Potassium Requirements of Lowland Rice

Rice is a staple food for about 50 percent of the world’s population. Potassium (K) is absorbed in large amounts by rice plants and adequate amounts of this element are fundamental to improve productivity and maintain sustainability of the cropping systems. A greenhouse experiment was conducted to determine the adequate rate of K for lowland rice grown on a Brazilian Inceptisol. The K rates used were 0, 50, 100, 200, 400, and 600 mg K kg^?1 soil. Most of the growth, yield, and yield components were significantly and quadratically increased with increasing K levels. Based on a quadratic equation, maximum grain yield was obtained with the addition of 371 mg K kg^?1 soil. Maximum plant height and shoot dry weight were obtained at 414 and 398 mg K kg^?1 soil, respectively. Root growth (maximum length and dry weight) was also significantly increased in a quadratic fashion with the increasing K rate in the growth medium. Maximum root length was achieved at 58 mg K kg^?1 whereas maximum root dry weight was obtained with the addition of 394 mg K kg^?1 soil. Plant height, shoot dry weight, 1000-grain weight, root length, and root dry weight were significantly associated with grain yield. Hence, manipulation of these growth and yield components with the addition of K fertilizer can improve yield of lowland rice in varzea soils of central part of Brazil. Potassium uptake increased significantly in a quadratic fashion with increasing K rate. However, K-use efficiency (mg grain per mg K applied) decreased significantly with increasing K rate in a quadratic fashion. Maximum grain yield was obtained with 117 mg kg^?1 Mehlich 1–extractable K, base saturation of 53 percent, Mg saturation of 9 percent, K saturation of 2 percent, and Ca/Mg ratio of 4.     

柔鱼不同部位的呈味物质含量比较

将柔鱼可食部分分成胴体，鳍和头足三部分，用80％乙醇抽提法分别对其其味物质作提取试验，测定了不同部位的原料和抽提物中主要呈味物质的含量，并对其中的甜菜碱，氨基酸及无机离子K^ ,Na^ ,Ca^2 ,Fe^2 ,Zn^2 ,PO4^3-,Cl^-等作比较研究。结果表明：无论是原料还是抽提物中，胴体部分甜菜碱和氨基酸含量都最高，而鳍和头足中的含量相对偏低且相差不大；无机离子在胴体，头足和鳍中的含量则依次减少，抽提物中牛磺酸的含量胴体比鳍和头足低。此外，对柔鱼中呈味成分的应用进行了可行性的初步探索。     

稻米蛋白质及其组分研究概况及其对稻米品质的影响

稻米蛋白质是决定其食味品质的重要因素,稻米蛋白质含量通常与米饭的食味品质呈显著负相关。作为典型的数量性状,稻米蛋白质含量受环境因素的影响较大。然而,稻米蛋白质含量及其构成的决定机制及环境因素对其的影响等方面还有诸多不明之处,其影响食味品质的机理也不清晰。本文综述了稻米蛋白质的种类、结构及其分布,稻米蛋白质的合成与积累过程以及蛋白质含量的遗传控制和影响因素,概括了稻米蛋白质及其组分含量与稻米品质关系的研究进展,为优质水稻的品种筛选及调优栽培提供参考和借鉴。     

脲铵氮肥施肥方式及用量对玉米产量及产量构成因素的影响

[目的]为摸清脲铵氮肥在玉米生产上的应用效果。[方法]以夏玉米为试验材料,通过田间小区试验,研究脲铵氮肥对玉米产量及产量构成因素的影响。[结果]脲铵氮肥肥效长,具有和尿素一样的增产效果,能明显改善玉米农艺性状和经济性状,增加产量。同时,脲铵氮肥养分减量40%施用(即只需使用纯氮60%的等量脲铵氮肥),就与尿素常规传统施肥方式取得相同的增产效果,投产比高,经济效益显著。[结论]该研究可为脲铵氮肥大面积推广应用提供科学的理论指导。     

施肥对稻米品质和产量影响的研究

通过1985～1087年的多点田间试验和盆栽试验,探索了施氮量,施氮时期,氮、磷、钾三要素及其组合方式,基肥种类以及稀土微肥对稻米产量和品质的影响,为优质稻合理施肥提供了理论依据。     

蚕蛹蛋白与畜禽肉蛋白营养差异比较与探讨

[目的]为蚕蛹蛋白的开发利用提供理论依据。[方法]通过对蚕蛹蛋白与猪肉蛋白、鸡肉蛋白的氨基酸含量进行比较,并对营养价值进行评价。[结果]通过对蚕蛹蛋白与畜禽蛋白的比较结果表明蚕蛹蛋白中含有18种氨基酸,其中人体必需氨基酸占总氨基酸的比例为42.20%,符合WHO/FAO评分模式。[结论]蚕蛹蛋白是一种非常优质的蛋白来源。     

基于主成分分析和聚类分析的贵州烟叶品质类型划分

本研究把烟叶外观质量评价和常规化学成分评价相结合,建立基于主成分分析和聚类分析的Fisher判别函数的烟叶质量评价模型,对贵州烤烟的品种类型进行划分,旨在为烟叶质量评价提供科学方法,并在生产上进行指导。     

白灵菇和杏鲍菇的营养分析与比较

[目的]比较白灵菇和杏鲍菇子实体的营养成分含量。[方法]以市售白灵菇和杏鲍菇鲜品为试材,采用凯氏定氮法和日立835—50型氨基酸分析仪等方法测定了白灵菇和杏鲍菇干品中的氨基酸和常规营养成分。[结果]白灵菇的氨基酸总量为167．2g／kg,其中,必需氨基酸、甜味氨基酸和鲜味氨基酸分别占氨基酸总量的40．07％、20．81％和19．20％;杏鲍菇氨基酸总量为140．8g／kg,其中,必需氨基酸、甜味氨基酸和鲜味氨基酸分别占氨基酸总量的40．06％、19．39％和24．64％。白灵菇的蛋白质、粗纤维和多糖含量分别比杏鲍菇高2．91％、4．11％和1．28％。杏鲍菇灰分含量比白灵菇高0．92％：[结论]从对食品高蛋白含量要求的角度分析,白灵菇的营养价值优于杏鲍菇;从对食品风味要求的角度来看,杏鲍菇优于白灵菇,     

野生及人工养殖暗纹东方鲀肌肉营养成分的比较分析(英文)

[Objective] The aim of this study was to evaluate the nutritive value of Takifugu obscurus and provide the scientific basis for artificially feed research.[Method] The nutrient components and nutritive qualities in the muscle of wild and artificially reared Takifugu obscurus were comparatively analyzed.[Result] The contents of crude protein,crude fat,crude ash,total amino acids,essential amino acids and half essential amino acid in the muscle of wild Takifugu obscurus were all higher than those of the artificially reared.The content of four delicious amino acids in the muscle of wild and artificially reared Takifugu obscurus was 17.59% and 14.44%(percentage of dry weight),respectively.The essential amino acid index(EAAI)was 52 and 40 separately,and the constitutional rate of the essential amino acids met the FAO/WHO standard.Valine was the first limiting amino acid of Takifugu obscurus.[Conclusion] The muscle of wild and artificially reared Takifugu obscurus were all high quality food full of animal protein,while the protein nutritive value of wild Takifugu obscurus was higher than that of the artificially reared.     

Day-to-Day variation of the urine protein: creatinine ratio in female dogs with stable glomerular proteinuria caused by X-linked hereditary nephropathy

BACKGROUND: Interpretation of serial urine protein:creatinine (UPC) values is confounded by a lack of data regarding random biologic variation of UPC values in dogs with stable glomerular proteinuria. HYPOTHESIS: That there is minimal day-to-day variability in the UPC of dogs with unchanging proteinuria and the number of measurements needed to reliably estimate UPC varies with the magnitude of proteinuria. ANIMALS: Forty-eight heterozygous (carrier) female dogs with X-linked hereditary nephropathy (XLHN) causing stable proteinuria. METHODS: Urine samples were obtained daily by cystocentesis for 3 consecutive days on 183 occasions (549 samples). The UPC was measured for each sample with a single dry-film chemistry auto-analyzer. Data were analyzed retrospectively by a power of the mean model because the variance of UPC values within the 3-day evaluation periods increased as the magnitude of proteinuria increased. RESULTS: To demonstrate a significant difference (P < .05) between serial values in these proteinuric dogs, the UPC must change by at least 35% at high UPC values (near 12) and 80% at low UPC values (near 0.5). One measurement is adequate to reliably estimate the UPC when UPC <4, but 2-5 determinations are necessary at higher UPC values. CONCLUSIONS AND CLINICAL IMPORTANCE: These guidelines for interpretation of serial UPC values in female dogs with XLHN may also be helpful for interpretation of UPC values in dogs with other glomerulopathies.