Global Maize Project in China: Dahe, Shijiazhuang, Hebei Province

Project was initiated in 2009 from summer maize rotated with winter wheat to test how the performance of ecological intensification (EI) compares to that of current farmer practice (FP).


24 Mar 2015

2014 Annual Interpretive Summary

This long-term field experiment was initiated in 2009 in Dahe Experimental Station, Shijiazhuang, Hebei, where maize is double-cropped and rotated with winter wheat. The main plot had two treatments: (1) ecological intensification (EI) with application of 182 kg N, 107 kg P2O5 and 86 kg K2O/ha in winter wheat and 182 kg N, 73 kg P2O5 and 70 kg K2O/ha in summer maize; and (2) farmers’ practice (FP) treatment with application of 225 kg N, 120 kg P2O5 and 55 kg K2O/ha in winter wheat and 225 kg N, 120 kg P2O5 and 50 kg K2O/ha in summer maize. Three subplots included: (1) N applied in all three years (N all yr), N applied in two of every three years (N 2/3 yr), and no N applied (N 0 yr). Winter wheat (the tenth successive crop) was planted on October, 2013 and harvested in June, 2014, while summer maize (the eleventh successive crop) was planted in the same plots on June, 2014 and harvested on October, 2014. In 2014, the EI maize treatment was optimized with a high yielding variety, with high plant density of 79,500 plants/ha. The FP treatment used a common variety with a density of 67,500 plants/ha. For the EI treatment, half the N, half the K, and all the P was applied basally, while the remaining N and K was topdressed at stalk elongation. For FP, half the N and all P and K fertilizer was applied basally and the remaining N was top dressed at stalk elongation.

No significantly difference in grain yields were found in winter wheat (EI = 7.6 t/ha and FP = 7.5 t/ha) despite the extra fertilizer input under FP. For summer maize, the EI treatment produced significantly higher grain yields (10.3 t/ha) than FP (8.3 t/ha), although less N and P were applied under EI. Therefore, the agronomic efficiency (AE) for N was much higher under EI (20.8 kg/kg) compared to FP (7.0 kg/kg). Similarly, partial factor productivity (PFP) of N was higher in under EI (57.6 kg/kg) compared to FP (37.0 kg/kg).

The results demonstrated that maize yield under EI can be improved not only through 4R nutrient management, but by other best agronomic practices like variety improvement and and plant density.