Enhancing Yields in Organic Crop Production by Eco-Functional Intensification

Laurent Bedoussac,Etienne-Pascal Journet,Georg Carlsson,Erik Steen Jensen,Henrik Hauggaard-Nielsen,Eric Justes

doi:10.5539/sar.v4n3p42

Abstract

Organic agriculture faces challenges to enhance food production per unit area and simultaneously reduce the environmental and climate impacts, e.g. nitrate leaching per unit area and greenhouse gas (GHG) emissions per unit mass produced. Eco-functional intensification is suggested as a means to reach these objectives. Eco-functional intensification involves activating more knowledge and refocusing the importance of ecosystem services in agriculture. Organic farmers manage agrobiodiversity by crop rotation (diversification in time). However, sole cropping (SC) of genetically identical plants in organic agriculture may limit resource use efficiency and yield per unit area. Intercropping (IC) of annual grain species, cultivar mixes, perennial grains, or forage species and forestry and annual crops (agroforestry) are examples of spatial crop diversification. Intercropping is based on eco-functional intensification and may enhance production by complementarity in resource use in time and space. Intercropping is based on the ecological principles of competition, facilitation and complementarity, which often increases the efficiency in acquisition and use of resources such as light, water and nutrients compared to sole crops, especially in low-input systems. Here we show that IC of cereals and grain legumes in European arable organic farming systems is an efficient tool for enhancing total grain yields compared to their respective sole crops. Simultaneously, we display how intercropping of cereals and legumes can be used as an efficient tool for weed management and to enhance product quality (i.e. cereal grain protein concentration). We discuss how intercropping contributes to efficient use of soil N sources and minimizes losses of N by nitrate leaching via Ecological Precision Farming. It is concluded that intercropping has a strong potential to increase yield and hereby reduce global climate impacts such as GHG kg-1 grain. Finally, we discuss likely barriers and lock-in effects for increased use of intercropping in organic farming and suggest a roadmap for innovation and implementation of IC strategies in organic agriculture.

Highlights

Organic agriculture is based on a set of principles one of these being the principle of ecology
Intercropping is based on the ecological principles of competition, facilitation and complementarity, which often increases the efficiency in acquisition and use of resources such as light, water and nutrients compared to sole crops, especially in low-input systems
We show that IC of cereals and grain legumes in European arable organic farming systems is an efficient tool for enhancing total grain yields compared to their respective sole crops

Summary

Introduction

Organic agriculture is based on a set of principles one of these being the principle of ecology. To a large extent this is achieved by promoting ecosystem services such as biological nitrogen fixation, soil carbon sequestration, nutrient circulation, pollination and biological pest control. This often results in a certain trade-off between the high yield of commodities versus the lower environmental impact and maintenance of natural capital (e.g. biodiversity, soil organic matter) for ecosystem services delivery, in a longer term perspective. Simple yield comparisons between organic and conventional systems, without considering externalities, product quality and net margins, are inappropriate. Global food production must increase while considering new ways of better distribution, the global diet, planetary boundaries and ability of www.ccsenet.org/sar

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