Sustainability Estimation of Oat:Pea Intercrops from the Agricultural Life Cycle Assessment Perspective

Abstract

Winter cereal:legume intercropping is considered a sustainable arable farming system not only in temperate regions but also in Mediterranean environments. Previous studies have shown that with suitable crop stand composition, high grain yield can be achieved. In this study, a life cycle assessment (LCA) of the influence of sowing ratio and nitrogen (N) fertilization on grain nitrogen yield of oat (Avena sativa L.) and pea (Pisum sativum L.) in intercrops was performed to find the optimal design to achieve low environmental impact. This study compared the environmental impact of oat:pea intercrops using agricultural LCA. Monocrops of oat and pea and substitutive intercrops, which were fertilized with different levels of N, were compared. The system boundaries included all the processes from cradle to farm gate. Mass-based (grain N yield) and area-based (land demand for generating the same grain N yield) functional units were used. The results covered the impact categories related to the agricultural LCAs. The ReCiPe 2016 Midpoint and Endpoint characterization model was used for the data expression. According to the results, an unfertilized combination of oat and pea (50%:50%) had the lowest environmental impact in comparison with the other 14 assessed variants and selected impact categories. In the assessed framework, pea monocrops or intensively fertilized oat monocrops can also be considered as alternatives with relatively low impact on the environment. However, an appropriate grain N yield must be reached to balance the environmental impact resulting from the fertilizer inputs. The production and use of fertilizers had the greatest impact on the environment within the impact categories climate change, eutrophication, and ecotoxicity. The results indicated that high fertilizer inputs did not necessarily cause the highest environmental impact. In this respect, the achieved grain N yield level, the choice of allocation approach, the functional unit, and the data expression approach played dominant roles.

Spatial differences influence nitrogen uptake, grain yield, and land-use advantage of wheat/soybean relay intercropping systems

“…Similarly, our results also showed the growth improvement in soybeans after the harvesting of wheat; in addition, the extra growing space for soybeans in wide strips than narrow strips led to better resource use and the formation of yield components and yield. Altogether, the higher total nitrogen uptake in intercropping systems with the same nitrogen inputs verified the better niche complementarity and less environmental impact of the wheat/soybean relay intercropping systems over their sole systems 54 , 55 . Furthermore, the highest total nitrogen uptake in wide strips of wheat/soybean relay intercropping systems verified that wider strips complement the temporal differences between wheat and soybean in obtaining yield and ecological advantages.…”

Row ratio increasing improved light distribution, photosynthetic characteristics, and yield of peanut in the maize and peanut strip intercropping system

“…Chlorophyll is the main carrier of plant photosynthesis, and Chla determines photosynthesis, while Chlb determines the breadth of the spectrum utilized (Brestic et al, 2015). Studies have shown that intercropping increases the relative chlorophyll content of intercropped oats, peanuts, and soybeans (Yao et al, 2017;Bernas et al, 2021;Shi et al, 2021). Our study showed that different row ratio configurations changed chlorophyll content and photosynthetic efficiency in peanut, with the M4P8 pattern increasing the content of Chla, Chlb, and Chla+b in leaves, decreasing the ratio of Chla/b, and enhancing the efficiency of strong and weak light utilization (Figure 3).…”

Application of Life Cycle Assessment (LCA) to cereal production: an overview

“…Entering on Scopus the keywords related to Oats, Barley, Rye, Sorghum and Millet (Table 3), there are 206 articles (15% compared to the production related to cereals and LCA), but among these, only few papers dealt with LCA. 2021) [62] whose objective was to evaluate the environmental profile of an oats-pea intercropping, and whose results show that, taking as FU 1 kg of product (from cradle to gate) and 9 impact categories, intercropping without the use of fertilizers is a sustainable and effective type of cultivation. As for the last two cereals, Rye and Millet, there are 18 and 4 research works respectively, but none of them deals with LCA.…”