What are the key factors affecting maize yield response to and agronomic efficiency of phosphorus fertilizer in China?

[Display omitted] • Summarized China's 7025 phosphorus (P) fertilizer field trials results on maize. • Average yield response to P (YR P) in China's maize was 16.58 %. • Average agronomic efficiency of P (AE P) in China's maize was 12.69 kg kg−1. • YR P and AE P are comprehensively affected by management and natural conditions. • Rational P fertilization should consider more on variety followed by soil fertility. Excessive phosphorus (P) fertilization in intensive agricultural areas in China has caused resource waste and serious environmental problems, resulting in a need to evaluate P use efficiency to develop reasonable, sustainable P use strategies. This study summarizes the yield response to P (YR P) and the agronomic efficiency of P (AE P) in maize (Zea mays L.) in the primary maize-producing regions of China. We collated data from 7025 field experiments performed between 2005 and 2010 in these regions to quantify the effects of different soil properties (soil type, pH, Olsen-P, organic matter, Ava-N, and Ava-K) and management practices (variety and planting system) on the YR P and AE P and to clarify their relative importance to the YR P and AE P. The average P fertilizer application rate, YR P and AE P of maize in China were 92.3 kg ha−1, 16.58 % and 12.69 kg kg−1, respectively. The YR P and AE P of maize in red soil were significantly lower than those in other soil types. In addition, the YR P and AE P of maize increased with increasing soil pH. At soil Olsen-P levels below 15 mg kg−1, the YR P and AE P decreased with increasing soil Olsen-P; however, the YR P and AE P remained relatively stable at higher soil Olsen-P levels. The YR P and AE P of 'Haiyu 6' and 'Xianyu 335' were higher than those of other maize varieties. Among the different planting systems, spring maize with irrigation achieved the highest YR P and AE P (23.52 % and 14.37 kg kg−1, respectively). In addition, random forest analysis indicated that the maize variety should be prioritized over soil fertility indicators and P application rates when integrated P management strategies are formulated for maize. It was suggested that YR P and AE P can be improved by altering such soil properties and management practices, furthermore, variety is the most important factor affecting YR P and AE P in maize production systems in China. [ABSTRACT FROM AUTHOR]