Simulating crop–parasitic weed interactions using APSIM: Model evaluation and application

The parasitic weed Orobanche crenata inflicts major damage on faba bean, lentil, pea and other crops in Mediterranean environments. The development of methods to control O. crenata is to a large extent hampered by the complexity of host–parasite systems. Using a model of host–parasite interactions can help to explain and understand this intricacy. This paper reports on the evaluation and application of a model simulating host–parasite competition as affected by environment and management that was implemented in the framework of the Agricultural Production Systems Simulator (APSIM). Model-predicted faba bean and O. crenata growth and development were evaluated against independent data. The APSIM-Fababean and -Parasite modules displayed a good capability to reproduce effects of pedoclimatic conditions, faba bean sowing date and O. crenata infestation on host–parasite competition. The r² values throughout exceeded 0.84 (RMSD: 5.36 days) for phenological, 0.85 (RMSD: 223.00 g m⁻²) for host growth and 0.78 (RMSD: 99.82 g m⁻²) for parasite growth parameters. Inaccuracies of simulated faba bean root growth that caused some bias of predicted parasite number and host yield loss may be dealt with by more flexibly simulating vertical root distribution. The model was applied in simulation experiments to determine optimum sowing windows for infected and non-infected faba bean in Mediterranean environments. Simulation results proved realistic and testified to the capability of APSIM to contribute to the development of tactical approaches in parasitic weed control.     

An overview of APSIM, a model designed for farming systems simulation

The Agricultural Production Systems Simulator (APSIM) is a modular modelling framework that has been developed by the Agricultural Production Systems Research Unit in Australia. APSIM was developed to simulate biophysical process in farming systems, in particular where there is interest in the economic and ecological outcomes of management practice in the face of climatic risk. The paper outlines APSIM's structure and provides details of the concepts behind the different plant, soil and management modules. These modules include a diverse range of crops, pastures and trees, soil processes including water balance, N and P transformations, soil pH, erosion and a full range of management controls. Reports of APSIM testing in a diverse range of systems and environments are summarised. An example of model performance in a long-term cropping systems trial is provided. APSIM has been used in a broad range of applications, including support for on-farm decision making, farming systems design for production or resource management objectives, assessment of the value of seasonal climate forecasting, analysis of supply chain issues in agribusiness activities, development of waste management guidelines, risk assessment for government policy making and as a guide to research and education activity. An extensive citation list for these model testing and application studies is provided.     

APSIM玉米模型在东北地区的适应性

利用东北地区6个典型农业气象试验站的玉米田间试验数据和同期逐日气象数据对APSIM模型(农业生产系统模型)在东北玉米产区的适应性进行了初步研究。先依据各站第一组玉米试验数据对模型相关参数进行调试、确定,再利用另一组试验数据检验模型模拟玉米生育期、叶面积指数、地上部总生物量和产量的可靠性。结果表明,APSIM模型模拟的播种至出苗、开花和成熟各阶段天数与实测天数有较好的一致性,其误差分别为0~2.0、0.7~2.0和0.7~2.3 d;哈尔滨地区模拟的叶面积指数和地上部总生物量相对均方根差分别为33%和11%,模拟效果较好;黑龙江哈尔滨、海伦、泰来,吉林桦甸、通化和辽宁本溪的模拟产量与实际产量的NRMSE分别为18%、13%、4%、4%、5%和2%。说明APSIM模型对东北地区玉米生育期、叶面积指数动态变化过程、地上部总生物量动态变化过程和最终产量具有较好的模拟结果,验证后的APSIM模型在东北地区具有较好的适应性。以上结果为今后在东北地区深入开展玉米生产潜力以及解析产量形成的限制因素等研究提供了技术平台与支撑。     

APSIM模型的研究进展及其在中国的应用

作物模型可以在已有研究资料基础上对在多种模拟条件下的作物生长情况进行模拟,预测未知风险,优化农业资源管理措施,为农业生产的管理经营提供科学指导。APSIM模型就是作物模型的典型代表。为了研究APSIM模型的结构特征和它在中国的应用现状,本文首先阐述了APSIM模型的发展历史、运行框架、模块结构组成,其次归纳总结了APSIM模型在中国气候变化评估和农田管理方面的应用以及在中国各个气候区域的应用,最后指出了APSIM模型在中国应用时所出现的问题,并为APSIM模型的应用提出了与RS技术和GIS技术相结合等一些意见。     

Use of the APSIM model in long term simulation to support decision making regarding nitrogen management for pearl millet in the Sahel

Soil fertility and climate risks are hampering crop production in the Sahelian region. Because experiments with only a few fertility management options on a limited number of sites and years cannot fully capture the complex and highly non-linear soil–climate–crop interactions, crop growth simulation models may suitably complement experimental research to support decision making regarding soil fertility and water management. By means of a long term (23 years) scenario analysis using the Agricultural Production Systems Simulator (APSIM) model, this study investigates millet response to N in view of establishing N recommendations better adapted to subsistence small-holder millet farming in the Sahel. Prior to this, the APSIM model was tested on a rainfed randomized complete block experiment carried out during the 1994 and 1995 cropping seasons, having contrasting rainfall conditions. The experiment combined, at three levels each, the application of cattle manure (300, 900 and 2700 kg ha^?1), millet residue (300, 900 and 2700 kg ha^?1) and mineral fertilizer (unfertilized control, 15 kg N ha^?1 + 4.4 kg P ha^?1 and 45 kg N ha^?1 + 13.1 kg P ha^?1) at ICRISAT Sahelian Center, Niger. The model suitably predicted plant available water PAW and the simulated water and nitrogen stress were in agreement with measurement (water) and expectation (N) regarding the fertilizer and rainfall conditions of the experiment. APSIM simulations were in satisfactory agreement with the observed crop growth except for the highest crop residue application rates (>900 kg ha^?1). For biomass and grain yield, the model performance was relatively good in 1994 but biomass yields were slightly overpredicted in 1995. The model was able to adequately reproduce the average trend of millet grain yield response to N inputs from manure and fertilizer, and to predict the overall observed higher grain yield in 1995 compared to 1994, despite the better rainfall in 1994. The 23-year, long term scenario analysis combining different application rates of cattle manure, millet residue and mineral fertilizer, showed that moderate N application (15 kg N ha^?1) improves both the long term average and the minimum yearly guaranteed yield without increasing inter-annual variability compared to no N input. Although it does imply a lower average yield than at 30 kg N ha^?1, the application of 15 kg N ha^?1 appears more appropriate for small-holder, subsistence farmers than the usual 30 kg N ha^?1 recommendation as it guarantees higher minimum yield in worst years, thereby reducing their vulnerability.     

基于APSIM模型模拟水氮调控对旱地春小麦(Triticum aestivum)叶面积的影响

本研究针对水氮调控对旱地春小麦(‘定西42号’)叶面积的影响,采用大田试验数据与农业生产系统模型(agricultural production system simulator, APSIM)的结合,分别设定不同降水和施氮梯度对叶面积的变化趋势进行研究,试验获取2015-2017年定西田间试验不同水氮肥施入的试验数据,并对模型予以检验。APSIM模型对叶面积模拟精度较高,决定系数(R2=0.96)、归一化均方根误差(NRMSE=27.37%)、模型一致性指标(D=0.91)。结果表明:(1)随施氮量的增加,叶面积指数呈现先增后减的趋势;(2)随降水量的增加,叶面积整体呈现单一增长趋势;(3)水氮耦合作用中,降水量在自然降水基础上增加20%,施氮量为157.5 kg/hm2时,叶面积指数最高达2.766。本研究为田间试验水氮肥的施入量提供科学依据,为旱地春小麦增产提供了理论参考。     

Wheat breeding in the Netherlands

Summary In 1886L. Broekema (Wageningen) laid the foundation for wheat breeding in the Netherlands. He succeeded in breeding Wilhelmina wheat (1901) and later Juliana, among other varieties.About the same timeJ. H. Mansholt (Westpolder) andDr. O. Pitsch (Wageningen) started their wheat breeding programmes.It should be stated that these pioneers practised line selection in hybrid populations from the very beginning.Among the other wheat breeders mention should be made ofDr. R. J. Mansholt (Westpolder) who, among other varieties, developed Wilobo and Lovink winter wheat and Van Hoek and Mansholt Witte spring wheat. The Breeding Station C.B. (Hoofddorp) bred the variety Staring,M. Rademakers (Bant, N.E. Polder) Mado, the Seed Company Wiersum (Groningen) Titan, Demeter and Tavero.It appears from the varietal ranges (Figs. 6 and 7) that at present foreign varieties are widely grown. However, wheat breeding in the Netherlands has not fallen asleep; at some breeding establishments large-scale breeding programmes are under way.     

Oat breeding in the Netherlands

Summary While towards the turn of the century the German yellow oat Probsteier had spread considerably in the Netherlands a shift occurred after about 1910 in favour of Svalöf varieties. First Victory spread, later other varieties followed. Dutch agriculture has derived much benefit from these varieties.However, oat breeding in the Netherlands developed also. In the course of years the breederMansholt produced several varieties, which together occupied about 20% of the area under oats. To the breederP. J. Hijlkema belongs the honour of creating the variety Marne, which could successfully compete with the Svalöf varieties.In 1953 Mansholt's varieties occupied 2% of the area under oats; Hijlkema's varieties 63%; the variety of the Central Bureau 5% and Black President 1%. That means that in 1953 home-bred varieties occupied 71% of the land under oats.The changes that have occurred in the varietal range are shown in Fig. 1.Some of the Dutch varieties are also appreciated abroad.

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Samenvatting Nadat in het laatst van de vorige eeuw de Duitse Probsteier gele haver zich sterk had verbreid in Nederland, is sedert ±1910 een verschuiving ingetreden in de richting van de Svalöf-rassen. De Zegehaver b.v. kreeg een zeer grote verbreiding; daarna volgden andere. De Nederlandse landbouw heeft dankbaar gebruik gemaakt van de buitenlandse haverrassen.Toch heeft de haververedeling in Nederland niet stilgestaan. In de loop der jaren zijn verschillende Mansholt-rassen gekweekt, die gedurende een aantal jaren tezamen ongeveer 20 % innamen van de in Nederland met haver beteelde oppervlakte.Aan de kwekerP. J. Hijlkema komt de eer toe, dat hij er in slaagde de Marne haver te kweken, die in staat was de concurrentie tegen de buitenlandse rassen op te nemen.Het Nederlandse haverareaal is thans voor meer dan de helft gebaseerd op Nederlandse rassen en verschillende daarvan vinden in het buitenland waardering. Het percentage van de Mansholt-rassen bedroeg in 1952 2 %, van de Hijlkema-rassen 63 %, van het C B-ras 5 % en van de Zwarte President 1 %; in totaal was dus 71 % van het Nederlandse haverareaal in 1953 bezet met Nederlandse rassen.De verschuiving in het rassensortiment van 1933 af is aangegeven in fig. 1.

     

Compatibility of cherries in the Netherlands

Summary Results of pollination trials, carried out between 1908 and 1963 in The Netherlands and adjacent parts of Belgium, were compiled to detect groups of inter-incompatible cherry varieties.In sweet cherry (Prunus avium L.) there appeared to be at least six groups of inter-incompatible varieties; in sour cherry (P. cerasus L.) only one group of inter-incompatible varieties was found. Moreover two groups of inter-compatible sour and hybrid cherries (P. avium x P. cerasus) were encountered.A weak relation was found between fruit set of a variety and the capacity of its pollen to induce fruit set.     

ASM2d模型改良及在DE型氧化沟中的应用

对国际水质污染与控制协会（IAWQ）推出的活性污泥2d号模型（ASM2d）进行优化,使之能够模拟含有菌胶团的污水处理工艺。使用改良后的ASM2d模型模拟并分析了有机物、氮和磷在DE型双沟式氧化沟中的降解过程,发现优化后模型能够较好地拟合这些物质的降解过程。依据所建立的模型计算出各组分在DE型氧化沟中1个周期4个阶段的转化速率,该结果有助于深入分析有机物、氮及磷不同形态之间的转化规律。     

The breeding of peas in the Netherlands

Summary The varietal assortment of Dutch round blue pea varieties has changed considerably. At the beginning of this century their cultivation was based entirely on the varieties bred by Dr R. J. Mansholt at Westpolder (Gr.). Since 1937 the Unica pea produced by P. J. Hijlkema, Mensingeweer (Gr.), has gained ground. Mansholt's G.E.K. and Unica were dominant for many years, and were also used abroad.A remarkable change in the varietal assortment of the round blue peas occurred since the appearance of varieties less susceptible to the Fusarium solani foot disease. Particularly the Rondo C.B. pea of the Plant Breeding Station C.B. (Dir.: Ir C. Koopman) at Hoofddorp has become widely grown (Fig. 2).In addition, it was this same station that succeeded in breeding a variety entirely resistant to fusarium wilt.It is clear that, in the course of the past few years, new varieties have been bred by the breeders. The new varieties excelled the established ones in one or more respects.Some varieties were widely distributed, others were discarded by the breeders after a couple of years, or (since 1924, the year when the first List of Varieties appeared) written off the List.Widely cultivated varieties had to retire in their turn when better ones came on the market.Even at present time Dutch plant breeders are working hard to improve the yield, quality and reliability of peas.     

Origin of white-flowering flax in the Netherlands

Summary In Euphytica (1) it was stated that the farmer G.Jensma of Ternaard, Friesland, obtained the Friesian white-flowering flax. In this at ticle it is reported to be the work of Geert Geerts Bijlstra, a gardener at Foudgum, Friesland.A correspondent of the Dutch Economic Society, Van Peijma, tells the story of the selection of the new flax in Bijlstra's own words. The merits of the new flax are mentioned and also the opposition against its introduction by commercial circles.     

客户细分模型的建立与应用

进入21世纪,国外许多种子公司相继进入我国市场,国内种子企业也在日益做强做大,营销管理从传统的以产品为中心发展到以客户为中心,ISO9000国际质量管理体系的"以顾客为关注焦点"的理念越来越受到种子企业的认同。新形势下,对种业客户信息的管理、分析与应用,显得十分重要,客户关系管理水平和效率已成为企业能否赢得客户、市场的一个有效指标     

Winter barley breeding in the Netherlands

Summary Various Dutch breeders have devoted themselves to winter barley breeding; the local variety Groningen Winter Barley used always to be the foundation material for breeding work. In the course of years 8 new varieties have been derived from it by line selection which demonstrates clearly the degree of variation.The varietal range (fig. 1) shows the peculiarity that the leading variety Vindicat has almost completely been superseded by Urania within some years. If ever, the slogan the Dutch farmer readily accepts new varieties applies here.Its sister variety Vinesco makes a favourable impression.The varieties of winter barley are now for 97 percent based on homebred material.