氟 对玉米产量品质及土壤性质的影响

适量氟对动物和人类健康有益, 而过量氟对动物和人类健康有害。为研究氟对玉米产量品质及土壤性质的影响, 采用盆栽试验研究了添加0、100 mg·kg^-1、200 mg·kg^-1、500 mg·kg^-1、1 000 mg·kg^-1 和1 500 mg·kg^-1 氟(NaF)对玉米产量、粗蛋白和淀粉含量及土壤pH、水溶性钙和微生物数量的影响。结果表明: 随氟处理浓度的增加玉米产量显著降低, 减产9.9%~85.4%; 玉米籽粒蛋白质含量显著增加, 从91.8 g·kg^-1 增加到108.8 g·kg^-1。加入氟100 mg·kg^-1 和200 mg·kg^-1 时, 淀粉含量表现为下降趋势，而当加入氟500 mg·kg^-1、1 000 mg·kg^-1 和1 500 mg·kg^-1 时, 淀粉含量表现为上升趋势。玉米不同部位氟含量基本上随氟浓度的增加而增加, 玉米根部和籽粒含氟量与氟添加量的相关性达极显著水平, 相关系数分别为r_根=0.998^**和r_粒=0.915^**; 叶含氟量与氟添加量的相关性达显著水平, r_叶=0.852^*; 玉米不同部位氟含量的大小顺序为根>叶>叶鞘>茎>籽粒。氟浓度在200 mg·kg^-1 时, 籽粒含氟量已超过无公害农产品标准1.0 mg·kg^-1。石灰性土壤添加氟后, 可使土壤pH 增加,从8.05 增加到8.70; 水溶性钙含量显著下降, 由2.71 g·kg^-1 下降到1.02 g·kg^-1。随氟浓度的增加土壤放线菌数量显著降低, 与对照相比, 降低0.92%~65.22%; 低浓度的氟可以促进土壤细菌、真菌的生长, 而高浓度的氟可以抑制细菌、真菌的生长。

Effects of fluoride on soil properties and yield and quality of maize

Fluorine is good for animal and human health, however, its excessive use is harmful for both animal and human health. A pot experiment was conducted to study the effects of fluorine on soil properties (pH, water soluble Ca and microbes) and on yield and quality of maize. The fluorine was added into the soil in form of NaF of 0, 100 mg·kg^-1, 200 mg·kg^-1, 500 mg·kg^-1, 1 000 mg·kg^-1 and 1 500 mg·kg^-1. The results showed that maize yield significantly decreased with increasing fluoride dose. Compared with the control, maize yield dropped on the average from 9.9% to 85.4%. However, maize grain protein content significantly increased on the average from 91.8 g·kg^-1 to 108.8 g·kg^-1. Under fluoride doses of 100~200 mg·kg^-1, starch content decreased. It, however, increased at fluoride doses of 500 mg·kg^-1, 1 000 mg·kg^-1 and 1 500 mg·kg^-1. Fluoride content in different parts of the maize plant increased with increasing fluoride dose. Fluoride contents in maize root, grain and leaf were significantly positively correlated with fluoride dose, coefficients were 0.998^**, 0.915^** and 0.852^*, respectively. The order of fluoride content in different parts of the maize plant was: root > leaf > leaf-sheath > stem > grain. With 200 mg·kg^-1 of fluoride dose, fluoride content in grains exceeded the safe agricultural product standard. Soil pH increased (from 8.05 to 8.70) and water soluble Ca decreased (from 2.71 g·kg^-1 to 1.02 g·kg^-1) with increasing fluoride dose. Compared with the control, actinomyce quantity decreased by 0.92%~65.22% with increasing fluoride dose. Low fluorine dose promoted bacteria and fungi growth, while the reverse inhibited bacteria and fungi growth.