Effects of the new nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on nitrate and potassium leaching in two soils

In this study, soil column was used to study the new nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on nitrate (NO3--N) and potassium (K) leaching in the sandy loam soil and clay loam soil. The results showed that DMPP with ammonium sulphate nitrate (ASN) ((NH4)2SO4 and NH4NO3) or urea could reduce NO3--N leaching significantly, whereas ammonium (NH4 -N) leaching increased slightly. In case of total N (NO3--N NH4 -N), losses by leaching during the experimental period (40 d) were 37.93 mg (urea), 31.61 mg (urea DMPP), 108.10 mg (ASN), 60.70 mg (ASN DMPP) in the sandy loam soil, and 30.54 mg (urea), 21.05 mg (urea DMPP), 37.86 mg (ASN), 31. 09 mg (ASN DMPP) in the clay loam soil, respectively. DMPP-amended soil led to the maintenance of relatively high levels of NH4 -N and low levels of NO3--N in soil, and nitrification was slower. DMPP supplementation also resulted in potassium leached less, but the difference was not significant except the treatment ASN and ASN DMPP in the sandy loam soil. Above results indicate that DMPP is a good nitrification inhibitor, the efficiency of DMPP seems better in the sandy loam soil than in the clay loam soil and lasts longer.     

3,5-二甲基吡唑磷酸盐硝化抑制作用初探

采用室内培养实验的方法,以不加抑制剂的尿素作为对照,对比研究DMPP及它的同分异构体3,5-二甲基吡唑磷酸盐作为硝化抑制剂对尿素氮在土壤中转化的影响.结果表明,3,5-二甲基吡唑磷酸盐具有一定的硝化抑制作用.在培养期间,施加3,5-二甲基吡唑磷酸盐的土壤中硝态氮的含量一周后始终低于对照,铵态氮的含量一用后始终高于对照.但在培养试验中后期(三周以后),3,5-二甲基吡唑磷酸盐的硝化抑制效果劣于DMPP.3,5-二甲基吡唑磷酸盐能否作为新型硝化抑制剂,还要对它的生理、生态效应等进行进一步的研究.     

连续流动分析法测定水中硫化物的显色剂配制方法研究

针对连续流动分析法测定水中硫化物方法中显色剂N,N-二甲基-1,4苯二胺二盐酸盐保质期短的问题,研究了不同体积比盐酸或硫酸介质对延长显色剂保质期的影响,确定了延长保质期的试剂配制方法,并对该方法的适用性进行了检验.结果显示,体积比10％硫酸介质的显色剂优于盐酸介质显色剂,可以存放一周.使用此显色剂进行硫化物分析检出限为0.003 mg/L,线性范围0.000 mg/L ～2.00 mg/L,平行测定相对偏差0.0％ ～11.8％,加标回收率82.0％～102％,可以满足环境样品分析需求.     

双氰胺和3,4-二甲基吡唑磷酸盐对蔬菜种植土壤氨氧化细菌和古菌的影响

硝化抑制剂双氰胺(DCD)和3,4-二甲基吡唑磷酸盐(DMPP)在抑制农业土壤硝化作用和提高氮肥利用率等方面效果显著,为了探讨它们对蔬菜种植土壤氨氧化细菌(AOB)和古菌(AOA)的作用机制,选取40 a以上蔬菜种植土壤,在施加尿素(CK)基础上,分别添加DCD和DMPP进行室内培养,系统监测了土壤中NH_4~+-N、NO_3~--N和硝化势的变化,同时运用荧光定量PCR和高通量测序等技术揭示了AOB和AOA种群丰度和多样性的演替规律.结果表明,相比CK处理,DCD处理和DMPP处理的NH_4~+-N含量升高了213%和675%; NO_3~--N含量降低了13. 3%和37. 2%;硝化势降低了20. 4%和82. 4%;同时,AOB丰度降低了51. 2%和56. 5%; AOA丰度降低了6. 0%和27. 0%.不同抑制剂处理间AOB和AOA的α多样性指数没有显著差异; nork-environmental-samples、unclassified-Nitrosomonadaceae、unclassified-Bactertia和Nitrosospira是AOB序列属水平的主要优势类群; norank-Crenarchaeota、norank-enviromental-samples和Nitrososphaera是AOA序列属水平的主要优势类群,施用DCD和DMPP显著改变了AOB和AOA的群落组成.综上所述,尿素与DCD和DMPP配施显著抑制NH_4~+-N的转化,降低AOB和AOA的种群丰度并改变其群落组成.相比DCD,DMPP对硝化作用的抑制和对AOB和AOA群落的影响更强.     

Effect of nitrification inhibitor DMPP on nitrogen leaching, nitrifying organisms, and enzyme activities in a rice-oilseed rape cropping system

DMPP （3,4-dimethylpyrazole phosphate） has been used to reduce nitrogen （N） loss from leaching or denitrification and to improve N supply in agricultural land. However, its impact on soil nitrifying organisms and enzyme activities involved in N cycling is largely unknown. Therefore, an on-farm experiment, for two years, has been conducted, to elucidate the effects of DMPP on mineral N （NH4^＋- N and NO3^--N） leaching, nitrifying organisms, and denitrifying enzymes in a rice-oilseed rape cropping system. Three treatments including urea alone （UA）, urea ＋ 1% DMPP （DP）, and no fertilizer （CK）, have been carded out. The results showed that DP enhanced the mean NH4^＋-N concentrations by 19.1%-24.3%, but reduced the mean NO3^--N concentrations by 44.9%-56.6% in the leachate, under a two-year rice-rape rotation, compared to the UA treatment. The population of ammonia oxidizing bacteria, the activity of nitrate reductase, and nitrite reductase in the DP treatment decreased about 24.5%-30.9%, 14.9%-43.5%, and 14.7%-31.6%, respectively, as compared to the UA treatment. However, nitrite oxidizing bacteria and hydroxylamine reductase remained almost unaffected by DMPP. It is proposed that DMPP has the potential to either reduce NO3^--N leaching by inhibiting ammonia oxidization or N losses from denitrification, which is in favor of the N conversations in the rice-oilseed rape cropping system.     

Role of nitrification inhibitor DMPP( 3,4-dimethylpyrazole phosphate) in NO3--N accumulation in greengrocery(Brassica campestris L. Ssp. Chinensis )and vegetable soil

The influence of nitrification inhibitor(NI) 3,4-dimethylpyrazole phosphate (DMPP) on nitrate accumulation in greengrocery ( Brassica campestris L. ssp. chinensis) and vegetable soil at surface layer were investigated in field experiments in 2002 and 2003.Results showed that NI DMPP took no significant effect on yields of edible parts of greengrocery, but it could significantly decrease NO3^--N concentration in greengrocery and in vegetable soil at surface layer. In addition, NI DMPP could reduce the NO3^--N concentration during the prophase stage of storage.     

Effects of a new nitrification inhibitor 3,4-dimethylpyrazole phosphate （DMPP） on nitrate and potassium leaching in two soils

In this study, soil column was used to study the new nitrification inhibitor 3,4-dimethylpyrazole phosphate （DMPP） on nitrate （NO3^-- N） and potassium （K） leaching in the sandy loam soil and clay loam soil. The results showed that DMPP with ammonium sulphate nitrate （ASN） （（NH4）2SO4 and NHaNO3） or urea could reduce NO3^--N leaching significantly, whereas ammonium （NH4^＋-N） leaching increased slightly. In case of total N （NO3^--N＋NH4^＋-N）, losses by leaching during the experimental period （40 d） were 37.93 mg （urea）, 31.61 mg （urea＋DMPP）, 108.10 mg （ASN）, 60.70 mg （ASN＋DMPP） in the sandy loam soil, and 30.54 mg （urea）, 21.05 mg （urea＋DMPP）, 37.86 mg （ASN）, 31.09 mg （ASN＋DMPP） in the clay loam soil, respectively. DMPP-amended soil led to the maintenance of relatively high levels of NH4^＋ -N and low levels of NO3^--N in soil, and nitrification was slower. DMPP supplementation also resulted in less potassium leached, but the difference was not significant except the treatment of ASN and ASN＋DMPP in the sandy loam soil. Above results indicate that DMPP is a good nitrification inhibitor, the efficiency of DMPP seems better in the sandy loam soil than in the clay loam soil and lasts longer.     

Influence of the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on ammonia-oxidizing bacteria and archaea in rhizosphere and bulk soil

In agricultural plant production nitrification inhibitors like 3,4-dimethylpyrazole phosphate (DMPP) are used to retard the microbial nitrification process of fertilized ammonium to enhance the nitrogen supply for cultivated crops and to reduce nitrogen losses from the production system. Besides the well-known ammonia-oxidizing bacteria (AOB) it is known for a few years that also ammonia-oxidizing archaea (AOA) are able to perform the first step in nitrification, hence being also a target for a nitrification inhibitor. However, so far no information are available concerning the effectiveness of DMPP and its extent towards AOB and AOA, neither in bulk soil nor in the root-rhizosphere complex. We investigated in a field experiment performed according to agricultural practice the effect of DMPP on the abundance of AOB and AOA two, four and eight weeks after fertilization. We observed impaired abundances of AOB but not of AOA in both soil compartments that were still visible eight weeks after application, possibly indicating a reduced effectiveness of the nitrification inhibitor in our study.     

DMPP对氮素垂直迁移转化及淋溶损失的影响

采用自制模拟原状土柱装置,进行新型硝化抑制剂3,4-二甲基吡唑磷酸盐（3,4-dimethyl pyrazole phosphate ,DMPP）对氮素淋溶效应试验,探讨其对氮素垂直迁移转化及降低淋溶损失的影响.结果表明,尿素添加1%的DMPP后,与不添加DMPP尿素相比,在60 d内能有效抑制土壤铵氧化反应的发生,显著提高20 cm以上耕作层土壤水铵态氮的浓度,降低硝态氮和亚硝态氮的浓度;20 cm以下深层土壤水铵态氮的浓度与未加DMPP的处理无显著差异,并没有明显导致铵态氮的垂直迁移;深层土壤水硝态氮的浓度显著低于未加DMPP的处理,明显降低硝态氮垂直迁移的淋溶损失;随施氮量增加,添加DMPP尿素的处理,60 d内土壤水中铵态氮与硝态氮的浓度在40 cm以下深层剖面并没有明显增加,其垂直迁移的淋溶损失差别不大.常规尿素添加1%的DMPP,可以调控土壤氮素的迁移转化,有利于土水环境的保护,降低对地下水氮素污染的潜在风险,具有显著的生态效益.     

3，5-二甲基吡唑磷酸盐硝化抑制作用初探

采用室内培养实验的方法，以不加抑制荆的尿素作为对照，对比研究DMPP及它的同分异构体3，5-二甲基吡唑磷酸盐作为硝化抑制剂对尿素氮在土壤中转化的影响。结果表明，3，5-二甲基吡唑磷酸盐具有一定的硝化抑制作用。在培养期间。施加3。5-二甲基吡唑磷酸盐的土壤中硝态氮的含量一周后始终低于对照，铵态氮的含量一周后始终高于对照。但在培养试验中后期（三周以后），3，5-二甲基吡唑磷酸盐的硝化抑制效果劣于DMPP。3，5-二甲基吡唑磷酸盐能否作为新型硝化抑制荆。还要对它的生理、生态效应等进行进一步的研究。