Abstract:

To investigate the effects of different dosages of biochemical fulvic acid (BFA) on the improvement of soda saline-alkali soil and the response mechanism of maize growth,a pot experiment was conducted using soda saline-alkali soil from Inner Mongolia as the test soil and maize Dongdan 181 as the test variety.Four BFA application rates were set as 0(CK),2(FA2),4(FA4),8 g/kg(FA8).Soil nutrients,microbial diversity,maize salt tolerance,biomass,and other indicators were measured.The results showed that compared to the CK,soil pH decreased with increasing BFA dosage.The soil available phosphorus content increased significantly after the application of BFA,but there was no significant difference among the three treatments of FA2,FA4 and FA8 at 30,62 and 80 days after sowing.Soil salinity increased with the increase of BFA dosage,with an increase of 23.30%—89.32%.Soil exchangeable potassium content increased with increasing BFA dosage,while exchangeable calcium content gradually decreased.The proportion of <0.053 mm silt and clay fractions in the soil decreased by 6.49,9.92 and 13.97 percentage points under FA2,FA4,and FA8 treatments,respectively,compared to the CK treatment.Meanwhile,the proportion of 0.053—0.250 mm aggregates increased by 5.90,8.99 and 13.75 percentage points,the proportion of 0.250—2.000 mm aggregates increased by 0.55,0.87 and 0.21 percentage points,while the proportion of >2.000 mm aggregates increased by 0.04,0.06 and 0.01 percentage points,respectively,under the FA2,FA4,and FA8 treatments relative to the CK.Soil microbial diversity was significantly higher than that of CK after the application of BFA,but the FA8 treatment was lower than the FA4 treatment.The Na⁺/K⁺ ratio in both shoots and roots of maize was lower under FA2 and FA4 treatments than under the CK treatment,while the FA8 treatment increased the Na⁺/K⁺ ratio in the shoots.Maize biomass significantly increased in the mid-to-late growth stages under FA2 and FA4 treatments,while biomass significantly decreased under the FA8 treatment.In summary,the application of 2 g/kg or 4 g/kg of biochemical fulvic acid can positively reduce the alkalinity of soda saline-alkali soil,increase the content of available phosphorus in the soil,improve soil structure,improve soil microbial diversity,and enhance maize salt tolerance and biomass.However,exceeding this dosage range will significantly increase soil salinity and inhibit maize growth.

Key words: Corn, Saline-alkali soil improvement, Biochemical fulvic acid, High-throughput sequencing, Na⁺/K⁺, Salt tolerance

CLC Number: 

• S156.2

• S156.4

• S513玉米(玉蜀黍)