Estimating a new approach of fertilizer recommendation across small-holder farms in China

Over and imbalanced fertilization has caused a series of environmental problems and threaten the food security in China. On-farm experiments were conducted from 2010 to 2012 at 408 sites in seven provinces to evaluate a new fertilizer recommendation approach, Nutrient Expert (NE) for Hybrid Maize (Zea mays L.), to meet the requirements of nutrient management for small-holder farms in China. Compared with the current farmers' fertilizer practices (FP), NE maintained grain yield and profitability, but decreased 30.4% of nitrogen (N) fertilizer (68 kg N ha−1) and 11.3% of phosphorus (P) fertilizer (7 kg P2O5 ha−1), while potassium (K) fertilizer rate increased by 38.8% (19 kg K2O ha−1). NE increased agronomic efficiency of applied N (AEN) by 47.0%, N recovery efficiency (REN) by 51.0%, and partial factor productivity of applied N (PFPN) by 35.5%. More importantly, NE decreased by 21.5 and 49.7 kg ha−1 of apparent N loss for summer maize and spring maize as compared with FP, respectively. The differences in agronomic and environmental parameters between NE and FP confirmed that the Nutrient Expert for Hybrid Maize is a promising nutrient decision support tool which not only increasing grain yield, nutrient use efficiency and profit, but also reducing nutrient loss and environmental pollution.