Life cycle assessment to compare the environmental impacts of different wheat production systems

Abstract

The share of fossil-based resources in the implementation of agricultural activities in Iran is very high. In this context, it is important to determine the environmental impacts of energy use in agricultural activities. The purpose of this study was to evaluate and compare the energy consumption and total environmental impacts of irrigated and rainfed wheat production in central Iran, Mahyar plain. For this purpose, data were collected from 120 irrigated and 90 rainfed wheat farms in three different farm size (<2 ha, 2-4 ha and more than 4 ha), through questionnaires and site visits. In this study, standard ISO life cycle assessment methodology was used to evaluate the total impact of all consuming inputs on environmental pollution and show the main hotspot in the production chain. Results of energy analyses showed that large farms used more energy per unit of farm land than that of small farms. Farmers also used higher input energy for irrigated wheat in comparison with rainfed system. The overall energy use efficiency for per unit farm of irrigated wheat production was only half of rainfed wheat production. Results of Life Cycle Assessment (LCA) models show that rainfed wheat actually produced more pollutions than irrigated wheat production because of lower yield in ha. In this study, the rate of Abiotic Depletion (AD) and Acidification (AC) impact were 0.002-0.003 kg Sb eq and 8.991-11.863 kg SO 2 eq for wheat production (irrigated and reainfed), respectively. Also the Ozone Layer Depletion (OLD) and Photochemical Oxidation (PO) were calculated 0.00002-0.00004 kg CFC11 eq and 0.145-0.174 kg C 2 H 4 eq for wheat production (irrigated and reainfed), respectively. The results showed that the main hotspots for irrigated and rainfed wheat production were chemical fertilizers and diesel fuel. Based on the results, it is suggested to use more intensive cropping systems (such as solar greenhouse) to decrease the intensity of input energy and increase the output level of productions with minimum environmental pollutions.

Towards Sustainable Farm Production System: A Case Study of Corn Farming

“…Furthermore, nitrogen fertilizers have also the highest negative effect on the resource depletion damage category followed by diesel fuel consumption. Our results are in line with the studies of Payandeh et al [45] and Taki et al [46]. Furthermore, the description of corn production indices through different impact assessment methodologies is presented in Table 4.…”

Optimizing Wheat Yield, Water, and Nitrogen Use Efficiency With Water and Nitrogen Inputs in China: A Synthesis and Life Cycle Assessment

“…The north region yielded higher environmental indexes that might attribute to N application rate, irrigation times, and seasonal precipitation ( Qiu et al, 2008 ; Liu et al, 2020 ). Our LCA results also indicated that irrigation and fertilization have a significant impact on environmental damages, such as GWP, emphasizing the need to decrease the intensity of input energy for sustainable wheat production ( Taki et al, 2018 ).…”

“…Comparable with other C 3 cereal crops, the productivity and agronomic input use efficiency of wheat is largely affected by many environmental and managerial factors, such as growing season temperature, irrigation methods, and N fertilization rate ( Fan et al, 2018 ). In addition, a lot of fossil fuel energy is used for producing agronomic inputs, such as chemical fertilizers, leading to severe environmental pollution, particularly, in those developing countries ( Taki et al, 2018 ). Information abounds with individual field studies investigating the impacts of one or two factors on wheat productivity and physiology at a single site ( Zwart and Bastiaanssen, 2004 ; Qin et al, 2015 ).…”

From Wood to Resin—Identifying Sustainability Levers through Hotspotting Lignin Valorisation Pathways

“…For emerging technologies and products, identifying environmental hotspots and providing information for decision-makers are seen as crucial starting points for sustainable product and process development [29,33]. Studies applying environmental hotspot analysis of various production systems of established technologies or process pathways can be found in the literature (e.g., in agricultural systems [39][40][41], food systems [38,[42][43][44], wastewater treatment [45,46], etc.). Besides investigating environmental aspects, approaches considering social aspects, such as sustainability hot spot analysis (SHSA), are also available in the literature [43].…”