Relationship between CH4 and N2O emissions from rice field and its impacting factors

To find out the relationship between CH4 and N2O emissions from rice field and determine the key factors affecting the emissions, and give a scientifie basis for working out mitigation options of their emissions from flooded rice field, we measured the emissions and their impacting environmental factors systematically and simultaneously from Mar to Dee in 1995-1996 in northern China.     

Effects of leaf N concentration and leaf area index on determining rice tillering

Relative tillering rate(RTR)increased linear-ly with the increasing of leaf N concentration(NLV)has been already reported.To testwhether this relationship could be used toquantitatively explain the difference in tilleringamong a wide range of N application,field ex- periments were conducted at the IRRI farm,Los Banos,Laguna,the Philippines.Two in- dica cultivars,IR 72 and IR68284H wereused.For each cultivar,12 treatments includ- ing 4 N levels(0,60,120,and 180kgN·ha~(-1))and 3 transplanting spacing(30×20,20×20,and 10×20cm)were arranged in a ran-domized split-plot design with 4 replications.The N treatments were designated as mainplots and spacings as subplots.Fourteen-day-old seedlings were transplanted with 3seedlings per hill.The subplot area was 20m~2.Nitrogen fertilizer was applied as basal,atmidtillering,and at panicle initiation in threeequal splits.P,K,and Zn were applied asbasal at normal dosage.The field was flooded.Plant samples were taken every 7-14 d from 14d after transplanting to flower     

Interspecific competition,N use and interference with weeds in pea–barley intercropping

Field pea (Pisum sativum L.) and spring barley (Hordeum vulgare L.) were intercropped and sole cropped to compare the effects of crop diversity on productivity and use of N sources on a soil with a high weed pressure. ¹⁵N enrichment techniques were used to determine the pea–barley–weed-N dynamics. The pea–barley intercrop yielded 4.6 t grain ha⁻¹, which was significantly greater than the yields of pea and barley in sole cropping. Calculation of land equivalent ratios showed that plant growth factors were used from 25 to 38% more efficiently by the intercrop than by the sole crops. Barley sole crops accumulated 65 kg soil N ha⁻¹ in aboveground plant parts, which was similar to 73 kg soil N ha⁻¹ in the pea–barley intercrop and significantly greater than 15 kg soil N ha⁻¹ in the pea sole crop. The weeds accumulated 57 kg soil N ha⁻¹ in aboveground plant parts during the growing season in the pea sole crops. Intercropped barley accumulated 71 kg N ha⁻¹. Pea relied on N₂ fixation with 90–95% of aboveground N accumulation derived from N₂ fixation independent of cropping system. Pea grown in intercrop with barley instead of sole crop had greater competitive ability towards weeds and soil inorganic N was consequently used for barley grain production instead of weed biomass. There was no indication of a greater inorganic N content after pea compared to barley or pea–barley. However, 46 days after emergence there was about 30 kg N ha⁻¹ inorganic N more under the pea sole crop than under the other two crops. Such greater inorganic N levels during early growth phases was assumed to induce aggressive weed populations and interspecific competition. Pea–barley intercropping seems to be a promising practice of protein production in cropping systems with high weed pressures and low levels of available N.     

Effects on rice yield and quality by applying N fertilizer at late growth stage

Rice quality is decided by genotype,environ-ment,and cultivation.We studied the effectson rice yield and quality by applying N fertiliz-er at late growth stage. Materials used were Peiza-maoxuan,alate binary hybrid rice.It was seeded on Jun16 and transplanted on Jul 19,1998,with aspace of 25.0cm×13.3cm,30hills/m~2 and 2seedlings/hill.The treatments were T1=1 2 3,T2=1 2,T3=1 3,T4=2 3,T5=1,and T6=CK(1:Applied N at boot-ing stage,2:Applied N at initiation stage,and 3:Applied N at grain filling stage).Theamount of N fertilization was 50g/plot·time     

新老玉米杂交种的N吸收、N分配及光合作用的N利用率

新老玉米杂交种的Ｎ吸收、Ｎ分配及光合作用的Ｎ利用率─—（Ｄ．Ｅ．ＭｃＣｕｌｌｏ－ｕｇｈ等），ＣａｎａｄｉａｎＪｏｕｒｎａｌｏｆＰｌａｎｔＳｃｉｅｎｃｅ，１９９４，Ｖｏ１．７４，Ｎｏ．３，３７９～４８４（英文）将老玉米杂交种（Ｐｒｉｄｅ５）和新杂交种（...     

The effect of various dynamics of N availability on winter pea–wheat intercrops: Crop growth,N partitioning and symbiotic N2 fixation

Cereal–legume intercrops are a promising way to combine high productivity and several ecological benefits in temperate agro-ecosystems. However, the proportion of each species in the mixture at harvest is highly variable. The aim of this study was to test whether the timing of small application of N fertilizer is an effective way of influencing the dynamic interactions between species during crop growth and affecting the percentage of each species in the biomass of the mixture without greatly disturbing N₂ fixation. The influence of timing of nitrogen fertilization in pea–wheat intercrops was studied as regards (i) the dynamics of crop growth, (ii) nitrogen acquisition of each species, (iii) the inhibition and recovery of symbiotic N₂ fixation (SNF) after N application and (iv) final performance (yield, % of wheat, grain protein content). This was assessed in winter pea–wheat (Pisum sativum L.–Triticum aestivum L.) intercrops in 2007 and 2008 at two locations in France. Whatever the stage of application, N fertilizer tended to increase wheat growth and to decrease pea growth. N fertilization (applied once at different dates from tillering to the end of stem elongation) delayed the decrease in the contribution of wheat to total biomass and maintained the competitive ability of wheat over pea for longer than in unfertilized intercrops. N acquisition dynamics and N sharing between the two species were modified by N fertilization and its timing. Crop conditions at the time of N application (growth and phenology of each species, and their proportions in the intercrop biomass) greatly influenced intercrop response to N fertilization. Partitioning between species of soil and fertilizer N was correlated with the proportion of wheat in the total intercrop biomass observed at the date of N application. Short-term inhibition of nitrates on SNF was shown during the few days after N application, whatever its date. SNF recovery after N applications was observed only until pea flowering, but was prematurely stopped by N fertilization after this stage. The effect of N fertilization on the amount of fixed N₂ at harvest was correlated with pea biomass. N fertilization affects N₂ fixation mainly by affecting crop growth rather than %Ndfa in pea–wheat intercrops. In conclusion, N fertilization could be used as a tool to enhance the contribution of wheat in the intercrop biomass but may reduce the amount of fixed N₂ in the intercrop by decreasing pea biomass.     

Adaptation of the STICS intercrop model to simulate crop growth and N accumulation in pea–barley intercrops

Cereal–legume intercrops are gaining increasing interest in Europe. Modelling, by taking into account the complexity of species interactions, can be a very useful tool to study such systems and to test new strategies in various soil and climatic conditions. The present work describes the adaptation of an intercrop model for pea–barley intercrops through the extrapolation of the STICS sole crop model and its parameterisation from experimental data recorded on sole crops. Several improvements have been added to the existing crop model to allow an inversion of dominance in height between species during the crop cycle and a trophic link between crop growth rate and the potential for N₂ fixation. A 2-year dataset on pea and barley sole crops grown under non-limiting water conditions and with full crop protection was first used for calibration. The intercrop model was subsequently tested on experimental datasets of pea–barley intercrops grown under the same conditions as the sole crops. The intercrop experiments used to test the intercrop model differed in soil type, soil N supply and plant densities of each species.     

Potato Crop Nitrogen Status Assessment to Improve N Fertilization Management and Efficiency: Past–Present–Future

Improving nitrogen use efficiency is important for the potato crop, because of its relatively low ability to take up available soil mineral nitrogen (N). Splitting of N fertilizer application is a suitable approach to better match N need and supply. In-season crop N monitoring methods are therefore required to support such strategies. This paper deals with the state of the art and potential development of characteristics, use and implementation of well known and more recent methods aimed to assess in-season potato Crop Nitrogen Status (CNS). A short overview of this concept is given for the potato crop. The most important and available methods for CNS assessment are evaluated for their accuracy, precision, sensitivity, sensibility and feasibility. These are: the petiole sap nitrate concentration test; the leaf chlorophyll concentration measurement using a hand-held chlorophyll meter; the measurement of crop light reflectance through a hand-held radiometer using passive sensors. More recent methods still under investigation based on near, ground-based, air-borne or space-borne remote sensing are discussed for their scientific and practical interest in the near future. The current and potential use and implementation of these methods into decision support systems for potato N fertilization management aimed at improving the potato crop nitrogen use efficiency are analysed by: comparing relative and raw data; establishing threshold values of CNS; and combining or integrating the CNS values into models dedicated to N recommendation or to crop growth simulation.     

九二○对N,N—二甲基哌啶鎓氯化物的解除效应

N,N——二甲基哌啶鎓氯化物已在棉花等作物上广泛使用,但在使用过程中,常因使用不当而出现抑制过甚的现象,致使果枝减少,产量降低。据报道:N,N——二     

澳大利亚油菜育种家N.N.Roy博士来江苏讲学

应江苏省农科院的邀请,澳大利亚西澳农业部高级植物育种家N.N.Roy博士于1987年11月1日至11月15日来江苏讲学与考察。江苏及邻省的油菜育种家30余人参加听讲与学术讨论。Roy的讲演受到与会者的欢迎。     

Preliminary studies on microbiological mechanism of the dynamics of CH4 and N2O emission from rice field

Greenhouse gases, CH4 and N2O emitted from rice field, are the products of microbial metabolism. So the characteristics of CH4 and N2O production and emission in rice field can be understood through microbiological study. In this paper, the relationships between the dynamics of CH4 and N2O emission from rice field in northern China and the related soil bacteria groups were discussed.     

Effects of Free-air CO2 Enrichment on Root Characteristics and C：N Ratio of Rice at the Heading Stage

The CO2 concentration in Earth’s atmosphere is increasing rapidly due to human activities, like fossil fuel combustion and rapid deforestation and is predicted to reach a concentration of 550 μmol/mol within this century [1]. The increase in atmospheric CO2 has a large potential to alter many ecosystem processes, particularly C and N cycling [2-4]. Plant C:N ratio not only serves as an important factor in maintaining the quality of plant tissue, but also a key index to keep balance betwee…     

农家大豆种质对花叶病毒病N1和N3株系的抗性鉴定

农家品种作为重要的种质资源,其抗病性鉴定对大豆遗传育种材料的选择至关重要。采用摩擦接种法对46份农家大豆种质进行N1和N3株系的抗性鉴定。结果表明:对N1株系表现高抗的农家种质为6份,分别是铁荚子、天鹅蛋、青仁黑豆、黑豆、大青仁和冬豆;对N3株系表现高抗的农家种质为6份,分别是铁荚子、天鹅蛋、青仁黑豆、黑豆、化眉豆和小白脐;对N1和N3株系均表现高抗的种质为4份,分别是铁荚子、天鹅蛋、青仁黑豆、黑豆。这为SMV抗性育种奠定了材料基础。利用前期研究获得的与大豆花叶病毒病抗性基因相关的SSR标记Satt114,进行分子辅助鉴定,46份农家种质通过Satt114分子辅助鉴定,共筛选出8份抗大豆花叶病毒病种质,分别是铁荚子、黑豆、天鹅蛋、大青仁、青仁黑豆、冬豆、丰地黄、小白脐,其中丰地黄和小白脐的鉴定结果与摩擦接种法的鉴定结果不符,需进一步试验鉴定。     

N95175抗条锈病的RAPD分析

为了在小麦杂种优势利用和杂交育种亲本选配中更好地利用抗源材料,以抗源材料N95175和铭贤169(高感条锈病茵“条中32号”)杂交的F1和F2代分离群体在田间病圃和盆栽条件下进行了抗条锈性鉴定和DNA的RAPD分析。结果表明,N95175的抗锈性(“条中32”)受一对显性主效基因控制。对F2代分离群体抗、感池DNA的RAPD分析表明,引物S509所获得多态性片段与该抗病基因紧密连锁,它可以应用于小麦抗条锈病茵“条中32”的分子标记辅助选择。     

糯玉米自交系丹N988的选育

糯玉米（waxycorn）是普通玉米发生基因的隐性突变，由WX突变为WX而形成的一个特殊玉米类型。WX基因位于第9染色体的第59座位点上。糯玉米也称为蜡质玉米，子粒的胚乳是由100％的支链淀粉组成。糯玉米育种与生产进入20世纪90年代后发展迅速，糯玉米WX基因的遗传功能及广泛的用途受到重视与应用。     

Nɛ-(carboxymethyl)lysine,Available Lysine,and Volatile Compound Profile of Biscuits Enriched with Grape by-Product During Storage

Plant Foods for Human Nutrition - We investigated the changes in N?-(carboxymethyl)lysine (CML) and available lysine content, antioxidant properties, volatiles, and oxidation products of...     

新土豪喝茶的N种秀法

正打着"飞的"去喝茶新土豪喝茶,讲究去原产地,要是没有去过那些出名茶的原产地,那都不好意思说自己是喜欢喝茶的。至于交通工具吗,在天则为"飞的",在地上则为"路虎",因而被人戏称为"飞泡一族"。就是国内有一片好水的名山大川,也一律都在土豪的"飞行"名单上。有位土豪朋友在喝茶飞行日记中写道,我更喜欢简单一点,带上茶,一个空杯。因为有低压反应,也会把茶膏带着,在飞机降落时,嚼嚼茶膏来舒缓下耳朵的失聪和耳鸣。但身边那些过分讲究的朋友却不那么看,他们到高海拔区域,会带上日本铁壶,一个大箱子里,全是各种茶器。     

棕色棉新品种--运彩N8283

以早熟的苏联棕棉为母本,高产抗逆性强的晋棉25号为父本杂交选育而成。2003年参加山西省南部中熟棉品种区域试验,2004年参加山西省南部中熟彩色棉新品种生产试验。2005年3月通过山西省农作物品种审定委员会审定。1特征特性生长势较强,植株筒形,铃较大,吐絮畅,较白色棉烂铃少,纤维棕色,较深,子皮棉均色调柔和美观。生育期126天,结铃性强,单株成铃17.9个,铃重5.2 g,衣分33.9%~37.0%;出苗快,出苗齐,对棉铃虫棉蚜都有一定的耐性。2产量表现2003年区域试验中,平均每公顷子棉产量3064.5 kg,皮棉939.0 kg,为对照晋棉31号的84.3%,2004年生产试验,平…     

恢复系N120系列组合高产制种技术

介绍了江西农业大学选育的强恢复系N120的生育期和开花习性及其系列组合秋季高产制种技术.