Annual Wildflower Strips as a Tool for Enhancing Functional Biodiversity in Rye Fields in an Organic Cultivation System

Krzysztof Kujawa,Paweł Sienkiewicz,Anna Kujawa,Zdzisław Bernacki,Dariusz Sobczyk,Maria Oleszczuk,Jolanta Kowalska

doi:10.3390/agronomy10111696

Krzysztof Kujawa, Paweł Sienkiewicz + Show 5 more

Open Access

https://doi.org/10.3390/agronomy10111696

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Abstract

Ecological intensification of agriculture (e.g., with the use of wildflower strips) is being currently discussed as a mean for gaining high yields, preserving high biodiversity of farmland. The aim of this study was to assess the efficiency of annual wildflower strips (WFSs) established in rye field (RF) in (1) increasing species richness and abundance in terms of beneficial arthropod groups (carabids, ground spiders, plant spiders, butterflies, insect pollinators and plant-dwelling insect predators), (2) decreasing the abundance of insect pests, (3) decreasing damages of the crop, and (4) increasing the yield. The field survey was carried out in 2019, in two WFSs and in the adjacent crop field at the distances of 3, 9, 21 and 45 m. The study was not skewed by pesticide use as it was carried out on an organic farm. Mean “site” species numbers (α-diversity) and the abundance of most groups were found to be significantly higher in WFSs than in RF. A negative relationship was found in most groups between distance from WFSs and species numbers and abundance. The mean total abundance of all observed pest insects was positively related to distance from WFSs and increased by 83% at distances between 3 and 45 m from WFSs. There was a negative exponential relationship between aphid abundance and total predator abundance, which suggests a mechanism reducing aphid abundance resulting from high levels of predator abundance in the nearby WFSs. The study shows that annual WFSs can be an efficient measure for enhancing cropland biodiversity and should be taken into account in agri-environmental schemes in the Common Agricultural Policy after 2020.

Highlights

The intensification of agriculture and the conversion of natural or semi-natural habitats to farmed land has led to a rapid decline in the biodiversity of farming areas [1], and of predatory and parasitoid species, which are important agents of biological pest control
The results of our study and the above discussion indicate that annual wildflower strips (WFSs) can be a valuable and effective measure for enhancing biodiversity as well as mechanisms for the biological control of pests on organic farms, where insecticide use is minimal
The magnitude of a WFS’s impact on cultivated fields differed between beneficial taxa, the results of the study suggest that the distance between parallel

Summary

Introduction

The intensification of agriculture and the conversion of natural or semi-natural habitats to farmed land has led to a rapid decline in the biodiversity of farming areas [1], and of predatory and parasitoid species, which are important agents of biological pest control. One of the measures contributing to ecological intensification is the establishment of wildflower strips (WFSs), which significantly increase the functional diversity of invertebrates in arable fields, including pollinators [8], parasitoids, predatory insects and spiders [9]. The last three mentioned arthropod groups can significantly increase the efficiency of biological pest control [10]. Another reason for establishing WFSs is the need to prevent the loss of biodiversity in general, including that of insects, whose resources are rapidly declining [11]. WFSs are already very common in some countries (Switzerland, the Netherlands and Germany), they are not used in other countries with well-developed agriculture, such as Poland

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