不同土壤肥力对芝麻生长发育及产量和效益的影响

在3年肥力定位试验地上进行不同土壤肥力对芝麻生长发育及产量和效益的影响研究。结果表明,芝麻株高、叶面积、叶片数、干物质质量均随土壤肥力的提高而增加,处理间差异均达极显著水平。土壤肥力越高芝麻籽粒产量和效益越高。处理1-4产量分别比处理5减产48.86%、55.52%、42.88%和28.18%,经济效益分别比处理5降低了49.87%、50.48%、36.40%、20.04%。在土壤基础地力较低的条件下,作物产量在本地同土壤类型居中高水平,为作物减量施肥、节资增效提供依据。     

腐植酸复混肥对甘薯产量及钾肥利用率的影响

以"济徐23"甘薯为试验材料,设置空白对照、腐植酸复混肥、等量无机养分、活化风化煤(等量腐植酸)4个处理,通过大田试验,研究腐植酸复混肥对甘薯产量、产量构成因素及钾肥利用率的影响。结果表明,施用腐植酸复混肥可促进块根膨大,甘薯产量高达50.39 t/hm2,与空白对照相比,增产26.07%;施用腐植酸复混肥显著提高了钾素产块根效率、钾素收获指数、钾肥农学利用率和钾肥偏生产力,降低了生育期甘薯T/R比值(茎叶鲜重与块根鲜重的比值)。     

复合微生物肥料对水稻生长发育及产量的影响

连续两年的试验结果表明,复合微生物肥料在水稻上施用能延长水稻叶片的功能期,促进叶片光合作用,增加分蘖数,有效地提高亩穗数和结实率。施用复合微生物肥料处理两年平均亩产量比不施肥处理、与其同养分含量的未接菌复合肥和等价值的普通复合肥分别增产36.2%、21.5%、16.5%。     

镁对小麦产量及生长发育的影响

镁是小麦体内叶绿素的重要组成成分,在小麦生长发育中起重要作用。植物体内的镁主要来源于土壤。近年来,随着作物产量不断提高,植物从土壤中携走镁的数量也不断增加,植物缺镁现象在各地陆续出现。目前关于土壤镁及镁肥效应的研究大多集中在南方红壤,关于北方土壤中镁素丰缺状况及镁肥效应的研究极为少见,对小麦影响的研究就更少。     

BcFA浸秧对甘薯形态,生理和产量的影响

本试验利用不同浓度的ＢｃＦＡ对甘薯秧苗进行浸秧，研究了其对甘薯形态，生理性状和产量的影响。结果表明，ＢｃＦＡ浸秧能促进根系发育，增加分枝数和分枝长度，提高叶片叶绿素含量（１１．７％）、叶水势和叶片含水率及其秧苗成活率，改善薯块构成，尤其是提高大、中薯块比率。甘薯增产２６．２１％，且达到显著水平，并提出较高产量和较高经济效益的浸秧浓度。     

含控释钾腐植酸复合肥对甘薯产量及品质的影响

为探明施用含控释钾腐植酸复合肥对甘薯产量及品质的影响,采用田间试验法,选取“济薯25”“济薯26”“龙薯9”“西瓜红”“烟薯25”共计5个品种,在不同土壤肥力条件下布置15个试验点,每个点分别设置普通复合肥（CK）和含控释钾腐植酸复合肥（KK）共2个处理,研究施用含控释钾腐植酸复合肥对甘薯膨大中期土壤速效钾、甘薯冠根比（T/R值）及收获期单株结薯数、商品薯率、产量、淀粉含量、可溶性糖含量的影响。结果表明：施用含控释钾腐植酸复合肥可提高甘薯膨大期土壤速效钾养分9.31%～49.08%,降低甘薯T/R值8.33%～10.84%,增大甘薯单株结薯数0～12.82%,增加商品薯率1.43%～21.09%,不同品种甘薯产量显著提高13.57%～43.60%,淀粉含量提高6.30%～13.50%,可溶性糖含量提高6.18%～16.02%,净利润率提高25.52%～156.12%。     

不同氮磷钾施肥水平对超级稻产量的影响

探讨各种土壤肥力状况下,不同氮磷钾施肥水平对超级稻(准两优1202)产量的影响,提出了超级稻合理的氮磷钾施肥水平和配比。     

甘薯新品种—福薯1933施肥技术研究

甘薯是我省主要杂粮作物,栽培面积较大,薯块除可食用外,还可提取淀粉,糖是酿酒加工业、化工工业和医疗工业的原料,同时薯蔓也是优质的家畜饲料。我们於1985年从福建、江苏等地引进了甘薯16个品种(系),在我省进行不同品种(系)抗性对比试验。结果筛选出福薯1933为高产抗病品种,为了进一步提高福薯1933的产量和品质,我们於1990～1993年进行了甘薯增施钾肥并与有机肥配合的施肥技术研究,为甘薯高产优质合理施肥提供科学依据,现将结果报导如下:     

不同施肥次数对西瓜产量和品质的影响

以西瓜为研究对象,在同等施肥量的条件下,开展了不同施肥次数对西瓜生长影响的田间试验。试验结果表明,采取先施足底肥,然后在膨瓜期进行一次追肥的施肥方式效果最好,不仅坐果率、产量、品质及植株生长都可达到较优的状态,而且可达到提质、增产、节省劳动力的目的。     

优化施肥增加作物产量

中国农业大学资源环境学院的土壤/植株动态测试优化推荐施肥技术的建立与应用项目,日前通过北京市科委组织的专家鉴定。该研究成果对于节肥、增效、提高作物产量、改善作物品质和保护环境具有重要理论和实践意义。该课题针对当前农业生产中存在施肥不合理、肥料利用率下降、作物产量和农产品品质降低以及环境污染等问题,经过近1 0年的研究,提出了养分资源综合管理的理论体系。把来自化肥、有机肥、灌水、土壤和其他环境中的养分视为资源,对养分资源进行统筹考虑,提高了养分资源的利用效率,减少了施肥对环境的污染。课题组以华北地区主要旱地…     

鲜食甘薯最佳施肥量的田间试验

为改善甘薯品质、提高产量和增加无公害甘薯的上市率,通过肥料的"3414"田间肥效试验来确定鲜食甘薯的最佳施肥量和配比。试验结果:中产地667 m2N、P2O5、K2O最佳施肥量分别为10、7、13.5 kg,低产地为6.5、13.62、12.62 kg。     

红薯中硒含量的测定

以超声波辅助红薯的消解过程以及硒与邻苯二胺的络合、萃取过程,利用紫外光谱法测定硒的含量。结果表明,硒在0～1.60μg/mL含量范围内具有良好的线性关系,相关系数为0.999 9。回收率达96.0%～100.7%。该方法使样品的消解时间大为缩短,并加快了硒的络合萃取过程。     

硫酸脲复合肥对玉米生长指标及产量的影响

通过田间试验方式研究硫酸脲复合肥、普通缓释肥、硫基肥、BB肥对玉米生长和产量的影响。结果表明,4种肥料处理均能促进玉米植株茎粗、穗粗和穗行数的增加,特别是硫酸脲复合肥处理,较CK分别增加了3.8%、3.6%和18.2%;而且4种肥料处理对玉米也有不同程度的增产效应,其中硫酸脲复合肥处理增产率最高,为21.09%。     

紫甘薯红色素及淀粉一体化提取方法研究

探讨了紫甘薯红色素及紫甘薯淀粉的一体化提取工艺,并由正交实验最终确定最优提取条件是:料液比1:3、提取时间90分钟、粉碎粒度60目、磷酸添加量2%。按照以上各因素最佳条件,得到色素提取率96.65%,淀粉提取率95.80%。     

Effects of pretreatments on properties of microwave-vacuum drying of sweet potato slices

Abstract

Pretreatments of blanching (BL); osmotic dehydration at 35°Brix of sucrose (OD); ultrasound in distilled water (UD), and ultrasound-assisted osmotic dehydration (UO) were carried out for microwave-vacuum drying (MVD) orange- and purple-flesh sweet potato slices, and effects on their properties were investigated in this study. UO had improvements effects on water loss, solid gain, and relaxation time of the samples compared to other pretreatments. Low-field nuclear magnetic resonance results offered a view of water state concerning the effects of different pretreatments on sweet potato. UD treatment following by BL showed a long relaxation time corresponding to the weaker degree of bound hydrogen proton or the greater freedom degree of hydrogen comparing to other pretreated samples. Differential scanning calorimetry parameters appeared to be sensitive to pretreatments by increased Tg value compared to blanched sample. The value of Tg shows that it does not depend only of the water content but also on the experimental conditions (pretreatments). The dried sweet potato exhibited amorphous structures as evidenced by the X-ray diffractograms due to the BL treatment and MVD. Concentration of total phenolics and anthocyanins were high in purple sweet potatoes, whereas content of vitamin C and total carotenoid were high in orange ones. Application of UO is suitable for retention of bioactive compound and stability of MVD sweet potato slices.     

Ultrasound-assisted osmotic process on quality of microwave vacuum drying sweet potato

The effects of pretreatment before microwave vacuum drying (MVD) on texture, color, expansion, rehydration, drying rate, microstructure, sensory evaluation, and other properties of sweet potato were investigated in this study. The pretreatment consisted in five processing conditions, using blanching; osmotic dehydration at 35°Brix of sucrose (OD); ultrasound in distilled water (US); ultrasound in distilled water before osmotic dehydration (US?+?OD), and ultrasound-assisted osmotic dehydration (USOD). Pretreatments of sweet potato before MVD have shown success in reducing drying time with US treatment relatively more effective regarding drying time than other treatments. Compared with other treatments, US showed the highest rehydration ratio values. The osmotic group pretreatment exhibited a pronounced effect on water loss and solid gain, improved the color, aroma, and taste of dried sweet potato, whereas sucrose impregnation resulted in a hard texture observed with OD sample. USOD samples had a higher expansion ratio, lower hardness and color difference values, appeared less cell damaged, and recorded better overall quality than the other samples. There was a slight difference between USOD and US?+?OD samples. Combining osmotic dehydration with ultrasound as a pretreatment can significantly accelerate the heat transfer rate, reducing the dried time accordingly and increasing energy efficiency.     

pH和Fe~(3+)对番薯紫色素稳定性的影响研究

研究了番薯紫色素稳定性及其变色反应机理,选择了辅色剂和护色剂来增加其显色效果和稳定性。结果表明,pH值和Fe3+是引起番薯紫色素变色和褪色的主要原因;EDTA-2Na有护色作用,Fe3+有辅色作用,两者协同作用能够增加其显色和稳定性,当两者浓度比为0.5∶1时,协同效果最好,增色率达到37%,转化率降低了32.2%。     

Hot air drying of purple-fleshed sweet potato with contact ultrasound assistance

A drying technique using a combination of a contact ultrasound apparatus and a hot air dryer is developed to investigate the strengthening effect of contact ultrasound on hot air drying. The effects of drying parameters such as ultrasound power and drying temperature on drying characteristics, effective moisture diffusivity (D_eff), microstructure, glass transition temperature (T_g), rehydration ratio, and color difference are discussed. The results show that the application of contact ultrasound causes a significant acceleration of internal mass transfer, and higher ultrasound power applied leads to faster drying rate. The effect of ultrasound power on drying rate decreases along with the reduction of moisture content during drying process. The increase in drying temperature significantly reduces drying time but has a little negative influence on the strengthening effect of ultrasound. D_eff values range from 1.0578?×?10^?10 to 5.4713?×?10^?10?m²/s in contact ultrasound-assisted hot air drying of purple-fleshed sweet potato and increase significantly with an increase in drying temperature as well as ultrasound power. The microstructure of purple-fleshed sweet potato is greatly different at different ultrasound powers during contact ultrasound-assisted hot air drying and shows more microchannels and dilated intercellular spaces in the cross-section of purple-fleshed sweet potato micrographs at higher ultrasound power. Contact ultrasound application during hot air drying could improve the mobility of water and consequently reduce glass transition temperature. Lower color difference and higher rehydration ratio could be achieved as drying temperature decreases and ultrasound power increases. The increase in contact ultrasound power could reduce energy consumption of drying process up to 34.60%. Therefore, contact ultrasound assistance is a promising method to enhance hot air drying process.     

Physical characteristics of sweet potato pulp/polycaprolactone blends

Sweet potato pulp (SSP) obtained as a by‐product from starch extraction was blended with polycaprolactone (PCL) to prepare a biodegradable plastic material. In the blends, PCL was used as a reinforcing agent. The SPP/PCL blends were prepared by compression‐molding under high temperature and pressure, at different SPP/PCL ratios, and the mechanical properties of the molded specimens were tested. Matrix structure and thermal properties were measured by using a Fourier transform infrared (FTIR) spectrophotometer, scanning electron microscope (SEM), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA). Mechanical properties (tensile and flexural properties) were also measured to find the most suitable ratio in a SSP/PCL blend. During compression molding of the SPP/PCL blends under high pressure and temperature, chemical reaction occurred between SPP and PCL, and thus, thermal stability and mechanical strength of the blends increased and water uptake decreased. Also, by increasing the PCL content in the blend, the matrix in the blend became more homogeneous, and consequently, mechanical strength of the molded specimen increased. At 7/3 or 6/4 weight ratio of SSP/PCL, water uptake of the molded specimen became substantially less than that at 8/2. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 861–866, 2004