以2014年、2017年260份调查问卷和582个土壤样品及年度农用化肥总量为依据,梳理了昌平区年际间施肥量、土壤养分、氮磷环境风险和污染源变化,以期为北运河上游化肥面源污染防控提供理论依据.结果表明,相比于2014年,2017年粮食、果类蔬菜、叶类蔬菜和草莓的化肥平均用量分别减少了26.3％、25.5％、20.4％和15.0％,蔬菜和草莓的有机肥平均用量分别减少了42.6％和6.67％.粮田和菜地氮盈余均为无风险,2017年氮素地下淋溶和地表径流损失相比于2014年分别减少了27.8％和56.0％.粮田不存在磷环境风险,菜地磷环境风险等级从2014年的高风险降至2017年的中风险.与2014年相比,2017年污染物流失量降低了47.8％.区域地表水环境均以总氮污染为主,其次是总磷和氨氮.本研究提出在夏玉米上推广环境友好型肥料和免耕措施;对果类蔬菜采取养分总量控制与分期调控的施肥策略;引导叶菜生产采用滴灌或微喷;开展草莓与多种作物间套作,加大土壤盈余氮、磷的吸收;探索建立推动土肥社会化服务的应用.

为研究含硝酸盐类水溶肥料的安全性,选取了5种硝酸盐类原料,设置了21种两两混配的硝酸盐样品,从获得农业农村部产品登记证的2 605个国内外硝酸盐水溶肥料中筛选出20种产品,分别采用固体氧化性试验方法对以上样品进行测试.结果 表明:肥料行业中常用的六水合硝酸锌与六水合硝酸镁为非氧化性物质,硝酸钾、硝酸钠和硝酸钙分别为Ⅱ类和Ⅲ类氧化性物质,氧化性顺序为硝酸钾＞硝酸钠＞硝酸钙;筛选的20种水溶肥料产品中有50％的样品为氧化性物质,表明存在一定的安全风险;建议在今后的产品审批中,对肥料配方中硝酸钾含量超过75％和硝酸钠含量超过85％的水溶肥料产品进行氧化性试验,对达到氧化性物质标准的应在产品备案、包装识别、标签、生产、运输、储存中加大管理力度.

[Objectives] In this paper, the contents and sources of toxic heavy metals As, Pb, Cd, Cr and Hg in water-soluble fertilizers were studied and their maximal limits in fertilizer standards are discussed, aiming to understand the safety situation of water-soluble fertilizers,reduce environmental risk of heavy metals and ensure the quality safety of agricultural products. [Methods] Samples were collected from all the fertilizer products registered in the National Center for Quality Supervision and Testing of Chemical Fertilizers (Beijing). Heavy metal contents were measured using method of agriculture standard NY/ T 1978 - 2010 ( Determination of mercury, arsenic, cadmium, lead and chromium content for fertilizers). The heavy metal source adopted an empirical investigation method. The data about the contents of heavy metals in raw materials were from openly published documents at home and abroad. [Results] The contents of As, Pb, Cd, Cr and Hg in five types of water-soluble fertilizers are all in the safe levels according to the agricultural standard (NY/ T 1110 -2010: Water-soluble fertilizers content limits of mercury, arsenic, cadmium, lead and chromium), and are far below the maximal limits. There are some fertilizer samples in which heavy metal contents exceed the maximal limits, but the proportion is very low and mainly occurred in As and Cd with exceeding percentage of 3. 50% and 1. 27% separately. The proportion for Pb, Cr and Hg are all less than 1% . The Cd contents in the samples above the limit is often several to several hundred times of the up limit, while the contents of As, Pb and Cr are just one to several times higher. The survey results of 127 samples show that heavy metals mainly come from raw materials, and more than half of the raw materials are used for phosphate and micronutrients fertilizer production. The heavy metals in water-soluble fertilizers containing nitrogen, phosphorus and potassium are mainly from phosphate fertilizers including monopotassium phosphate and monoammonium phosphate, followed by zinc sulfate and other micronutrients fertilizers. In water-soluble fertilizers containing micronutrients, the heavy metals mainly come from zinc sulfate and ferrous sulfate. Most As and Cd in water-soluble fertilizers containing amino-acids derive from zinc sulfate, ferrous sulfate and amino-acids, And the heavy metals, especially As, in water-soluble fertilizers containing humic-acids,mainly come from sodium humate, potassium humate and phosphate fertilizers. The researches at home and aboard all reported the extremely low heavy metal contents in nitrogen and potash fertilizers, but relatively high in phosphate and micronutrient fertilizers. Therefore, nitrogen and potash fertilizers are environmentally safe as raw materials of water-soluble fertilizers, phosphate and micronutrient fertilizers should be monitored for the heavy metal contents before used as raw materials of water-soluble fertilizers. Considering the fertilizer standards,the maximal limits of As, Pb, Cd, Cr and Hg are absent or too broad, lack of pertinence. [Conclusions] On the whole, the quality of water-soluble fertilizers is satisfactory, occasionally the contents of As, Pb, Cd, Cr and Hg exceed the up limit in the relative standards in China. So they are generally safe to farmland. However, attention still should be paid to the As and Cd contents in water-soluble fertilizers. The fertilizer standardization system should be strengthen the construction for suitable fertilizer environmental evaluation and fertilizer quality consciousness.

以5种水溶肥料为研究对象,采用原子荧光光谱法和原子吸收分光光度法检测了As、Hg和Pb、Cd、Cr含量,并采用内梅罗单因子污染指数和综合污染指数对重金属污染程度进行了评价.结果显示,水溶肥料中As、Pb、Cd、Cr、Hg平均含量分别为1.8、15.8、2.4、2.3和0.0 mg kg-1,均符合农业行业标准NY/T 1110-2010限量要求.部分样品中As、Pb和Cd含量超标,超标率分别为4.2％、0.2％和1.0％.5种重金属单因子污染指数都小于0.6,全部为清洁级别,As、Pb、Cd污染程度高于Cr和Hg.5种肥料的综合污染指数在0.14～0.40之间,属于安全级别,综合污染程度从大到小依次为:中量元素水溶肥料≈大量元素水溶肥料＞微量元素水溶肥料≈含腐植酸水溶肥料＞含氨基酸水溶肥料.总之,水溶肥料重金属产品质量安全,环境风险较小,但As和Cd在大量元素水溶肥料、微量元素水溶肥料和含腐植酸水溶肥料中的安全性值得关注.

综述了新建设施菜田土壤培肥措施的研究进展与趋势,阐述了增施有机肥、有机肥化肥配施、施用生物有机肥、深耕改土、轮作倒茬一系列培肥措施对新建设施菜田的影响,指出了京郊新建设施菜田土壤存在的问题与今后的发展方向。

Root configuration and rhizosphere characteristics of the different efficiency-phosphorus maize inbred line types were studied by using a three-chamber-root-bag culture experiment.Three high-effcient-phosphorus maize inbred lines and three low efficiency-phosphorus maize inbred lines were selected for the study.Crop biomass,phosphorus absorption amount,root configuration,rhizosphere pH and phosphatase activity under two P levels were investigated as well.Results showed that under the low P level,root weight,phosphorus absorption amount,number of root tips,root length and rhi- zosphere phosphatase activity were high for the high-efficient-phosphorus maize inbred lines,and low for the low-efficient- phosphorus maize inbred lines.Root weight of the high-efficient-phosphorus maize inbred line 1(hpl)was significantly higher than that of the low-efficient-phosphorus maize inbred line 2(lp2),while root weight of hp2 was higher than that of lpl,lp2 and lp3,respectively.Phosphorus absorption amounts of shoots and roots of hpl and hp2 were higher than those of lp2 and lp3.Number of root tips and lengths of hpl and hp2 were both higher than those of lp2 and lp3.Rhizo- sphere acid phosphatase activities of hpl,hp2 and hp3 were higher than those of lp2 and lp3.There was certain superior- ity in high-efficient-phosphorus maize inbred lines too,such as dry weight of shoot and pH.Among all cuhivars,the dif- ferences between hp2 and lp3 were the most significant ones.

本标准规定了肥料效果试验相关术语、试验要求和内容、效果评价、报告撰写等要求。 本标准适用于粮食作物、经济作物、蔬菜、花卉、果树等肥料效果试验和评价。缓释肥料、肥料增效剂、土壤调理剂等除特殊试验要求外应执行本标准。 本标准不适用于微生物肥料。

本标准规定了土壤调理剂效果试验相关术语、试验要求和内容、效果评价、报告撰写等要求。 本标准适用于土壤调理剂试验效果评价。

本标准规定了缓释肥料效果试验相关术语、试验要求和内容、效果评价、报告撰写等要求。 本标准适用于缓释肥料试验效果评价。

本标准规定了尿素硝酸铵溶液登记要求、试验方法、检验规则、标识、包装、运输和贮存。 本标准适用于中华人民共和国境内生产和销售的尿素硝酸铵溶液。产品是以合成氨与硝酸中和形成的硝酸铵溶液、尿素溶液为原料按比例加工而成的水溶肥料。

本标准规定了肥料增效剂双氰胺（C2H4N4）含量测定的高效液相色谱法试验方法。 本标准适用于添加双氰胺肥料及双氰胺制剂的测定。

本标准规定了土壤调理剂效果试验相关术语、试验要求和内容、效果评价、报告撰写等要求。 本标准适用于土壤调理剂试验效果评价。

本标准规定了中量元素水溶肥料的技术要求、试验方法、检验规则、标识、包装、运输和贮存。 本标准适用于中华人民共和国境内生产和销售的，以中量元素钙、镁为主要成分的固体或液体水溶肥料。

本标准规定了农业用改性硝酸铵登记要求、试验方法、检验规则、标识、包装、运输和贮存。 本标准适用于中华人民共和国境内生产和销售的、作为肥料使用的农业用改性硝酸铵。产品是在硝酸铵生产过程中添加碳酸钙、碳酸镁等原料成分，并将浓缩的熔融混合物经造粒而成的非全水溶均质固体。