外包服务对中老年劳动力参与水稻生产的影响

【目的】随着中国社会老龄化的加速,农业劳动者高龄化的趋势进一步凸显。本研究以水稻生产为例,分析并检验农业生产外包服务对中老年劳动力参与生产的影响,为理解和适应农业部门老龄化提供一个新的视角。【方法】从提高老年人自我养老能力的角度,分析外包服务对农业劳动力年龄水平和年龄结构的影响,并将生产外包服务的环节差异纳入分析框架,采用内生转换模型(EndogenousSwitchModel,ESM)检验农业生产外包服务对老年劳动力参与生产的影响。【结果】水稻生产外包服务显著提高了低龄老年劳动力生产参与率,对中龄老年劳动力生产参与率则无显著影响。在水稻种植的不同生产环节中,采用耕地、育种和收割环节外包服务对老年人农业参与起到促进作用,而采用移栽和病虫害防治环节外包服务表现出抑制作用。【结论】水稻生产外包服务总体上能放松老年人进行农业生产的约束,有利于老年劳动力参与生产,但仍需加强移栽和病虫害防治环节的生产社会化服务建设。     

2-羟基-1,4-萘醌在土壤中降解作用和淋溶行为研究

采用室内培养法和土柱法,研究了2-羟基-1,4-萘醌在土壤中的降解作用和淋溶行为。结果表明,2-羟基-1,4-萘醌在灭菌和非灭菌土壤中的降解半衰期分别为3.47～6.98d和0.42～0.53d,且随着2-羟基-1,4-萘醌浓度增加,其降解半衰期延长。说明微生物对其降解过程起主导作用。参考POPs国际公约关于化学品持久性的定义,2-羟基-1,4-萘醌在土壤中属于易降解有机物。通过2-羟基-1,4-萘醌在土壤中的淋溶研究发现：当其添加浓度为5mg·kg-1和10mg·kg-1时,各处理土层中均未检出2-羟基-1,4-萘醌;当添加浓度为20mg·kg-1时,仅在0～10cm土层样品中检测到2-羟基-1,4-萘醌。与未老化土壤相比,2-羟基-1,4-萘醌在老化土壤中的淋溶作用减弱。     

低效林改造对土壤理化性质及水源涵养功能的影响

 通过调查分析广西苍梧县低效马尾松、湿地松纯林经采取异龄混交荷木、大叶栎等阔叶树种的改造措施后土壤理化性状及水源涵养功能,表明:1)低效林改造后,林地土壤养分含量得到提高,土壤物理性状得到改善;2)林地土壤水分状况和渗透性能得到显著提高;3)与低效马尾松纯林（2166 t/hm2）和湿地松纯林（2 075 t/hm2）相比,马尾松+荷木、湿地松+荷木和湿地松+大叶栎林地土壤蓄水量显著提高,分别达到2 543、2506和2 483 t/hm2;4)0～20 cm土层土壤理化性状改善幅度大于20～40 cm土层。低效林混交荷木、大叶栎后,改造效果明显,是低效林改造措施之一。     

The effect of urban refuse compost and different tractors tyres on soil physical properties, soil erosion and maize yield

Application of urban refuse compost to agricultural soil could help to solve municipalities' problems related to the increasing production of waste only if soil property improvement and environmental conservation can be demonstrated. The use of low-pressure tractor tyres is another proposal in modern agriculture for reducing soil compaction. This study thus aimed to detect the effects of both compost and low-pressure tractor tyres on soil loss, runoff, aggregate stability, bulk density, penetrometer resistance and maize (Zea mays L.) yield. A 3-year field experiment was carried out on a hilly (15% slope) clay loam soil in central Italy. Twelve plots (200 m² each) were monitored with tipping-pot devices for runoff and soil erosion measurement. Treatments were: compost addition (64 Mg ha⁻¹), mineral fertilisation, use of low-pressure tyres, use of traditional tyres, with three replicates, in a fully randomised block design. Compost was applied once at the beginning of the experiment. Runoff reduction due to compost ranged between 7 and 399 m³ ha⁻¹ during seasons, while soil erosion was reduced between 0.2 and 2.4 Mg ha⁻¹. Mean weight diameter (MWD) of stable aggregates, measured on wheel tracks, increased by 2.19 mm, then progressively decreased. Compost significantly increased bulk density by 0.08 Mg m⁻³ due to its inert fraction content. This effect was less evident in the second and third year, probably due to harrowing. Maize yields were slightly, but significantly, reduced in composted plots by 1.72 Mg ha⁻¹ in the third year. Low-pressure tyres significantly reduced soil loss in the third year by 1 Mg ha⁻¹. Furthermore, they did not significantly influence runoff volumes and soil structural stability. Low-pressure tyres or compost addition were singly able to prevent an increase in penetrometer resistance due to agricultural machinery traffic. Low-pressure tyres increased the maize yield during the 3 years and the difference (0.4 Mg ha⁻¹) became significant in the third year. In conclusion, results show the positive lasting effect of compost in ameliorating soil physical properties and reducing runoff and soil erosion. Low-pressure tyres appear justifiable both for the observed increase of grain production and reduction of soil compaction. This latter effect is, nevertheless, masked by compost addition which is also able to reduce penetrometer resistance. Further research is required to explain the causes of the slight inhibition of grain yield observed when compost was compared with mineral fertilisation.     

三元社会结构下贫困农村"三位一体"的综合养老模式探析

随着经济的发展与社会的变迁,流入城市的农民工突破了传统的城乡二元结构,开创了三元社会结构,也使得农村的家庭养老模式面临着严峻的挑战。现阶段,要促进农村经济发展与社会稳定,实现整个国民经济的良性循环和可持续发展,实现全面建设小康社会的宏伟目标,就必须从农民养老保障的客观需求出发,顺应我国农村养老方式的综合化、多元化。     

传统山西老陈醋增香酵母菌的筛选及其特性研究

为选育山西老陈醋用微生物发酵剂,从传统发酵工艺生产的山西老陈醋中分离筛选到5株增香酵母菌。结合形态学和酵母菌26S rDNA Dl/D2区序列分析,初步鉴定Y1为酿酒酵母(Saccharomyces cerevisiae),Y26为毕赤酵母(Pichia scaptomyzae),Y30为假丝酵母(Candida humilis),Y68为红酵母(Rhodotorula sp.),Y70为盔形毕赤酵母(Pichia membranifaciens)。采用固相微萃取和气-质联用技术分析这5株酵母发酵液的主要挥发性成分。结果表明,醇类和酯类挥发性成分种类和组成差异较大;对这5株酵母菌进行耐酸性、乙醇耐受性、高温耐受性发酵试验,结果表明毕赤酵母Y26具有优良的耐酸性、乙醇耐受性。综合其具有高产乙酯类、低产高级醇的特性,毕赤酵母Y26有望开发为山西老陈醋的新型发酵剂。     

农村生活垃圾处理方式调查

对我国农村生活垃圾处理方式进行了初步调查。主要方式有卫生填埋;焚烧;堆肥;太阳能垃圾减量化;高温高压湿解法;垃圾衍生燃料;气化熔融处理技术;沼气池的利用技术。     

杭州的四季茶会——Ⅰ.春天的敬老茶会

本文主要介绍了杭州四季茶会之春天的敬老茶会,包括茶会的缘起,历年茶会进行回眸,以及敬老茶会的特色。     

多功能睡床的人性化设计

分析了老年人及残疾人的生活习惯,基于人性化设计理念,探讨针对这一特殊人群多功能睡床应具备的功能,并从舒适性、安全性和易用性三个方面分析了多功能睡床的设计原则。     

植物性抗生育剂防治幼林地兔害研究

在山西省吕梁山国有林管理局下李林场新造油松和侧柏混交林内,以20m×40m的面积投放一堆植物性抗生育剂和红胡萝卜混合药饵200g,对照地不放药。通过对施药前后试验地与对照地兔粪和苗木为害率调查数据进行统计分析,结果表明,与对照相比,投放植物性抗生育剂能显著减少幼林地内野兔活动频率和对苗木的为害。