The aim of this study was to investigate the effect of biochar application on the water holding capacity and fertility of the soil composited with feldspathic sandstone and sand. A pot experiment with five treatments [0 g/kg biochar (CK)

10 g/kg biochar (T10)

20 g/kg biochar (T20)

30 g/kg biochar (T30)

50 g/kg biochar (T50)] was conducted over a corn growing season. Results showed that the application of biochar significantly decreased soil bulk density

but it was not a linear correlationship between the reduction of soil bulk density and biochar application rates. Specifically

soil bulk density was the minimum with 30 g/kg biochar applied

but 50 g/kg biochar application instead increased soil bulk density. There was a positive correlation between field water capacity and biochar application rates ranging from 0 g/kg to 30 g/kg

but the application of 50 g/kg biochar decreased soil field water capacity. Soil pH

total salt content

organic matter content and available potassium content increased with the increases of biochar application rates. Soil available phosphorus content firstly increased with biochar application rate but then decreased when 50 g/kg biochar was applied. Briefly

soil pH

total salt content were 8.80

2.51 g/kg respectively with 50 g/kg biochar applied. Furthermore

it was also found that the dry weight of maize roots

the dry weight of maize aboveground part

the 100-grain weight and the yield per plant showed a significant increase with the increases of biomass application rates ranging from 0 g/kg to 30 g/kg

but the application of 50 g/kg biochar decreased these biomass indexes significantly. Overall

the application of biochar could improve soil physicochemical properties and fertility and the growth and yield of maize

but the effect would be lowered when biochar application rate is more than 30 g/kg. Accordingly

the recommended biochar application rate is 30 g/kg to improve soil quality and crop yield under the present experimental conditions.