Study Of The Influence Mechanism Of Bio-Organic Fertilizer On Soil Fertility And Its Subsequent Effects

With the excessive and blind use of chemical fertilizer,the problems such as the deterioration of soil fertility,nutrient imbalance,low fertilizer utilization rate,environmental pollution and other problems have been aggravated in recent years.Based on the current situation and the background of organic fertilizer substitution advocated by the country,actively seeking efficient and environmentally friendly chemical fertilizer alternatives has become the focus of agricultural research.As a new type of fertilizer,bio-organic fertilizer has the dual effects of organic fertilizer and microbial fertilizer.In recent years,the application of bio-organic fertilizer in agricultural production has achieved good results.This makes it more meaningful to study the effect of bio-organic fertilizer on soil fertility.In this paper,a soil culture experiment was conducted to explore the effects of different application rates of bio-organic fertilizer on the fertility of red soil and yellow cinnamon soil,including physical,chemical and biological fertility;pot experiments and field experiments were used to verify the effects of bio-organic fertilizer on cash crops and tea garden soil.The treatments of outdoor soil culture and pot experiment are: T0: no fertilization,T1:0.67g/kg,T2:1.33g/kg,T3:3.33g/kg,T4::6.67g/kg,T5:13.33g/kg;The experimental treatments of indoor soil culture are CK: no fertilization,treatment 1:3.33g/kg,treatment 2:6.67g/kg,treatment 3:13.33g/kg and treatment 4:20g/kg.The test results are as follows:1.The application amount of bio-organic fertilizer has a significant effect on soil bulk density,and the bulk density decreases with the increase of fertilizer application rate and culture time.Under the influence of time,all fertilization treatments could significantly reduce the soil bulk density.The number of > 0.25 mm grain size aggregates in two kinds of soil basically increased with the change of fertilizer application rate and time.2.For yellow cinnamon soil,bio-organic fertilizer decreased the soil p H value,and the p H value of each fertilizer application group was finally stable between 6.57 and6.59.The contents of soil organic matter,total nitrogen,available nitrogen,available phosphorus,available potassium and CEC were increased.The content of organic matter in T5 was significantly higher than that in other treatments,and there was no significant difference between T0 and T1.There was no significant difference in total nitrogen content between T1,T2,T3 and T0 during the sampling period,but there was significant difference between T4,T5 and other treatments.There was no significant difference in available nitrogen content between T0 and T1,and there was no significant difference among T2,T3,T4 and T5.The content of available phosphorus in soil was T4 > T5 > T3 > T2 > T1 > T0.The content of available phosphorus increased little in the early stage of culture,and then began to increase.There were significant differences in available potassium content and cation exchange capacity between T2,T3,T4,T5 and T0.For red soil,the application of bio-organic fertilizer decreased the soil p H value,and the p H of each treatment increased with the increase of culture time.Fertilization increased the contents of soil organic matter,total nitrogen,available nitrogen,available phosphorus,available potassium and CEC.With the extension of culture time,the content of organic matter in T0,T1,T2 and T3 increased at first and then decreased,reaching the maximum at 120 days,while the content of organic matter in T4 and T5 increased with the increase of culture time.There was no significant difference between T1,T2 and T0,while there was significant difference between T3,T4,T5 and T0.The contents of T0 and T1 available nitrogen changed little,but the contents of T2,T3,T4 and T5 showed differences in the later stage of culture.The content of available phosphorus is T5 > T4 > T3 > T2 > T1 > T0.At the same time,T2,T3,T4 and T5 could significantly increase the content of available potassium.The CEC of T1 and T2 reached the maximum at 60 days,T3 reached the maximum at 90 days,and T4 and T5 reached the maximum at 120 days.3.The content of microbial biomass carbon and nitrogen increased with the increase of fertilizer application in the two kinds of soil,and reached the maximum at120 days;there was significant difference among all treatments of yellow cinnamon soil,and there was no significant difference between T1 and no fertilizer application group in red soil.There was significant difference between other treatments and no fertilizer application group.4.For yellow cinnamon soil,the application of bio-organic fertilizer had a certain effect on the soil bacterial community.At the genus level,the application of bio-organic fertilizer increased the abundance of some beneficial bacteria,such as Lysobacter(lysobacteria),Massilia(Maasai),and decreased the abundance of Gemmatimonadaceae＿uncultured.For red soil,the effect of low and medium dose bio-organic fertilizer on soil bacterial community diversity is non-directional,while the effect of high-dose bio-organic fertilizer on soil bacterial community diversity is directional.At the genus level,the application of high-dose bio-organic fertilizer increased the abundance of Gemmatimonadaceae＿uncultured,Ellin6067,Sphingomonas and SC-I-84＿norank,and decreased the abundance of Vicinamibacterales＿norank,Subgroup 7＿norank,Vicinamibacteraceae＿norank and RB41.5.The biomass(dry weight)and total phosphorus,total nitrogen and total potassium of pakchoi increased with the increase of fertilizer application in yellow cinnamon soil,and there were significant differences among treatments.For red soil,the biomass(dry weight)of pakchoi and the content of total nitrogen,total phosphorus and total potassium increased with the increase of fertilizer application.After the application of bio-organic fertilizer,the contents of porosity,p H,organic matter,cation exchange capacity,available phosphorus and available potassium in tea garden soil were increased,and the fertility of tea garden soil was improved.