Influence of nitrogen and sulfur fertilization on quality of canola (<Emphasis Type="Italic">Brassica napus</Emphasis> L.) under rainfed conditions

Field experiments were conducted at Cereal Crops Research Institute, Pirsabak, Nowshera, Pakistan, during winter 2003~2004 and 2004~2005 to evaluate the effect of nitrogen and sulfur levels and methods of nitrogen application on canola (Brassica napus L. cv. Bulbul-98) under rainfed conditions. Four levels of S (0, 10, 20, and 30 kg/ha) and three levels of N (40, 60, and 80 kg/ha) and a control treatment with both nutrients at zero level were included in the experiments. Sulfur levels were applied at sowing while N levels were applied by three methods (100% soil application, 90% soil 10% foliar application, and 80% soil 20% foliar application). The experiments were laid out in randomized complete block (RCB) design having four replications. Oil content increased significantly up to 20 kg S/ha but further increase in S level did not enhance oil content. Glucosinolate content increased from 13.6 to 24.6 μmol/g as S rate was increased from 0 to 30 kg/ha. Protein content increased from 22.4% to 23.2% as S rate was increased from 0 to 20 kg/ha. Oil content responded negatively to the increasing N levels. The highest N level resulted in the highest values for protein (23.5%) and glucosinolate (19.9 μmol/g) contents. Methods of N application had no significant impact on any parameters under study.     

Targeted yield concept and a framework of fertilizer recommendation in irrigated rice domains of subtropical India

Soil test crop response （STCR） correlation studies were carried out in Vindhyan alluvial plain during 2001 to 2004 taking IR-36 as test crop to quantify rice production in the context of the variability of soil properties and use of balanced fertilizers based on targeted yield concept. The soils were developed on gently sloping alluvial plain with different physiographic settings and notable variation in drainage condition. Soil properties show moderate variation in texture （loamy to clay）, organic carbon content （4.4 to 9.8 g/kg）, cation exchange capacity （10,2 to 22.4 cmol （p＋）/kg） and pH （5.3 to 6,4）, Soil fertility status for N is low to medium （224 to 348 kg/ha）, P is medium to high （87 to 320 kg/ha） and K ranges from medium to high （158 to 678 kg/ha）. Database regarding nutrient requirement in kg/t of grain produce （NR）, the percent contribution from the soil available nutrients [CS （%）] and the percent contribution from the applied fertilizer nutrients [CF （%）] were computed for calibrating and fbrmulating fertilizer recommendations. Validity of the yield target for 7 and 8 t/ha was tested in farmers＇ fields and yields targets varied at less than 10%. The percent achievement of targets aimed at different level was more than 90%, indicating soil test based fertilizer recommendation approach was economically viable within the agro-ecological zone with relatively uniform cropping practices and socio-economic conditions.     

Potential production simulation and optimal nutrient management of two hybrid rice varieties in Jinhua,Zhejiang Province,China

Potential growth of two widely-grown hybrid rice varieties in the Jinhua district of Zhejiang Province, Shanyou63 for mid-rice and Xieyou46 for late rice, was simulated using a crop growth model of WOFOST. Parameters of the rice growth in WOFOST were calibrated through field experiments from 1999 to 2002 in Jinhua. The potential yield simulated with WOFOST was about 12 t/ha for Shanyou63 and 10 t/ha for Xieyou46, which are in good agreement with the highest recorded yield obtained in this area. Under farmers practice, current yield is about 7.5 t/ha for Shanyou63 and 6.5 t/ha for Xieyou46. There is a gap between the actual rice yield and the potential yield for these two hybrid rice varieties grown in this area. The attainable target yields were set to 70% to 75% of their potential yields for the two varieties. A recently developed software ＂Nutrient Decision Support System （NuDSS）＂ for irrigated rice was used to optimize nutrient management for these two rice varieties. According to NuDSS, the optimal fertilizer N requirement for the target yields was about 150 kg/ha for Shanyou63 and about 120 kg/ha for Xieyou46, which were only about 70% of the fertilizer N application under current farmers＇ practice. Comparing with farmers＇ practice, there is great potential to increase actual rice yields and to reduce fertilizer N use rates by improving rice crop management practice in Jinhua.     

太白山太白红杉林的群落学特征及生物量的研究

笔者研究了太白山北坡海拔3250m处的太白红杉林的群落学特征,对其生物量用多种生物回归模型作了预测,得到了太白红杉生物量的最优模型是:.各种灌木的模型形式不同.草本植物用收获法测定.太白红杉林的总生物量为205.565t/ha,其中乔木层166.587t/ha,灌木层37.673t/ha.草本层 1.305t/ha.最后讨论了曲线回归模型的形式和检验问题.     

我国超级稻育种计划目标是2015年单季超级杂交稻大面积示范产量达900公斤／亩（13500kg／ha）

据中国军网2010年1月15日援引新华社海南博螯1月15日电,由袁隆平院士提出并主持的我国超级杂交稻育种计划已经取得了举世瞩目的成就,分别于2000年和2004年如期实现了第一期700公斤／亩（10500kg／ha）和提前一年实现第二期800公斤／亩（12000kg／ha）的产量指标。科技部于2005年启动的超级稻第三期900公斤／亩（13500kg／ha）的计划研究至今也取得了可喜的成绩,在     

两个几何等式

文[1]中收入三角形旁切圆半径（ra,rb,rc）和高（ha,hb,hc）间的三个不等式∑hahb≤∑rarb;∑ ha＋hb/ra＋rb;∑ ha＋hb/ra=rb≤3;∏ hb＋hc/ra＋ha≤1.我们把它们“加强”为等式：     

上海市松江区农技中心培育的“五彩大米”试种成功

据2010年11月《新民晚报》消息,松江区农技中心在总共约1亩（合1／15ha）的试种的“五彩大米”获得成功,亩产400～500kg（合6000～7500kg／ha）。     

Synthesis and Biological Evaluation of Novel N-Benzoxazolonyluracils as Protox-Inhibitor

Protoporphyrinogen oxidase inhibitor has become the focus research field as herbicides.Seven novel N-benzoxazolonyluracils were obtained by cyclization of 6-aminobenzoxazolone derivatives with ethyl 3-dimethylcarbamoylamido-4,4,4-trifluorocrotonate and then methylation or amination, and the reaction yields were between 59%-86%. The chemical structures of the compounds were identified by Elemental Analysis, MS and ^1H NMR. Biological results indicate that some compounds exhibit excellent control of broadleaf weeds at post-emergence by low dosage 18.75 ga.i/ha, but are not effective for grass weeds below dosage 37.5 ga. i/ha. In addition, these compounds show no damage at high-dosage 150 ga. i/ha to wheat and corn, but are unsafe to dicotyledonous plants such as cole, soybean and sorghum even at lower dosage 18.75 ga. i/ha.     

原子吸收法测定不同种类大米中的Zn、Fe、Ca含量

利用原子吸收法对大米中的Zn、Fe、Ca的含量进行了检测。实验结果得到的相关系数(r~2)在0.99454—0.99885之间,说明该方法具有简便快速、高效准确的特点。所测的大米中Zn、Fe、Ca的含量分别为:4.1mg/kg—24.400mg/kg,37.050mg/kg—92.550mg/kg,15.350mg/kg—28.750mg/kg。将本实验应用于本科教学,使学生掌握原子吸收法的原理,学会绘制标准曲线,掌握从样品处理到定量分析整个复杂样本的元素含量分析。     

山东省科学家培育出高产小麦品种,单位面积产量达世界平均水平的3倍

据中国军网2010年12月13日援引新华社济南2010年12月13日电,山东省农科院培育的“济麦22”小麦新品种日前通过了专家鉴定,研究成果总体达到国际领先水平,单产可达世界平均水平的3倍。据介绍,目前世界小麦平均单产在3000kg／ha（合200千克／亩）左右,我国平均单产为4950kg／ha（合330千克／亩）。验收结果显示,     

Bread wheat varieties as influenced by different nitrogen levels

INTRODUCTION Dera Ismail Khan lies in Pakistan’s arid zone (71.07° longitude, 31.57° latitude and 500 m above sea level). This zone is in the extreme south of (NWFP) Pakistan at the bank of the River Indus. Dera Ismail Khan is bounded by Sulaiman Range to the West, the Indus River on the East, Marwat and Bhit- tani Ranges on the North and Vehowa Nala (Punjab) on the South. Besides certain local variability the area is comprised of four basic divisions viz mountains, a series …     

“燕麦枯”麦田优化施用技术研究

本研究采用二次通用旋转组合设计的方法,建立了以小麦产量和野燕麦防除率(％)为目标函数,考虑“燕麦枯”药剂施药量(公斤/公顷),喷液量(公斤/公顷)和施药时期(月/日)三个决策变量的数学模型。通过对模型的综合分析寻优提出:在麦田野燕麦危害严重地区(减产30％以上),“燕麦枯”施药量为8.25——10.05公斤/公顷,喷液量为450——675公斤/公顷,施药时期为12月/10日或翌年3月/10日前后的优化技术方案。运用此“燕麦枯”麦田施用技术,可获小麦每公顷产量4050公斤以上和野燕麦防除率75％以上。     

Detection of nitrogen-overfertilized rice plants with leaf positional difference in hyperspectral vegetation index

The main objective of this work was to compare the applicability of the single leaf (the uppermost leaf L1 and the third uppermost leaf L3) modified simple ratio (mSR₇₀₅ index) and the leaf positional difference in the vegetation index between L1 and L3 (mSR_705L1-mSR_705L3) in detecting nitrogen (N)-overfertilized rice plants. A field experiment consisting of three rice genotypes and five N fertilization levels (0, 75, 180, 285, and 390 kg N/ha) was conducted at Xiaoshan, Hangzhou, Zhejiang Province, China in 2008. The hyperspectral reflectance (350–2500 nm) and the chlorophyll concentration (ChlC) of L1 and L3 were measured at different stages. The mSR_705L1 and mSR_705L3 indices appeared not to be highly sensitive to the N rates, especially when the N rate was high (above 180 kg N/ha). The mean mSR_705L1-mSR_705L3 across the genotypes increased significantly (P<0.05) or considerably from 180 to 285 kg N/ha treatment and from 285 to 390 kg N/ha treatment at all the stages. Also, use of the difference (mSR_705L1-mSR_705L3) greatly reduced the influence of the stages and genotypes in assessing the N status with reflectance data. The results of this study show that the N-overfertilized rice plants can be effectively detected with the leaf positional difference in the mSR₇₀₅ index.     

湖南村镇住宅产业化发展战略分析

住宅建设是国民经济发展的基础。目前湖南省村镇住宅建设仍处于低水平发展阶段，实现村镇住宅产业化，促进湖南村镇住宅产业的发展，有助于拉动农村经济。     

Studies on nutrient uptake of rice and characteristics of soil microorganisms in a long-term fertilization experiments for irrigated rice

The ecosystem characteristics of soil microorganism and the nutrient uptake of irrigated rice were investigated in a split-block experiment with different fertilization treatments, including control (no fertilizer application), PK, NK, NP, NPK fertilization, in the main block, and conventional rice and hybrid rice comparison, in the sub block. Average data of five treatments in five years indicated that the indigenous N supply (INS) capacity     

近代湖南粮食史研究述评

湖南自清代以来一直是国内粮食主产区,也是全国重要的粮食供给省份之一。对于湖南这个重要的中国中部粮仓省份相关粮食问题研究,民国以来就备受学术界关注。从文本解读的视角细致地梳理了国内外学界对清代至民国湖南粮食研究的现状、特征及不足。     

我院体育专业学生教学能力现状及培养方式的改革研究

湖南科技学院体育教育系学生就业主方向是中小学教师。随着新课标的颁布,对中小学校教师提出了更新更高的要求,面对时代的新形势,新要求,湖南科技学院体育教育专业学生教学能力的现状如何？如何根据新能力,新要求来调整和改革湖南科技学院的培养方式？这两个问题是本文的研究重点。