恭城沙田柚果实品质与土壤环境化学的研究

Discussion on the Quality of Shatianyou (Citrus grandis) and Soil Environmental Chemistry in Gongcheng

在恭城县城选择三种不同情况的沙田柚环境（挂果好，当年产３００多个；挂果一般，当年产５０个；从不挂果，树龄已有８年，结果无望）采样，分析土壤、果实、树枝叶的常量元素和微量元素。结果表明，恭城沙田柚全糖含量平均值达１０％以上，可溶性固形物含量达１７％，柠檬酸０．３１％，糖酸比和固酸比多在３０以上。品质优的沙田柚生长的土壤Ｋ２Ｏ、Ｐ２Ｏ５含量分别为１．８００３％～２．２１２５％和０．１５２４％～０．１８１８％，不挂果沙田柚土壤中Ａｌ２Ｏ３含量高达２１．１５％。认为恭城沙田柚土壤环境化学背景条件是：Ｌａ＜５０×１０－６，Ｙ＜３０×１０－６、Ｐｂ＜６×１０－６；果皮中相应微量元素的含量特征是：Ｌａ＜１×１０－６、Ｙ＜５×１０－６、Ｂａ＜１００×１０－６。建议恭城县的沙田柚适当增施Ｚｎ、Ｃｕ。

The soil, fruits, leaves and twigs of Shatianyou (Citrus grandis) were collected to test macroand micro elements from three kinds of different environments of Gongcheng county, in which the first situation is excellent fruitage with more than 300 fruits per tree in the current year; the second one is a common fruitage with 50 fruits, and the third one hasnt any fruits in the tree for 8 years and hopeless in the future. The results showed that the average content of sugar was more than 10%,the soluble solid state materials was 17%, citric acid was 031%. The ratios of sugar to acid and solid sate materials to acid were more than 30.The contents of K2O and P2O5 in the soil where the good quality Shatianyou trees growed were 130% to 221% and 015% to 018%, respectively. The soil where the trees are fruitless contains more than 2115% of Al2O3 . The soil environmental chemistry background of the Shatianyou is La<50×10-6, Y<30×10-6,Pb<6×10-6,and the element contents of the fruitcoat are La<1×10-6, Y<5×10-6. It is suggested that the fertilizers of Zn, Cu and B should be added more in the Shatianyou gardens of Gongcheng county area.