Effects Of Water And Fertilization Regulation And Exogenous Input On Soil Nitrogen Cycle In Mulberry Garden

The growing world population and food demand have led to a significant increase in global fertilizer application,which has stimulated the increase of nitrogen emissions from agricultural soils?such as NH₃and N₂O?and exacerbated environmental problems such as nitrogen loss and the greenhouse effect.In recent years,various emerging functional materials may also enter the soil system and have a certain impact on the nitrogen cycle.The research on nitrogen cycle of different types of agricultural soil is helpful to further clarify the migration and transformation of soil nitrogen and its contribution to global greenhouse gases.At present,there have been many studies focusing on typical agricultural systems,and little is known about soil nitrogen cycling in the mulberry system.Mulberry is a high-nitrogen crop,and the large amount of nitrogen fertilizer consumption makes the soil have a higher nitrogen gas emission potential.This study used a combination of field observation experiments and indoor simulation to study the short-term emission characteristics of N₂O flux in mulberry garden soil under different water and fertilizer management,and to find out the short-term response law of N₂O and NH₃ flux in mulberry garden soil under different input of external sources.To reveal the impact of agricultural management and other exogenous input on the soil nitrogen cycle.At the same time,the effects of water and fertilizer management and foreign matter input on soil physical and chemical properties and enzyme activity were analyzed.The main research contents and results were as follows:?1?Impact of water and fertilizer management on N₂O flux and soil properties in mulberry fields.Through field observations and indoor simulations,the effects of low,medium and high nitrogen fertilizer application rated and soil moisture content on the N₂O emission flux of mulberry garden soil and the effects of conventional soil enzyme activity were obtained.The study found that mulberry garden soil was a source of N₂O emissions,and the increase in nitrogen fertilizer had a promoting effect on N₂O flux;the increase in soil water content would stimulate the production and discharge of N₂O,but when the water content was too high,the soil was in a flooded state The N₂O flux was significantly reduced.The results showed that the N₂O emission flux of mulberry soil had a very significant positive correlation with soil p H,nitrate nitrogen,urease and sucrase activity,and a negative correlation with soil moisture and phosphatase activity.?2?The effect of different external sources on the nitrogen gas flux of mulberry soil.Through indoor simulation experiments,the effects of different exogenous substances on N₂O and NH₃ fluxes,soil properties and enzyme activities in mulberry fields were compared and analyzed.Compared with the control group,the soil applied with urea superimposed nano silver and graphene all released more N₂O gas.Among them,nano silver had a low promotion and high inhibition effect on N₂O,and the inhibitory effect of nitrification inhibitor on N₂O was extremely significant.Compared with single application of urea,stacking nitrification inhibitors and nano-silver both increased the NH₃ flux,while stacking graphene had a certain inhibitory effect on the production of NH₃,and the inhibitory effect weakened with the increase of graphene application.In addition,the input of different Ti O₂photocatalytic materials significantly increased the emission fluxes of the three gases N₂O,NH₃ and CO₂in the soil.The results of the study showed that different functions had significant differences in the nitrogen cycle of mulberry fields.Some nano-functional materials could promote the generation and emission of nitrogen gas and accelerate the loss of soil nitrogen.