Abstract:

Based on the data collection through soil fertility survey of apple orchards，farmer interviewing and agricultural statistics database，the characteristics of P input，surplus and P load were studied using nutrient balance method at major apple production regions in Shandong Province. The results showed that the average application rate of P fertilizer（P₂O₅）was 676.17 kg · hm^-2，and the P through inorganic fertilizer application was 477.36 kg · hm^-2（70.60% of the total P input）. The characteristic of P input was significantly difference between the three different regions. The highest P input rate（776.52 kg · hm^-2）was found in Jiaodong apple production region，and the percentage of chemical phosphorus was 69.14%，which was the lowest in the three regions；the lowest P input rate（348.90 kg · hm^-2）was found in Southwestern area of Shandong，and the percentage of chemical phosphorus was 82.95%，which was the highest in the three regions. P surplus was investigated in the 97.82% of surveyed orchards，with the average amount of 407.45 kg · hm^-2，and the highest P surplus rate was found in Jiaodong apple production region（615.62 kg · hm^-2），followed by Central south area of Shandong（342.81 kg · hm^-2），and South western area of Shandong（263.92 kg · hm^-2）was the lowest. Soil Olsen-P level in 67.34%，40.51%，and 19.13% in the surveyed orchards had been over the risk threshold level of Olsen-P（50 mg · kg^-1）in Jiaodong，Central south area of Shandong，and South western area of Shandong apple production region，respectively. Overall，up to 56.69% of the apple orchards exist phosphorus environment risk in Shandong Province，and the soil Olsen-P content in these orchards was 108.34 mg · kg^-1，which 2.17 times of the risk threshold level of P.

Key words: apple, orchard, phosphorus input, phosphorus surplus, phosphorus environment load risk