Yield and soil system changes from conservation tillage in dryland farming: A case study from North Eastern Tanzania

Yield levels in smallholder farming systems in semi-arid sub-Saharan Africa are generally low. Water shortage in the root zone during critical crop development stages is a fundamental constraining factor. While there is ample evidence to show that conservation tillage can promote soil health, it has recently been suggested that the main benefit in semi-arid farming systems may in fact be an in situ water harvesting effect. In this paper we present the result from an on-farm conservation tillage experiment (combining ripping with mulch and manure application) that was carried out in North Eastern Tanzania from 2005 to 2008. Special attention was given to the effects of the tested treatment on the capacity of the soil to retain moisture. The tested conservation treatment only had a clear yield increasing effect during one of the six experimental seasons (maize grain yields increased by 41%, and biomass by 65%), and this was a season that received exceptional amounts of rainfall (549 mm). While the other seasons provided mixed results, there seemed to be an increasing yield gap between the conservation tillage treatment and the control towards the end of the experiment, and cumulatively the yield increased with 17%. Regarding soil system changes, small but significant effects on chemical and microbiological properties, but not on physical properties, were observed. This raises questions about the suggested water harvesting effect and its potential to contribute to stabilized yield levels under semi-arid conditions. We conclude that, at least in a shorter time perspective, the tested type of conservation tillage seems to boost productivity during already good seasons, rather than stabilize harvests during poor rainfall seasons. Highlighting the challenges involved in upgrading these farming systems, we discuss the potential contribution of conservation tillage towards improved water availability in the crop root zone in a longer term perspective.     

板栗贮藏保鲜技术及配套设备的研究

针对板栗的生理特性，研究将机械作业技术、无残留化学处理技术、微波技术、气调、负离子发生等技术有机结合起来，应用于板栗的贮藏、保鲜，使板栗贮藏保鲜的总损失率控制在6％以内，从而形成板栗欧藏、保鲜的技术体系。     

Developing a methodology for identifying,mapping and potentially monitoring the distribution of general farming system types in Vietnam’s northern mountain region

This study tests a method to identify and map the spatial distribution of general farming system types in five districts of the northern mountain region (NMR) of Vietnam. Over the last 50 years the NMR has suffered from a large loss of forest cover, often blamed on the swidden farming systems that are found in the mountains. As a result different programs have been put forward to change local land use practices: to decrease the amount of swidden land, “sedentarize” farmers responsible for practicing swidden agriculture, and introduce new farming systems. However, some researchers have identified one type of swidden farming system, composite swiddening, as ecologically more stable, causing little net deforestation and less environmental degradation than other farming systems in the NMR. To date no study has identified how widespread this or other types of farming systems are in the NMR. This study makes use of geographic data for five districts in the NMR within a GIS, combined with field checking, to characterize, identify and map the spatial distribution of the general farming system types, including composite swiddening, by commune for these districts. The results of the mapping indicate that there are few communes where a single farming system type is found. As these districts are spread over five provinces, the results reinforce the view that in Vietnam’s NMR, farming system types vary down to below the commune level. An 80% agreement between the results shown on the map and field checking resulted from an examination of 19 communes in the districts mapped. A comparison was done of 2000 data to 1992 data for one district. An analysis of the communes’ farming systems for 1992 and for 2000 indicate that permanent agriculture farming systems of both rice paddy agriculture and permanent upland agriculture are appearing and replacing swiddening systems.     

Shifting from extensive to intensive agricultural systems: a case study in the Sudan

The development of the mechanized vertisols of Sudan has been very successful in achieving rapid expansion of crop area. Unfortunately, there has been minimal use of purchased inputs. Hence, crop yields have been low and declining over time with increasing variability of output. Now the frontier is disappearing and past land and credit subsidies have been eliminated. With modeling, we show that in the absence of the area-expansion option, even risk-averse farmers shift to the more intensive technologies involving improved cultivars and fertilization. We explore several options involving further research or policy changes that would induce intensification even before the passing of the frontier.     

Improving agricultural water management in the semi-arid region of Brazil: experimental and modelling study

Agricultural practice in the semi-arid region of Brazil is highly dependant on irrigation. As access to water is limited in the region, there is a need to guarantee its efficient use, especially in small-scale farming schemes. Models adequately calibrated for semi-arid conditions and for typical crops are useful tools for analysis of on-farm strategies to improve water use efficiency. A physically based agrohydrological model, SALTMED, is calibrated and validated for carrots (Daucus carota L., Brasília variety) and cabbage (Brassica oleracea var. capitata), two of the main crops in small-scale irrigated agriculture in the northeast of Brazil. SALTMED is also calibrated for castor beans (Ricinus communis L.) under rainfed conditions. The results demonstrated the suitability of the SALTMED model for simulating soil water dynamics and crop yield in the area. Predicted time series of soil water content and matric potential of root zone showed good agreement with observed values, as shown graphically and statistically. Using the calibrated and validated model, management scenarios were analysed in terms of applied irrigation water, irrigation frequency, soil and crop types. Impact of climate change on the irrigation water requirements was also briefly analysed for possible changes in annual temperature using two different emission scenarios. Analysis of possible impact of climate change on temperature related to two emission scenarios on the area showed an increase around 11% of the crop water requirement for carrots and cabbage, for the low emission scenario, and around 17% for the high emission scenario. The analysis of management scenarios indicated possible over-irrigation in the area. The simulation showed that the deficit irrigation was a useful water-saving strategy for the region. The simulations also indicated that irrigation frequency affected crop water use and differed according to the soil type.     

Economic and environmental analysis of sustainable farming practices – a Bavarian case study

Within the Research Network on Agro-ecosystems Munich (Forschungsverbund Agrarökosysteme München, FAM) strategies to approach optimal land use have been investigated since 1990 in terms of minimization of environmental impacts and maximization of profit from agricultural lands. The purpose of this paper is to analyze the interactions of the economic and ecological demands on agricultural land use with model calculations for the integrated farm section of the research station of the Research Network, Klostergut Scheyern in Bavaria, Germany, with a whole farm modeling approach.For this purpose the model system MODAM was used. MODAM simulates agricultural land use at farm level, calculates the economic returns and environmental impacts and runs farm optimizations with a linear programming tool. The integration of agri-environmental indicators in the model framework enables a multi-criteria optimization and the calculation of trade-offs. Optimization runs for the experimental farm show the complex interactions which occur when the farm considers environmental concerns in the objective function. Trade offs and abatement cost curves illustrate the relationship between agri-environmental indicators and economic returns of the farm. Here, soil erosion, nitrogen balance, global warming potential and gross energy input were implemented as agri-environmental indicators in MODAM.     

标准化引领农业机械化高质量发展——以江苏省为例

标准化是推进农业机械化高质量发展的内在要求,在农业机械化转型升级的背景下,加快构建科学高效的农业机械化标准体系,推动农业机械化标准实施应用对于提升我国农业机械化质量水平具有重要作用。对现阶段中国和江苏省农业机械化标准发展的总体现状进行梳理总结,重点分析现行农业机械化标准体系和农业机械化标准制修订工作中存在的问题,并提出针对性的意见和建议,以期通过构建完善高效的农业机械化标准体系、制定统筹协作的标准制修订机制、推动标准落地实施应用、加强标准监督检查力度,充分发挥农业机械化标准在农业机械化发展中的基础性、引领性作用,推动江苏省乃至全国农业机械化高质量发展。     

基于层次模糊评价的高素质农民线上培训课程推荐技术研究及应用*——以某农机化教育培训中心为例

为了加快适应新时期高素质农民教育培训的发展需求,利用信息化手段提高素质农民在线培训参与度。通过层次分析方法对高素质农民培训质量进行详细分析,针对高素质农民现状需求问题,提出培训质量评价算法,构建培训质量综合模型,并通过实例验证,证实所提方法的有效性。最后重点研究基于学员课程评分的协同过滤推荐算法应用于培训课程推荐模块的设计思路,并给出课程推荐系统关键部分实现方法。     

Application of simulation technique to activity-based costing of agricultural systems: a case study

The aim of this paper is to analyse the operational costs of the Pu-Shin wholesale fish market in Taiwan, using both the activity-based costing (ABC) model and the simulation technique. By using simulation results in the calculated model of ABC, allocated resource costs are more accurate and arbitrary allocation is avoided. The objective of this study is to compute the processing cost per kilogram of fish. We conclude by providing relevant and accurate information about cost management of the Pu-Shin wholesale fish market, comparing ABC with traditional costing methods, and discussing key related issues which may provide opportunities for future research. We believe that the use of the ABC model in conjunction with simulation techniques can also be applied to agricultural systems in other countries.     

农业工程与信息技术硕士教学案例库建设与应用

农业工程与信息技术硕士是能够综合运用专业理论与方法分析并解决生产实际问题的专业人才.目前,农业工程与信息技术硕士教学存在过于注重实践、课程内容庞大、知识点间难以融会贯通等问题,采用传统教学模式往往无法达到预期的教学效果.青岛农业大学机电工程学院教学团队在以往教学模式基础上,构建了以学生为中心的案例教学模式.教学实践表明,通过建设农业工程与信息技术硕士教学案例库,有利于培养学生的实践能力,促进理论与实践有机结合.     

Technical and economic criteria in agricultural production: A case for a systems approach to farm decision-making in the Pakistan Punjab

This paper defines the criteria of ‘technical’ and ‘economic’ efficiencies. The relationship between these criteria is identified, and its implications are discussed. These two sets of criteria do diverge, with ramifications both at the farm and the national levels. An illustration of their relationship at the farm level is provided by examining the nature of water allocation to crops in the Punjab of Pakistan. The divergences that exist between ‘technical’ and ‘economic’ efficiencies at both farm and national levels are highlighted by considering the process of mechanisation in the Punjab in some detail. Finally, it is pointed out how a ‘systems approach’ can accomodate both the technical and economic criteria and their interaction.     

Analysing agricultural users’ patterns of behaviour: The case of OPTIRas™, a decision support system for starch crop selection

Redesigning IT systems for specific user groups encompasses a lot of effort with respect to analysing and understanding user behaviour. The goal of this paper is to provide insights into patterns of behaviour of agricultural users, during the usage of a decision support system called OPTIRas™. This system aids agricultural users in their cultivar selection activities. We analyse logs resulting from OPTIRas™, and we get insights into user’s navigational patterns. We claim that the results of our analysis can be used to support the redesign of decision support systems in order to address specific agricultural users’ characteristics.     

Temporal and spatial soil water management: a case study in the Heilonggang region,PR China

Long-term over-extraction of groundwater since the 1980s in the Heilonggang region, the East Hebei Plain of North China, has led to serious environmental problems such as seawater or saline water invasion into fresh water, land subsidence, etc. The conflicts between socio-economic development, water shortage and environmental degradation have become increasingly critical. Agriculture, the largest water user in the area and requiring 84% of total water supplied, is creating an unsustainable demand. Soil water is a very important resource in the Heilonggang region as 76% of mean annual precipitation becomes soil water. Effective use of this soil water is, thus, a key for full rational utilisation of water resources in the area. A concept of temporal and spatial management of soil water (TSMSW) is proposed here as a means to ensure effective use of soil water, viz.: management of soil water in full time and possible space dimensions and readjustment of crop distribution in order to harmonise as much as possible crop water demand and soil water availability. Four aspects are included: readjusting crop structures and rotations to fit changes in soil water, increasing the soil water resources, reducing soil water evaporation and managing soil water to meet temporal and spatial crop water demand. Field experiments show that temporal and spatial management of soil water can significantly increase water use efficiency (WUE). For cotton, adopting an integration of micro-topography and plastic mulch has increased WUE from 0.49 to 0.76–0.86 kg/m³; stalk mulch with manure for winter wheat reached to 2.41 kg/m³ and straw mulch with deep furrows (micro-topography) for summer maize increased it from 2.06 to 2.34 kg/m³.     

Linking icon-based models to code-based models: a case study with the agricultural production systems simulator

The traditional code-based modelling approach in agriculture and ecology has many strengths, particularly in terms of model flexibility, efficiency and power. Nonetheless code-based programming is a specialist skill and a barrier to simulation modelling to most scientists and students. Icon-based modelling systems on the other hand are easy to use and learn and have opened up simulation modelling to a much broader group of researchers. However there are limitations to the flexibility of these modelling systems and sometimes the size and complexity of models that can be constructed in them.One approach by which researchers can gain the best of both types of models is by linking icon-based models to code-based models within a modular modelling framework. By developing largely self-contained modules that communicate with other modules solely by means of defined input/output variables, modules can be developed in an easy to use icon-based modelling system and subsequently `plugged in' to a larger code-based model. In this paper, we demonstrate this approach using Vensim^TM to develop a new seed bank module for the Agricultural Production Systems Simulator (APSIM). In an example application we compare the persistence of two hypothetical annual pasture plants with differing life histories under two contrasting farming systems.This approach has the benefits of: (i) rapid and efficient model development that allows specialist scientists and programmers to focus on their respective areas of expertise; (ii) ongoing maintenance and development of modules by science specialists without need for constant recourse to programmers; (iii) ease of sharing, exchange and comparison of icon-based modules between researchers; and, (iv) ease of communication of model structure.     

FSSIM, a bio-economic farm model for simulating the response of EU farming systems to agricultural and environmental policies

The disciplinary nature of most existing farm models as well as the issue specific orientation of most of the studies in agricultural systems research are main reasons for the limited use and re-use of bio-economic modelling for the ex-ante integrated assessment of policy decisions. The objective of this article is to present a bio-economic farm model that is generic and re-usable for different bio-physical and socio-economic contexts, facilitating the linking of micro and macro analysis or to provide detailed analysis of farming systems in a specific region. Model use is illustrated in this paper with an analysis of the impacts of the CAP reform of 2003 for arable and livestock farms in a context of market liberalization. Results from the application of the model to representative farms in Flevoland (the Netherlands) and Midi-Pyrenees (France) shows that CAP reform 2003 under market liberalization will cause substantial substitution of root crops and durum wheat by vegetables and oilseed crops. Much of the set-aside area will be put into production intensifying the existing farming systems. Abolishment of the milk quota system will cause an increase of the average herd size. The average total gross margin of farm types in Flevoland decreases while the average total gross margin of farms in Midi-Pyrenees increases. The results show that the model can simulate arable and livestock farm types of two regions different from a bio-physical and socio-economic point of view and it can deal with a variety of policy instruments. The examples show that the model can be (re-)used as a basis for future research and as a comprehensive tool for future policy analysis.     

大豆玉米带状复合种植模式与技术——以内蒙古为例

当前我国粮食生产基本实现“谷物基本自给,口粮绝对安全”,但是粮食生产还面临着一系列的挑战。大豆玉米带状复合种植技术是保障我国玉米和大豆产量的一项关键性技术,在对大豆玉米带状复合种植概念、含义及原理梳理的基础上,结合大豆玉米带状复合种植“选配品种、扩间增光、缩株保密”的核心技术,以及合理选地、选择种植带型和田间管理的必要技术要点,并基于2021年内蒙古实际试点情况,指出当前大豆玉米带状复合种植技术主要存在农户对种植技术认知不足、技术应用具有挑战性,节水灌溉、专业机械设备和金融支持政策还未跟上,并提出下一步应加强农技指导和宣传、推进高标准农田建设和提高财政金融支持力度的对策建议。     

加强农机科技推广项目管理的若干思考

本文对机科技推广项目管理中存在的问题进行了深入剖析，提出了若干改建建议。     

加强农机科技推广项目管理的若干思考

本文对机科技推广项目管理中存在的问题进行了深入剖析,提出了若干改建建议.     

农产品经销管理系统关键技术研究

为了对农产品经销过程进行信息化管理,笔者对农产品经销管理系统关键技术进行了研究,主要完成了系统结构设计、功能模块设计、数据库设计、查询算法的设计与实现,最后对软件进行了测试和应用,通过关键技术的研究基本实现了农产品经销管理系统,能够满足水果蔬菜类农产品的信息化管理,较大幅度的提升了工作效率。     

Modelling the fate of water and nitrogen in the mixed vegetable farming systems of northern Tasmania, Australia

A combination of high input management systems, high annual rainfall and deep, permeable soils in northern Tasmania create conditions that are conducive to high drainage and nitrogen losses below the root zone. An understanding of the extent and mechanism of such losses will enable farm managers and their consultants to identify and implement more sustainable management practices that minimise potential adverse financial and environmental consequences. Analysing the fate of water and nutrients in farming systems is complex and influenced by a wide range of factors including management, soil characteristics, seasonal climate variability and management history of the paddock/farm in question. This paper describes a novel farm system modelling approach based on the model APSIM, for analysing the fate of nitrogen and water in mixed vegetable-based farming enterprises. The study was based on seven case farms across the Panatana catchment in northern Tasmania. Substantial simulated drainage losses (>100 mm average seasonal loss) were apparent for all crop and rotation elements across all farms in response to the surplus between crop water supply and crop water use. Crop nitrogen demand was found to be close to crop nitrogen supply for all crop and pasture rotation elements with the exception of potato, which had an average surplus nitrogen supply of 89 kg N/ha. This resulted in potato having much higher nitrate nitrogen leaching losses (32 kg N/ha) compared to other crops (<10 kg N/ha). Simulations suggest that practicable management options such as deficit-based irrigation and reduced N fertiliser rates will maintain current levels of productivity while reducing potential offsite N loss and generating significant financial savings via reduced input costs.