1Institute of Vegetable,Guangdong Academy of Agricultural Sciences,Guangzhou 510640,Guangdong,China;2College of Horticulture,South China Agricultural University,Guangzhou 510642,Guangdong,China
Abstract:The soils from the vegetable fields in Guangdong were sampled and analyzed in this study.The results indicated that the pH values of soil from different vegetable bases varied from 3.15 to 8.45,the average value was 5.71,and 77.09 percent of the analyzed soil were weakly acid.The contents of alkali dispelled nitrogen in all analyzed soil varied from 9 to 554 mg·kg-1,averaged 96.59 mg·kg-1,and 84.6 percent of them were lower than the medium level,which indicated that these soil need supplement of nitrogen.The contents of available phosphorus in soil varied from 1.03 to 1 075 mg·kg-1 and averaged 63.59 mg·kg-1,which were at medium and high level.The contents of available potassium varied from 12.4 to 1 275 mg·kg-1 and averaged 138.67 mg·kg-1,and 65.98 percent of the vegetable fields required to apply potassium fertilizer.The contents of commutative calcium in soil varied from 0.012 to 28.210 cmol·kg-1 and averaged 8.96 cmol·kg-1.82.0 percent of the soil were abundant in calcium.There is no need to supply calcium.The contents of commutative magnesium varied from 0.23 to 8.58 cmol·kg-1 and averaged 1.34 cmol·kg-1.77.58 percent of the vegetable fields were deficient in magnesium,thus magnesium fertilizer should be applied.In conclusion,the soil nutrients,such as nitrogen,phosphorus,potassium,calcium,magnesium,in the different vegetable planting soils were imbalanced in Guangdong,and most vegetable fields were lack of nitrogen,potassium,and magnesium,but were rich in calcium contents.