Increasing the appropriate seedling density for higher yield in dry direct-seeded rice sown by a multifunctional seeder after wheatstraw return

Dry direct-seeded rice(DDR) sown using a multifunctional seeder that performs synchronous rotary tillage and sowing has received increased attention because it is highly efficient,relatively cheap,and environmentally friendly.However,this method of rice production may produce lower yields in a rice–wheat rotation system because of its poor seedling establishment.To address this problem,we performed field experiments to determine the rice yield at five seedling density levels(B1,B2,B3,B4,and B5=100,190,280,370,and 460 seedlings m-2,respectively) and clarify the physiological basis of yield formation.We selected a representative high-quality rice variety and a multifunctional seeder that used in a typical rice–wheat rotation area in 2016 and 2018.The proportion of main stem panicle increased with increasing seedling density.There was a parabolic relationship between yield and seedling density,and the maximum yield(9.34-9.47 t ha-1) was obtained under B3.The maximum yield was associated with a higher total spikelet number m-2 and greater biomass accumulation from heading to maturity.The higher total spikelet number m-2 under B3 was attributed to an increase in panicle number m-2 compared with B1 and B2.Although the panicle numbers also increased under B4 and B5,these increases were insufficient to compensate for the reduced spikelet numbers per panicle.Lower biomass,smaller leaf area,and lower N uptake per plant from the stem elongation stage to the heading stage were partially responsible for the smaller panicle size at higher seedling density levels such as B5.The higher biomass accumulation under B3 was ascribed to the increases in the photosynthetic rate of the top three leaves m-2 of land,crop growth rate,net assimilation rate,and leaf area index.Furthermore,the B3 rice population was marked by a higher grain–leaf ratio,as well as a lower export ratio and transport ratio of biomass per stem-sheath.A quadratic function predicted that 260-290 seedlings m-2 is the optimum seedling density for achieving maximum yield.Together,these results suggested that appropriately increasing the seedling density,and thereby increasing the proportion of panicles formed by the main stem,is an effective approach for obtaining a higher yield in DDR sown using a multifunctional seeder in a rice–wheat rotation system.

基于机器深度学习的小麦播种机控制系统研究

针对我国小麦播种机自动控制系统的可靠性及灵敏度不高的问题,基于机器深度学习对小麦播种机的控制系统进行了设计和改进。小麦播种机的主要组成包括控制系统、排种系统、监控系统、电力系统、机架和驾驶室、覆土镇压和排肥装置。为了使播种机的控制系统能有效进行图像检测识别,提升播种机的控制精度,采用机器深度学习中的卷积神经网络算法对控制系统进行设计,并采用迁移学习的方式对模型进行训练和检测。为了验证播种机控制系统的性能,对其进行播种精度控制和播种性能测试试验,结果表明:播种机的精度和性能均符合播种机的设计要求。

基于预知维修的小麦播种机运行监控系统设计

为了减少播种机故障频率,提升小麦播种机的播种效率和播种质量,基于预知维修对小麦播种机的运行监控系统进行了设计。系统的主要组成包括主控单片机、检测系统、显示监控系统、报警系统及电源。为了对播种机进行预知维修,将灰色模型和神经网络模型结合,建立了动态灰色神经网络模型,并进行了算法设计。为了验证小麦播种机监控系统性能和预知维修算法的有效性,对其进行了监测精度和趋势预测试验,结果表明:监测系统的监测精度较高,播种机可有效对数据趋势进行预测。

种子破损率快速检测方法研究

旋耕播种机推广鉴定时,需要人工检测种子的破损率。为提高检测效率,以小麦种子为例,对种子破损率快速检测方法进行研究。设计种子破损率自动检测平台,可一次性采集50 g小麦种子图像,基于图像处理技术和机器学习方法,提取小麦种子图像13个形状特征和8个纹理特征,建立基于特征的种子破损识别模型;识别的破损种子图像与种子质量的关系,建立基于图像的破损种子质量预测模型,按照鉴定大纲要求实现小麦种子破损率的快速检测。对江苏省“丹阳001”“A888”“泰州014”“无锡004”4个品种的小麦种子破损率进行试验测试,每个品种3次取样测定。结果表明:4个品种小麦种子破损率自动检测的平均相对误差分别为0.08%、0.07%、0.06%、0.08%,检测的相对均方根误差为0.08%,检测平均时长为5.216 s。该研究实现小麦种子破损率自动、快速检测,节省农机鉴定时间,推动农机鉴定过程的标准化和智能化。

基于PID控制的小麦智能播种机研制与试验

针对小麦播种机工作时地轮打滑和手动播量调整不精准等问题,研发了基于PID控制的小麦智能播种机。该播种机控制系统工作时,由速度传感器获取播种机行进速度,根据行进速度、单位面积播种量及播种机相关参数,计算排种轮转速的给定值,利用PID控制器实现对排种轮转速的控制。室内试验结果表明,播种机在不同作业条件下实际单位面积播种量与设定单位面积播种量误差均<2%,满足小麦精量播种的农艺要求。在中速和中高速作业条件下,智能排种系统控制精度较高、稳定性好。田间试验结果表明,小麦播种机的实际单位面积播种量与设定单位面积播种量之间最大误差2.33%,略大于室内试验结果,主要是由田间作业环境等因素造成的。基于PID控制的小麦智能精量播种机能有效提高播种精度。

基于EDEM的小麦小区双圆盘开沟器仿真分析

双圆盘开沟器具有不易堵塞和不乱土层优良作业的特点,为了配备在小型小麦播种机上,设计了一种小型双圆盘开沟器。为了获得双圆盘开沟器最小开沟阻力和最优的播深稳定性,以圆盘直径、圆盘聚点位置和圆盘夹角为试验因素,进行了仿真试验分析,得到最优工作参数数据(圆盘直径为210mm,圆盘聚点位置为60°,圆盘夹角为12.60°),此时双圆盘开沟器作业阻力为319.65N,开沟深度变异系数为7.51%。通过土槽试验加以验证,结果表明:与仿真试验相比,开沟作业阻力误差率为2.64%,开沟深度变异系数误差率为2.52%,仿真试验具有一定的可靠性,可为双圆盘开沟器设计优化提供理论依据。

小麦精量播种机设计与试验

设计一种播深稳定、镇压质量高且具有堵塞疏通清理机构的小麦精量播种机。利用平行四边机构和镇压轮的限深作用,播种单体能够实现随地表高低仿形而保持播种深度不变。堵塞疏通清理机构采用曲柄导杆机构,把曲柄的旋转运动转化为导杆的往复直线运动,通过导杆在排种管内上下运动,从而把堵塞物推出落种口。田间试验表明,该机简化了播种机的结构和操作方式,能够实时监测作业状态,确保播种作业质量。试验结果以期为后续小麦精量播种机设计优化提供参考。

尧都区小麦播种机适应性选型试验

在尧都区小麦生产区对5种小麦播种机进行了适应性选型试验,以通过实地测试选型最适合当地使用的播种机型。试验结果表明,试验所用的5种小麦播种机在尧都区均有良好的适应性和高效的表现,有助于推进小麦播种的机械化作业,提升小麦生产的效率和经济效益。

Effects of Residue Management and Cropping Systems on Wheat Yield Stability in a Semiarid Mediterranean Clay Soil

Agriculture is the single biggest user of land and water in Morocco;however its performances are still low due to high rainfall variation and rates of soil productivity depletion. Increasing concerns about soil and environment quality degradation have raised the need to review existing tillage management systems and develop new systems for seed-bed preparation. Consequently, No-tillage is found a promising practice of soil management to improve simultaneously soil quality and wheat production in semiarid Morocco. However, residue management under No-tillage was Not yet studied in conjunction with wheat rotation. Therefore, a field study was conducted in the semiarid Chaouia Plain of Morocco during the period from 1994 to 2003, in order to evaluate the impacts of different tillage practices (conventional tillage (CT), No-tillage (NT));No-tillage wheat residue management scenarios (total NTr, partial NTp and No-removal of residues NTm) and crop rotations (continuous wheat (CW), Wheat-Fallow (WF), Wheat-Maize-Fallow (WMF), Wheat-Lentil-Fallow (WLF) and Wheat-Barley-Fallow (WBF)) on wheat production. Over-years, conventional tillage system permitted lower yield of wheat while NT maintenance of crop residue at the surface is needed to increase it. Basically, NTp could be adopted in mixed crop-livestock systems of semiarid areas for the purpose of guarantying grain and feed. Wheat yields were the lowest under continuous wheat for all years. Wheat-fallow rotation is an important option in dry years or areas, while wheat-fallow-lentil or barley rotations are recommended in better environments. Stability analysis indicated that yields in the No-tillage system were less influenced by adverse growing conditions than conventional tillage system, particularly under low rainfall. These results indicate that improved soil quality under No-tillage enhanced wheat yield stability by reducing the impact of adverse growing conditions.

Genotype×tillage interaction and the performance of winter bread wheat genotypes in temperate and cold dryland conditions

Growing concerns for food security and the alleviation of hunger necessitate knowledge-based crop management technologies for sustainable crop production.In this study,13 winter bread wheat genotypes(old,relatively old,modern,and breeding lines)were evaluated under three different tillage systems,i.e.,conventional tillage(CT,full tillage with residue removed),reduced tillage(RT,chisel tillage with residue retained)and no-tillage(NT,no-tillage with residue retained on the soil surface)in farmer’s fields under rainfed conditions using strip-plot arrangements in a randomized complete block design with three replications in the west of Iran(Kamyaran and Hosseinabad locations)over two cropping seasons(2018–2019 and 2019–2020).The main objectives were to investigate the effects of tillage systems and growing conditions on the agronomic characteristics,grain yield and stability performance of rainfed winter bread wheat genotypes.Significant(P<0.01)genotype×tillage system interaction effects on grain yield and agronomic traits suggested that the genotypes responded differently to the different tillage systems.The number of grains per spike and plant height were positively(P<0.0)associated with grain yield under the NT system,so they may be considered as targeted traits for future wheat breeding.Using statistical models,the modern cultivars(“Sadra”and“Baran”)were identified as high yielding and showed yield stability across the different tillage systems.As per each tillage system,genotype“Sadra”followed by“Zargana-6//Dari 1-7 Sabalan”exhibited higher adaption to CT;while cultivars“Jam”and“Azar2”showed better performance under the RT system;and cultivars“Varan”and“Baran”tended to have better performance expression in the NT condition.The increased grain yields achieved in combination with lower costs and greater profits from conservation agriculture suggest that adapted cultivar and NT systems should be evaluated and promoted more widely to farmers in the west of Iran as an attractive package of crop management technologies.In conclusion,variations in the performance of genotypes and the significant genotype×tillage system interaction effects on grain yield and some agronomic traits assessed in this study suggest that the development and selection of cultivars adapted to the NT system should be considered and included in the strategies and objectives of winter wheat breeding programs for the temperate and cold dryland conditions of Iran.

Control of Common Chickweed in Winter Wheat with Postemergence Herbicides

A total of six experiments were conducted over a two-year period (2018, 2019) at the University of Guelph Ridgetown Campus to assess the efficacy of various herbicides applied postemergence (POST) for the control of common chickweed in winter wheat. Fluroxypyr/bromoxynil/MCPA, pyrasulfotole/bromoxynil,pyrasulfotole/bromoxynil/fluroxypyr,pyrasulfotole/bromoxynil/thiencarbazone, pyrasulfotole/bromoxynil/thiencarbazone + MCPA ester, tolpyralate and fluroxypyr/halauxifen + MCPA EHE, applied POST, controlled common chickweed only 5% - 42% at 2 weeks after treatment (WAT) and 1% - 23% at 4 WAT and resulted in common chickweed density and biomass that was similar to non-treated weedy control. Fluroxypyr/halauxifen + pyroxsulam + MCPA EHE, applied POST, provided 57% - 82% control of common chickweed and reduced density 93% and biomass 98% compared to the non-treated control. Thifensulfuron/tribenuron, thifensulfuron/tribenuron + MCPA ester, thifensulfuron/tribenuron + fluroxypyr + MCPA ester, tribenuron + thiencarbazone, and tribenuron + thiencarbazone + MCPA ester, applied POST, controlled common chickweed 98% - 100% and reduced common chickweed density 96% - 98% and common chickweed biomass 99%. Based on these results, herbicide treatments which contained tribenuron including thifensulfuron/tribenuron, thifensulfuron/tribenuron + MCPA ester, thifensulfuron/tribenuron + fluroxypyr + MCPA ester, tribenuron + thiencarbazone, and tribenuron + thiencarbazone + MCPA ester were the most efficacious for the control of common chickweed in wheat. In addition, fluroxypyr/halauxifen + pyroxsulam + MCPA EHE, applied POST, can provide adequate control of common chickweed in winter wheat.

小麦播种机电气控制系统的设计与试验

为了解决传统小麦播种机播种量的调节范围小、播种不均匀等问题,设计了一种基于PLC控制的自动播量调节电气控制系统。系统由PLC控制器、速度传感器、步进电机等组成,替代了传统的地轮和侧边箱式机械驱动模式。其主要的工作原理是将速度传感器安装于拖拉机主动轮内侧,当速度传感器采集到拖拉机速度信号后,发送给PLC,经过运算处理后发送相应的控制信号给步进电机;步进电机按控制指令调节转速,同时带动外槽轮式排种器的排种轴转动。排种轴的速度发生变化,排种槽轮中的种子数量随之改变,使小麦的播量得到调节。试验结果表明:系统能够控制小麦的亩播量误差在5%以内,播种均匀性系数小于40%,满足小麦精播的需求。

小麦小区条播机电控排种系统设计与试验

针对小麦小区条播机排种系统智能化水平低的问题,本文基于差分定位原理设计了一套小麦小区条播机电控排种系统。该系统主要由北斗差分定位系统、STM32F4主控系统、锥体格盘驱动系统、离心分种驱动系统和人机交互系统等组成,主控系统采集北斗差分定位信息计算锥体格盘匹配转速,控制格盘电机和分种电机运转,并显示作业信息。通过正交试验法优选了离心分种器结构参数,建立了播种机车速和锥体格盘转速控制模型。试验结果表明:各行排量一致性变异系数为5.69%,均匀性变异系数为20.77%,验证了本电控排种系统的可行性。

黏土地稻茬麦反旋条带播种机设计与试验

针对我国黏土地地区稻茬麦机械化播种作业,设计了一种新型的黏土地稻茬麦轻型反旋控深条带播种机,集反旋灭茬、开沟播种、覆土镇压于一体,解决了传统黏土地播种机旋耕碎土不彻底、排种管易堵漏及播深不一致的问题。对播种机整体结构进行总体方案设计,并对大直径旋耕灭茬机构和限深压槽覆土机构关键装置的参数进行优化。设计其传动系统,确定齿轮箱传动比分别为2.04和2.70,并计算其功耗选取拖拉机型号。最后,进行机具制造与试验,结果表明:机具适合黏土地稻茬麦播种作业,耕深为13.9cm,播深为2.7cm,碎土率平均值达到78.56%,漂种率平均值控制在2.55%以内,排种管防堵漏效果好。所设计的黏土地稻茬麦轻型反旋控深条带播种机完全符合设计要求,适应黏土地地区的小麦播种作业。

2BF-9型小麦播种机研制

为了满足辽宁省朝阳市农业生产需要,设计了一种小麦播种机,可以一次性完成开沟、施肥、播种和覆土作业。田间试验结果表明,播种深度40 mm,行距120 mm,苗带宽度70 mm,效率0.43 hm2/h。其创新点是链轮通过链轮定位板限位,在后横梁上交错设置后开沟器架和前开沟器架;优势是苗带宽、结构简单、调整方便。

2BMX-5型小麦-玉米免耕播种机设计

针对用于一年一熟区免耕播种机的尖角型开沟器易磨损,且磨损后导致土壤扰动大、动力消耗增加、影响播种质量等问题,研究了能够拆卸前刀的楔刀型免耕开沟器以及传动机构,设计了刃口为圆弧形的前刀,并在此基础上设计了2BMX-5型小麦-玉米免耕播种机。样机分别在内蒙古、宁夏等小麦、水稻茬地进行了性能试验。试验结果表明,该机在播种过程中未发生堵塞,楔刀型免耕开沟器提高了通过性,开沟破茬效果良好,播种后土壤扰动小,种肥深度能够满足播种要求,在稻茬地的破茬率超过85%。

动力甩刀式小麦固定垄免耕播种机

针对我国西北绿洲农业区现有固定垄免耕播种机种类少,且在玉米秸秆地固定垄免耕播种小麦易堵塞、破坏垄形等问题,提出了动力甩刀碎、抛茬和刀刃型开沟器破茬结合防堵及双翼型犁铧修垄的方法。设计了动力甩刀破茬式小麦固定垄免耕播种机,并确定了L型甩刀、开沟器、双翼型犁铧等关键部件的参数。在玉米秸秆覆盖地试验结果表明,动力甩刀破茬式小麦固定垄免耕播种机能有效地解决秸秆堵塞问题,具有较强的防堵能力;该机在减少动土量的情况下,其产量与2BMF-5型固定垄免耕播种机基本持平,且修垄效果更好。

小麦免耕播种机浮动支撑式防堵装置

针对我国华北一年两熟区秸秆量大,根茬粗,免耕播种机开沟器前易产生壅堵,影响机具通过性能和播种质量等问题,设计了一种浮动支撑式防堵装置,阐述了其工作原理,设计了主要工作部件,确定了其结构参数,并进行了田间性能试验。试验结果表明:安装有浮动支撑式防堵装置的小麦免耕播种机通过性能良好,符合农艺要求;与带状旋耕防堵装置相比,土壤扰动量减少约25%,油耗降低约7.04%。

条带式旋切后抛防堵装置设计与试验

针对我国华北平原一年两熟区玉米秸秆覆盖地小麦少免耕播种机易堵塞、动力防堵装置功耗大等问题,设计了一种条带式旋切后抛防堵装置。结合防堵装置工作原理,从秸秆流动、抛撒、防堵装置受力角度分析确定影响防堵性能和功耗的关键因素为:防堵装置与开沟器间距、旋切刀滑切角、刀轴转速;通过离散元模拟仿真与正交试验有限元仿真结合,以秸秆拥堵量和作业功耗为性能评价指标,对防堵单体和开沟器的组合装置进行参数优化,仿真结果表明,旋切刀滑切角为50°、刀轴转速为320 r/min、间距为100 mm时综合作业质量较优,防堵单体及开沟器功耗为2.8 k W,秸秆拥堵量为43根/dm,通过性能良好;对优选方案旋切刀进行有限元校核,其最大应力为1.387×108Pa,满足强度要求。在玉米秸秆覆盖地进行了小麦播种田间试验,结果表明,条带式旋切后抛防堵装置在3种秸秆覆盖量0.8、1.6、2.4 kg/m2和3种前进速度1、1.25、1.5 m/s作业条件下,通过性能均满足免耕施肥播种机国标要求,所设计旋切刀与传统旋耕刀相比,在通过性能基本一致的情况下,功耗减小13.83%,土壤扰动量减小37.5个百分点,沟深稳定性系数提高8.2个百分点。

轻型高防堵性能免耕播种机研究

以主动防堵的思路,提高国产免播机质量与尺寸受限情况下的防堵性能。先后研制出带状旋耕、条带粉碎和驱动圆盘3种主动防堵的轻型免播机,防堵能力强,能胜任高产玉米地免耕播种小麦,质量316～500 kg/m,与国产拖拉机匹配,价格为国外免播机1/8左右。田间对比试验表明,轻型主动防堵免播机动土量和动力消耗比国外免播机大一些,但在小麦出苗、长势和产量上优于国外机器。2006年推广近2万台,玉米地免耕播种小麦约40×10~4hm^2。