| Biochar-based fertilizer is a potential fertilizer with high utilization efficiency and environmental friendliness.It is of great significance to evaluate the application effect of biochar-based fertilizer in rice production and seek the best fertilization mode for safe,highyield and efficient production of rice.In this experiment,Nanjing 5718 was used as the test material and four treatments were set up in sandy loam soil and silty clay soil,namely conventional fertilization treatment(U),biochar-based fertilizer substitute for common urea throughout the growth period(BSU),biochar-based fertilizer substitute for common urea during base fertilizer and tiller fertilizer period(BSU1),biochar-based fertilizer substitute for common urea only during panicle fertilizer period(BSU2),and the effects of different treatments on rice yield,nitrogen uptake and utilization,quality,and soil microorganisms were analyzed.The main results are as follows:1.In the experiment conducted in 2021 in the soil culture pool of the campus,three biochar-based fertilizer treatments all increased the yield of rice in sandy loam soil and silty clay soil to varying degrees.Among them,the BSU2 treatment had the most significant promoting effect on rice yield due to the formation of suitable panicles and high grain number,seed setting rate and thousand-kernel weight.Compared with the U treatment,the yield of BSU2 treatment under sandy loam soil increased by 16.45%,while that under silty clay soil increased by 16.60%.The yield of BSU2 treatment under Sandy loam soil was significantly higher than that of the other three treatments,while that under silty clay soil was significantly higher than that of U and BSU treatments and the yield of BSU1 treatment was significantly higher than that of U treatment;under the same treatment,the yield of silty clay soil is higher than that of sandy loam soil;in the field experiment of the modern agricultural industrial park in Dongtai City,the yield of BSU2 treatment was significantly higher than that of the other three treatments,with a significant increase in grain number and thousand-kernel weight per ear.Compared with the U treatment,the yield of BSU2 treatment increased by 5.34%while there was no significant difference in yield among the other three treatments.2.The nitrogen accumulation in the mature period of BSU2 treatment was significantly higher than that of the other three treatments.There was no significant difference in nitrogen accumulation in the mature period of U,BSU and BSU1 treatments.Compared with the U treatment,the other three treatments applying biochar-based fertilizer had significantly improved nitrogen agronomic efficiency,nitrogen physiological efficiency and nitrogen partial factor productivity in both soils.Under the same soil,the nitrogen agronomic efficiency,nitrogen recovery efficiency and nitrogen partial factor productivity of BSU2 treatment was significantly higher than those of the other three treatments.The nitrogen physiological efficiency of BSU2 treatment under sandy loam soil was significantly higher than that of the other three treatments,while the nitrogen physiological efficiency of BSU2 treatment under silty clay soil was significantly higher than that of U and BSU treatments,and there was no significant difference from that of BSU1 treatment;there was no significant difference in nitrogen recovery efficiency among the three treatments of U,BSU and BSU1 under sandy loam soil.The nitrogen recovery efficiency of BSU2 and BSU1 treatments under silty clay soil were significantly higher than that of U and BSU treatments,and there was no significant difference between U and BSU treatments;compared with the U treatment,the nitrogen agronomic efficiency of BSU2 treatment under sandy loam soil and silty clay soil increased by 3.67 kg/kg and 4.98 kg/kg respectively,and the nitrogen recovery efficiency increased by 9.84%and 14.39%respectively.And the nitrogen partial factor productivity increased by 11.43%and 13.73%respectively;under the same treatment,the nitrogen agronomic efficiency,nitrogen recovery efficiency and nitrogen partial factor productivity of rice in silty clay soil were significantly higher than those in sandy loam soil,resulting in higher nitrogen utilization efficiency.3.In the experiment conducted in 2021 in the soil culture pool of the campus,the BSU2 treatment improved the processing quality of rice compared with the U treatment.The head milled rice rate in both soils were significantly higher than that in the U treatment,but there was no significant difference in appearance quality compared with the U treatment.The BSU and BSU1 treatments improved the appearance quality of rice,while the chalkiness rate and chalkiness degree under silty clay soil were significantly lower than those in the U and BSU2 treatments;the taste value of BSU2 treatment under sandy loam soil was the highest.significantly higher than that of U and BSU treatments.The taste value of BSU treatment under silty clay soil was the highest,and there was no significant difference in taste values among the four treatments;under the same treatment,silty clay soil has a certain improvement in cooking taste quality compared with sandy loam soil;similarly,in the field experiment of the modern agricultural industrial park in Dongtai City,compared with the U treatment,BSU2 treatment significantly improved the processing quality of rice,with a certain improvement in appearance quality,but did not reach a significant level.The appearance quality of BSU and BSU1 treatments was significantly improved,and the taste value of the three biochar-based fertilizer treatments was significantly increased.4.Compared with U and BSU treatments,BSU2 treatment is richer in bacterial diversity and changes the composition of bacterial community,which is significantly different from U and BSU treatments.The BSU2 treatment significantly increased the relative abundance of Azotobacter(2.45%),Buchnera(0.67%),Terrimonas(0.76%),Geobater(2.63%)and Subdivision3_genera_incertae_sedis(5.11%)in silty clay soil,as well as Geobater(2.41%)and Saccharibacteria_genera_incertae_sedis(0.91%)in sandy loam soil.The relative abundance of these genera is positively correlated with yield and processing quality,while most are negatively correlated with NH4+.The Observed species index and Shannon index of bacterial communities were significantly affected by soil types,and were lower in silty clay soil than in sandy loam soil.There were also significant differences in bacterial communities in different soil types.In summary,the application of biochar-based fertilizer substitute for common urea during the panicle period has a certain yield increase effect,improves nitrogen fertilizer utilization efficiency and rice quality.It is worth promoting and applying in production. |
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