白浆土腐殖质测定方法的比较研究

白浆土含有的五种形态 Zn 中,RES—Zn 占85%以上,含量顺序依次为:RES—Zn>OM—Zn>EXC—Zn>R_2O_3—Zn>Ca—Zn。各种形态 Mn 的含量顺序为:R_2O_3—Mn>RES—Mn>OM—Mn>EXC—Mn>Ca—Mn。R_2O_3—Mn 平均占 Mn 总量的37%,可能与频繁的土壤氧化还原过程有关。Mn 在土壤中的变化、移动、淀积和分布主要受土壤水分的变化—氧化还原过程所控制。从养分观点看,Zn 和 Mn 的有效态的含量都较高,可以大致满足植物的需要,但是否由此引起的离子颉抗作用妨碍 Fe、Ca 及 P 等的吸收,尚有待进一步研究。

RESEARCH ON COMPARISON OF METHODS FOR HUMIC ACID DETERMINATION OF ALBIC PLANOSOL

Three kinds of extracting solutions were used for humic acid research of planosol.NaOH,Na_4P_2O_7 and NaOH+Na_4P_2O_7.They are all suitable for this purpose.The extracting quantity gives a good correlation,and correlation coefficients for the three extractants are:r=0.9900~(**),0.9879~(**)and 0.9978~(**)respe- ctively.Comparison of Turin's method and quick method shows,both methods can be used for total humic acid analysis of planosolt as for cratical concentra- tion of coagulation and light thickness tests...