本文在分析讨论四川紫色土、黄壤中硼、锌含量状况及其影响因素的基础上,对它们的丰缺趋势进行了评价。指出这两类土壤均系缺硼土壤;缺锌的差别甚大,紫色土比黄壤普遍。据此提出因地制宜地推广应用硼、锌微肥的建议。

In the paper,contents of B and Zn in purplish soil and yellow earth of Sichuan were shown,the availability and its effeeting factors of B and Zn were discussed. At the same time, the rich-deficient status of available B and Zn were evaluated from developing agro-production. The average contents of total B in purplish soil and yellow earth are 70 and 97 ppm respectively. Their available B contents are 0.19 and 0.18ppm. In94.3 to 100% of the analysed samples of purplish soil,the available B are below the critical value(0.5ppm),and in 96.7to 100%of the samples of yellow earth, the available B are below that,too.They are considered to be B deficient soil and have been proved by a series of field experiments. The average contents of total Zn in purplish soil and yellow earth are 106 and 129 ppm respectively.Their availabel Zn contents are 1.16 and 1.75 ppm respectively.However,the content of available Zn varies greatly among different kinds of those soil. Cailcareous purplish soil of which is the lowest,in72% of the analysed samples(nonirrigated farming land)and 85% of the collected samples(paddy field)are below the critical value(1.0 and 1.5 ppm)respeetively.Consequently,it is the most important soil of Zn deficiency in Sichuan. In neutral purplish soil and acidic purplish soil, the area of Zn def icient soil are about half of their distributing area. As a whole of yellow earth,the available Zn content of them are richer but a part of them uased as paddy field has 50 to 75% to be below the critical value,except yellow earth developed on limestone. In future,it is indispensable to apply B and Zn fertilizers in the soils of B and Zn deficiency. there will be an increase in yield of rapeseeds,cotton, maize,paddy,and some fruit trees,etc.