不同改良剂对土壤盐渍化特性及燕麦生物排盐作用的影响

Effects of Amendments on Soil Salinization Characteristics and Biological Salt Removal of Oat

为探讨不同土壤改良剂在旱区盐渍土上的应用效果,通过单因素随机区组试验,以不施改良剂(T0)为对照,探究粉煤灰(T1)、生物炭(T2)、普通有机肥(T3)、糠醛渣(T4)、蚯蚓粪(T5)、腐殖酸(T6)六种改良剂单施以及分别使用单施用量的1/2进行不同改良剂粉煤灰+有机肥(T7)、粉煤灰+糠醛渣(T8)、生物炭+糠醛渣(T9)、蚯蚓粪+腐殖酸(T10)配施对土壤盐渍化特性和燕麦盐分积累的影响。结果表明,与T0处理相比,T1~T10处理下土壤Na^(+)、HCO_(3)^(-)、Cl^(-)和SO_(4)^(2-)含量分别降低37.18%~67.83%、35.25%~78.10%、45.16%~69.51%和6.60%~13.94%,K^(+)、Ca^(2+)和Mg^(2+)含量均增加;土壤全盐含量和钠吸附比(SAR)分别降低8.41%~15.97%和41.94%~69.70%;施用改良剂后土壤的pH值不同程度降低,T1、T2处理因改良剂自身的碱性导致土壤pH值降低效果不显著,T3~T10处理的土壤pH值较T0处理降低了5.09%~8.61%。改良剂配施对土壤Na^(+)、HCO_(3)^(-)、Cl^(-)、SO_(4)^(2-)含量、全盐含量及SAR、pH值的降低程度均优于单施,其中T7处理的降低效果最好。施用改良剂提高了燕麦的干草产量、地上部分的含盐量和盐分积累量。除T6处理外其他处理的燕麦盐含量较T0处理增加了1.43%~3.52%;T1~T10处理的燕麦盐分积累量增加了14.92%~34.64%,且盐分积累量增加幅度亦表现为配施大于单施。施用改良剂加速了耕层土壤的脱盐,T1~T10处理的脱盐率是T0处理的5~9倍,T7处理的脱盐率较T1~T5处理提高了4.99%~7.41%。综合来看,供试改良剂的单施及四种配施均具有降低试区盐渍土耕层土壤的盐度和碱化度的作用,且提升了燕麦的生物排盐作用;以粉煤灰与普通有机肥配施对耕层土壤盐渍化程度的降低效果最好。

To investigate the application effects of different soil amendments on saline soil in arid areas,a single factor randomized block experiment was conducted,with no amendment applied(T0)as the control,to explore the effects of six amendments,namely fly ash(T1),biochar(T2),ordinary organic fertilizer(T3),furfural residue(T4),earthworm castings(T5),and humic acid(T6),applied alone,as well as composite amendments of fly ash+organic fertilizer(T7),fly ash+furfural residue(T8),biochar+furfural residue(T9),and earthworm castings+humic acid(T10)applied at half of the single application rate,on soil salinization characteristics and oat salt accumulation.The results showed that compared with T0 treatment,the contents of Na^(+),HCO_(3)^(-),Cl^(-),and SO_(4)^(2-)in soil decreased by 37.18%-67.83%,35.25%-78.10%,45.16%-69.51%,and 6.60%-13.94%,respectively,under T1-T10 treatment,while K^(+),Ca^(2+),and Mg^(2+)contents increased.The total salt content and sodium adsorption ratio(SAR)of the soil decreased by 8.41%-15.97%and 41.94%-69.70%,respectively.After the application of amendments,the pH of the soil decreased to varying degrees.The T1 and T2 treatments had no significant effect on reducing the soil pH due to the alkalinity of the amendments themselves.The soil pH under the T3-T10 treatments decreased by 5.09%to 8.61%,compared with that under T0 treatment.The combined application of amendments showed better reduction in Na^(+),HCO_(3)^(-),Cl^(-),SO_(4)^(2-)contents,total salt content,SAR,and pH than single application did,with T7 treatment showing the best reduction effect.The application of amendments increased the forage yield,aboveground salt content,and salt accumulation of oats.Except for T6 treatment,the salt content of oats under other treatments increased by 1.43%to 3.52%compared with that under T0 treatment.The salt accumulation of oats treated with T1-T10 increased by 14.92%-34.64%,and the combined application showed greater increase in salt accumulation than the single application did.The application of amendments accelerated the desalination of topsoil.The desalination rate of T1-T10 treatments was 5-9 times higher than that of T0 treatment,and the desalination rate of T7 treatment increased by 4.99%-7.41%compared with T1-T5 treatments.In summary,the single application and four combination applications of the tested amendments all had the effect of reducing the salinity and alkalinity of the saline soil layer in the experimental area,and improving the biological salt excretion effect of oats.The combination of fly ash and ordinary organic fertilizer has the best effect on reducing the degree of soil salinization in the plow layer.