ObjectivesSoil nutrients status in the main apple production regions of Shaanxi Province was studied to provide a scientific support for formulating a suitable fertilization strategy and soil nutrients management.

MethodsFrom 2012 to 2016, soil samples in 0–40 cm depth were collected from apple orchards in the main production regions located in Yan’an, Tongchuan, Weinan, Xianyang and Baoji cities of Shannxi Province, China, and the numbers of sampling sites were 17208, 2634, 8589, 14723 and 303, respectively. Soil organic matter, available N, available P and K were determined and were further analyzed by classification standards of the soil nutrients status in apple orchards.

ResultsThe mean contents of soil organic matter, available N, P and K were 11.5 g/kg, 57.1 mg/kg, 13.0 mg/kg and 160.4 mg/kg, respectively, which occupied 33.3%, 61.8%, 85.0% and 50.4% of the orchards in the low and lower levels. The soil nutrient contents were different in different regions, basically higher in the west and south and lower in the east and north, and with the highest in Baoji City and lowest in Yan’an City. In Yan’an, the average soil organic matter, available N, available P and K contents were 9.5 g/kg, 49.4 mg/kg, 9.0 mg/kg and 140.0 mg/kg, respectively, their proportion in the low and lower levels accounted for 61.6%, 77.7%, 99.3%, 67.5%, respectively. In Tongchuan City, the average soil organic matter, available N, P and K contents were 14.2 g/kg, 62.0 mg/kg, 13.9 mg/kg and 181.6 mg/kg, and the percentages of the orchards in the medium level and above was 88.9%, 53.6%, 24.7% and 67.2%, respectively. Soil organic matter, available N, available P and K in Weinan orchards were 13.1 g/kg, 61.6 mg/kg, 13.7 mg/kg and 170.1 mg/kg on average, and those in Xianyang were 12.3 g/kg, 62.7 mg/kg, 16.7 mg/kg and 173.2 mg/kg. In Weinan, the soil organic matter content was in the medium level and above in 83.2% of the orchards, while that in Xianyang was 85.7%. In terms of soil available N, 54.6% of the orchards of Weinan and 49.4% of the orchards of Xianyang were in the low and lower levels. What’s more, the percentages of soil available P in the low level and below in Tongchuan and Xianyang were higher than 70%. For the soil available K, 57.4% of the orchards in Weinan and 60.9% of the orchards in Xianyang were in middle and upper level. The average contents of soil organic matter, available P and K of Baoji were 17.5 g/kg, 23.4 mg/kg and 179.2 mg/kg respectively, which made up 97.4%, 64.9% and 70.0% of the orchards separately in the medium and above levels. Meanwhile the mean available N was 78.3 mg/kg, and only 21.7% of the orchards were in the low and lower levels.

ConclusionsSoil nutrients in the main apple production regions of Shaanxi Province were relatively low, and varied among the apple orchards in different areas, so specific fertilization plans should be made according to local soil nutrient conditions.