| A pot experiment was carried out to research the combination of biochar and nitrogen fertilizer on soil physical and chemical properties and the growth of maize,meanwhile a laboratory experiment was carried out to research the rule of N2O,CH4 and CO2 emission in calcareous cinnamon soil.Four treatments were set:control(CK),urea(N),urea plus 5 t·hm-2 biochar(NBL)and urea plus 10 t·hm-2 biochar(NBH).This study was aimed to promote the utilization of biochar in agriculture and prove the suitable amount of biochar application amount in calcareous cinnamon soil,and provide a theory basis for the popularization and application of dry land in the north of China.The main results are as follows:(1)The effect of the combination of biochar and nitrogen fertilizer had no significant effect on the increase of soil water content and soil temperature.Meanwhile different fertilizer treatments had no significant effect on soil pH value.(2)The contents of soil organic carbon,alkali-hydrolysable nitrogen,available phosphorus and available potassium were higher than those in the CK treatment and increased as the increase of biochar application during maize growth stages.The soil urease,sucrase and alkaline phosphatase activities were increased by the biochar and nitrogen fertilizer application treatment during the maize growth period,while the difference was not significant between 5 t·hm-2 and 10 t·hm-2 biochar application treatment.From seedling stage to heading stage,soil catalase activity shows the trend that gradually increased by the combination of biochar and nitrogen fertilizer treatment,while the effect was not significant.In mature period,the catalase activity was significantly increased by biochar application in soil.(3)At seedling stage,the combination of biochar and nitrogen fertilizer treatment had no significant effect on the stem diameter,maximum leaf area,dry weight of stem and leaves and dry weight of root.From jointing stage to maturity stage,the combination of biochar and nitrogen fertilizer significantly increased the maize stem diameter,maximum leaf area,dry weight of stem and leaves and dry weight of root,while the difference was not significant between 5 t·hm-2 and 10 t·hm 2 biochar application treatment.From seedling stage to jointing stage,plant height was significantly promoted by 10 t·hm-2 biochar and nitrogen fertilizer application treatment,while from heading stage to maturity stage,plant height was significantly promoted by 5 t·hm-2 biochar and nitrogen fertilizer application treatment.At the growth period,the contents of nitrogen,phosphorus and potassium of maize above ground increased with the increase of the amount of biochar.(4)In the laboratory experiment period,the cumulative emission of N2O and CO2 decreased with the increase of the amount of biochar application.Compared with nitrogen application treatment,the combination of biochar and nitrogen fertilizer application treatment could reduce N2O and CO2 emissions.N2O cumulative emission was decreased by 6.94%?15.47%and CO2 cumulative emission was decreased by 6.93%?17.69%,while still significantly higher than CK treatment.During the laboratory experiment period,biochar had no significant effect on the CH4 emissions.In general,biochar combined with nitrogen fertilizer had effect on increasing soil nutrient content and inhibiting greenhouse gas emissions,and promoting the growth of maize.Therefore,biochar is of great significance in improving the soil properties,promoting the growth of maize and the sustainable development of agriculture in calcareous cinnamon soil. |
PDF Full Text Request