Study On The Effect Of Fertilizing Management On Nitrogen Transition In Black Soil

The paper studied the rules of functional bacteria diversification (ammonifying bacteria,nitrobacteria, denitrobacteria) on the nitrogen transitions and soil enzyme transformation (urease,catalase) under the different fertilizer managements in agro-ecosystem of the black soil district inSongnen Plain and effects on the intensity of the process of ammonification, nitrification anddenitrification in soils in order to further study the mechanism of nitrogen transition in soils, supplyscientific basis on reasonable use of the nitrogen in soil and guidance for the nitrogenous fertilizerutilization in field practice and provide scientific reference for protecting black soil resource,reducing agricultural non-point pollution and producing the organic food.Main conclusions educed from this experiment were as follows:1. The effect of different fertilizing treatments on soil ammonifying bacteria, nitrobacteria,denitrobacteria was significant. The impact of separate fertilizer on ammonifying bacteria was notremarkable, but it could improve the growth of denitrobacteria. The manure application couldimprove the quantities of soil ammonifying bacteria, nitrobacteria and denitrobacteria.2. In the whole growing period, the effect of different fertilizing treatments on the soilammonification intensity, the nitrification intensity and denitrification intensity was significant. Theseparate manure and fertilizer application and combining of manure and fertilizer could improvesoil ammonification intensity, whereas the fertilizing application could decrease soilammonification intensity. The separate manure and fertilizer application and combining of manureand fertilizer treatments play the role in promoting nitrification intensity.3. The separate manure and fertilizer application and combining of manure and fertilizertreatments could improve the soil urease activity and catalase activity. However, the impact on soilenzyme was different among them; the effect of manure application is higher than that of fertilizeron improving the soil caralase activity.4. The separate manure and fertilizer application and combining of manure and fertilizertreatments could also improve the soil total nitrogen content. The degree of high manure level washighest. The next was low manure level. The fertilizing treatments were the lowest, however, theextent between high fertilizer treatment and low fertilizer treatment was similar. 5. Soil pH value, soil water content had definite impacts on the soil bacterium related with soilnitrogen transformation and biochemical intensity respectively. The higher pH value inhibited thegrowth of ammonifying bacterial, whereas increased the quantifies of nitrobacterial anddenitrobactedal.6. The content of NO₃-N in soil showed the positive relationship with nitrobacteria in soil.7. The rates of NO₃^--N leaching under different treatments of manure and fertifizer applicationwere significantly higher than that of control treatment. The rates of NO₃^--N leaching in the higherand lower fertilizer application treatments were 3247.53 mg/m² and 2545.58 mg/m² respectively.The rate of NO₃^--N leaching in the treatment of equal amount of manure and fertilizers was 2383.03mg/m², whereas those in higher and lower manure application were 391.82 mg/m² and 382.53mg/m² respectively, but that of control was only 88.06 mg/m². The lose of nitrogen in soil underthe manure treatment was 1425.29 mg/m² much lower than that under the fertilizers treatmentwhich was as higher as 12.5～15%.8. The rate of NO₃^--N leaching in soil was negatively related to pH value ha soil, and increasedwith the increasing of the content of NO₃^--N and nitrobacterium in soil.9. Manure and fertilizer application, and haft of manure and half of fertilizer increased thecontent of nitrogen in maize plant, which was significantly increased under high fertilizerapplication, and was lower under the high manure and low fertilizer application and was the lowestunder halt of manure and halt of fertilizer application.10. Different fertilizing treatments could improve the maize production which was the mostsignificant under high manure treatment according to data of maize production.11. Soil ecosystem with no fertilizers was an exhausted ecosystem, however manure andfertilizer could effectively increase soil nitrogen contents and the effect of manure was more evidentthan that of fertilizer.