农业高等院校推广人员激励实践探索 ——以西北农林科技大学为例

在当前社会发展的新形势下,通过构建激励机制,在更广大范围内、更深层次上调动教职工的积极性,是深化高校内部体制改革的根本指导思想。根据合校以来推广工作实践,总结了激励的基本内涵,分析了西北农林科技大学的科教优势,筛选了五种对推广人员的激励模式。可供决策部门参考。     

关中灌区夏播陕单8806玉米密度与播期耦合技术研究

【研究目的】为了明确陕单8806玉米在关中灌区种植的适宜播期和合理密度,从而使优良品种与地区生态环境相适应,发挥群体优势而夺取高产。【方法】采用二次饱和-D最优试验设计,研究了密度与播期对陕单8806玉米籽粒产量和生物学产量及农艺性状的影响。【结果】明确了在关中灌区夏播条件下,播期对玉米的影响效应显著大于密度,关中灌区夏玉米生产应力争早播。【结论】通过对玉米产量及农艺性状与密度和播期二因素建立的数学模型的回归分析,筛选确定了陕单8806玉米在关中灌区夏播的适宜播期为6月11日—18日,合理种植密度为60494￣70442株/hm2。     

玉米高产高效低耗技术措施研究

建立了灌区夏玉米高产，高效数学模型，并对模型进行了多目标解析，确定了农艺措施对产量的主效应用 和互作效应大小，筛选出关中灌区夏玉米采用紧凑大穗型玉米杂交种陕单911高产，高效模式[(8250(kg/hm^2)≤y(产量）≤9750(kg/hm^2)，yc(纯收入）≥6000元／hm^2]为：密度52500株／hm^2,纯氮256.5-310.5kg/hm^2，纯磷117－150kg/hm^2。     

Sphingobium属细菌土壤中降解异丙隆的特性

通过在不同环境条件的土壤中接入异丙隆降解菌悬液,研究了Sphingobium属的3株细菌—YBL1、YBL2和YBL3在土壤中降解异丙隆的特性,分析了土壤类型、温度、碳氮源、土壤含水量和菌株接种量等因素对3株细菌降解土壤中异丙隆的影响。结果表明,3株细菌在马肝土(pH 6.7)中能够高效降解异丙隆,在红壤(pH 4.5)中不能降解异丙隆,菌株YBL3在潮土(pH 8.2)中也有较好的降解效果;当接种量低于105CFU g-1土时,3株细菌均不能降解马肝土中的异丙隆,接种量高于106CFU g-1土时,菌株可以高效地降解土壤中的异丙隆;马肝土含水量低于40%时,3株细菌降解土壤中异丙隆的速率与土壤含水量呈正相关关系;在16~37℃范围内,菌株降解马肝土中异丙隆的速率与温度亦呈正相关关系。     

Remote Sensing of Soil and Water Quality in Agroecosystems

Mismanagement of soil and water resources may not only contribute to an escalation of global poverty but also jeopardize ecosystem services, with significant costs to the environment. Although not concentrated within one geographic location (3,500 million hectares), an equivalent of approximately 24 % of the earth’s land surface is degraded land, and about 2 billion people (one third of the global population) lack access to safe and affordable water for domestic purposes. It is therefore critical to develop strategies targeted at the root causes of these problems. However, to do so would require a rapid and reliable information system that has been elusive because of the complexity of the environment and the limitations of the existing tools. The increased availability and development of remote sensing and geographic data analysis tools have opened up new possibilities for exploring and monitoring environmental variables influencing key land use and soil management options. Here, we explore the major concepts, describe the constraints, and the future potential of remote sensing for mapping and providing near real-time information on soil and water quality in the context of major land use practices employed at the global scale.     

长蒴黄麻产叶量的多元回归与偏相关的R语言分析

黄麻的主要产量性状之间存在相关性,长蒴黄麻MW-1以收获叶片为目的,影响产叶量的主要因素包括株高、茎粗、皮厚及分枝数,揭示这些因素对产叶量影响大小的研究非常重要.本试验设计种植密度梯度以形成产量性状上的差异,获得不同水平的5个产量性状数据集,应用R语言对长蒴黄麻MW-1产叶量建立多元线性回归模型,得到多元回归方程:产叶量=(0.0036×株高+0.0372×茎粗+0.0265×分枝数-1.37)2,并分析各产量性状之间的相关性,研究结果显示产叶量和分枝数、皮厚和茎粗两两间存在极显著正相关,茎粗和株高存在显著正相关,而分枝数和株高之间呈负相关.     

Regeneration strategies influence ground bryophyte composition and diversity after forest clearcutting

Context

Natural regeneration with broadleaved species and reforestation with coniferous trees are two widely practiced forest regeneration strategies after timber harvesting. They lead to different tree species composition and may cause different understory biodiversity, but the effects on ground bryophyte composition and diversity are not well-known.

Aims

We tested whether natural regeneration with broadleaved species and reforestation with spruce induced different diversities of the ground bryophyte populations 20–40 years after old-growth spruce forest clearcutting in the subalpine regions of southwestern China.

Methods

Differences between natural stands and plantations were compared through the analysis of 13 paired stands, with 78 plots, 390 shrub/herb quadrats, and a total of 1,560 bryophyte quadrats.

Results

Naturally regenerated forests were characterized by lower density and cover and lower tree height but higher herbaceous plant height, shrub cover, and bryophyte diversity. They also harbored many more ground bryophytes. The species richness of pleurocarpous mosses and fans, mats, and turfs were significantly higher in naturally regenerated forests. Frequency difference analysis demonstrated that more bryophyte species preferred ground habitats in naturally regenerated forests than in plantations (116 vs. 48 species). The canonical correspondence analysis indicated that stand structure attributes were more important determinants of ground bryophyte diversity and abundance.

Conclusion

Natural regeneration and reforestation resulted in large differences in ground bryophyte populations. A larger diversity was observed in the former case, and natural regeneration practices can be an effective measure for the protection of ground bryophyte diversity after clearcutting.     

适宜沿海地区生态修复的优良树种——巨桉

巨桉具有速生、抗风、耐盐碱、抗逆性强的特点,既耐水湿,也耐干旱,与木麻黄相比,具有更强的抗风和抗病虫害能力,是沿海防护林的优选造林树种。     

陕A群、陕B群选育的玉米自交系氮效率评价

为阐明不同类型玉米自交系氮效率差异特征,筛选氮高效的玉米自交系,以陕A群、陕B群选育的33份玉米自交系为材料,以4份骨干自交系(‘郑58’、‘昌7-2’、‘PH6WC’和‘PH4CV’)为对照,调查了2种施肥条件下[0 kg(N)·hm?2、180 kg(N)·hm?2]玉米自交系的穗位叶SPAD值、叶面积、干物质积累量、叶片、茎秆和籽粒氮含量等生理指标。利用主成分分析和模糊隶属函数,采用逐步回归分析方法建立最优回归方程,筛选耐低氮性综合评价指标。结果表明:穗位叶SPAD值、吐丝期绿叶面积、吐丝期茎干重、吐丝期叶干重和籽粒氮含量,可作为玉米自交系耐低氮能力的第2性状筛选指标。以产量作为第1性状指标,可将37份玉米自交系划分为14份高产氮高效型,5份低产氮高效型,15份低产氮低效型和3份高产氮低效型。以耐低氮能力综合值D值筛选,将37份玉米自交系可分成3种类型,其中耐低氮能力较强的15份(D值≥0.5),耐低氮能力中等的15份(0.35≤D值0.5),耐低氮能力较差的7份(D值0.35)。综合分析,2种施氮条件下,‘KB215’、‘KB417’、‘KA225’、‘KB081’和‘L123098-2’5份玉米自交系具有吐丝期绿叶面积大,吐丝期茎叶干重、籽粒氮含量高和籽粒产量高,耐低氮能力强的特点。因此,强化育种环境的选择压力,实施低氮选择策略,可有效提高玉米种质对氮肥的利用效率。     

不同来源玉米自交系及杂交组合杂交当代子粒性状的差异分析

玉米杂种优势的研究对于提高玉米产量和品质有重要意义。对2013年海南三亚种植收获的89份温带自交系、59份热带/亚热带自交系和由这148份自交系随机组配的179份杂交组合进行当代子粒性状的测定。分析了温带玉米与热带/亚热带玉米自交系子粒性状的多样性与差异性,同时依据亲本来源的不同,探索了不同组合的杂交当代子粒性状的差异性。结果表明：温带来源的玉米自交系粒长和百粒重比热带/亚热带材料的粒长和百粒重显著偏长偏重;不同来源的自交系组配的杂交当代F₁,母本来源于温带的杂交当代F₁粒长显著长于母本来源于热带/亚热带材料;杂种优势分析结果说明,杂交当代F₁在粒厚和百粒重性状上表现的相对高亲和相对中亲优势强于粒长和粒宽。