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71.
张中亚 《畜牧兽医科学(电子版)》2021,(4):36-37
我国农业经济快速发展,养殖工作的重要性变得更为突出,其中以生态放养鸡的饲养管理工作最为重要。但是在生态放养鸡的饲养管理工作开展过程中,却发现存在一定的问题,这些问题来自于人为及自然等2个方面,导致生态放养鸡的饲养管理技术没有从根本上得到最大程度的提升。养殖者应对生态放养鸡饲养管理工作的开展予以全面化重视,只有确保相关的技术要点得到实现,才能提升生态鸡的养殖水平。 相似文献
72.
Phosphorus availability and farm structural factors: examining scarcity and oversupply in north‐east Germany 下载免费PDF全文
Assessing factors influencing phosphorus (P) availability in soils is important in preventing its overexploitation and excessive application in agricultural systems. Despite high historical P applications in the federal state of Brandenburg (Germany), county data on soil test P (STP) reveal considerable disparities in soil available P. In addition, negative soil balances as a result of small mineral P and manure inputs have been observed, raising questions about the factors leading to this situation. Our work focused on identifying possible causes operating at the farm management level by conducting a letter survey in two administrative districts of Brandenburg, the counties Barnim and Uckermark, linking farm management factors (ownership type, farm size, land tenure, animal husbandry with or without grassland and its intensity, presence of a biogas plant and organic production) to farmers’ self‐indicated levels of STP. Small‐ to medium‐sized individual farms tended to have (very) high STP, while large partnership farms and companies/cooperatives were sensitive to factors resulting in low STP. Farms with low shares of land ownership, the presence of grassland, extensive cattle farming and stockless organic farming had lower STP. On the other hand, biogas plants, partly in combination with intensive livestock (cattle) farming, were associated with larger STP. It was concluded that more care should be devoted to the design of agricultural policies and that further (inter‐ and transdisciplinary) research on this topic is needed. 相似文献
73.
Drought Tolerance and Water Use of Cereal Crops: A Focus on Sorghum as a Food Security Crop in Sub‐Saharan Africa 下载免费PDF全文
Sub‐Saharan Africa (SSA) faces twin challenges of water stress and food insecurity – challenges that are already pressing and are projected to grow. Sub‐Saharan Africa comprises 43 % arid and semi‐arid area, which is projected to increase due to climate change. Small‐scale, rainfed agriculture is the main livelihood source in arid and semi‐arid areas of SSA. Because rainfed agriculture constitutes more than 95 % of agricultural land use, water scarcity is a major limitation to production. Crop production, specifically staple cereal crop production, will have to adapt to water scarcity and improved water productivity (output per water input) to meet food requirements. We propose inclusion and promotion of drought‐tolerant cereal crops in arid and semi‐arid agro‐ecological zones of SSA where water scarcity is a major limitation to cereal production. Sorghum uniquely fits production in such regions, due to high and stable water‐use efficiency, drought and heat tolerance, high germplasm variability, comparative nutritional value and existing food value chain in SSA. However, sorghum is socio‐economically and geographically underutilized in parts of SSA. Sorghum inclusion and/or promotion in arid and semi‐arid areas of SSA, especially among subsistence farmers, will improve water productivity and food security. 相似文献
74.
茶园间作芳香植物罗勒和紫苏对茶园生态系统影响的研究 总被引:4,自引:0,他引:4
通过茶园间作芳香植物研究其对茶园害虫和天敌种群数量、土壤养分状况、茶树生长及茶叶生化成分等的影响,分析间作芳香植物对幼龄茶园的生态综合调控效果。幼龄茶园间种芳香植物能减少小贯小绿叶蝉和绿盲蝽的数量,增加茶园中瓢虫、草蛉、寄生蜂和蜘蛛等天敌的数量;芳香植物间作区土壤中铵态氮、有效磷和速效钾的含量高于绿肥间作区和对照;茶园间作芳香植物能在一定程度上促进茶树生长、培养幼龄茶园的树势和树冠、增加茶叶产量。茶园间作芳香植物能减少茶叶中茶多酚和咖啡碱含量,提高可溶性糖和儿茶素含量,改善茶叶品质。可见茶园间作芳香植物是一种具有较好生态效益的茶园栽培管理模式,能促进生态茶园的发展。 相似文献
75.
Prevention and Controlling Effect of Intercropping on Pests and Diseases and Its Risk Control in Cotton Fields 总被引:1,自引:1,他引:0
Cotton is one of the major field crops which are seriously threatened by pests and diseases. In recent years, the ecological management of cotton pests and diseases with intercropping has become to be an interesting approach. Intercropping possibly increases the population of natural enemies and finally reduces the population density of pests as a result of changes in ecological structure and environmental conditions of farmland. Intercropping thus has been considered an important alternative in controlling pests and diseases. However, cotton field intercropping also has some limitations in controlling pests and diseases. Unreasonable intercropping system has many risks such as increasing labor input, increasing the difficulty of pests’ control, and aggravating pests and diseases. In this paper, the effects and the underlying mechanisms of cotton intercropping on cotton pests and diseases were reviewed. The possible risks and countermeasures used for ecological control of intercropping were also put forward, and the future and application of ecological management of cotton pests and diseases with intercropping were prospected. 相似文献
76.
Modern cities use straightened and concrete watercourses with simple greening for riparian zones, which has been criticised for insensitivity to natural system integrity and cultural identity. This increases the challenge to urban ecologists, landscape designers and managers to conceive innovative and effective design solutions that do not jeopardise hydraulic efficiency yet are culturally acceptable to local communities. This paper introduces the field of local ecological knowledge (LEK) as rich sources of inspiration and design solutions to meet this challenge. LEK refers to knowledge and practices of various local cultures about the relationship of living beings (including humans) with their environments. Wepropose a pragmatic framework that integrates LEK with modern landscape design. It includes steps: (1) investigate existing practices, skills andmeasures relating to LEK; (2) explore how and whereLEKcan inspire or integrate withdesign. Here we propose three aspects for integration in accordance with the nature of landscaping process: overall structure, component and maintenance.(3)evaluate and test the integration in terms of its acceptability by local communities. Taking the riparian revegetation project of Hanfeng Lake Urban Wetland Park (Chongqing Municipality) as an example, we illustrate the utility of this framework. 11 local common practices relating to LEK were identified. According to thethree aspects for integration, alternative design solutions were offered. The survey showed that LEK based designwas more highly valued than other conventional ways in terms of useracceptance. We conclude that LEK provides actionable ecologically sound and culturally desirablesolutions for urbanlandscape. We also recognise that LEK evolveswith changing environments and new harmonious and dynamic human-nature relationships arecontinually re-forming. The process of acquisition and application of LEK could encourage multidisciplinary and synthetic approaches to urban ecosystems. Such adaptability and interdisciplinary engagementare crucial totoday’schanging and complexurban environments. 相似文献
77.
78.
为研究复方中草药添加剂对稻鸭共作模式下成都麻鸭生长性能、血清生化指标、抗氧化指标及免疫指标的影响,试验选取体重相近、体况健康的15日龄成都麻鸭240只,随机分为4组,每组5个重复,每个重复12只。4组为对照组饲喂基础饲粮;试验1、2、3组在基础饲粮中按照质量比分别添加0.5%(低剂量组)、1%(中剂量组)、2%(高剂量组)的复方中草药,试验期90 d。结果显示:(1)试验1、2、3组的平均日增重分别较对照组提高2.19%、4.34%、4.98%(P<0.05);试验2、3组的料重比分别较对照组降低3.37%、3.63%(P<0.05);(2)试验2组和3组的总蛋白(TP)分别较对照组提高4.20%、6.08%(P<0.05);试验2组和3组的尿素氮(BUN)分别较对照组降低12.72%、16.36%(P<0.05);试验2组和3组的谷草转氨酶(ALT)分别较对照组降低15.84%、19.22%(P<0.05);试验3组的谷丙转氨酶(AST)较对照组降低19.34%(P<0.05);(3)试验2组和3组超氧化物歧化酶(SOD)分别较对照组提高15.80%、20.00%(P<0.05);试验3组的总抗氧化能力(T-AOC)较对照组提高22.37%(P<0.05);(4)三个试验组的IgA、IgM、IgG、IFN-γ、IL-2显著高于对照组(P<0.05),试验2组的肿瘤坏死因子-α(TNF-α)较对照组提高10.06%(P<0.05),试验2组和3的组溶菌酶(LZM)分别较对照组提高6.79%、5.66%(P<0.05)。综上,中草药添加剂能有效提高稻鸭共作模式下成都麻鸭的生长性能、血清生化指标、抗氧化指标及免疫指标,本试验条件下,最佳饲喂剂量为1%。 相似文献
79.
针对宁南山区春季降雨少、低温不利于马铃薯出苗,而作物生育中后期高温胁迫限制马铃薯块茎形成导致减产等问题,于2016年设置垄覆地膜沟内覆盖塑料地膜(DM)、玉米秸秆(JG)、生物降解膜(SM)、麻纤维地膜(MM)、液态地膜(YM)及沟不覆盖(BM),以传统平作为对照(CK),研究沟垄覆盖模式对土壤温度、土壤水分、旱作马铃薯生长及块茎产量的影响.结果表明:处理DM,SM,MM和YM马铃薯生育期耕层土壤温度表现出增温效应,而处理JG和BM表现为降温效应,其中处理DM增温效果和处理JG降温效果最佳.处理YM,JG对马铃薯生长前期保水效果较好,分别较CK显著提高13.3%,27.0%,而处理JG,DM对生育中后期的保墒效果较佳,分别较CK显著提高22.4%,13.2%.处理JG可显著促进马铃薯生长,其增产效果最为显著,DM次之,分别较CK增产47.8%,44.8%,其他处理较CK差异不具有统计学意义.可见,在宁南山区实施垄覆地膜沟覆秸秆模式可调控土壤水热环境,对旱作马铃薯生长及增产效果最佳. 相似文献
80.
通过研究皖北石灰岩山地生态系统的植被群落,分析不同植被恢复群落的组成、结构、多样性和生活型组成,进而阐明石灰岩山地生态系统植被恢复模式对群落结构特征以及植物物种多样性的影响。结果表明:研究区有54种植物,隶属26科54属。侧柏(Platycladus orientalis)+构树(Broussonetia papyrifera)人工混交林有植物种类16科26种,分别占总数的61.5%和48.1%。酸枣(Ziziphus jujuba var.spinosa)+牡荆(Vitex negundo var.cannabifolia)灌丛和荩草(Arthraxon hispidus)+牡荆草灌丛植物种类分别为32和33种,分别占调查总物种数的59.3%和61.1%。不同植被恢复群落生活型也有差异。侧柏+构树人工混交林群落高位芽植物占优势,而酸枣+牡荆灌丛和荩草+牡荆草灌丛则以地面芽植物所占比例较大。分析表明,多样性指数、均匀度指数和优势度指数均表现为侧柏+构树混交林>酸枣+牡荆灌丛>荩草+牡荆草灌丛,但物种丰富度表现为荩草+牡荆草灌丛>酸枣+牡荆灌丛>侧柏+构树混交林。Sörensen较高值出现在酸枣+牡荆灌丛与侧柏+构树混交林和荩草+牡荆草灌丛之间,侧柏+构树混交林与荩草+牡荆草灌丛Sörensen多样性值较低。研究结果表明,石灰岩山地独特的地貌特征和人工植被恢复对植物群落组成、多样性及其生活型组成产生重要影响。 相似文献