上海土壤中微量元素的含量与分布的研究

植物必需的微量营养元素锌、锰、钼、硼、铜在土壤中供给不足或过剩时,都可能引起植物、动物及人体生理功能失调,生长发育受阻,诱发出各种特殊的生理病害。明确土壤中微量元素含量分布规律及其有效性问题,有助于采取措施来调剂微量元素的供应水平,对于农业生产的发展,以及维护人类和动物的健康,都具有重要的意义。本文就1978-1979年关于上海土壤中微量元素的含量分布及其有效性问题的研究,作一总结。

CONTENT AND DISTRIBUTION OF TRACE ELEMENTS IN THE SOILS OF SHANGHAI

Shanghai is an alluvial plain in the Yangtze delta. The main soil types are mostly swampy soil, meadow soil and coastal saline soil derived from alluvium of the Yangtze river. Variation of trace elements content in soils is mainly depended upon the different parent material. The range and mean value of the total content (in parenthesis) of trace elements in soils of Shanghai are as follows: Zn 20-102 ppm (65.5±11.0 ppm),B 20-76 ppm (52.6±11.8 ppm),Mo 0.3-2.0 ppm (0.75±0.34 ppm), Cu 11-38 ppm (23.0±4.6 ppm), Co 11-27 ppm (19.4±3.7 ppm), Mn 280-1076 ppm (540.7±127.7 ppm). The content of available trace elements varied greatly. The content of available copper of the soils in Shanghai (extracted by DTPA) was rather high with a mean value of 5.2±2.2 ppm. However the content of available molybdenum was very low with an average of 0.14±0.05 ppm (extracted by Tamm sol.).At the same time, there are a larger area of soils with lower or deficient in B, Co, Mn and Zn.Among the soil types mentioned above, coastal saline soil was higher in available B (0.82±0.30 ppm, extracted by hot water) and Mo (0.16±0.06 ppm), but lower in available Zn (0.82±0.42 ppm, estraeted by DTPA) and Co (0.34±0.18 ppm, extracted by 0.1 N HCl);the swampy soil was lower in available B (0.57±0.23 ppm),Mo (0.13±0.05 ppm) and Mn (122±49 ppm, extracted by 1 N neutral NH₄Ac+0.2% Hydroquinone),but was higher in available Co (1.09±0.38 ppm). The available content of B, Mo, Co, Zn in some meadow soils were lower. In recent years, more than 50 field experiments of trace element fertilizers in the suburbs of Shanghai revealed that B, Zn, Mn, Mo were effective to rape, wheat and vegetables in some soils.