硫酸铝对新开垦苏打盐碱水田的快速改良和培肥效果

Effects of Aluminium Sulphate on Rapid Amelioration and Fertility Improvement of Newly Reclaimed Soda Saline-alkali Paddy Field

通过田间试验,研究了硫酸铝(0,300,500,900,1400kg/hm^2)施用对新开垦苏打盐碱水田的快速改良和培肥效果。结果表明:与不施用硫酸铝的对照处理相比,施用硫酸铝后土壤pH、全盐量、交换性钠、阳离子交换量和碱化度降低;可溶盐组成中,CO32-、Ca2+、K+、Na+含量通常降低,SO42-含量增加,而HCO3-、Cl-和Mg2+含量没有显著的变化,从而使得(CO32-+HCO3-)/(Cl-+SO42-)比值下降;土壤有机碳、胡敏酸碳、富里酸碳、胡敏素碳及各粒径水稳性团聚体有机碳含量均显著增加,而水溶性有机碳含量则显著降低;土壤有机碳组成中,烷基碳和烷氧碳的比例增加,而芳香碳和羰基碳的比例降低,导致烷基碳/烷氧碳和疏水碳/亲水碳比值降低而脂族碳/芳香碳比值增加;此外,土壤中>2mm水稳性团聚体和<0.053mm粉黏粒组分的比例降低,而2~0.25,0.25~0.053mm水稳性团聚体的比例增加,导致水稳性团聚体的平均重量直径降低;随硫酸铝施用量的增加,上述规律性通常表现得更为明显,但900,1400 kg/hm^2硫酸铝用量间通常没有明显的差异。说明硫酸铝施用能降低土壤碱性和盐分含量,同时有助于提高土壤有机碳含量并改善其品质,是快速改良和培肥苏打盐碱土的有效方式;但值得注意的是,硫酸铝单独施用不利于土壤结构性的改善,还需要与其他改良措施配合使用。

The effects of aluminium sulphate(0,300,500,900 and 1400 kg/hm^2)application on the rapid amelioration and fertility improvement of newly reclaimed soda saline-alkali paddy field were studied through a field experiment.Compared with the control treatment without aluminium sulphate,the pH value,total salt content,exchangeable sodium,cation exchange capacity,alkalinity,CO32-,Ca2+,K+,Na+,water soluble organic carbon(C),aromatic C,carbonyl C,ratios of alkyl carbon/O-alkyl C and hydrophobic C/hydrophilic C,proportions of>2 mm water-stable aggregates and<0.053 mm silt plus clay fractions,and mean weight diameter of water-stable aggregates in soil generally declined,while SO42-,(CO32-+HCO3-)/(Cl-+SO42-)ratio,total organic C,humic acid C,fulvic acid C,humin C,organic C associated with various water-stable aggregate size fractions,alkyl C,O-alkyl C,aliphatic C/aromatic C ratio,proportions of 2~0.25 mm and 0.25~0.053 mm water-stable aggregates increased after the application of aluminium sulphate.The above effects were generally more obvious with the increase of aluminium sulphate application rates,but the differences between 900 and 1400 kg/hm^2 application rates were generally not statistically significant.The above results suggested that the application of aluminium sulfate could decline soil alkalinity and salinity,increase soil organic C contents and improve its quality,which was thus an effective way for the rapid amelioration and fertility improvement of soda saline-alkali soil.However,it is noteworthy that the application of aluminium sulfate alone is not beneficial to the improvement of soil structure,and it is necessary to combine aluminium sulfate with other amelioration measures.