The Carbon Footprint of Energy Consumption in Pastoral and Barn Dairy Farming Systems: A Case Study from Canterbury, New Zealand

Hafiz Muhammad Abrar Ilyas,Majeed Safa,Sara Rauf,Alison Bailey,Marvin Pangborn

doi:10.3390/su11174809

Abstract

Dairy farming is constantly evolving to more intensive systems of management, which involve more consumption of energy inputs. The consumption of these energy inputs in dairy farming contributes to climate change both with on-farm emissions from the combustion of fossil fuels, and by off-farm emissions due to production of farm inputs (such as fertilizer, feed supplements). The main purpose of this research study was to evaluate energy-related carbon dioxide emissions, the carbon footprint, of pastoral and barn dairy systems located in Canterbury, New Zealand. The carbon footprints were estimated based on direct and indirect energy sources. The study results showed that, on average, the carbon footprints of pastoral and barn dairy systems were 2857 kgCO2 ha−1 and 3379 kgCO2 ha−1, respectively. For the production of one tonne of milk solids, the carbon footprint was 1920 kgCO2 tMS−1 and 2129 kgCO2 tMS−1, respectively. The carbon emission difference between the two systems indicates that the barn system has 18% and 11% higher carbon footprint than the pastoral system, both per hectare of farm area and per tonne of milk solids, respectively. The greater carbon footprint of the barn system was due to more use of imported feed supplements, machinery usage and fossil fuel (diesel and petrol) consumption for on-farm activities.

Highlights

Dairy farming represents one of the most important agricultural systems in New Zealand, with about 11,748 dairy herds with 4.8 million dairy cows which annually produce more than 21 billion liters of milk
The difference in total carbon footprints between the two dairy systems is 522 kgCO2 ha−1, a 15% lower CO2 emission in the pasture-based dairy farming system (PDF) system compared to the barn dairy farming system (BDFs) system
The results indicated that NZ PDF systems have 15% lower carbon footprints on a per hectare basis compared to BDF systems

Summary

Introduction

Dairy farming represents one of the most important agricultural systems in New Zealand, with about 11,748 dairy herds with 4.8 million dairy cows which annually produce more than 21 billion liters of milk. New Zealand is renowned for its traditional pasture-based dairy farming system (PDF), where farmers aim to increase their profits by minimizing production costs through maximizing the proportion of grazed grass in the diet of lactating cows [3,4]. NZ pasture-based dairy systems (PDF) have intensified due to higher financial benefits in the dairy sector, resulting in increased use of farm inputs (fertilizer, water, electricity, fuel etc.) in dairy systems to produce more milk per hectare of grassland [3,5]. The use of barn facilities, requires further intensification of the system, in terms of the use of energy inputs to make the system profitable, making it difficult to achieve both financial and environmental benefits simultaneously [7]

Methods

Results

Discussion

Conclusion