模糊物元分析法在耕地地力评价中的应用

本文利用模糊物元分析方法,以耕地的理化指标为评价依据,对黑龙江农垦总局某农场的耕地地力进行评价。实验结果表明：利用计算机技术可以完全依据耕地的地力要素对耕地进行评价,从而克服了凭经验确定地力的主观方法的弊端,能准确地反映耕地地力的差异。     

油菜不同栽培方式的投入产出比较研究

2000-2007年在长江流域多个试验基地连续开展定点试验和调查,研究了运行费、人工投入、种植单元和收益等随油菜栽培模式的不同而变化的情况,并应用计量经济学原理,对不同地区和年份间油菜栽培方式的投入和产出差异进行了研究。结果显示:翻耕移栽、免耕移栽、翻耕直播、免耕直播等栽培方式在运行费、人工费、单产水平以及净收益等方面均存在显著差异;我国油菜栽培方式与世界主要油菜生产国相比较,存在着劳动力投入过多、种植单元小,机械化程度低等问题,阻碍了我国油菜生产效益的提升。据此研究提出推广省工、省力、可操作性强的直播高产栽培技术,并适度发展机械化农机农艺,鼓励土地流转或季节性承包,扩大油菜连片种植规模,是新时期我国油菜栽培科技发展的主导方向。     

大通白桦林改造措施及成效分析

大通县白桦低效林在白桦林分中占29%,在乔木林中占10.6%,且有逐年增加的趋势。通过对大通县老爷山公园后山白桦更新造林措施、成效分析,提出白桦林改造的较好途径。     

Mineral composition of tobacco leaf samples part I: As affected by soil fertility,variety, and leaf position

Abstract

Three tobacco varieties were grown under four soil fertility conditions. Leaf samples were taken at bloom stage from upper and lower positions and analyzed for eleven elements. Results show how leaf position and variety affect leaf mineral composition with variable soil conditions. Therefore, variety and leaf position should be clearly defined before leaf nutrient levels can have a suitable degree of diagnostic value. However, variety differences were of less importance because nutrient concentration differences were generally related to appropriate changes in yield measurements.     

拖拉机悬浮式前驱动桥的应用研究

研究了农用拖拉机悬浮式前驱动桥的现状,列举了几种悬浮机械结构,重点介绍分析了一种悬浮式前驱动桥的机械、液压、电气工作原理。     

Microsatellite markers based assessment of genetic diversity in Iranian olive (Olea europaea L.) collections

To study the genetic variation in Iranian olive collections and some foreign olive cultivars, 47 accessions of 18 local cultivars from 6 olive collections of Iran (Roudbar, Zanjan, Ahvaz, Dezful, Kazeroon and Shiraz), were analyzed along with 30 imported cultivars using 16 microsatellite primer pairs. All the used microsatellite loci revealed polymorphism in the studied genotypes, except GAPU14 and GAPU113 markers. Fourteen microsatellite primers amplified 126 polymorphic alleles in the 87 selected olive accessions. The average number of alleles per locus was 9, ranging from 3 to 14. Polymorphic information content (PIC) was 0.85. The genetic similarity based on Jaccard coefficient ranged from 0.15 to 1. The genetic relationships among accessions were investigated using cluster analysis and principal component analysis (PCA). Most of the accessions with the same name were grouped together; some exceptions were also observed. As expected, close relationship was observed among accessions within same cultivar. Most of the Iranian olive accessions were clustered to a main distinct group. Two-dimensional scatter plot of principal component analysis revealed a clear separation of most of the Iranian olives from Syrian and other introduced cultivars. These suggest that Iranian cultivars have different origin related to West Mediterranean basin cultivars and have evolved independently from the others. Between and within Iranian and foreign cultivars (cultivars including three or more accessions) genetic diversity was analyzed using analysis of molecular variance (AMOVA). AMOVA revealed higher within cultivar genetic variation (62.76%) as compare to that between cultivar variations (37.24%). The intra- and inter-cultivar variance tested by permutation test showed significant genetic variation at both levels. The high level within cultivar genetic variance could be due to mislabeling and presence of homonyms in cultivars produced by vegetative propagation from original plants.     

财政支农资金投入结构合理性选择分析

财政支农资金是我国支持农业发展和解决“三农”问题的重要力量。诸多的因素造成了我国支农资金效益的低下,然而支农资金投入结构的不合理则是造成我国支农效益低下的一个重要原因。就我国财政支农资金投入结构作了合理性分析,得出目前我国支农资金投入结构极不合理的结论,提出了优化调整我国财政支农资金投入结构的措施。     

雷州半岛甘蔗植期的分析

分析了雷州半岛甘蔗不同植期的优缺点,提出了该蔗区不同植期所占配比的建议:以冬植蔗为主,占30%～40%,稳定宿根蔗面积40%,合理搭配春植蔗10%～15%,秋植蔗占5%;抓好夏植蔗的试验、示范、推广工作。     

毕节市烤烟质量分析与评价

[目的]探讨毕节市不同区域、不同时期烤烟质量状况。[方法]对毕节地区8个县市的494份烤烟样品外观质量、物理性状、化学成分和感官质量进行分析和评价。[结果]毕节市不同区域的烤烟具有明显的品质特征,但近年来烟叶质量有所下降。[结论]该研究可为毕节烤烟生产合理布局提供理论依据。     

毛竹若干性状相关性和主成分分析

通过对毛竹若干性状相关性的研究,为毛竹的系统选育和栽培提供理论依据.结果表明:毛竹性状存在较大变异,RSD最大的性状是10 m处直径,RSD最小的性状是地径壁厚;毛竹各性状间的相关系数一般呈极显著或显著水平,各性状之间存在普遍的相关性;毛竹29个性状根据变量之间差异的大小可分为4类;主成分分析中前两个主成分对变异的贡献率达到85％以上.