对旱作农业耕作机械系统的研究

首先从宏观上论述了国内外旱作农业耕作机械的发展历程;研究了旱作农业耕作机械发展的3个阶段;探讨了旱作农业机械耕作方法所存在的问题及旱作农业耕作机械系统.在此基础上,分析了适合我国农业可持续发展的农业耕作机械系统.农业耕作机械将逐步向智能化和自动化方向发展,最终使我国农业走上可持续发展的道路.     

北方旱作农业区耕作体系关键技术

对构成北方旱作区蓄水保墒耕作体系的关键技术进行了阐述,以地表覆盖、少耕免耕技术为核心,以联合作业为手段,达到蓄水保墒、培肥地力的目的.总结出了6项新技术:一次完成玉米秸秆、根茬粉碎并部分覆埋复合作业的秸秆根茬联合处理技术;在同一刀辊与刀盘上完成旋耕、碎茬两种作业的旋耕碎茬通用技术;只在种床部分进行少量耕作(或只开沟)的条带少(免)耕精密播种技术;垄上覆膜沟内播种的起垄膜侧沟播技术;利用仿生学设计土壤耕作部件的机械仿生减阻技术;无秸秆种床进行免耕播种的免耕播种秸秆防堵技术.同时给出了耕作体系构成图.     

机械化旱作农业耕作技术探讨

概括了机械化旱作农业的内涵,详细介绍了深耕蓄水耕作技术、机械化抗旱播种技术、机械镇压保墒技术等8种机械化旱作农业技术的特点和技术要求。     

简述保护耕作与旱作农业耕作的异同

旱作农业是指依靠和充分利用降水及有限灌溉水源进行的农业生产，是雨养和集雨补灌两种农业生产活动的总称。其核心是利用各种农艺技术和工程措施，尽可能地提高降水的保蓄率和利用率。     

实施保护性耕作技术实现旱作农业可持续发展

本文针对乌拉特中旗开展保护性耕作的现状,积极探索出适合该地区旱作农业保护性耕作的技术模式及实施保护性耕作采取的措施,阐明实施保护性耕作技术是实现旱作农业可持续发展的有效途径。     

建立机械化旱作农业高产耕作栽培制度实现农业可持续发展

论述了机械化旱作农业高产耕作栽培制度的内容以及建立此项制度的意义和目的;分析了实施机械化旱作农业高产耕作栽培技术的经济效益;提出了实施机械化旱作农业高产栽培制度的实现目标和保障措施.     

辽西地区旱作农业保护性耕作技术的应用分析

针对辽西地区农业的基本特征和生产发展实际情况,总结了辽西地区农业生产耕作中存在的主要问题,阐述了农业保护性耕作在辽西地区农业生产中应用的意义和作用。     

辽西地区旱作农业保护性耕作技术的应用分析

针对辽西地区农业的基本特征和生产发展实际情况,总结了辽西地区农业生产耕作中存在的主要问题,阐述了农业保护性耕作在辽西地区农业生产中应用的意义和作用.     

齐齐哈尔市旱作农业机械化技术现状与发展对策

目前，我国对于干旱定义的综合提法是巾于水分的收支或供求不平衡，而形成的水分短缺现象，或者是一种因长期无降水和降水异常偏少而造成空气干燥、土壤缺水的一种现象。由于干旱是一个分复杂的综合现象，其形成的原因和所造成的影响，不仅与众多自然环境因素有关，也与人类社会因素有关。因此，针对齐齐哈市旱灾频繁和旱作农业现状，提出了旱作农业发展对策和几点建议，对大力发展蓄水保墒的综合性农业机械化旱作新技术、提高防灾抗灾能力，有一定的指导意义。     

Life cycle assessment of Swiss farming systems: I. Integrated and organic farming

Organic farming (OF) is considered a promising solution for reducing environmental burdens related to intensive agricultural management practices. The question arises whether OF really reduces the environmental impacts once lower yields and all the changes in farming methods are taken into consideration. This question is addressed in a comprehensive study of Swiss arable cropping and forage production systems comparing OF to integrated production (IP) systems by means of the life cycle assessment (LCA) method.The LCA study investigated the environmental impacts of two long-term farming system experiments: the DOC experiment comparing bio-dynamic, bio-organic and conventional/integrated farming and the “Burgrain” experiment encompassing integrated intensive, integrated extensive and organic production. All treatments received similar amounts of farmyard manure. The system boundary encompasses the plant production system; storage and application of farmyard manure is included in the system boundary, the animal husbandry is not included. The Swiss Agricultural Life Cycle Assessment method (SALCA) was used to analyse the environmental impacts.In the overall assessment OF was revealed to be either superior or similar to IP in environmental terms. OF has its main strengths in better resource conservation, since the farming system relies mainly on farm-internal resources and limits the input of external auxiliary materials. This results in less fossil and mineral resources being consumed. Moreover the greatly restricted use of pesticides makes it possible to markedly reduce ecotoxicity potentials on the one hand, and to achieve a higher biodiversity potential on the other. This overall positive assessment is not valid for all organic products: some products such as potatoes had higher environmental burdens than their counterparts from IP.The main drawbacks identified for Swiss OF systems are lower yields. As a consequence some production factors are used less efficiently, thus partly negating the advantages of OF. Furthermore, the different manure management strategy leads to relatively high nutrient losses in relation to yield. These two points were shown to be the main priorities for the environmental optimisation of OF systems. The differences between the bio-organic and the bio-dynamic farming systems consisted in a slightly higher input of organic matter, a few applications of mineral fertilisers and copper applications in the former.The eco-efficiency analysis led to the conclusion that the optimisation of OF is mainly output-driven, i.e. that higher yields of good quality should be achieved with the available (limited) resources. On the contrary, optimisation of IP was found to be input-driven; the inputs should be used in a quantity and manner which minimise the environmental burdens per unit produced. The study showed that despite the efforts of recent years, there is still considerable room for the environmental optimisation of Swiss farming systems.     

Towards sustainable farming systems: Effectiveness and deficiency of the French procedure of sustainable agriculture

There is a widespread consensus about the importance of sustainable agriculture. In France, the Farming Orientation Law of July 1999 has set down a precise procedure for the implementation of sustainable agriculture: the contrat territorial d’exploitation – or territorial farm contract (TFC). This paper aims to analyse the TFC effectiveness. An analysis has been made of the TFCs signed in the Midi-Pyrenees Region in south-western France, using statistical analysis and qualitative surveys of a sample of farms. The results show that the most valuable effects have been mainly economic. Effects regarding social and environmental aspects were very limited. But from the point of view of an integrated approach, indirect effects of TFCs can be observed on social and environmental aspects. These results are explained, on the one hand, by farmers’ motivations guided by economic objectives, and on the other hand, by the dominance of professional farming organisations in the implementation of TFC’s procedure. Given these results, two ways of improving the elaboration procedure for TFCs are proposed. Firstly, technical improvements can be made to the diagnostic assessment of farms, and to the choice of actions addressed by the contract. Secondly, organisational improvements can be applied to TFCs elaboration and implementation process, in order to adopt a participatory approach which would involve all rural stakeholders.     

机械类专业实践教学体系的构建探究

我国目前正在教育改革阶段,素质教育大行其道.在素质教育中,要求学生不仅要学习理论知识,还要参与实践活动,将理论与实践相结合.但是我国目前实践教学体系改革的情况并不乐现,特别是高校中机械类专业的实践教学体系的改革还存在着很多问题,这些问题阻碍了改革的进程.文章就针对机械类专业实践教学体系实施中存在的问题和解决措施两个大的方面进行详细的探讨.     

Advances in farming systems analysis and intervention

In this paper, we recognize two key components of farming systems, namely the bio-physical ‘Production System’ of crops, pastures, animals, soil and climate, together with certain physical inputs and outputs, and the ‘Management System’, made up of people, values, goals, knowledge, resources, monitoring opportunities, and decision making. Utilising upon these constructs, we review six types of farming systems analysis and intervention that have evolved over the last 40 years, namely: (1) economic decision analysis based on production functions, (2) dynamic simulation of production processes, (3) economic decision analysis linked to biophysical simulation, (4) decision support systems, (5) expert systems, and (6) simulation-aided discussions about management in an action research paradigm. Biophysical simulation modelling features prominently in this list of approaches and considerable progress has been made in both the scope and predictive power of the modelling tools. We illustrate some more recent advances in increasing model comprehensiveness in simulating farm production systems via reference to our own group's work with the Agricultural Production Systems Simulator (APSIM). Two case studies are discussed, one with broad-scale commercial agriculture in north-eastern Australia and the other with resource poor smallholder farmers in Africa. We conclude by considering future directions for systems analysis efforts directed at farming systems. We see the major challenges and opportunities lying at the interface of ‘hard’, scientific approaches to the analysis of biophysical systems and ‘soft’, approaches to intervention in social management systems.     

Conversion to organic arable farming in The Netherlands: A dynamic linear programming analysis

Several studies show that organic farming is more profitable than conventional farming. However, in reality not many farmers convert to organic farming. Policy makers and farmers do not have clear insight into factors which hamper or stimulate the conversion to organic farming. The objective of this paper is to develop a dynamic linear programming model to analyse the effects of different limiting factors on the conversion process of farms over time. The model is developed for a typical arable farm in The Netherlands central clay region, and is based on two static liner programming models (conventional and organic). The objective of the model is to maximise the net present value over a 10-year planning horizon. The results of the analysis of a basic scenario show that conversion to organic farming is more profitable than staying conventional. In order to arrive at the actual profitable phase of organic farming, the farmer has to pass through the economically difficult 2-year conversion period. Sensitivity analysis shows that if depreciation is 25% higher than conventional fixed costs due to machinery made superfluous by conversion, conversion is less profitable than staying conventional. Also the availability of hired labour, which can be constrained in peak periods, has a strong effect on the cropping plan and the amount of area converted. Further analysis shows that a slight drop (2%) in organic prices lowers the labour income of the farmer and makes conversion less profitable than conventional farming. For farmers, a minimum labour income can be required to ‘survive’. The analysis shows that constraint on minimum labour income makes stepwise conversion the best way for farmers to overcome economic difficulties during conversion.     

Life cycle assessment of Swiss farming systems: II. Extensive and intensive production

Extensive or low-input farming is considered a way of remedying many problems associated with intensive farming practices. But do extensive farming systems really result in a clear reduction in environmental impacts, especially if their lower productivity is taken into account? This question is studied for Swiss arable cropping and forage production systems in a comprehensive life cycle assessment (LCA) study.Three long-term experiments (DOC experiment comparing bio-dynamic, bio-organic and conventional farming, the “Burgrain” experiment including integrated intensive, integrated extensive and organic systems and the “Oberacker” experiment with conventional ploughing and no-till soil cultivation, are considered in the LCA study. Furthermore, model systems for arable crops and forage production for feeding livestock are investigated by using the Swiss Agricultural Life Cycle Assessment method (SALCA).The analysis covers an overall extensification of cropping systems and forage production on the one hand and a partial extensification of fertiliser use, plant protection and soil cultivation on the other. The overall extensification of an intensively managed system reduced environmental impacts in general, both per area unit and per product unit. In arable cropping systems medium production intensity gave the best results for the environment, and the intensity should not fall below the environmental optimum in order to avoid a deterioration of eco-efficiency. In grassland systems, on the contrary, a combination of both intensively and extensively managed plots was preferable to medium intensity practices on the whole area. The differences in yield, production intensity and environmental impact were much more pronounced in grassland than in arable cropping systems.Partial extensification of a farming system should be conceived in the context of the whole system in order to be successful. For example, the extensification solely of fertiliser use and soil cultivation resulted in a general improvement in the environmental performance of the farming system, whereas a reduction in plant protection intensity by banning certain pesticide categories reduced negative impacts on ecotoxicity and biodiversity only, while increasing other burdens such as global warming, ozone formation, eutrophication and acidification per product unit. The replacement of mineral fertilisers by farmyard manure as a special form of extensification reduced resource use and improved soil quality, while slightly increasing nutrient losses.These results show that a considerable environmental improvement potential exists in Swiss farming systems and that a detailed eco-efficiency analysis could help to target a further reduction in their environmental impacts.     

The whole-farm benefits of controlled traffic farming: An Australian appraisal

Controlled traffic farming (CTF) uses a range of technologies to confine traffic-induced compaction to permanently defined tramlines within a farm’s cropping area. CTF concentrates and improves trafficability whilst simultaneously supporting soil structure improvement between tramlines, thereby raising crop yields and offering other advantages such as reduced overlap that saves on crop inputs. This study uses whole-farm modelling to assess the profitability and role of CTF in different farming systems in Australian dryland agriculture. Farming system scenarios with and without the CTF are compared. Stepwise analysis, combined with sensitivity analysis, reveals the characteristics of CTF that most affect its value. Results indicate that the most valuable aspect of the technology is its beneficial impact on the yield and quality of crops grown on soils most subject to compaction. Hence, on farms dominated by these soils and where their faming system emphasizes cropping, CTF forms an especially valuable role. For a typical farm in the study region, employing conservative measures, farm profit increases by around 50% through use of CTF. Hence, CTF represents a remarkably profitable innovation for farming systems, offering input savings and output increases.     

农业机械节油问题浅析

随着我国农业机械化程度的不断提高,使得农业机械节油问题越来越受到人们的关注,如何解决农业机械节油问题成为了现今的首要任务,文章就农业机械节油问题进行了相应的探讨,从而使农业机械的使用达到节油的目的。     

机电一体化在机械工程中的应用浅析

随着计算机技术的迅猛发展和广泛应用,机电一体化技术获得前所未有的发展,并广泛应用于工程机械领域。而工程机械的电气与电子控制系统部分质量与性能的优劣又直接影响到工程机械的动力性、经济性、可靠性、施工质量、生产效率及使用寿命等。