黑土累积磷的释放动力学特征及主要影响因素  

Release kinetics characteristics and the main drivers of phosphorous accumulated in black soil

作　　者：李佳琪 孙凤霞 孙楠[2] 李然 周宝库 马星竹 徐明岗[2] LI Jia-qi;SUN Feng-xia;SUN Nan;LI Ran;ZHOU Bao-ku;MA Xing-zhu;XU Ming-gang(College of Grassland Resources and Environment,Inner Mongolia Agricultural University,Hohhot,Inner Mongolia 010011,China;Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences/Key Laboratory of Cultivated Land Quality Monitoring and Evaluation,Ministry of Agriculture and Rural Affairs,Beijing 100081,China;Heilongjiang Academy of Black Soil Conservation and Utilization,Harbin,Heilongjiang 152052,China)

机构地区：[1]内蒙古农业大学草原与资源环境学院,内蒙古呼和浩特010011 [2]中国农业科学院农业资源与农业区划研究所/农业农村部耕地质量监测与评价重点实验室,北京100081 [3]黑龙江省黑土保护利用研究院,黑龙江哈尔滨152052

出　　处：《植物营养与肥料学报》2023年第2期253-263,共11页Journal of Plant Nutrition and Fertilizers

基　　金：国家重点研发计划(2021YFD1500205)。

摘　　要：【目的】长期大量施用磷肥致使农田土壤磷快速累积,磷肥增产效率和利用率下降。研究不同施肥措施下土壤累积磷的释放动力学特征及其机制,为累积磷的活化利用和磷肥高效施用提供理论依据。【方法】黑土长期定位试验位于黑龙江省哈尔滨市,在5个不同处理采集土样,分别标记为P1、P2、P3、P4和P5,其Olsen-P含量依次为15.5、20.2、93.2、199和216 mg/kg。采用0.5 mol/L NaHCO3连续浸提法测定5个土壤样品中有效磷的释放量,以5个动力学方程拟合或描述有效磷的释放动力学。采用Hedley法测定了浸提前后土壤活性磷(Resin-P、NaHCO3-Pi、NaHCO3-Po)、中活性磷(NaOH-Pi、Na OH-Po、DilHCl-P)和稳性磷(ConcHCl-Pi、ConcHCl-Po、Residual-P)含量。【结果】连续浸提过程中,供试5个土壤的Olsen-P释放均呈先快后慢的趋势,在浸提1400 min (10次)时基本达到平衡。以米氏方程(Michaelis)、一级方程、Elovich方程、抛物线方程和幂函数方程描述有效磷的释放动力学特征,拟合方程的决定系数(R2)均在0.964及以上(P<0.01),其中又以米氏方程和一级方程为佳,其R2分别为0.9955和0.9922。由米氏方程可知,供试5个土壤的有效磷最大释放量分别为59.8、60.9、332.6、589.7和717.0 mg/kg,随Olsen-P含量的增加而增加,Olsen-P每增加1 mg/kg,磷释放量平均增加3.12 mg/kg;5个土壤有效磷的最大释放量占土壤全磷的比例分别为13.68%、14.86%、45.44%、60.67%和66.45%,也随Olsen-P含量的增加而增加,但土壤浸提残留磷(全磷与可提取有效磷之差)均为373.99 mg/kg左右,说明施磷对土壤残留磷的影响较小,长期施肥累积的磷具有较高的活性。一级方程和Elovich方程表明,黑土有效磷的释放是以扩散为主的动力学过程。连续浸提后,土壤活性磷平均减少了82.9%(67.8%~93.5%),中活性磷平均减少了34.6%(17.2%~52.0%),稳定性磷无显著变化。活性磷中的Resin-P和Na HCO3-Pi显著降低了89.8%(78【Objectives】Long-term phosphate(P) fertilization leads to P accumulation in soil,decreasing yield and P fertilizer use efficiency.We studied the release kinetic characteristics of the accumulated P to provide a scientific basis for P fertilizer management.【Methods】The long-term fertilization experiment was located in Harbin,Heilongjiang Province.Soil samples from different treatments were marked P1,P2,P3,P4,and P5,corresponding the soil Olsen-P contents were 15.5,20.2,93.2,199,and 216 mg/kg,respectively.The five soil samples were extracted continuously with 0.5 mol/L NaHCO3for the determination of the release of available P,and the release dynamics were fitted or described using different kinetic equations.The soil labile P fraction(Resin-P,NaHCO3-Pi,Na HCO3-Po),moderate labile P fraction(NaOH-Pi,NaOH-Po,DilHCl-P),and stable P fraction(ConcHCl-Pi,ConcHCl-Po,Residual-P) before and after the extraction were analyzed using the Hedley method.【Results】In all the five treatments,the available P was released fast at beginning and then slowed down,and reached equilibrium after 10 repeated extraction in 1400 minutes.The dynamics of available P release were illustrated by Michaelis equation,first-order equation,Elovich equation,parabola equation and power function equation,with the coefficient of determination(R~2) above 0.964.Michaelis and first-order equation were preferable as the R~2 values were 0.9955 and 0.9922,respectively.From the Michaelis equation,the maximum available P releases of the five treatments were 59.8,60.9,332.6,589.7,and 717.0 mg/kg,every 1 mg/kg increase of Olsen-P produced 3.12 mg/kg more P release.The maximum release proportion of soil total P was increased with the Olsen-P content which were 13.68%,14.86%,45.44%,60.67%,and 66.45% for the five treatments,respectively,however,the difference between total P and extractable P in treatments was about 373.99 mg/kg,indicating that the stability of extractive residual P in soil.The first-order equation and the Elovich equation showed that the

关 键 词：黑土 磷释放动力学 OLSEN-P 活性磷 中活性磷 有机质 PH 

分 类 号：S143.2[农业科学—肥料学]