摘要
为了分析灌溉施肥活动引起的包气带土壤pH值变异特征及其对地球化学条件的响应,通过历时3 a的野外原位灌溉施肥试验,应用不同季节灌前、灌后6 m土层中不同深度的测定资料,系统分析了土壤pH对灌溉、施肥的响应过程,结果表明:各深度pH值呈弱变异性(CV=1.01%~2.28%),与灌溉前相比,灌后土壤pH值的均值和变异系数均呈现明显的变化;灌前包气带各层pH具有强烈的空间自相关性,灌后受水分、基质等相互作用影响,pH的空间自相关性有所减弱,C_0/(C_0+C)和变程a分别由7.23 m和3.54 m(灌前0 d)减少到3.26 m和2.76 m(灌后第10天)。土壤基质是决定土壤酸碱性的主要因素,在灌溉施肥活动对pH的响应过程中,地球化学条件(土壤含水量、土壤温度、土壤有机质(SOM)、氧化还原电位(RP)等)、土壤基质组成和氮底物浓度(NH~+_4-N)等的交互作用影响pH的动态。土壤含水量和温度单独对pH影响不显著,两者交互作用对pH有显著影响。引起土壤pH变化的主要变异源为Cl~-、土壤有机质(SOM)、NO~-_3-N、NH~+_4-N等营养物质和不同空间深度土壤基质的差异,表明灌溉施肥改变了包气带pH地球化学动力场、营养物质和土壤基质的交互作用,引起各深度的生物地球化学反应,控制pH值的空间变异特性。当包气带介质土壤水分变化时,首先营养物氨态氮以分子态或水合态形式被介质吸附,H~+得到释放,使得灌后第4天pH值下降。随着氨氧化过程中H~+的释放,pH在灌前和灌后第10天和第30天有显著差异。氨的氧化引起硝酸盐含量不断增加,使得硝酸盐对pH值的影响在灌后不断增强,相关系数由0.24(0 d,P<0.05)增加到0.41(30 d,P<0.01),而氨态氮对pH值的影响逐步降低,相关系数由0.43(0 d,P<0.01)降低为0.19(30 d,P>0.05)。
To reveal the variation of soil pH resulted from irrigation and fertilization and the changes in geochemical conditions in vadose zone,we conducted a three-year of irrigation and fertilization field test.Using the monitoring data at different depths of 6 m soil profile before and after irrigation in different seasons,we systematically analyzed the responding process of the soil pH to irrigation and fertilization.The results showed that the pH had low variability in all tests(CV=1.01%~2.28%). Compared with that before irrigation, its mean value and coefficient of variation(CV) changed responsively after irrigation. Before irrigation,the pH of each measured layer had strong spatial correlation,after irrigation due to the impact of water, substrate, and their interaction, the spatial correlation was weakened. The C_0/(C_0+C) decreased from 7.23 m and 3.54 m(0 d before irrigation) to 3.26 m and 2.76 m(10 d after irrigation), respectively.The pH mainly depended on the soil matrix. With the responding of the soil pH to the irrigation and fertilization, the geochemical conditions(soil moisture content, soil temperature, soil organic matter, redox potertial(RP), etc.), soil matrix, nitrogen concentration(NH~+_4-N) and their interaction affected the dynamic characteristics of pH. The moisture content or temperature did not have significant impact to pH, but their interaction did. The soil nutrients such as Cl~-, soil organic matter(SOM), NO~-_3-N, NH~+_4-N and space soil matrix at different depths were the main causes for pH variation.These indicated that irrigation and fertilization processes changed the geochemical dynamics, soil pH, the interaction of nutrients and soil matrix components leading to the biogeochemical reaction that controlled the characteristics of pH at each depth.With the change in soil moisture, NH~+_4-N was adsorbed as molecule or hydrated formand H~+ was released. This resulted in the decrease in soil pH on the 4 th day after irrigation.With the release of H~+ in the process of ammonia oxidation, the pH lowered significantly after the irrigation on the 10 th day and 30 th day of irrigation.Due to ammonia oxidation process, the soil nitrate content increased, and its impact on pH enhanced step-by-step after irrigation, the correlation coefficient increased from 0.24(0 d, P<0.05) to 0.41(30 d, P<0.01). While the influence of NH~+_4-N on pH gradually reduced,the correlation coefficient decreased from 0.43(0 d, P<0.01) to 0.19(30 d, P>0.05).
引文
[1] Yang H,Ding W H,Wang J X,et al.Soil pH impact on microbial tetraether lipids and terrestrial input index (BIT) in China[J].Science China Earth Science,2012,55(2):236-245.
[2] 熊毅,李庆逵.中国土壤(第二版)[M].北京:科学出版社,1987:20-38.
[3] 赛迪古丽·哈西木,海米提·依米提.于田绿洲土壤pH值的空间异质性及其对芦苇生长的影响研究——以喀尔克乡为例[J].新疆师范大学学报(自然科学版),2012,31(2):9-15.
[4] Bolan N S,Hedley M J,White R E.Processes of soil acidification during nitrogen cycling with emphasis on legume based pastures[J].Plant and Soil,1991,134(1):53-63.
[5] Muhammad I R,De Goded R G M,Corral Nunez G A,et al.Soil pH and earthworms affect herbage nitrogen recovery from solid cattle manure in production grassland[J].Soil Biology & Biochemistry,2014,68:1-8.
[6] Kee K K,Chew P S.Oil palm responses to nitrogen and drip irrigation in a wet monsoonal climate in peninsular Malaysia[C]//Basiron E.International palm oil conference:Progress,prospects and challenges towards the 21st century,Kuala Lumpur:PORIM,1991:321-339.
[7] Aini I N,Ezrin M H,Aimrun W.Relationship between soil apparent electrical conductivity and pH value of Jawa series in oil palm plantation[J].Agriculture and Agricultural Science Procedia,2014,2:199-206.
[8] Hejnak H,Lippold H,Hnilicka F,et al.The effect of soil pH on utilization of nitrogen fertilizer by spring barley in the year of application and in the following year[J].Scientia Agriculturae Bohemica,2001,32(2):85-95.
[9] ?imunek J,Jacques D,Van Genuchten R,et al.Multicomponent geochemical transport modeling using hydrus-1d and HP1[J].Jawra Journal of the American Water Resources Association,2010,42(6),1537-1547.
[10] Nelson P N,Su N H.Soil pH buffering capacity:a descriptive function and its application to some acidic tropical soils[J].Australian Journal of Soil Research,2010,48(3):201-207.
[11] Hillel D.Research in soil physics:a review[J].Soil Science,1991,15(1):30-34.
[12] Russo D.A geo-statistical approach to solute transport in heterogeneous fields and its applications to salinity management[J].Water Resource Research,1984,20(9):1260-1270.
[13] Burgess T M,Webster R.Optimal interpolation and isarithmic mapping of soil properties:The semi-variogram and punctual kriging[J].European Journal of Soil Science,2019,70(1):11-19.
[14] Burrough P A.Multiscale sources of spatial variation in soil[J].Journal Soil Science,1983,34(3):577-579.
[15] Webster R.Quantitative spatial analysis of soil in the field[J].Advance Soil Science,1985,3:1-70.
[16] Mishra T K,Banerjee S K.Spatial variability of soil pH and organic matter under Shorea robusta in lateritic region[J].Indian Journal of Forestry,1995,18(2):144-152.
[17] Kuzel S,Nyd V,Kolar L,et al.Spatial variability of cadmium,pH,organicmatter in soil and its dependence on sampling scales[J].Water,Air,and Soil Pollution,1994,78(1-2):51-59.
[18] 孙波,赵其国,闾国年.低丘红壤肥力的时空变异[J].土壤学报,2002,39(2):190-198.
[19] 蒋勇军.流域尺度的岩溶区土壤pH值空间变异研究——以云南小江流域为例[J].中国岩溶,2009,28(1):80-86.
[20] 朱祖祥.土壤学(上册)[M].北京:农业出版社,1983:350-356.
[21] 鲁如坤.土壤农业化学分析方法[M].北京:中国农业科技出版社,2000:106-152.
[22] 鄢来斌,张福锁.土壤科学面临的挑战及发展方向//土壤与植物营养研究新动态[M].北京:北京农业大学出版社,2000:16.
[23] Hollocher T C,Tate M E,Nicholas D J.Oxidation of ammonia by Nitrosomonase uropaea.Definitive 18O-tracer evidence that hydroxylamine formation involves a monooxygenase[J].Journal of Biological Chemistry,1981,256(21):10834-10836.
[24] Wett B,Raunch W.The role of inorganic carbon limitation in biological nitrogen removal of extremely ammonia concentrated wastewater[J].Water Research,2003,37(5):1100-1110.
[25] 朱礼学,邓泽锦.土壤pH值及CaCO3在多目标地球化学调查中的研究意义[J].四川地质学报,2001,21(4):226-228.
[26] Liu X H,Simunek J,Li L,et al.Identification of sulfate sources in groundwater using isotope analysis and modeling of flood irrigation with waters of different quality in the Jinghuiqu district of China[J].Environmental Earth Sciences,2013,69(5):1589-1600.
[27] Zhang J B,Zhu T B,Cai Z C,et al.Nitrogen cycling in forest soils across climate gradientsin Eastern China[J].Plant Soil,2011,342(1-12):419-432.
[28] Zhao W,Cai Z C,Xu Z H.Does ammonium-based N addition influence nitrification and acidification in humid subtropical soils of China[J].Plant Soil,2007,297(1-2):213-221.
[29] Katyal J C,Cater M F,Viiek P L G.Nitrification activity in submerged soils & its relation to denitrification loss[J].Biology & Fertility of Soils,1988,7(1):16-22.
[30] Zhang J B,Cai Z C,Zhu T B,et al.Mechanisms for the retention of inorganic N in acidic forest soils of southern China[J].Scientific Reports,2013,3(6145):2342.