Effects Of Biochar Application On Properties Of Greenhouse Soil With Paddy-upland Rotation

Vegetable production is a dense industry,in line with China’s labor conditions sufficient.With the implementation of high yield,high efficiency,high quality agriculture and national basket project,the status and function of vegetables in the development of national economy are becoming more and more prominent.Development of vegetable production can not only enrich the catering needs of urban and rural residents,it is also a viable way to generate income for farmers and to get rid of poverty.However,with the growth of the vegetable industry,the continuous cropping barrier is becoming increasingly prominent.With the development of facilities agriculture and the increase of market demand especially,and the excessive use of over-exploitation and over-exploitation of the same crop in the same field.A large number of chemical fertilizers,high soil salinity,long-term growth leads to the short growth of the crop and it will darken leaf color and the cover the surface with waxy.The mode of paddy-upland rotation can better solve the problem of continuous cropping of perennial facilities,and increase the production efficiency and income of farmers.The application of biochar technology,not only can greatly reduce the carbon dioxide and other greenhouse gas emissions,to achieve carbon sequestration,and biochar can also improve the soil after the physical and chemical and biological properties.In recent years,with the continuous reduction of renewable energy,biochar application has recieved wide attention.However,there are different views on the effect of biochar application,which may be related to the nature of biochar,soil type and soil micro-organismsand less research-related.In this study,we take fallow as a control treatment,with adding and without adding biochar as a contrast.By using the flooding cultivation of Sagittaria and moisturizing cultivated celery,and then changed to pepper dry and dry rotation to investigate different influences on basic physical and chemical properties,Available nutrient and organic matter content and total nutrient content after application of biochar and paddy cultivation mode.At the same time,different kinds of crops were planted under the condition of adding biochar,and the soil were measured after harvest.The difference of nutrient contents between different treatments was compared.The main findings are as follows:(1)Compared with the fallowing treatment,the salt content of the soil decreased by 48.48%-54.54%.The flooded cultivation reduced the organic matter,available phosphorus,available potassium,nitrite content and ammonium nitrogen content in the soil to varying degrees;After flooding planting of Sagittaria,soil total nitrogen decreased by 8.41%-25.21%,the total phosphorus content also increased.The addition of biochar can reduce the EC value and reduce the soil bulk density.The biochar can increase soil pH due to its alkaline characteristic and has little influence on the moisture content.The addition of biochar reduces the content of soil ammonium nitrogen,nitric nitrogen,available potassium and organic matter and the contents of available phosphorus in flooded soils.The addition of biochar increases the total nitrogen and total phosphorus content of flooding Sagittaria.The pH declines and EC increases when it changes into dry farming,also the available N、P、K increase while the organic matterdecreased.The content of organic matter in dry land was higher than that without adding biochar.(2)Moisture cultivated cress cultivation method increased soil pH and decreased EC value,which effectively relieved soil acidification and salt accumulation,and had little effect on water content and bulk density.In semi-flooded state,ammonium nitrogen and available phosphorus increased,Nitrogen and available potassium were decreased to some extent,and the content of organic matter was higher than that of fallow and dry soil.Under the wet condition,the content of total nitrogen decreased slightly,the range was 1.38%-3.92%and also the total phosphorus increased.With adding biochar and without adding biochar,the pH increased,the conductivity decreased,the water content and the bulk density decreased slightly.The addition of biochar reduced the contents of ammonium nitrogen,nitric nitrogen and available phosphorus in greenhouse soil,The content of available potassium increased by 13.77%,and the content of organic matter increased with the addition of biochar.Compared with adding biochar,total nitrogen and total phosphorus were lower than those without adding biochar.After a round of peppers cultivation,the pH decreased obviously,the soil changed from alkaline to moderately acidic;ammonium nitrogen,nitrate nitrogen increased,available phosphorus increased,soil available potassium increased continuously,soil moisture decreased,Soil organic matter generally showed a downward trend.(3)The addition of biochar reduced the bulk density of soil of green garlic,corn and soybean and improved the physical structure of soil to a certain extent.The soil pH of planting garlic was relatively high with relatively low EC value.The content of NH4 +-N and available P in garlic was the highest,the content of available nitrogen and available potassium was the highest in the treatment of corn with biochar,and the content of organic matter in the soybean soil treated with biochar was the highest.Adding biochar reduced the contents of ammonium nitrogen and available phosphorus in the soil to a certain extent,Nitrate,available potassium and organic matter increased also.The soybean planting increased the total nitrogen content of soil,the total content of whole phosphorus and garlic was the highest,and the addition of biochar improved the total nitrogen content of maize and garlic field,and reduced the total phosphorus content of garlic and soybean.After the harvest,the pH decreased,the range was 8.17%-17.97%,the salt accumulation,the ammonium nitrogen and available phosphorus increased,the organic matter and the total nutrient content decreased.In general,the soil nutrient content of garlic is higher.In summary,the addition of biochar under the condition of paddy upland rotation can effectively improve the soil physical and chemical properties,alleviate the continuous cropping barrier and provide a good soil ecological environment for the later crops.