Attainable CO2 Emission of Ware Potatoes Under High Yield Conditions in Southern Chile

Abstract

The objective of the analysis was to calculate the attainable CO2 emissions associated with the production of one ton of potatoes in a high yield environment in southern Chile. Two field experiments were performed. The first field experiment used an optimal sowing date while the second experiment used a late sowing date. In each experiment, treatments were the factorial combination of (i) four N fertilization rates (0, 75, 150 and 250 kg N ha−1) and (ii) four P fertilization rates (0, 150, 300 33 and 450 kg P2O5 ha−1). The Cool Farm Tool – Potato (CFT) was used to calculate the amount of CO2 produced per one ton of potatoes and LINTUL-Potato was used to simulate potential yields. High variations in tuber yields were observed across experiments (90 and 36 t ha−1). The average tuber yield in experiment one (82 t ha−1) was greater than experiment two (51 t ha−1). Tuber yields were not significantly affected by N fertilization in either experiment. In contrast, tuber yield responded (P < 0.01) positively to P fertilization (10–82 %). The gaps between maximum and potential yields simulated in experiments one and two were 4 and 14 %, respectively. In experiment one, the average total CO2 emissions per ton of potatoes were lower than experiment two (41 and 72 kg CO2 eq t−1, respectively). In both experiments the total CO2 emissions were affected (P < 0.01) by both N and P fertilization. We conclude an average CO2 emission of 46 CO2 eq t−1 could be considered an attainable value for potato production systems with high technology intending to improve their carbon footprints in southern Chile.