The Effect Of Different Biochar And Its Application Method On The Dynamic Changes Of Water And Soil Nutrient And Rice Growth

Biochar because of its good physical and chemical properties had been widely studied in the field of agricultural production,utilization of agricultural wastes and agricultural nonpoint source pollution control.However,the experimental conditions between different studies had significant differences,with no direct comparability.Especially,the research of different biochar applied way was very scarce.A pot experiment was conducted to explore the effect of different biochar and its application method on rice and environment in the same system.The experiment was conducted to 14 treatment groups according to biochar materials(wheat straw and wood sawdust),calcination temperature(700 and 500 centigrade),quantity(0.5%and 3.0%)and its application method(biochar and surface soil mix,biochar mix with all the soil).The main conclusions are as follows:1.The effect of different biochar and its application method on the dynamic changes of nitrogen and phosphorus in paddy field waterAll treatments with biochar reduced NH4+-N,NO3--N,TN losses.And the influence was even more remarkable in the early stage of the fertilization.The control capacity of biochar for NH4+-N was the most significant,and the NH4+-N content of all treatments with biochar was reduced 18.00%on average than CKU.The control capacity of more amount of biochar(3.0%)for nitrogen was very effective than the treatments of small amount of biochar(0.5%)under certain conditions.The effect of biochar of high temperature firing(700 centigrade)for nitrogen was even more significantly than the treatments of low temperature firing(500 centigrade)in certain circumstances.The treatment of biochar and surface soil mix effect was more significant than the treatments of biochar mix with all the soil.Different biochar and its application method tends to increase nitrogen content.2.The effect of different biochar and its application method on rice growth and yieldUnder this experimental condition,all the treatments with biochar promoted rice yield.And the treatment of biochar and surface soil mix had a better effect,growth of 7.80%to 20.99%.The treatment of biochar and surface soil mix shortened the growth period of the rice.At mature period,the SPAD value and NDVI was significantly reduced than(CKU),this suggests that nitrogen level of the biochar surface treatment is a low level.All the treatments with biochar promoted the rice yield,and effect of biochar conventional was better.3.The effect rule of different biochar and its application method on rice soil nutrientsAll the treatments with biochar reduced NH4+-N content in soil.In the rice tillering stage,The NH4+-N content of more amount of biochar(3.0%)was higher than the treatments of small amount of biochar(0.5%).The effect of wood sawdust biochar for NH4+-N content decreased more significantly than the treatments of wheat straw biochar in certain circumstances.The effect of biochar and surface soil mix for NH4+-N content decreased more significantly than the treatments of biochar mix with all the soil.The effect of biochar applied method on NO3--N content in soil was different.The treatments of biochar mix with all the soil reduced NO3--N content in soil.The treatments of biochar and surface soil mix increased NO3--N content in soil.All the treatments with biochar had a tendency to increase the NH4+-N content of rhizosphere soil.Under the condition of applying wheat straw biochar,the NH4+-N content of the treatments of small amount of biochar(0.5%)was higher than the treatments of more amount of biochar(3.0%).Instead,the treatments of more amount of wood sawdust biochar(3.0%)had more remarkable effect.The treatments of wheat straw biochar and surface soil mix than the treatments of wheat straw biochar mix with all the soil of non rhizosphere soil NH4+-N content was higher.The effect of different biochar applied method on rhizosphere soil NO3--N content was different.The treatments of biochar mix with all the soil increased rhizosphere and non rhizosphere soil NO3--N content.For rhizosphere soil NO3--N content,the treatments of more amount of biochar(3.0%)had better effect than the treatments of small amount of biochar(0.5%).The treatments of biochar and surface soil mix increased rhizosphere soil NO3--N content,but reduced non rhizosphere soil NO3--N content.The treatments of biochar mix with all the soil had better effect on rhizosphere soil NO3--N content than the treatments of biochar and surface soil mix.The effect rule of different biochar and its application method increased the conventional and rhizosphere soil TP content.