Effects Of Biochar And Phosphorus Addition On Soil Aggregates And Phosphorus Component Conversion And Availability In Camellia Oleifera Forest

Camellia Oleifera Abel(Camellia Oleifera)is peculiar to our country important woody edible oil tree species,with olive oil,palm and coconut called the world's four major woody oil plants.Jiangxi province as one of the main production of Camellia Oleifera,soil are mainly composed of red soil,there are serious problems of P restriction and poor availability of phosphorus,causing a great influence on the growth and yield of Camellia Oleifera.Rational use of phosphate fertilizer is one of the measures to improve soil fertility and ensure good plant growth and high yield.Biochar is a soil improver.Both can affect soil directly or indirectly.Therefore,this paper took jiangxi Camellia Oleifera forest red soil as the research object,and set up two factors of biochar and phosphate fertilizer,and the effects of postgraduates'material carbon and phosphate fertilizer on the basic physico-chemical properties of oiltea forest soil,the composition of soil aggregates and their stability,phosphorus transformation and availability of soil aggregates.The results of thr study are as following:(1)The addition of biochar has no significant effect on the soil physical properties of Camellia Oleifera in a short time.The addition of biochar can increase the soil total nitrogen content and improve the soil nutrient status.(2)The distribution of mechanical stable aggregates in Camellia Oleifera forest land was 0.25-2mm,>2mm,0.053-0.25mm,<0.053mm;and the mechanical stable aggregates with small particle size in forest land were cemented and transformed into larger particle size aggregates under the action of biochar.The distribution order of water-stable aggregates was>2mm,0.25-2mm,0.053-0.25mm,<0.053mm.The soil water-stable large aggregates and soil clay particles were transformed into water-stable micro-aggregates and water-stable small aggregates under the action of biochar.The application of phosphate fertilizer will cause the fragmentation of the large aggregate into the smaller aggregate.The addition of biochar and phosphorus had significant influence on MWD of mechanical stability aggregates,but not on R_0.25.Soil water erosion resistance in Camellia Oleifera forest land is stronger than mechanical damage resistance(3)The distribution of phosphorus content in all morphology of Camellia Oleifera land was generally shown as Redisual-P>Na OH-po>Na OH-pi>Sonic-Po>Na HCO₃-Po>Na HCO₃-Pi,Sonic-Pi>H₂O-P>HCL-P in different aggregates.The accumulation of phosphorus components in different aggregates was higher than that in<0.053mm and<0.053mm aggregates.The application of high level biochar and high level phosphate fertilizer can significantly increase the content of phosphorus components which are easy to be absorbed and utilized by plants,such as H₂O-P,Na HCO₃-P,Na OH-P,Sonic-Pi,etc.The effect of biochar and phosphate fertilizer on total phosphorus in forestland aggregates was obvious,but the effect on total phosphorus in soil was small.The response of inorganic phosphorus component to biomass carbon and phosphate fertilizer was significant,while the response of organic phosphorus component to biochar was only significant.(4)The addition of biochar and phosphorus can affect the conversion of phosphorus components to a certain extent.0.25-2 mm together in vitro,in addition to carbon phosphorus add can promote soil phosphorus machine components to the transformation of inorganic phosphorus component,high stability,low efficiency of phosphorus component to low stability and high efficiency of phosphorus components,biochar added can promote Redisual-P to easily be plants by using phosphorus component transformation.(5)Effects of biochar and phosphorus addition and their interactions on soil availability in Camellia Oleifera Forest Land are significant.Application of biochar with phosphorus addition can significantly improve the availability of soil phosphorus in Camellia Oleifera forest land,and the Level of C2 was better.(6)There was a significant positive correlation between soil total phosphorus and soil H₂O-P,Na HCO₃-Pi,Na OH-P,HCL-P and Redisual-P,as well as a significant positive correlation between soil available phosphorus and soil inorganic phosphorus components.To some extent,soil phosphorus was affected by total nitrogen in soil,and Na HCO₃-Po was more responsive to the basic physical and chemical properties of soilIn summary,from the perspective of improving soil nutrients and soil quality in a short time,combined with the phosphorus conversion and availability of Camellia Oleifera forest,it is found that the addition of biochar can improve the soil structure of Camellia Oleifera forest and improve the soil nutrients of forest,and the effect is better with the increase of biochar.The addition and application of biochar with phosphate fertilizer can significantly improve the availability of phosphorus in woodland soil,and biochar can promote the conversion of phosphorus components that are difficult to be absorbed and utilized by plants to phosphorus components that are easy to be absorbed and have high availability.The increase of soil nutrients and the increase of phosphorus availability in forest is more conducive to the growth and yield of Camellia Oleifera,which provides practical technical guidance for the production and management of Camellia Oleifera.