Effects Of Different Ratios Of Carbon-based Fertilizer And Nitrogen Fertilizer On Soil Properties Of Jinggang Pomelo Orchard

Jinggang pomelo is not only one of the three fruit brands in Jiangxi Province but also the first of six rich people’s industries in Ji’an city.However,due to long-term fertilizer application,soil acidification,nutrient imbalance,and other problems become increasingly prominent,which seriously restricted the high-quality development of the Jinggang pomelo industry.Carbon-based fertilizer can improve soil structure,acidity and nutrient availability effectively because of its porous structure and rich nutrient content.In this study,the key soil factors limiting industrial development were found by investigating the soil status quo of the pomelo orchard in Jinggang,Ji’an city.At the same time,the field experiment was conducted to study the effects of different ratios of carbon-based fertilizer and nitrogen fertilizer on soil physical characteristics,chemical characteristics and enzyme activities of Jinggang pomelo orchard,which provides the scientific basis for the improvement of soil characters of Jinggang pomelo orchard by substituting carbon-based fertilizer for nitrogen fertilizer,providing theoretical and data support for the high-quality development of Jinggang pomelo orchard.First of all,this study explored the current situation of the orchard soil in the Jinggang pomelo planting area of Ji’an city based on the platform of Jiangxi Jinggang Pomelo Science and Technology Backyard.The results showed that the average p H value of surface soil was 4.93,and the soil acidity was strong accounting for 94.54%.The acidic soil accounted for a large proportion,which was not conducive to pomelo growth.In Jinggang pomelo orchards,the ratio of lack of alkali-hydrolyzed nitrogen was 40%,the ratio of lack of available phosphorus was 32.73%,and the ratio of lack of exchangeable calcium and exchangeable magnesium was 97.27% and 42.73%,respectively.Secondly,in view of the soil acidity of the Jinggang pomelo orchard,this study explored the effects of different ratios of carbon-based fertilizer and nitrogen fertilizer on the soil physical properties of the Jinggang pomelo orchard.The results showed that soil bulk,porosity,water content and maximum water holding capacity did not differ significantly between treatments as the amount of carbon-based fertilizer increased,but there was a tendency for the physical properties of the soil to improve.Thirdly,this study explored the effects of different ratios of carbon-based fertilizer and nitrogen fertilizer on the soil chemical properties of the Jinggang pomelo orchard.The results showed that under different ratios of carbon-based fertilizer and nitrogen fertilizer,soil p H,the content of basic-ion exchangeable calcium and magnesium,and cation exchange capacity were significantly increased,which showed that carbon-based fertilizer had a better effect on replacing 40%nitrogen fertilizer(BF40%).Soil p H,exchangeable calcium,magnesium and cation exchange capacity increased by 27.22%,93.17%,42.07% and 43.22%,respectively,compared with the OF treatment.Finally,this study explored the effects of different ratios of carbon-based fertilizer and nitrogen fertilizer on soil enzyme activities of the Jinggang pomelo orchard.The results showed that the activities of nitrite reductase,protease and sucrase in soil were the highest under the treatment of carbon-based fertilizer instead of 40% nitrogen fertilizer(BF40%),which were increased by 140.74%,116.67% and 63.73%,respectively,compared with optimal fertilization(OF).The activities of urease and acid phosphatase in soil treated with carbon-based fertilizer instead of 40% nitrogen fertilizer(BF40%)were higher.