Global Maize Project in China: Liufangzi, Gongzhuling, Jilin Province

A long-term field experiment was established in 2009 in Liufangzi, Gongzhuling City, Jilin Province, where mono-cropping of spring maize is common. The experiment was conducted to compare the performance of ecological intensification (EI) practices with farmers’ practices (FP) for maize yield and nitrogen (N) use efficiency. The EI and FP practices differed in fertilizer rates, time, cultivars, and planting density. The applied fertilizer rates for EI and FP were 200-75-90 kg N-P2O5-K2O/ha and 251-145-100 kg N-P2O5-K2O/ha, respectively. Three subplots included: N applied in all years (N all yr); N applied in two out of three years (N 2/3 yr.); and no N applied in any year (N 0 yr.).

The EI (N all yr.) treatment produced 13 t/ha of grain yield, which was higher than the grain yield (11.4 t/ha) in the FP treatment that received higher N input. The agronomic efficiency (AE), partial factor productivity (PFP), and recovery efficiency (RE) of N were calculated for the treatments to assess the agronomic effectiveness of the EI treatment. The AE, PFP, and RE of N were 44.9 kg/kg, 61.0 kg/kg, and 75.1% in the EI treatment; while the corresponding values in the FP treatment were 30.6 kg/kg, 42.7 kg/kg, and 52.5%, respectively. The EI treatment with N application in two out of three years (N 2/3 yr) produced similar grain yield (13 t/ha) as the EI (N all yr.) treatment.