An Assessment of Direct on-Farm Energy Use for High Value Grain Crops Grown under Different Farming Practices in Australia

Tek Maraseni, Guangnan Chen, Thomas Banhazi, Jochen Bundschuh, Talal Yusaf
2015 Energies  
Several studies have quantified the energy consumption associated with crop production in various countries. However, these studies have not compared the energy consumption from a broad range of farming practices currently in practice, such as zero tillage, conventional tillage and irrigated farming systems. This study examines direct on-farm energy use for high value grain crops grown under different farming practices in Australia. Grain farming processes are identified and "typical" farming
more » ... "typical" farming operation data are collected from several sources, including published and unpublished literature, as well as expert interviews. The direct on-farm energy uses are assessed for 27 scenarios, including three high value grain crops-wheat, barley and sorghum-for three regions (Northern, Southern and Western Australia) under three farming conditions with both dryland (both for conventional and zero-tillage) and irrigated conditions. It is found that energy requirement for farming operations is directly related to the intensity and frequency of farming operations, which in turn is related to tillage practices, soil types, irrigation systems, local climate, and crop types. Among the three studied regions, Western Australia requires less direct on-farm energy for each crop, mainly due to the easily workable sandy soils and adoption of zero tillage systems. In irrigated crops, irrigation energy remains a major contributor to the total on-farm energy demand, accounting for up to 85% of total energy use. As a developed country and a major party of UNFCCC, Australia has a significant responsibility for emissions reduction. Currently, Australia shares 1.18% of global GHG emissions, 1.21% of global GDP and 0.33% of the global population [6] . From 2008 to 2013, Australia reduced its annual average carbon intensity by 4.6% [3] , and in fact, this was the world record. This was achieved mainly by structural changes, new technologies, fuel switching and improvements in energy efficiency [7] . However, as noted, this is not enough yet. Globally, agriculture is one of the major sources of energy consumption and therefore GHG emissions. With more intensive and modernized farming systems, during the period 1990-2005, global GHG emissions from agriculture increased by 14%, at an annual rate of 49 Mt CO 2 e/year [8] . In 2010, GHG emissions from agriculture are estimated to be 5.6 Gt CO 2 e/year to 6.4 Gt CO 2 e/year [9-11], i.e., about 11.4% to 13.1% of global emissions. If the production of agricultural inputs and various downstream activities are considered, the agricultural sector contributes a further 3% to 6% of global emissions [12] . Australia is one of the largest GHG emitting countries from the agriculture sector in the world. Its agricultural sector accounts for 15% of national GHG emissions and is the second largest source of emissions [13] . This proportion is significantly higher than those in Central and Eastern Europe, the former Soviet Union and the USA [14] . In order to reduce GHG emissions from the agricultural sector, the previous Australian Government implemented Carbon Farming Initiatives (CFIs). The current Government replaced it with the Direct Action Plan called "Emission Reduction Fund (ERF)" and allocated A$2.55 billion to establish the Fund in the 2014-2015 budgets [15] . ERF allows farmers and other land managers to earn carbon credits by storing carbon or reducing GHG emissions on land. This would allow them to adopt some best management practices and earn carbon credits and reputational benefits at the same time. The uptake of ERF is likely to be good. As of 31 August 2015, 390 projects are registered and 16.3 million Australian Carbon Credit Units (ACCUs) have been issued to these projects [16] . Australia has set 5% unconditional emission reduction targets for 2020 from 2000 levels, and with this initiative agriculture is expected to meet this target [16] . So far, the majority of the registered projects under the ERF are from sequestration projects, mainly from forestry activities. However, the grain industry in Australia could have a good opportunity in reducing energy consumption and thereby GHG emissions. However, due to limited research the grain industry is not able to target where they have an opportunity to increase energy efficiency and participate in the ERF. This study aims to examine and compare on-farm energy use for three high value grain crops grown under three major farming practices in three agro-ecological zones in Australia. This will help farmers to understand the range of energy uses and also to pinpoint where their energy use is highest and the potential savings achievable. Several studies have quantified the energy consumption associated with crop production in various countries including: (1) sugar beet production in the UK [17]; (2) arable and outdoor vegetable production in New Zealand [18]; (3) field crops (wheat, cotton, maize, sesame) and vegetables (tomato, melon, watermelon) [19], tomato [20], sugar beet [21], stake-tomato [22] and grape production [23] in Turkey; (4) wheat production in India [24] ; and cotton and lucerne production in Australia [25] [26] [27] . However, these studies have not compared the energy consumption from a broad range of farming practices currently in practice such as zero tillage, conventional tillage and irrigated farming systems. This paper is the first in this direction. In this study, direct energy used for various on-farm operations such as tillage, fertiliser application, boom spraying, planting, aerial spraying and water pumping is considered. A large amount of indirect energy is also required for: (1) the production, packaging, storing and transportation of various farm inputs such as fertilisers, chemicals (herbicides, insecticides, fungicides and plant regulator), fuels and farm machineries; and (2) post-harvesting operations such as transportation and drying of harvested products. However, energy used for these operations are not considered in this study. Similarly, human energy is also required for on-farm operation but it is
doi:10.3390/en81112353 fatcat:j7gkd5uphffidce3rwqgz2sq7a