Nitrogen release from differently aged Raphanus sativus L. nitrate catch crops during mineralization at autumn temperatures          下载免费PDF全文

I. K. Thomsen  L. Elsgaard  J. E. Olesen  B. T. Christensen 《Soil Use and Management》2016,32(2):183-191

In temperate climates with surplus precipitation and low temperatures during autumn and winter, nitrate catch crops have become crucial in reducing nitrate leaching losses. Preferably, the N retained by the catch crop should remain in the soil and become available to the next main crop. Fodder radish (Raphanus sativus, L.) has emerged as a promising nitrate catch crop in cereal cropping, although the course of remineralization of residue N following termination of this frost‐sensitive crucifer remains obscured. We incubated radish residues of different age (different planting and harvest dates) with a loamy sand soil; mineralization of residue N was determined after 1, 2, 4 and 7 months of incubation at 2 °C and 10 °C. Incubations with soil only and with residues of white mustard (Sinapis alba, L) and perennial ryegrass (Lolium perenne, L.) were included as references. Using linear regression, net N release was fitted to plant chemical characteristics (initial concentrations of N, fibre fractions, lignin and C/N ratio). Residue C/N ratio (ranging from 10 to 25) and N concentration (ranging from 17 to 40 mg N/g dry matter) showed superior fits to net N release at both temperatures (r², 0.64–0.94) while fibre analyses provided inferior fits (r², 0.12–0.64). This was true across planting date and plant age. Net N release after 7 months of incubation at 2 °C and 10 °C accounted for up to 40% and 50% of residue N, respectively. During most of the incubation period, nitrate dominated the mineral N pool at both temperatures. The N mineralization and nitrification potential at these low soil temperatures suggest that a considerable fraction of the N captured by nitrate catch crops may be remineralized, nitrified and thus available for plant uptake but also for loss by leaching and denitrification.  相似文献   

A rice geranylgeranyl reductase is essential for chloroplast development          下载免费PDF全文

LIU Xi  YI Xin  YANG Yan-rong  HUANG Qian-qian 《农业科学学报》2021,20(10):2592-2600

Chloroplasts are essential for plant photosynthesis and growth. Many genes have been identified that regulate plant chloroplast development. However, it is not known at a molecular level how these genes regulate chloroplast biogenesis. In this study, we isolated a mutant ygl2(yellow-green leaf2) that exhibited a pigment-defective phenotype. YGL2 encodes a geranylgeranyl reductase, and in mutant ygl2, there was a single base change(T1361 G) located in the third exon of YGL2 that resulted in a missense mutation(L454 R) in the encoded product. Transmission electron microscopy revealed that chloroplast development was impaired in the ygl2 mutant. The expression levels of plastid-encoded genes were significantly altered in the ygl2 mutant. Furthermore, in a yeast two-hybrid assay, we found that YGL2 interacted with the RNA editing factor MORF8.  相似文献   

Automated method for determining nitrate and nitrite in water and soil extracts     

《Communications in Soil Science and Plant Analysis》2012,43(6):625-636

Abstract

This paper describes an AutoAnalyzer method for measuring nitrate plus nitrite in thirteen commonly used soil extraction solutions. The AutoAnalyzer is normally equipped with a column containing cadmium chips. In this study the column is replaced with a cadmium‐silver wire inserted in plastic tubing which has several advantages. There is no compaction of cadmium chips, it eliminates the need to debubble the sample stream before it enters the reductor, the dead volume is decreased, and it eliminates the copper sulfate treatment process except for one given the first time the wire is used. The method is also excellent for measuring nitrate plus nitrite in rain water.  相似文献   

Nitrogen nutrition and use efficiency in rice as influenced by crop establishment methods,cyanobacterial and phosphate solubilizing bacterial consortia and zinc fertilization     

《Communications in Soil Science and Plant Analysis》2012,43(12):1487-1499

ABSTRACT

A field experiment was conducted at the ICAR-Indian Agricultural Research Institute, New Delhi during wet season of 2013 and 2014, involving three crop establishment methods (CEMs) viz. puddled transplanted rice (PTR), system of rice intensification (SRI), and aerobic rice system (ARS). Three rates of nitrogen (N) and phosphorus (P) application (0%, 75%, and 100% of recommended dose of N and P) (RDN) (120 kg N ha^–1 and 25.8 kg P ha^–1) and two sources of N and P (fertilizer and cyanobacterial-bacterial inoculation) were tested with and without zinc (Zn) fertilization in all CEMs. The concentration of N in PTR and SRI was significantly higher than ARS with higher uptake of 10.3 and 11.1 kg ha^–1 in PTR and SRI over ARS. Treatment with 100% RDN led to significantly higher N availability and uptake than 75% RDN and absolute control, i.e. 14.5 and 32.0 kg ha^–1, respectively. Application of Anabaena-Pseudomonas biofilm formulation (MC2) in conjunction with 75% RDN increased total uptake of N by 12.7 kg ha^–1 compared to 75% RDN only. A positive correlation was found between N concentration and acetylene reductase activity at 70 days after sowing (DAS) (R² = 0.52) and 100 DAS (R² = 0.38) based on mean of 2 years study. Zn fertilization significantly increased N concentration in rice straw and milled rice irrespective of the crop establishment methods. Our study signifies the importance of microbial inoculation, optimal N fertilization along with SRI and PTR as more effective crop establishment methods for deriving greater benefits in terms of N nutrition in rice.  相似文献   

Effects of Molybdenum,Nickel, and Nitrogen Sources on the Mineral Nutrition and Growth of Rice Plants     

《Communications in Soil Science and Plant Analysis》2012,43(21-22):3238-3251

Upland rice plants, cultivar ‘IAC 202,’ were grown in nutrient solution until full tillering. Treatments consisted of ammonium nitrate (AN) or urea (UR) as nitrogen (N) source plus molybdenum (Mo) and/or nickel (Ni): AN + Mo + Ni, AN + Mo ? Ni, AN ? Mo + Ni, UR + Mo + Ni, UR + Mo ? Ni, and UR ? Mo + Ni. The experiment was carried out to better understand the effect of these treatments on dry‐matter yield, chlorophyll, net photosynthesis rate, nitrate (NO₃ ^?‐N), total N, in vitro activities of urease and nitrate reductase (NR), and Mo and Ni concentrations. In UR‐grown plants, Mo and Ni addition increased yield of dry matter. Regardless of the N source, chlorophyll concentration and net photosynthesis rate were reduced when Mo or Ni were omitted, although not always significantly. The omission of either Mo or Ni led to a decrease in urease activity, independent of N source. Nitrate reductase activity increased in nutrient solutions without Mo, although NO₃ ^?‐N increased. There was not a consistent variation in total N concentration. Molybdenum and Ni concentration in roots and shoots were influenced by their supply in the nutrient solution. Molybdenum concentration was not influenced by N sources, whereas Ni content in both root and shoots was greater in ammonium nitrate–grown plants. In conclusion, it can be hypothesized that there is a relationship between Mo and Ni acting on photosynthesis, although is an indirect one. This is the first evidence for a beneficial effect of Mo and Ni interaction on plant growth.  相似文献   

烟草及烟草制品中硝酸盐/亚硝酸盐流动分析模块的建立     

尚军  王鹏  吕祥敏  戴迎雪  兰中于  朱立军 《安徽农业科学》2011,(11):6509-6510,6512

[目的]组建流动分析模块,并用于检测烟草中硝酸盐/亚硝酸盐的含量。[方法]收集可用材料、配件组装模块,然后对样品以及标准物质进行检测,确定其重复性、回收率、检测限,以验证模块可用性。[结果]通过反复改进组装模块,对多个烟草样品硝酸盐/亚硝酸盐含量分别测定多次,测定模块重复性,结果RSD〈2.92%;向样品中加入标准溶液测定回收率,回收率为97.2%～104.9%。[结论]组装模块能够满足烟草及烟草制品中硝酸盐/亚硝酸盐含量检测需要,节省了新购仪器的费用,同时提高了现有仪器的使用率。  相似文献   

甘蓝过量表达硝酸还原酶基因对硝酸盐积累的影响     

张正英  陈玉梁 《西北农业学报》2016,25(7):1024-1028

为探索过量表达硝酸还原酶基因对甘蓝(Brassica oleracea L.var.capitata L.)硝酸盐积累的影响,以‘中甘11号’下胚轴为外植体,采用根癌农杆菌(Agrobacterium tumefaciens)介导法将烟草硝酸还原酶基因(NR)导入甘蓝,获得13株卡那霉素抗性植株。PCR和Southern blot检测证实,NR基因已经成功导入并整合到甘蓝的基因组。4个转基因株系硝酸盐质量分数明显低于非转基因供体株系,降幅为13.9%~23.0%。说明:将重组硝酸还原酶基因导入甘蓝且得到超量表达,创制低硝酸盐育种材料的方法可行。  相似文献   

芥蓝品质分析的两种取样方法比较研究     

雷玉玲  吴朝江  宋世威 《长江蔬菜》2014,(6):44-47

以芥蓝为材料,采用分产品器官(叶片、叶柄、薹茎和花蕾)和整个产品器官匀浆两种取样方法,分别测定维生素C、可溶性糖、游离氨基酸和硝酸盐含量,并分析了其在产品器官中的分配和累积规律。结果表明,花蕾维生素C含量、游离氨基酸含量均最高,叶柄中最低;薹茎的可溶性糖含量最高,叶片最低;叶柄的硝酸盐含量最高,花蕾最低。产品器官中维生素C、可溶性糖、游离氨基酸均为分配至薹茎的比例最高,分别为48.02%、61.14%、49.73%,其次是叶片和叶柄,花蕾的分配比例最低;硝酸盐分配到薹茎的比例最高,达48.04%,其次为叶柄和叶片,分别为41.63%和10.02%,花蕾的分配比例最低。对菜薹整体匀浆法和分器官测定后加权求和的结果进行统计分析表明,两种测定方法无显著差异,在实际中可根据研究目的选用不同的测定方法。  相似文献   

外源氮对琼北不同类型土壤甲烷氧化能力的影响   总被引：1，自引：0，他引：1  

齐润杰  陈金霞  但建国 《热带作物学报》2016,37(8):1534-1539

氮输入是影响土壤氧化吸收大气甲烷(CH_4)的重要因子之一。通过对琼北5种旱地土壤进行室内培养实验,评价不同类型土壤对低浓度CH_4的吸收能力及其对硝态氮和不同浓度铵态氮的响应。结果表明:火山灰土、富铁土、雏形土、铁铝土和淋溶土的CH_4氧化速率分别为67.01,50.05,47.00,72.82和57.10 ng/(kg·h)。按100(mg/kg)N添加的硝态氮仅对铁铝土CH_4氧化有显著的抑制效果,而按此浓度添加的铵态氮能显著降低5种土壤的CH_4氧化速率。铵态氮对5种土壤CH_4氧化的抑制率与铵态氮添加量均呈极显著的线性正相关。每单位(mg/kg)铵态氮添加量对铁铝土CH_4氧化的抑制率最低,仅为其他4种土壤的53%~60%,这很可能跟铁铝土的高C/N和低N/P有关。因此,对这些土壤进行科学管理时,应根据土壤类型选用适宜的N肥类型,同时,还应提高土壤有机质含量,增施P肥,充分发挥土壤对大气CH_4的氧化潜力。  相似文献   

氮素浓度及形态对韭菜硝酸盐及硝酸还原酶活性的影响   总被引：2，自引：0，他引：2  

卢凤刚  陈贵林 《北方园艺》2011,(4):41-43

水培条件下,研究了氮素浓度及氮素形态对"汉中冬韭"体内硝酸盐含量和硝酸还原酶活性的影响。结果表明:随营养液供氮浓度的提高,韭菜叶片硝酸盐含量及硝酸还原酶活性均呈上升趋势;随营养液中铵态氮浓度的增加,韭菜叶片的硝酸盐含量及硝酸还原酶活性均逐渐降低;以硝酸盐作为衡量标准,韭菜适宜的氮肥施用量为4～8 mmol/L,适宜的NO₃^-←NH₄⁺为1←3～0←4。  相似文献