天然橡胶研究前沿及其演进的可视化分析

采用CiteSpace软件对1988—2017年WebofScience收录的天然橡胶文献进行共被引分析,以可视化图谱方式呈现该领域的研究前沿、知识基础和演进历程,期望为政府决策和产业发展提供科学依据。结果表明:该领域形成了以胶乳过敏、乳胶?水果综合症、天然橡胶生物合成为主的早期研究前沿,以丁苯橡胶或天然高分子/天然橡胶纳米复合材料为主的中期研究前沿,以纳米颗粒/天然橡胶复合材料及其应变诱导结晶、橡胶延伸因子为主的当前研究前沿;演进历程分为4个阶段:即研究对象的建立、研究仪器或工具的发展、新技术所支持的研究问题、知识的转化。     

施用不同配比生物炭对橡胶树根系生长的短期响应

本研究探讨施用4种用量的生物炭对橡胶根系短期的影响。结果表明:随着生物炭用量的增加,土壤有机质、全氮、速效磷、速效钾含量和pH呈增加趋势,而容重呈下降趋势;施用不同用量生物炭处理对橡胶树根重、根长、根面积和根体积的影响各异,与对照相比,生物炭低配比(1%)和高配比(10%和15%)的施用量短期内对橡胶树根鲜重、根长、根表面积和根体积均无显著影响,而施用配比含量为5%的生物炭处理短期内显著提高了橡胶树根鲜重、根长、根表面积和根体积;同时,不同施用量生物炭处理的橡胶树吸收根占总根重的比例介于64.8%~76.1%之间。综上所述,施用配比含量为5%的生物炭可在短期内显著促进橡胶根系的生长。     

水肥耦合对橡胶树根系垂直分布的影响

水分和养分是限制橡胶树生长和产胶量的重要因子.以17a树龄的热研7-33-97橡胶树为试验材料,通过田间小区试验研究了不同水肥耦合水平对橡胶树根系垂直分布特征的影响,结果表明:橡胶树吸收根系主要分布在0～20 cm土层,随土壤层次的加深,橡胶根系干重在垂直分布上呈递减趋势,可用乘幂函数模型表示.适量增施氮、磷肥均能促进0～20 cm土层根系的生长;氮肥施用量过大,深层根系比重增大;轻度降低土壤水分能够促进根系扎深.水肥耦合对根系生长和分布具有调节作用,本试验条件下,各土层根系干重总量以丰氮丰水和丰磷丰水组合处理最高,分别达0.33和0.31 kg/m3,并且根系在土壤剖面上的分布与养分分布具有一致性.     

炭基复混肥氮钾缓释特性研究

为探究生物质炭及其用量对肥料养分的缓释效果,利用实验室圆盘造粒机制备了生物质炭用量为10%、20%、30%的炭基复混肥,采用土柱模拟淋溶法研究了炭基复混肥在土壤中氮、钾淋出率。结果表明:添加生物质炭能够减少肥料氮、钾淋出量,且随着生物质炭用量的增加炭基复混肥氮、钾素累积淋出率逐渐减小。当第10次淋溶时,生物质炭用量为10%、20%、30%炭基复混肥的氮素累积淋出率分别较不添加处理减少了6.03%、12.49%、33.72%,钾素累积淋出率较不添加处理分别减少了5.15%、5.29%、13.58%,且添加30%生物质炭处理显著大于其他处理。用一级动力学方程、Elovich方程和抛物线方程对各处理养分释放曲线拟合,结果显示一级动力学方程拟合效果最好,可用于表征氮、钾素累积淋出率与时间的关系。      

遮阳网颜色和覆盖时间对菠萝产量及品质的影响

为云南菠萝优质高产种植提供技术依据,采用田间试验研究不同颜色遮阳网(黑色、绿色和蓝色)与覆盖时间(菠萝谢花后60d、45d、30d覆盖)对菠萝日灼率、产量和品质的影响。结果表明:绿色和蓝色遮阳网防日灼效果优于黑网,尤其以蓝色遮阳网效果最佳;覆盖时间对菠萝外观性状及品质影响明显,谢花后60d覆盖蓝色遮阳网菠萝果实的纵、横径大,果眼数适中,果形指数适宜,果实硬度较大,Vc含量高,总酸度低,可溶性糖含量高,外观及品质综合性状好,产量较高。谢花后60d覆盖蓝色遮阳网可实现菠萝的优质高产种植。     

Crop Identification Based on TWDTW Method and Time Series GF-1 WFV

【Objective】 Yanqi Basin is an important production base of characteristic agricultural products in Xinjiang, and the planting structure of crops is complicated. In this study, the time series remote sensing data were used to classify and identify crops in the study area, so as to obtain the spatial distribution of different crops and their planting areas, which were the important basis for government sectors to formulate grain policies and economic plans. At the same time, the applicability of time-weighted dynamic time warping (TWDTW ) method in crop classification and the application potential of GF-1 WFV in agriculture were also discussed.【Method】 The normalized vegetation index (NDVI), calculated from the 2018 time series GF-1 WFV data set in Yanqi Basin, Xinjiang, was used to study the crops recognition based on TWDTW method. Sample points of different crops were collected to form standard sequence of NDVI for each crop. The TWDTW similarity matching algorithm was used to calculate the similarity distance between each pixel to be classified and the standard sequence of different crops. The smaller the distance was, the higher the similarity was. The similarity was used to determine the crop type of the pixel, and the final classification result was obtained. At the same time, the classification rules of decision tree were established according to the NDVI curve of time series, and the classification result was obtained by manually setting the classification threshold, and compared with that of the TWDTW method. 【Result】 The classification results of the two methods were very consistent. Peppers were the most widely planted and the wheat was mainly distributed in the northern part of the Yanqi Basin and the 21st Division of the Second Agricultural Division. The distributions of tomato and sugar beet were relatively sporadic. Among the results of planting area, pepper had the largest planting area, followed by tomato, wheat and sugar beet. The accuracy of the classification results of the TWDTW and decision tree methods was verified by the field sample points: The overall accuracy of them were 89.58% and 90.97%, respectively, and the kappa index of them were 0.804 and 0.830, respectively. The classification accuracy of the TWDTW method was slightly higher than that of the decision tree method. 【Conclusion】 Compared with the decision tree classification method, the classification accuracy of the TWDTW method was slightly improved, the classification result was more objective and reliable. The algorithm of TWDTW method was not limited by geographical factors and had strong flexibility and applicability. The experimental results showed that using TWDTW algorithm to identify crops based on the GF-1 WFV data set of dense temporal phase could get better classification results, and it had great application and popularization value in agricultural field.     

基于相对迁移率的节节麦醇溶蛋白组成分析

为准确揭示节节麦醇溶蛋白的组成情况,对不同地理分布的212份节节麦的种子蛋白进行酸性聚丙烯酰胺凝胶电泳(A-PAGE)分析。由于麦醇溶蛋白现有的"数字字母命名"系统并不具备广泛的普适性,将普通小麦——‘中国春’(对照)第1条谱带的迁移率作为标准,其他供试材料的谱带与它的比值作为相对迁移率来确定每条醇溶蛋白条带的位置。结果显示,212份节节麦材料中共存在422种不同迁移率的谱带。所有条带可分为ω、γ、β和α4个区,α区的多态性条带最多,达34.70%。多态性条带品种间遗传相似系数(GS)的变幅为0～0.58,遗传变异较大。聚类分析结果表明,节节麦可能是以伊朗为中心向四周各地扩散传播。中国境内的节节麦至少存在3种类型。基于相对迁移率的表示方法,无需除‘中国春’以外的其他对照材料,即可有效区分A-PAGE胶上距离较近的蛋白条带,为不同麦类作物醇溶蛋白的研究提供统一标准。     

海南农垦橡胶树叶片钙镁含量年际变化分析

对15年来海南农垦主产区橡胶树叶片钙镁养分含量年际变化进行分析,发现在所采集的叶片样本中镁素养分含量整体偏低,约有45%的样本低于正常指标值下限;钙素养分含量大部分高于正常指标上限,但仍有部分样本低于正常指标值。从近5年的变化趋势来看,钙镁养分呈现逐年降低,这可能与橡胶树专用肥中选用的磷肥原料品种有关。     

马铃薯嫁接番茄试验初报

马铃薯和番茄同属茄科植物,两者的亲缘关系较近,为探讨二者能否嫁接及嫁接后的结果情况,2009年春,用1个马铃薯品种和6个番茄品种进行异种嫁接试验。结果表明:从嫁接成活率、结果率看品种间有差异,嫁接苗普遍结薯率较低,番茄口感和生长势相对不嫁接苗普遍变差。通过试验认为番茄与马铃薯嫁接,应选用口味淡的马铃薯品种,嫁接时机应在马铃薯茎秆没有中空以前,低位嫁接为好。     

不同施肥和灌溉水平对三七生长特性和发病率的影响

为了探究利于三七生长发育和降低发病率的灌溉施肥模式.以3年生三七为研究对象,采用大田试验,试验共设置3个灌水水平:W1(低水,0.5FC,FC为田间持水量)、W2(中水,0.7FC)、W3(高水,0.9FC),设置4个施肥水平:F1、F2、F3、F4,全年施肥量均为96 kg·667m-2,根增重期:苗期:花期:果期的...