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

This long-term field experiment was initiated in 2009 in Liufangzi, Gongzhuling City, Jilin province, where mono-cropping of spring maize is common. The aim of the experiment was to compare the performance of ecological intensification (EI) practices with common farmers’ practice (FP) for yield and N use efficiencies. The main plot had two treatments: EI treatment with application of 180 kg N, 75 kg P₂O₅, 90 kg K₂O, 20 kg S , and 5 kg Zn/ha and FP treatment with application of 251 kg N, 145 kg P₂O₅ and 100 kg K₂O/ha. Three sub-plots included: N applied in all years (N all yr); N applied in 2 of every 3 years (N 2/3 yr); and no N applied any year (N 0 yr). In the year 2012, spring maize was planted on April 29 and harvested on September 24.

The EI treatment produced grain yields (12.3 t/ha) similar to the FP treatment (12.4 t/ha), although more N, P and K were applied in FP. However, the agronomic N efficiency (kg grain yield increase per kg N applied) was higher (37 kg/kg) in the EI treatment than in the FP treatment (8.4 kg/kg). Similarly, partial factor productivity of N (kg grain yield per kg N applied) was higher (68.5 kg/kg) in the EI treatment when compared with the FP treatment (49.4 kg/kg). This was possibly due to lower fertilizer N use in the EI treatment compared to the FP treatment. Grain yield under N 2/3 yr treatment was significantly lower than under the N all yr treatment, which demonstrated the value of N application in every spring maize growing season at the experimental site. IPNI-20