黑龙江省青贮玉米收获机械现状及发展趋势

青贮玉米收获机是青贮玉米饲料机械化生产中重要的农业装备之一。为此,分析了黑龙江省青贮玉米收获机械的现状和发展趋势;指出了青贮玉米收获机械发展中存在的问题;提出了相应的解决对策。其目的是为进一步加快黑龙江省青贮玉米收获机械的发展献计献策。     

西兰花选择性采收作业平台识别切割装置设计与试验

针对当前人工采收西兰花存在季节性劳动力需求强、劳动强度大以及成本高等问题,该研究基于西兰花的农艺特性与形态特征设计了一种西兰花选择性采收作业平台,旨在能够实现对西兰花的自主识别切割作业。首先,该平台采用“识别-采收”一体化作业模式,通过对采收作业平台的关键部件进行设计与选型,建立了西兰花的视觉识别系统和定心切割机构。其次,根据西兰花茎秆与割刀之间的相互作用关系,采用对数螺线作为切割曲线设计了一种等滑切角割刀,确定了割刀滑切角40o、切割半径135 mm、割刀长度260 mm等关键切割参数。根据西兰花茎秆的材料属性参数,基于ANSYS Workbench/LS-DYNA软件对茎秆切割过程进行显式动力学仿真分析,以割刀刃角和转速为控制因子,以最大切割力为试验指标,利用正交试验优化设计,确定了茎秆切割过程的最优参数组合为割刀刃角20°、转速1 rad/s,在此参数下最大切割力为725.82 N,切割质量较优。最后,对采收作业平台进行性能试验,结果表明视觉系统能够有效识别自然环境下的成熟西兰花植株,检测效果良好;定心切割机构可快速平稳的切入并切断西兰花茎秆,切断表面平整光滑;采收作业平台整体漏收率在10%以下、检测准确率为90%、切茎合格率为88.9%,可满足西兰花选择性采收的作业需求。本研究可为西兰花选择性采收作业装备的设计开发提供理论参考和实际借鉴。     

不同播期夏播小豆产量性能动态指标与光温水效应

为探讨光、温、水等气象因子对夏播小豆产量的影响,达到合理利用气象资源、进一步挖掘小豆增产潜力的目的,以中晚熟小豆品种花小豆(V1)和中早熟品系德红5261(V2)为材料,设T1(6月17日)、T2(6月22日)、T3(6月27日)、T4(7月2日)和T5(7月7日)5个播期,形成不同的光、温、水生长环境,对夏播小豆产量...     

不同播期、收获期和储存期对优质长粒籼稻整精米率的影响

整精米率是影响优质长粒籼稻发展的重要因素之一.为明确长江中下游稻区优质长粒籼稻适宜的播期、收获期和储存期,以3个长粒优质常规籼稻为材料,探讨了不同播期(5月10日、5月20日、5月25日、5月30日)、收获期(90％谷粒成熟、完全成熟、完全成熟后6d)、储存期(10 d、40 d、60 d)对水稻整精米率的影响.结果 ...     

根茎类作物单摆铲栅收获装置渐变抛掷特性

单摆铲栅是基于变幅变向振动技术研发的铲栅一体收获装置。为明确单摆铲栅工作特性及抛掷分离作业机理,该研究在运动学及动力学分析基础上建立了铲栅工作面抛掷系数解析方程,铲栅工作面各点抛掷系数随工作长度逐渐增大且具有明显的渐变抛掷特性和较强的抛掷能力,分离区最大抛掷系数达9.98～19.72;建立了单摆铲栅EDEM-MBD耦合仿真模型,以振幅、振动频率、前进速度为因素开展单因素仿真试验,试验结果表明：受工作面抛掷特性及土壤粘塑性影响,牵引阻力、驱动转矩具有明显的强弱周期,在强周期内：单摆铲栅与土壤互作力较大,分离间距最大值发生在该周期切削行程终点时刻分离区中点处;振幅为7～11 mm时,牵引阻力均值约1 580.93～2 019.9 N、最大驱动转矩约224.04～322.11 、最大分离间距约59.58～98.3 mm;振动频率为6.67～10.67 Hz时,牵引阻力均值约1 416.43～1 866.38 N、最大驱动转矩约315.28～364.19 、最大分离间距约78.43～94.67 mm;前进速度为0.2～0.4 m/s时,牵引阻力均值约1 429.43～2 110.48 N、最大驱动转矩约241.27～387.78 、最大分离间距约62.5～102.5 mm。甘草收获试验结果表明：甘草收获机牵引阻力32.17 kN、驱动转矩802.02 、挖掘深度468 mm时,收净率为96.42%,单摆铲栅作业过程流畅有序,渐变抛掷作用明显,根茎土壤分离效果良好。该研究结果可为根茎作物特别是深根茎作物节能高效收获提供参考。     

割秧后花生收获机捡拾装置设计与试验

先将秧蔓切割再进行收获可较好地实现覆膜种植花生秧蔓饲料化利用。该研究针对割秧后花生植株变短、横向尺寸变小、荚果-秧蔓比增加,原有收获机捡拾装置适应性差的问题,在已有花生捡拾收获技术基础上,对捡拾弹齿间距、弹齿转速、折弯角度、弹齿排数等关键结构和运动参数进行改进,研制了一种适于割秧后收获的弹齿式花生捡拾装置。运用SPSS软件对割秧后花生植株横向尺寸进行统计分析,确定了弹齿间距为7 cm;通过对花生植株低损捡拾和顺畅抛送条件的理论分析,在回转半径为21 cm的条件下,确定捡拾弹齿转速为60 r/min;通过对花生植株被弹齿捡起时的受力情况分析,确定捡拾弹齿折弯角度为102°,并根据铺放厚度,确定捡拾弹齿折弯部分长度为4 cm;建立捡拾弹齿齿尖运动方程,运用Matlab软件对不同排数弹齿齿尖运动轨迹进行分析,确定捡拾弹齿排数为6排。田间试验结果表明,弹齿式花生捡拾装置的平均捡拾率为98.07%,捡拾装置造成的平均落果率为1.23%;满足割秧后花生捡拾收获作业需求。该研究可为割秧后花生以及其他作物捡拾收获机具研发和改进提供借鉴。     

Considering sink strength to model crop production under elevated atmospheric CO2

Climatic changes and elevated atmospheric CO₂ concentrations will affect crop growth and production in the near future. Rising CO₂ concentration is a novel environmental aspect that should be considered when projections for future agricultural productivity are made. In addition to a reducing effect on stomatal conductance and crop transpiration, elevated CO₂ concentration can stimulate crop production. The magnitude of this stimulatory effect (‘CO₂ fertilization’) is subject of discussion. In this study, different calculation procedures of the generic crop model AquaCrop based on a foregoing theoretical framework and a meta-analysis of field responses, respectively, were evaluated against experimental data of free air CO₂ enrichment (FACE) environments. A flexible response of the water productivity parameter of the model to CO₂ concentration was introduced as the best option to consider crop sink strength and responsiveness to CO₂. By varying the response factor, differences in crop sink capacity and trends in breeding and management, which alter crop responsiveness, can be addressed. Projections of maize (Zea mays L.) and potato (Solanum tuberosum L.) production reflecting the differences in responsiveness were simulated for future time horizons when elevated CO₂ concentrations and climatic changes are expected. Variation in future yield potential associated with sink strength could be as high as 27% of the total production. Thus, taking into account crop sink strength and variation in responsiveness is equally relevant to considering climatic changes and elevated CO₂ concentration when assessing future crop production. Indicative values representing the crop responsiveness to elevated CO₂ concentration were proposed for all crops currently available in the database of AquaCrop as a first step in reducing part of the uncertainty involved in modeling future agricultural production.     

气候变化与土壤湿度关系的研究进展

在分析气候变化与土壤湿度关系研究现状的基础上,综述了该研究的进展。首先,描述了用数值模拟方法研究气候变化与土壤湿度之间关系的现状;论述了该研究取得的成果和需要进一步研究的问题;其次,简要总结了目前研究仍显薄弱的资料诊断分析工作及取得的成果。土壤湿度的监测与预报是制定合理的灌溉制度从而实现适时适量灌溉的基础,因此本文对气候变化条件下土壤湿度变化趋势的研究及节水灌溉(特别是干旱地区)具有重要的意义。     

Effect of Harvest Timing on Yield and Mineral Nutritional Value of Kabuli Type Chickpea Seeds

Chickpea (Cicer arietinum L.) seeds are a good source of protein and mineral nutrients. However, there is no information regarding harvest timing on yield and mineral composition of chickpea seeds. The effect of harvest timing on seed yield, some yield components and mineral nutritional value of seeds of field grown chickpea plants in two different sites were studied. The mineral composition of chickpea straw depending on harvest timing was also evaluated in order to explain the variations of seed mineral concentrations in sink-source relationship manner. Yield and mineral nutritional value of chickpea were significantly affected by harvest timing. When compared to the seed yield at optimal harvest time, seed yield was 18% and 9% lower in the early harvest and 27% and 31% in the late harvest in Site 1 and Site 2, respectively. Late harvest of chickpea crops resulted in significant pod dropping and shattering. Generally, protein, phosphorus (P), calcium (Ca), magnesium (Mg), copper (Cu), zinc (Zn), and manganese (Mn) concentrations of the seeds in optimal harvest were found to be greater than in early and late harvested plants. Harvest timing also results in significant variations in straw mineral nutrient concentrations of the plants. As the results of this study, it was concluded that the harvest timing is critical for yield losses and mineral nutritional value of chickpea seeds.     

玉米梳齿摘穗单体机构设计与试验

针对现有玉米收获机摘穗机构行距固定,难以实现按需调整以适应各类行距的问题,设计了一种玉米梳齿摘穗单体机构。该机构主要由梳齿滚筒、梳齿杆、梳齿杆安装座及传动轴等组成。相邻两梳齿杆的间隙小于玉米果穗大端的直径且大于玉米茎秆的直径,利用冲力将玉米果穗强制摘下。初步试验表明,玉米梳齿摘穗单体机构能够可靠地完成玉米摘穗作业。在玉米籽粒含水率为35.5%,玉米梳齿摘穗单体机构转速为110~170 r/min时,工作状况较好,籽粒破碎率的范围为0.14%~0.48%,落地籽粒损失率范围为0.03%~0.17%。正交试验结果表明,当转速为110 r/min,梳齿杆圆弧半径为240 mm,梳齿传动轴位于果穗大端下方100 mm时工作情况较好,籽粒破碎率为0.09%,落地籽粒损失率为0.04%,果穗损失率为1.96%。