The impact of long-term organic farming on soil-derived greenhouse gas emissions

Abstract

Agricultural practices contribute considerably to emissions of greenhouse gases. So far, knowledge on the impact of organic compared to non-organic farming on soil-derived nitrous oxide (N2O) and methane (CH4) emissions is limited. We investigated N2O and CH4 fluxes with manual chambers during 571 days in a grass-clover– silage maize – green manure cropping sequence in the long-term field trial “DOK” in Switzerland. We compared two organic farming systems – biodynamic (BIODYN) and bioorganic (BIOORG) – with two non-organic systems – solely mineral fertilisation (CONMIN) and mixed farming including farmyard manure (CONFYM) – all reflecting Swiss farming practices–together with an unfertilised control (NOFERT). We observed a 40.2% reduction of N2O emissions per hectare for organic compared to non-organic systems. In contrast to current knowledge, yield-scaled cumulated N2O emissions under silage maize were similar between organic and non-organic systems. Cumulated on area scale we recorded under silage maize a modest CH4 uptake for BIODYN and CONMIN and high CH4 emissions for CONFYM. We found that, in addition to N input, quality properties such as pH, soil organic carbon and microbial biomass significantly affected N2O emissions. This study showed that organic farming systems can be a viable measure contributing to greenhouse gas mitigation in the agricultural sector.

Organic Food Consumption in Italy: The Role of Subjective Relevance of Food as Mediator between Organic Food Choice Motivation and Frequency of Organic Food Consumption

“…Despite this increase in consumption and the relevance of it, it is necessary to promote, in a stronger way, the consumption of these products in order to boost the organic agriculture that could respond to the environmental problems that our planet is experiencing [15]. To encourage the consumption of organic food products, it is necessary to understand what are the personal levers that lead consumers to buy these types of food.…”

Social Farming: Heterogeneity in Social and Agricultural Relationships

“…Furthermore, SF is part of the ecological conversion to organic farming, contributing, as well to the improvement of the environment (improvements in biodiversity and soil fertility, higher water holding capacity, mitigation of the greenhouse effect, and adaptation to climate change), and the decrease in health risk [58][59][60][61][62][63]. This aspect is particularly important in SF experiences, where organic farming assumes a fundamental role in protecting the vulnerable (mentally disadvantaged, children, teenagers, etc.…”

The potential of decarbonising rice and wheat by incorporating carbon capture, utilisation and storage into fertiliser production

“…Fertiliser production and utilisation is one of the most representative contributors of GWP in rice and wheat production which is successively dominated by CO 2 , N 2 O, and CH 4 . 2,28 For example, the GWP of urea (fertiliser) production and supply in wheat represent around 34%, where 26%, 6.4% and 1.6% are related to CO 2 , N 2 O, and CH 4 , respectively. 28 Table 3 shows the contribution of GHG by fertiliser production in rice and wheat for Bangladesh, Thailand, China, Japan, Sweden, and Australia.…”

“…In the recent Paris Agreement on climate change established with the Intergovernmental Panel on Climate Change (IPCC), a new goal has been set to limit temperature rise to 2°C. 1 The agricultural sector also contributes to worldwide greenhouse gas (GHG) emissions, 2,3 with a share that is 10-12% of CO 2 equivalent. Considering indirect emissions from other activities related to agriculture such as fertiliser production, land use change, food storage, packaging etc., this share can be up to one-third of the total GHG emissions.…”