Survey of soil available zinc content in navel orange orchards in southern Jiangxi province

【Objective】This study was to understand the content of soil available zinc in navel orange orchards in southern Jiangxi province.【Method】Uncultivated soil samples(US) and cultivated soil samples(CS) collected from 446 orchards in 16 counties were analyzed.【Result】The results showed that soil acidification was obvious,80.78% US and 90.87% CS were acidic(pH5.5),among which 30% of US and 40% of CS were highly acidic(pH4.5).Both the average organic matter(OM) contents of US and CS were in the low range(15 g.kg-1),but the average OM content of CS was higher than that of the US.The average available zinc(AZ) contents of the US and CS were 1.50 mg.kg-1 and 3.09 mg.kg-1,respectively.77.29% of US and 58.10% of CS were zinc-deficient(AZ 2 mg.kg-1),and only 10.92% of US and 16.35% of CS were zinc-suitable(2 to 3 mg.kg-1AZ).Both the soil pH values and OM contents showed highly significant positive correlation with the soil AZ contents.Both the soil available phosphorus and copper contents showed 0.420 and 0.502 significant positive correlation with the soil AZ contents,respectively.【Conclusion】Both the US and CS in navel orange orchards of southern Jiangxi province were highly acidifying and severe zinc-deficient,and the application of lime,organic fertilizer and alkaline zinc fertilizers was recommended.