Determination of Upland Rice Cultivar Coefficient Specific Parameters for DSSAT (Version 4.7)-CERES-Rice Crop Simulation Model and Evaluation of the Crop Model under Different Temperature Treatments conditions

To develop basis for strategic or arranged decision making towards crop yield improvement in Thailand, a new method in which crop models could be used is essential. Therefore, the objective of this study was to measure cultivar specific parameters by using DSSAT (v4.7) Cropping Simulation Model (CSM) with five upland rice genotypes namely Dawk Pa-yawm, Mai Tahk, Bow Leb Nahng, Dawk Kha 50 and Dawk Kahm. Experiment was laid out in a Completely Randomized Design (CRD) with split plot design. Results showed that five upland rice genotypes had significantly affected each other by different temperature treatments (28°C, 30°C, 32°C) with grain yield, tops weight, harvest index, flowering, and maturity date. At the same time, all the phenological traits had highly significant variation with the genotypes. The cultivar specific parameters obtained by using a temperature tolerant cultivar (Basmati 385) with five upland genotypes involved in the DSSAT4.7-CSM. Model evaluation results indicated that utilizing the estimated cultivar coefficient parameters, model simulated well with varying temperature treatments as indicated by the agreement index (d-statistic) closer to unity. Hence, it was estimated that model calibration and evaluation was realistic in the limits of test cropping seasons and that CSM fitted with cultivar specific parameters can be used in simulation studies for investigation, farm managing or decision making. This electronic document is a “live” template. The various components of your paper [title, text, heads, etc.] are already defined on the style sheet, as illustrated by the portions given in this document.

CERES-Rice模型在江汉平原的验证与适应性评价

基于江汉平原武汉、荆州农业气象试验站双季早、晚稻及单季中稻多年田间试验数据和同期逐日气象数据,在利用GLUE参数估计模块结合"试错法"对模型参数标定基础上,对CERES-Rice模型叶面积指数及生物量动态、发育期、成熟时地上部生物量、产量等的模拟能力进行了验证。结果表明,模型对水稻发育期模拟较好,开花期和成熟期的模拟误差在3d以内,其中对感光性较弱的早稻模拟最好,感光性较强的晚稻模拟最差;生育期内叶面积指数和生物量动态模拟良好,一致性指数分别达0.98和1.0;模拟产量和地上部总生物量的相对均方根误差分别为8.72%和5.91%,总体效果较好,其中生殖关键期遭遇寒露风的晚稻产量NRMSE为11.16%,模拟效果偏差。说明CERES-Rice模型在无明显异常天气条件下对江汉平原地区水稻模拟具有较好的适应性,CERES-Rice模型可为江汉平原水稻生育期预测提供技术支撑,在考虑极端天气条件胁迫产量形成过程的基础上,可应用于该地区气象影响评价及产量预报业务。

CERES-Rice模型在中国主要水稻生态区的模拟及其检验

本文利用水稻生长观测资料和气象资料,采用CERES- Rice模型在中国主要稻区开展应用研究,对水稻产量、开花期和生物量等的模拟能力进行了评价。所选试验站点分布在不同的水稻生态区,地跨北纬2 0°0 2′(海南海口)至北纬4 5°4 5′(黑龙江五常)。结果表明,在不同的水稻生态区,CERES Rice模型模拟水稻开花期、每平方米粒数、单位产量及生物量的误差在合理的范围内,其中模拟开花期分布在- 10 %～+15 %的相对误差线内,模拟产量分布在- 15 %～+2 0 %相对误差范围内,模拟和观测值的分布具有很好的一致性。如果考虑田间观测10 %～15 %的误差,且排除害虫和病害的影响可得出以下结论:在中国不同水稻生态区,应用文中的水稻品种,该模型能够合理模拟水稻开花期、产量、生物量及产量构成要素(每平方米粒数)。

CERES-Rice在水稻氮肥管理中的应用与分析

利用CERES Rice做模拟试验,分析了施氮量和氮肥运筹对水稻产量形成的影响。结果表明:当施氮水平较低时,CERES Rice能较好地模拟施氮量对水稻产量形成的影响,但在施氮水平较高的情况下,CERES Rice的模拟结果不太理想。模型能反映不同N肥运筹下模拟水稻产量的差异,但不能反映高产栽培的施氮特征。结合试验资料进一步分析认为,误差产生的原因是模型中仅用氮素丰缺因子对光合效率进行订正,而没有考虑氮素对物质分配和转移的作用。

水稻生长模型CERES-Rice的研究进展及展望

简单介绍了CERES-Rice模型的基本原理、主要参数和相关功能,重点阐述了该模型在国内外的研究和应用进展,总结了CERES-Rice模型研究中存在的问题,并在加强模型的机理研究、数据的可获得性、与信息技术的结合和界面友好化等4个方面对CERES-Rice模型研究的趋势进行了展望。

基于CERES-Rice模型分析黔中高原水稻生产对气候变化的响应

将贵州省花溪站2004-2005年的气象资料以及同期贵州省农业科学研究院的水稻种植田间试验资料输入作物模型CERES-Rice,通过校准和验证获得贵州水稻品种黔两优的遗传参数,利用1962-2006年的气象资料动态模拟该品种水稻的生长发育过程。结果表明,44a来,在黔中高原春、夏季气温略有下降和秋季气温略有增加的气候背景下,水稻模拟产量下降趋势不显著;模拟的水稻开花期有一定的稳定性;分期播种的模拟产量差异不显著,表明当前水稻的播种期合适,同时可适当提前以规避秋风等自然灾害对水稻产量的影响。

改进CERES-Rice模型模拟覆膜旱作水稻生长

覆膜旱作是节水稻作生产体系的重要措施之一,采用CERES-Rice模型模拟覆膜旱作水稻生长需另外考虑覆膜的增温效应和根系层土壤水分布差异及由此所带来的影响。该文借鉴部分旱地作物的相关研究成果,对原CERES-Rice模型中的积温和土壤温度、蒸发和土壤水分胁迫等模拟计算过程进行了改进,并进一步通过2个水稻生长季的田间试验予以验证。试验于2013、2014年在湖北房县进行,共涉及淹水(对照)、覆膜湿润栽培和覆膜旱作共3个水分处理,采用原模型和改进模型分别对2个生长季、2个覆膜处理的生育期、叶面积指数与地上部干物质质量的变化过程及产量进行模拟。结果表明:原CERES-Rice模型难以准确刻画覆膜旱作水稻的生长发育过程,经改进后,模拟效果大大改善,可有效反映环境变化(水分、温度)对覆膜水稻生育进程的影响和产量形成,维持生育期与产量模拟的相对误差在15%以内;覆膜水稻叶面积指数的动态模拟基本满足要求,其均方根差≤1.54 m^2/m^2、相对均方根差≤27%、建模效率≥0.85;对覆膜水稻地上部干物质质量变化过程的模拟也呈现出较好的效果,均方根差和相对均方根差分别小于1 490 kg/hm^2、16%,建模效率则高于0.95。总体而言,经改进后的CERES-Rice模型基本可满足要求,较好地用于模拟覆膜旱作水稻的生长发育规律。

基于CERES-Rice模型的覆膜旱作稻田增温效应模拟

水稻覆膜旱作技术具有显著的节水、增温、防污和减排效应,是节水稻作技术体系的重要措施之一,将CERES-Rice模型用于覆膜旱作条件时,必须首先解决覆膜增温效应的准确模拟问题。该文拟应用热量传输理论及目前旱地作物生产系统中采用的覆膜增温效应模拟方法,来模拟水稻覆膜旱作生产体系中的增温效应,从而为完善CERES-Rice模型并使其能用于覆膜旱作水稻的生长模拟奠定基础。参数调校与模型检验验证通过2013、2014年在湖北房县开展的2 a水稻覆膜旱作田间试验来进行,共涉及淹水(对照)、覆膜湿润栽培和覆膜旱作共3个水分处理,分别对2个生长季、2个覆膜处理地表5 cm及地下10、20 cm处温度的变化过程进行了模拟,结果表明:经过参数调校后,所建立的覆膜增温模型可较好地模拟覆膜稻田地表和剖面上土壤温度的变化规律,地表5 cm处土壤温度模拟值与实测值的均方根差、相对均方根差分别低于1.8℃和10%,相关系数在0.89以上(P<0.01);尽管地下10、20 cm处的模拟误差稍大,也基本可满足要求,相应的均方根误差<3.2℃,相对均方根差<15%,相关系数>0.65(P<0.01)。

站点CERES-Rice模型区域应用效果和误差来源

作物区域模拟是利用有限的空间数据,最大限度地反映出生育期、产量等作物性状的时空变化规律。由于目前的作物模型大多是田间尺度的站点模型,把它运用到区域水平的效果如何研究甚少。文章利用CERES-Rice模型,对作物模型在我国的区域应用效果进行了分析。首先利用田间观测数据在各实验点上对模型进行了详细的站点校准,以验证模型在我国的模拟能力;然后以我国水稻生态区(精确到亚区)为单位,运用均方根差(RMSE)法进行了区域校准和验证;最后利用区域校准后的CERES-Rice模型,模拟了1980～2000年的网格(50km×50km)水稻产量,并与同期农调队调查产量进行统计比较,以验证区域应用的效果,为区域模拟的推广和应用提供参考。结果表明:经过空间校准后的CERES-Rice模型,在水稻的主产区1～4区(占种植面积的95%)模拟的平均产量与调查产量相对均方根差在22%以内,两者的符合度也较好,个别区域(5、6)RMSE%在24%～30%之间;1980～2000年水稻各产区模拟的平均产量与调查产量随时间变化趋势也具有一定的一致性;全国1896个网格中,大部分网格(71.01%)模拟的21年水稻年产量与调查产量的RMSE%在30%之内,且大部分分布在水稻主产区,考虑到水稻种植面积的权重后,认为利用区域校准和验证后的CERES-Rice模型进行水稻区域模拟,可以反映出产量的时空分布特征,能够为宏观决策提供相应的信息。但目前区域模拟中还存在着一定的误差,有待今后进一步研究。

CERES-Rice模型中宜香3728水稻遗传特性参数调试与校验

利用在湖北省房县所开展的两年(2012、2013年)田间试验,对水稻品种宜香3728在CERES-Rice模型中的遗传特性参数进行了调试与校验。首先,根据2013年田间实测数据,如关键生育期及其叶面积指数、地上部干物质量和产量等,采用"GLUE+试差法"对宜香3728的遗传特性参数进行了调试。当达到设定的误差控制标准时(10%以内),停止调试,并将此时模型中的遗传特性参数作为调试结果。然后,再应用2012年实测数据对此组遗传特性参数进行校验。模型模拟值与田间实测值之间的对比关系表明此组遗传特性参数基本准确,可用于表征宜香3728水稻品种在房县的遗传特性。研究成果为利用CERES-Rice模型在房县及周边同类地区开展相关研究工作奠定了基础,同时也可为CERES-Rice模型在其他地区的本地化应用提供借鉴。

基于CERES-Rice模型的湖南省一季稻极端高温损失评估及适应性措施

以湖南省4个农业气象站点的一季稻为研究对象,基于1990—2012年逐日气象数据,精细的土壤以及田间管理记录,分析了过去23年极端高温的变化趋势,并利用校准后的CERES-Rice模型评价了高温热害的致损率,着重探讨了不同的适应性措施对缓解高温热害的作用,以期提出科学合理的减灾措施来保障我国的粮食安全。结果表明:(1)CERES-Rice能很好地捕捉本研究区不同天气和管理条件下的水稻物候期和产量,除桑植站开花期外,其余各参数的模拟误差均小于10%。(2)一季稻生育期内极端高温频发且在本世纪有增强趋势,灾损率由高到低依次为古丈>桑植>怀化>靖州,分别为10.4%,8.2%,7.5%和4%。随着气候变暖的加剧,一季稻生产将面临着日趋严重的高温热害风险。(3)选用耐高温品种产量最大可提升29.8%,但在极端高温年份,提高品种高温抗性的方法收效甚微。调节播种期会导致-25%—20%的产量波动,其中提前10 d或5 d种植均可缓解极端高温的危害。增加灌溉的贡献为1%—8%,其中6—8 cm灌水量效果最佳。极端高温期间增施氮肥的贡献稳定且显著,平均增产2%—20%,80—100 kg/hm2的施氮量能带来较为理想的避热增产效果。

Dynamic Responses of Super Rice IIyou602 Plants to Different Nitrogen Levels and Configuration Modes

[Objective] The paper was to study the dynamic responses of super rice Ilyou602 plants to different nitrogen levels and configuration modes. [Method] With super rice Ilyou602 as test material, the dynamic changes of total N content in functional leaves, leaf sheaths and stems under different, application amount of nitrogen and configuration modes were analyzed. [Result] The highest total N content of functional leaves under different N levels appeared in the different periods, which was the highest during rehydration period in A3 level. The total N content in various plant positions during full heading stage and maturity stage showed fertilization treatments 〉 CK, functional leaves 〉 leaf sheaths 〉 stems. The total N content in different plant positions showed obvious difference in different treatments. When the super rice Ilyou602 was planted in Chengdu plain, the proper application level of N and configuration mode was as follows： 165 kg/hm2, fertilizer： topdressing = 6：4. [Conclusion] The study provided theoretical basis for nitrogen regulation of high yield cultivation of super hybrid rice.

N_2O Emission from Paddy Field under Different Rice Planting Modes

Measurements of N2O emissions from conventional rice cultivation （CRC）, CRC with straw mulching, system of rice intensification （SRI） and SRI with plastic film mulching were conducted through static chamber/gas-chromatography techniques. The results show that daily fluctuation of N2O emissions in jointing stage are much higher than in others. A type peak of N2O seasonal emission presented between jointing and bearing stages companying with high daily average temperature and low precipitation. Biomass and leaf stomatal conductance were observed. Total quantities of N2O emission were budgeted. The results showed that after jointing stage the average N2O emission flux of SRI with plastic film mulching increased significantly than CRC with straw mulching and SRI, the leaf stomatal conductance of those showed the same trend （p〈 0.05）. Yield and total quantity of N20 emission in CRC with straw mulching enhanced 13. 7% and 10.7% compared with those of CRC, respectively. The total quantity of N20 emissions reduced 3. 6% in SRI with plastic film mulching compared with CRC, however, the yield increase of that was not significant.

Water-temperature Characteristics of Rice-field-crab "Panshan Mode"

In this paper,rice crab ＂ Panshan mode＂ in the paddy fields of temperature and meteorological monitoring data,an analysis of the model at different depths of water-temperature characteristics with changes in the weather,combined with test base in 2009 the productivity of crab and rice,to discuss the ＂ Panshan mode＂ due to a large ridge with two rows,around the ring groove of the kind of interpolation method to the temperature change caused by the benefits of ecological culture of crab：crab rice first winding mode to a certain extent,good Improved survival of crab of the most important one of environmental factors-water temperature;2 is the expansion of the vertical space crab survival activities,and ultimately increase production of rice,crab size increase the purpose of cultivation.

A Field Study on Effects of Nitrogen Fertilization Modes on Nutrient Uptake,Crop Yield and Soil Biological Properties in Rice-Wheat Rotation System

Rational application of nitrogen （N） fertilizers is an important measure to raise N fertilizer recovery rate and reduce N loss.A two-year field experiment of rice-wheat rotation was employed to study the effects of N fertilization modes including a N fertilizer reduction and an organic manure replacement on crop yield,nutrient uptake,soil enzyme activity,and number of microbes as well as diversity of microbes.The result showed that 20% reduction of traditional N fertilizer dose of local farmers did not significantly change crop yield,N uptake,soil enzyme activity,and the number of microbes （bacteria,actinomycetes,and fungi）.On the basis of 20% reduction of N fertilizer,50% replacement of N fertilizer by organic manure increased the activity of sucrose,protease,urease,and phosphatase by 46-62,27-89,33-46,and 35-74%,respectively,and the number of microbes,i.e.,bacteria,actinomycetes,and fungi by 36-150,11-153,and 43-56%,respectively.Further,organic fertilizer replacement had a Shannon＇s diversity index （H） of 2.18,which was higher than that of other modes of single N fertilizer application.The results suggested that reducing N fertilizer by 20% and applying organic manure in the experimental areas could effectively lower the production costs and significantly improve soil fertility and biological properties.

Research Progress of High Yield Cultivation Mode of Rice

Optimized high-yielding cultivation is of great significance to ensure stable and high yield of rice in China. This paper reviewed several super high-yielding cultivation modes, analyzed the effects of different cultivation modes on rice agronomic traits and physiological characteristics, and discussed the advances in rice mechanized cultivation and mode. Finally, the future development prospects of rice cultivation were put forward.

Effect of irrigation modes on the senescence of hybrid rice after heading

The pot experiment was designed to investigate therelationship between the senescence of hybrid riceand the irrigation mode and conducted during1984-1985.There were 30 pots for each treatmentand each pot contained 17.5 kg soil.Hybrid riceShanyou 6 was sown on 10 Jun ahd transplanted

基于改进滑模控制的水稻直播机路径跟踪研究

为了提高水稻直播机自动作业时路径跟踪的精度和稳定性,提出了一种基于新型非线性滑模面和改进快速变幂次趋近率的滑模路径跟踪控制方法。首先,建立Frenet坐标系下直播机的路径跟踪运动学模型;然后,为保证路径跟踪过程中横向偏差和航向偏差全局收敛,采用双曲正切函数设计滑模面;最后,在快速幂次趋近率的基础上设计了变指数幂次项,提高了系统趋近速度并有效抑制了抖振。在Simulink上搭建模型并进行仿真,与基于快速幂次趋近率和指数趋近率的滑模控制方法相比,本文改进滑模控制方法的路径跟踪误差收敛时间最短并且无抖振现象发生。直播机采用改进算法以0.8 m/s的速度在水田实际自动作业时,横向偏差和航向偏差的平均绝对误差为0.016 9 m和1.099 9°,均方差为0.021 5 m和1.499 2°,提高了路径跟踪的精度和稳定性,满足了实际作业需求。

Effect of Different Irrigation Patterns on Transportation and Allocation of Carbohydrate During Grain Filling of Rice

Using intersubspecific hybrid rice Xieyou 9308 and Liangyou Peijiu as the tested materials, the effects of differentirrigation patterns on transportation and allocation of carbohydrate during grain filling stage was observed by the designwith three level of soil water content in irrigated field. The results showed that in the conventional flooding and thealternate dry-watering cultivations, the exported rate of stored carbohydrate from stem and photophate from the leaves were60 and 90 % respectively. The exported rate of carbohydrate was decreased significantly (P<0.01) in the non-floodingcultivation. There was no significant difference between the conventional flooding and dry-wet alternation treatments interm of the exported rate of carbohydrate. The filling grains were the major sinks for carbohydrate storage during grainfilling stage. Grains received nearly 50% of stored carbohydrate from leaf sheath and 80% of photophate from leaves. Atthe nonflooding condition the absorbing rates of grains were significantly decreased by 10 % from leaf sheath and 20 %from leaves photophate. Water stress leaded much decrease in absorbing ability for inferior grains, which might be one ofthe main causes for low seed-settling rate in non-flooding cultivation.

Effect of side deep placement of nitrogen on yield and nitrogen use efficiency of single season late japonica rice

Side deep placement of nitrogen plays an important role in improving rice yield and nitrogen use efficiency.Few studies have examined the effects of reducing the times of nitrogen(RTN)application and reducing the nitrogen rate(RNR)of application on rice yield and nitrogen use efficiency under side deep placement of nitrogen in paddy fields.Therefore,a field experiment of RNT and RNR treatments was conducted with nine fertilization modes during the 2018–2019 rice growing seasons in a rice–wheat cropping system of the lower reaches of the Yangtze River,China.Rice yield and nitrogen use efficiency were investigated under side deep placement of nitrogen.We found that under the same nitrogen application rate,the yield of RTN3 increased by 9.64 and 10.18%in rice varieties NJ9108 and NJ5718,respectively,compared with the farmers’fertilizer practices(FFP).The nitrogen accumulation of RTN3 was the highest at heading stage,at 11.30 t ha^(–1)across 2018 and 2019.Under the same nitrogen application rate,the N agronomic use efficiency(NAE),N physiological efficiency(NPE)and N recovery efficiency(NRE)of RTN3 were 8.1–21.28%,8.51–41.76%and 0.28–14.52%higher than those of the other fertilization modes,respectively.RNR led to decreases in SPAD value,leaf area index(LAI),dry matter accumulation,nitrogen accumulation,and nitrogen use efficiency.These results suggest that RTN3 increased rice yield and nitrogen use efficiency under the side deep placement of nitrogen,and RNR1 could achieve the goals of saving cost and increasing resource use efficiency.Two fertilization modes RTN3 and RNR1 both could achieve the dual goals of increasing grain yield and resource use efficiency and thus are worth further application and investigation.