Effects Of Litter Addition On Soil Nitrogen Mineralization Of Red Soil Erosion Plantations

Litter is not only the metabolite of green plant growth and development,but also an important component of nutrient cycle in forest ecosystem.soil physiochemical properties and nutrition characteristics of Nitrogen,Phosphorus and Potassium all have direct relationship with the rate of litter decomposition.It plays an important role in the maintenance and sustainable development of the land.The amount of litter and the speed of decomposition directly affect the accumulation of surface litter.It also restricts the return of N,P and other elements,and the return of materials to soil and the effectiveness of soil nutrients,thus affecting the accumulation and formation and decomposition of organic matter in soil,and the physical and chemical properties of soil.Litter decomposition is the main pathway for material circulation and energy conversion in terrestrial ecosystems,playing an important role in maintaining soil fertility,ensuring the regrowth of plants and the availability of nutrients,and has a significant impact on the carbon accumulation of ecosystems.Changting county of Fujian province is the typical area of soil erosion area of red soil in south China.Comprehensive control of soil and water loss in Changting County in 2000 was listed as a practical item of Fujian Provincial Party Committee and Government,And has implemented key management for several years.After many years of vegetation restoration,there has been a good ecological recovery effect.In recent years,Changting County has a large area of soil and water loss,especially in Hetian.Due to the low vegetation coverage,the situation of soil erosion is still very serious.In recent years,there has been a great deal of research work on the relationship between vegetation restoration and ecological environment in subtropical soil and water loss areas.The research focuses on reducing soil erosion,soil erosion and soil nutrient pool changes after vegetation restoration.However,Litter decomposition and soil nutrient availability less research.In this paper,field investigation and indoor control experiment method are selected,the distribution characteristics of vegetation species and coverage in different restoration samples were analyzed,and the distributions of 6 indexes of soil total carbon.total nitrogen,total phosphorus,ammonium nitrogen,nitrate nitrogen and available phosphorus in different plant litter culture cycle were added,The impact of litterfall input on soil nutrients and its relationship with soil nutrient during the process of ecological restoration in eroded and degraded areas were discussed.The effects of nutrient return from different types of litter on soil nutrient status of Pinus massoniana plantation,plant community development and artificial Promoting effect of restoration measures on soil nutrient recovery.This study provides a reference for further study on nutrient cycling of litter in the process of ecological restoration.The conclusions of the study are as follows:1)The input of litter increased the source of soil organic matter,improve the mineralization rate of soil organic nitrogen,and then effectively increase the content of available nitrogen in soil in the relatively barren state.The overall performance of broad-leaved species higher than herbs and pioneer conifers.As for the effect of soil phosphorus,with the decomposition of litter,the availability of available phosphorus in soil could be slowed down and inorganic phosphorus could be fixed,and the content of soil available P remained relatively stable.However,the input of herbicide such as PaspalumwettsteiniiHackel could be significantly increased available phosphorus content in soil.2)Compared with the litter of coniferous tree species,the deciduous leaves of broadleaf trees are more easily decomposed in soil,but the difference of decomposition rate between litter of single tree species is decreased relative to the different species of leaf litter in the condition of suitable temperature and humidity.3)When the water is sufficient,the litter is decomposed slowly under ambient temperature,and the decomposition of litter and the mineralization of soil organic nitrogen are significantly increased when the temperatures rise to 40 ?.The content of ammonium nitrogen in the litter treatment group was significantly higher than that of low-temperature wetting and cold wetting.After 120 days of decomposition,the content of ammonium nitrogen in the soil was in the treatment group of Pinus massoniana,which was High-temperature wetting>high-temperature drough>room-temperature wetting>low-temperatures wetting.The wood-loading treatment group,High-temperature wetting>room-temperature wetting/high temperature and drought>low temperature and humidity.The change of hydrothermal conditions had no significant effect on the soil nitrogen mineralization in the blank control group,and the difference was not obvious.