滨海区水稻产量与磷肥效率模型的建立

通过分析盘锦地区磷肥的施用情况,研究了土壤高、中、低肥力的田块磷肥的施用效果以及肥料利用的情况,对水田土壤磷肥的供应能力建立了不同的分级指标,探讨了水稻磷肥最适宜的施用量,最后建立了滨海区水稻产量与磷肥效率的模型。主要研究结果如下:将土壤供磷能力分为5个级别,高地力地区推荐最佳施肥量为75~85 kg/hm^2,中地力区域最佳施肥量为81~90 kg/hm^2,低地力区域最佳施肥量为85~95 kg/hm^2,高、中、低地力田块水稻最佳经济施磷量为82.5 kg/hm^2、81.8 kg/hm^2和82.2 kg/hm^2。高地力区域产量效应模型为y=-0.0301x^2+6.1689x+11003.5,R^2=0.5207;中地力区域产量效应模型为y=-0.0312x^2+6.3026x+10941.27,R^2=0.626;低地力区域产量效应模型为y=-0.0311x^2+6.3111x+10920.2,R^2=0.6697。产量肥效模型归结为y=ax^2+bx+c形式,其中b为植株对土壤磷肥的需求程度,c为不施肥情况下的产量,可见土壤肥力越高,产量越高。如果想要提高磷肥的极限利用率,则可以增加有机肥来达到目的。     

Impact of push–pull cropping system on pest management and occurrence of ear rots and mycotoxin contamination of maize in western Kenya

Push–pull involves intercropping of cereals with Desmodium as a “push” crop and planting Napier grass/Brachiaria as the “pull” crop at the border. The technology has been reported to effectively control stemborers, striga weed, and fall armyworm (FAW), and to improve soil nutrition, resulting in increased grain yield. This study evaluated the impact of stemborer and FAW management using this technology on incidence of maize ear rots and preharvest contamination of grains with aflatoxin and fumonisin in western Kenya. The study was conducted during three cropping seasons on maize grown under the push–pull system and as a monocrop. Incidence of stemborer and FAW damage was determined as percentage of damaged plants, while incidence of ear rots was determined as percentage of ears with symptoms. At harvest, fungi were isolated from kernels and aflatoxin and fumonisin were quantified using enzyme-linked immunosorbent assay. Stemborer and FAW damage was significantly (p = .001) reduced by over 50% under the push–pull system. There was also a significant (p < .001) reduction in the incidence of Fusarium verticillioides (60%) and Aspergillus flavus (86%), which was reflected in a reduced incidence of ear rots (50%) with the push–pull system (p = .001). Fumonisin in maize from push-pull farms was significantly (p = .048) reduced (39%) but the technology had no significant (p > .05) effect on aflatoxin. The study showed that push–pull is an effective strategy for managing maize ear rots and fumonisins, and therefore could play a role in improving food safety among smallholder maize farmers in the region.     

大麦田草地贪夜蛾的发生为害及抽样技术

草地贪夜蛾在中国可取食为害玉米、高粱、小麦等禾本科作物,但其在大麦田的发生为害情况尚不清楚。我们对云南省曲靖市马龙区处于苗期至分蘖期大麦田的调查结果表明,草地贪夜蛾的虫田率高达62.5%、大麦受害株率为9.33%~100%、虫口密度为1~46头/m2,其中1~3龄幼虫比例达98.6%,受害株率与虫口密度呈显著正相关。大多数草地贪夜蛾幼虫藏匿于大麦心叶为害,取食后叶片形成半透明薄膜窗孔,幼虫在大麦田呈聚集分布。基于空间分布型的研究结果,我们提出了大麦田草地贪夜蛾幼虫理论抽样模型。本研究表明草地贪夜蛾可对大麦生产构成严重威胁。研发的幼虫抽样方法为大麦田草地贪夜蛾幼虫种群调查提供了技术支撑。     

油松人工林组成部分的水土保持作用

分析了油松人工林各部分的水土保持作用,及根系层的渗透和不同处理林地的产流产沙量。结果表明,林冠层和枯枝落叶层的截留率分别为19.76％和9.3％;枯枝落叶层阻延径流流出时间与其厚度呈正比例关系,且给出了与其被影响因子之间的回归方程。     

森林植被水土保持功能评价

文章评价了乔层、灌层、草层、枯落物层、根层及盖度对水土保持的影响,认为矮草层和死被层是决定水土保持效益的关键。盖度的有效性与高度关系紧密,草层和死被层仍最为有效。黄土高原人工林水土保持效益不好,其主要原因是没有完好的草层和死被层。如果林分具有良好的结构,黄土高原建造植被的减沙潜势为30%以上。     

播种量+施肥量对水分胁迫下胡麻生长、产量及收获指数效应研究

以陇亚13号为材料,探究水分胁迫下播种量+施肥量协同作用对胡麻生长、产量和收获指数（harvest index,HI）的影响。通过相关性分析,揭示灌区/旱区不同水分环境对胡麻产量构成、HI的关键性状因子影响特征。结果表明:水分胁迫影响灌区/旱区产量构成因子的形成规律,以改变胡麻生长发育指标为代价达到对极端环境的适应性。灌区/旱区产量与产量构成因子间正、负相关性不同,且旱区胡麻产量构成因子的正效应因子减少,负效应因子增加。相同水分条件下,播种量+施肥量协同作用对胡麻产量的提高有限,旱区HI较灌区受水分胁迫的影响更突出。灌区千粒重、株高对产量起主导促进作用,旱区无回归分析。灌区每株结果粒数、单株果数对HI起抑制作用,千粒重起促进作用;旱区单株果数对HI起主导抑制因子,说明水分胁迫对灌区/旱区胡麻的生长及产量形成的主效应因子有不同侧重点。     

小麦施钾的增产效果及对钾素吸收的影响

１９９７－１９９８年在高水肥地进行了钾肥用量试验研究,结果表明,含速效钾２４５ｍｇ．ｋｇ＾－１的土壤施钾增产不显著,含速效钾２０９ｍｇ．ｋｇ＾－１的土壤施钾达到了显著的增产效果。施钾后,小麦植株干重,吸钾强度,吸钾数量明显提高。适宜施肥量（Ｋ２Ｏ）７．５－１０ｋｇ／６６７ｍ＾２,增产幅度１８％－２５％。     

Growth and cocoon production by the earthworm Metaphire houletti (Oligochaeta) in different food sources

 Quantitative observations on the biology of Metaphire houletti were made in cow and horse manure and oak litter in laboratory conditions over a period of 240 days. The study revealed that copulation is not a prerequisite for production of viable cocoons, indicating that M. houletti may be parthenogenetic. The mean growth rate was 2.86 mg worm^–1 day^–1 reaching sexual maturity at 45 days and producing 0.015 cocoons worm^–1 day^–1 (kept singly) and 2.82 mg worm^–1 day^–1, reaching sexual maturity at 45 days and producing 0.03 cocoons worm^–1 day^–1 (kept in batches) in cow manure; 4.08 mg worm^–1 day^–1, reaching sexual maturity at 46 days and producing 0.02 cocoons worm^–1 day^–1 (kept singly) and 2.97 mg worm^–1 day^–1, reaching sexual maturity at 45 days and producing 0.016 cocoons worm^–1 day^–1 (kept in batches) in horse manure; 3.73 mg worm^–1 day^–1 reaching sexual maturity at 45 day and producing 0.023 cocoons worm^–1 day^–1 (kept singly) and 2.73 mg worm^–1 day^–1, reaching sexual maturity at 47 days and producing 0.028 cocoons worm^–1 day^–1 (kept in batches) in oak litter. After an incubation period of 31.9±1.2 days 82% of the cocoons hatched with a mean of 1.12±0.06 hatchlings per cocoon. The earthworms reared in batches did not demonstrate any advantage over those reared singly in all substrates. Higher growth rates were observed in earthworms raised singly than those raised in batches in all substrates. Received: 30 April 1998     

Cytology of Cicer Songaricum Steph. ex DC, a Wild Relative of Chickpea

The karyotype of C. songaricum has been analysed which shows a closer similarity with those of C. reticulatum, C. echinospermum and C. arietinum, as compared with other annual or perennial species studied. The 2C DNA amount of C. songaricum is 20.5% less than that of C. arietinum which shows that the cultivated chickpea has the largest genome size of all the annual and perennial species studied so far.     

生态脆弱带煤田开发中的抗旱造林种草技术

在神府煤矿进行的造林种草试验研究结果表明,春季造林以３月下旬至４月初为宜,采用覆膜、埋苗、浇水等技术。待罚大风过后４月下旬气温回升的时将苗木刨出,能够显著提高造林成活率和保存率,且每次浇水量以５ｋｇ／株为宜。采用容器苗和带状整地,实行径流林业能够保证较高的成活率和保存率,而种草以雨季播种为宜。