Response of carbon footprint of spring maize production to cultivation patterns in the Loess Plateau, China

Agriculture is a primary contributor of greenhouse gas emissions and thus plays an important role in global climate change. Assessments of the carbon footprints of agricultural products are therefore helpful in climate change mitigation. The objective of this study was to provide a quantitative estimate of the carbon footprint of spring maize (Zea mays L.) production under different cultivation patterns. Four cultivation patterns were assessed in this study: traditional pattern, optimal pattern, super-high-yield pattern, and high-yield and high-efficiency pattern. The results showed that the greenhouse gas emissions from the agricultural inputs were 3225.2, 3152.9, 4557.2, and 4259.7 kg CO2-eq ha−1 for the traditional, optimal, super-high-yield, and high-yield and high-efficiency patterns, respectively, in the spring maize production process. Fertilizers, including chemical fertilizers and organic fertilizer, predominated among the contributors of total greenhouse gas emissions from agricultural inputs, accounting for 66.8, 65.9, 76.1, and 74.4% among the traditional, optimal, super-high-yield, and high-yield and high-efficiency patterns, respectively. The carbon footprint per yield among different cultivation patterns ranged from 0.48 kg CO2-eq kg−1 in the traditional pattern to 0.64 kg CO2-eq kg−1 in the high-yield and high-efficiency pattern, with intermediate values for the super-high-yield and optimal patterns. The N2O from soil and fertilizer application was the greatest contributor to the carbon footprint in spring maize production. Overall, higher yield and lower carbon footprint were concurrently observed under the super-high-yield pattern in the current study. Moreover, a reduction in the rate of fertilizers may provide a potential solution for reducing the carbon footprint of spring maize.