management. Floristic composition was compared within and between crops by calculating the additive partition of the abundance-based Bray-Curtis dissimilarity. We compared the frequency and mean cover of functional groups between crops through generalized linear models. Finally, canonical correspondence analysis was carried out to analyze the associations between floristic composition and agronomic variables. Mean alpha and gamma diversity was greater in corn (10.0 and 80 species, respectively) than in soybean (7.6 and 46 species, respectively). Furthermore, species composition of weed communities was more similar among soybean fields than among either cornfields or fields of both crops. Hence, floristic differences between crops are potentially the result of different microenvironmental heterogeneity above- and belowground, with corn likely to be more permissive to weed establishment compared with soybean. The higher frequency of annual, dicotyledonous, and native species, and the high proportion of rare species, mostly native, suggest a strong legacy of the original vegetation that thrived in these recently cultivated systems. The functional composition was also affected by agronomic management, with sulfur, nitrogen, and grass herbicide application being the most important factors related to the floristic composition of weed communities. This early description can be used as a starting point for studies concerning trajectories, mechanisms, and processes of weed communities related to environment and management.

Weed incidence and sowing time affect soybean development

“…The highest RF% of weeds in the second and third sowing times was found with the BMX-TornadoRR cultivar (Table 3). (Kamoshita et al, 2014;Pinke et al, 2016;Rauber et al, 2018).…”

Effect of Soil Properties on the Diversity and Distribution of Weeds in Citrus Farms in Arid Region

“…Despite, a total of 12 environmental variables were included in the analysis, only the above three variables were significant in the regression model. The possible justification is that the environmental variables are not the only factors controlling the weeds communities in citrus farms as reported on other agroecosystems (see Rauber et al, 2018). Other biotic interaction may contribute in structuring the weeds communities in agroecosystems.…”

“…However, Fried et al (2008) found that the soil pH and soil texture are the most important factors structuring the weed communities in temperate region (France). On the other hand, some studies highlighted the agricultural practices are the main driver for diversity and abundance of weeds in agroecosystems (Rauber et al, 2018).…”

Application of remote sensing technology in the analysis of periodic precipitation change in China’s Northern semi-arid area

“…Dalian is a coastal city, which is affected by the continental monsoon and marine climate. Therefore, it is of great significance to analyze the 50 year precipitation law of four stations for understanding the precipitation cycle change law in the semi-arid area of northern China under the background of global change (Rauber et al, 2018).…”