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 is 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: (a) EI treatment with 180-75-90-20-5 kg N-P₂O₅-K₂O-S-Zn/ha fertilizer application and (b) a FP treatment with 251-145-100 kg N-P₂O₅-K₂O/ha fertilizer application. Three sub-plots included: (a) N applied in all years (N all yr); (b) N applied in 2 of every 3 years (N 2/3 yr); and (c) no N applied any year (N 0 yr). In the year 2011, spring maize was planted on April 27 and harvested on September 24.

Ecological intensification treatment produced significantly higher grain yield (11.7 t/ha) than the FP treatment (11.1 kg/ha). Agronomic N efficiency (kg grain yield increase per kg N applied) was 42.3 kg/kg in the EI treatment and 29.2 kg/kg in the FP treatment. Similarly, partial factor productivity of N (kg grain yield per kg N applied) was 64.8 kg/kg with EI and 44.5 kg/kg with FP. EI with lower nutrient input obtained higher grain yield and nutrient use efficiency. Grain yield under N 2/3 yr treatment was significantly lower than under N all yr treatment, which demonstrated the value of N application in every spring maize growing season at the experimental site. IPNI-20