| Coal resources are relatively rich in the north of China,with the exploitation of open-pit Coal Mines,large-area waste dump has been formed,which has caused serious damage to the ecological environment.But the soil fertility of the waste dump is poor,and the nutrient elements such as nitrogen and phosphorus,which are needed for plant growth,are deficient,especially the phosphorus content in the soil,which seriously affects the recovery of plant.Therefore,vegetation restoration of waste dump is an important problem to be solved at present.Phosphorus fertilizer application can promote the growth of plants significantly,but in the process of application,it is easy to lose phosphorus and cause secondary pollution to the surrounding environment.As a carbon-rich material,biochar has large specific surface area and porous structure,which can not only improve soil environment,but also is a good slow-release carrier,solid adsorption of nutrients can slow the loss of nutrients,improve fertilizer utilization.In this paper,the effect of biochar based phosphate fertilizer on the growth of Ryegrass,soil physical and chemical properties and soil phosphorus loss was studied.The main results are as follows:(1)The biomass of Ryegrass in each treatment showed that each treatment had a certain promoting effect on the increase of plant height,dry and fresh weight of ryegrass.Compared with granular phosphate and granular biochar,the total plant height,total fresh weight and total dry weight of Ryegrass were increased at all phosphorus levels,and the trend of increasing first and then decreasing was presented with the increase of phosphorus level;when the granular carbon superphosphate was at 5 mg/kg phosphorus level,compared with granular superphosphate and granular biochar,the total plant height and total fresh weight of Ryegrass were effectively improved Compared with the total dry weight,but at the 10 and 20 mg/kg P levels,the effect of granular carbon Superphosphate on the yield of Ryegrass was not as good as granular superphosphate and granular biochar;compared with granular carbon superphosphate,the total plant height,total fresh weight and total dry weight of Ryegrass were improved at all P levels,but the difference was not significant.(2)The results of soil physical and chemical properties showed that each treatment had no significant effect on soil pH value,but could significantly improve the content of soil organic matter,soil soluble organic carbon(DOC),soil available phosphorus,soil available nitrogen and soil total nitrogen,and the difference wassignificant(P < 0.05).Compared with granular carbon based phosphorite powder and granular biochar,granular carbon based phosphorite powder increased the content of soil organic matter,soil available phosphorus and soil total nitrogen,but decreased the content of soil soluble organic carbon(DOC)and soil available nitrogen.Compared with granular carbon based superphosphate and granular biochar,granular carbon based superphosphate powder was similar to granular carbon based phosphorite powder.In addition,the results of high-throughput sequencing of soil bacteria showed that granular biochar could significantly improve the diversity of soil bacteria,while the effects of granular carbon based superphosphate and granular carbon based phosphate ore powder on the diversity of soil bacteria were related to the form of phosphorus.PCA analysis showed that the bacterial community structure of granular carbon based phosphate rock treatment was significantly different from that of other treatments and CK.The correlation analysis showed that there was a certain correlation between the diversity of soil bacterial community and the physical and chemical properties,and the change of dominant bacteria affected the physical and chemical properties of soil,further promoting the growth of Ryegrass.(3)The results of leaching experiment showed that the loss of soil phosphorus was slightly higher than that of granular carbon based phosphate rock,but the difference was not significant,and it was still significantly lower than that of granular superphosphate;compared with granular carbon based superphosphate,granular carbon based superphosphate could effectively reduce the loss of soil phosphorus at all levels of phosphorus,reducing 28.77%-49.82%;granular carbon based phosphate rock was better than granular carbon based superphosphate There was no significant difference in soil phosphorus loss. |
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