采棉头采摘装置的设计及试验

为小型自走梳齿式采棉机的采棉头设计了采摘装置,该采摘装置由10组带齿链条在采棉室内按一定规律分布而成,由链轮链条机构传动,单向回转。为研究该装置的齿片长度、齿片在链条上的排列方式、带齿链条的转速、采棉装置前进速度对采摘装置的采净率、籽棉含杂率和撞落棉损失率的影响,进行了单因素试验和多因素正交试验。试验结果表明：当齿片的长度为22 mm,齿片在链条上等间距对称安装,带齿链条的回转速度为100 r/min,采棉装置的前进速度为0.3 m/s时效果最好,采摘装置采收棉花的采净率为89.74%,籽棉含杂率为10.32%,撞落棉损失率为6.24%。     

水稻机收减损技术研究

通过大田试验研究了不同收获时期、不同留茬高度、1d内的不同收获时间和不同档位收割对稻谷机收损失率的影响。结果表明:2种机型均以稻谷85%成熟度时收割损失率最大,90%成熟度时收割损失率最小;不同留茬高度处理的机收损失率以40cm最高,20cm次之,lOcm最小;1d之内不同收割时间的机收损失率以7:00最高,l0:O0次之,14:00最低;不同档位作业处理的机收损失率均以高档最大,中档次之,低档最小。2种机型之间,在留茬高度大于20cm条件下半喂入式收割机机收损失率显著高于全喂入式收割机;在档位为高档条件下,全喂入式收割机的机收损失率显著高于半喂入式收割机。综合来看,应选择性能优良的国产或进口收割机在水稻成熟度为90%时及时收获,机收的适宜留茬高度为10cm,保持中低档行走速度于上午10:00以后进行收割。     

油菜毯状苗移栽机拨苗装置的设计与试验

针对2ZY-4型油菜移栽机人工投苗效率低、劳动强度大等问题,设计了一种油菜毯状苗自动拨苗装置,分析了影响油菜毯状苗拨苗伤苗率和漏拨率的主要因素,对拨苗角度、转速和基质含水率等影响因素进行了单因素和多因素正交回归试验。因素试验结果表明,当拨苗角度为55°~65°,转速为50~ 60 r/min,基质含水率为26.38%~28.56%时,拨苗装置能够满足农艺要求。多因素正交回归试验结果表明,影响伤苗率的因素大小依次为拨苗角度、转速、基质含水率;影响漏拨率的因素大小依次为拨苗角度、基质含水率、转速;当拨苗角度为64.05°、基质含水率为26.66%、转速为52.62 r/min时,伤苗率为5.49%,漏拨率为11.38%。因此,该试验表明,该拨苗装置能够满足农艺要求,并为后期设计一种4行全自动油菜毯状苗移栽机提供基础。     

油菜苗期性状与其稻茬免耕直播产量损失的关系

稻茬油菜免耕直播技术可减少用工,降低冬闲田面积,但其产量常低于翻耕栽培模式。为探讨免耕直播油菜产量制约因素,在盆栽试验条件下测定各品系苗期根冠比、抗旱性、耐渍性及氮肥利用率等生理指标,在大田试验条件下测定15个油菜品系免耕产量损失率,并比较苗期各生理指标与免耕产量损失率的关系。结果表明,(1)同一油菜品种成熟期性状表现、产量及其构成因素在不同栽培模式下的差异因品系而异;(2)与翻耕比,免耕栽培时地上部干重、经济系数或千粒重降幅小的品系产量损失率也小;(3)稻茬免耕直播油菜产量损失率与油菜苗期根冠比、抗旱性及耐渍性显著负相关,与苗期氮肥利用率显著正相关;(4)栽培管理上应选用苗期根冠比大,抗旱性、耐渍性强及苗期生长稳健的品种,抗旱防渍,平衡施肥可提高稻茬免耕直播油菜的生产效率。     

免耕栽培措施对稻田油菜生长及产量的影响

2007～2008年,在湖北省公安县和红安县试验基地开展了免耕栽培措施对油菜生长发育特征的影响研究,结果表明,油菜播种后旋耕盖草和留茬30cm+稻草覆盖处理出苗快,所有处理播种至出苗时间分别为5～7d和7～9d;油菜越冬期苗高、绿叶数、叶面积指数、开展度、地上部分干重和地下部分干重均为稻草覆盖处理高于对应的未覆盖处理;冻害指数以留茬30cm+稻草覆盖后最低,公安县的油菜大多数表现为0,1,2级冻害,红安县的油菜大多数表现为2级和3级冻害;旋耕盖草后产量最高,比留茬10cm不覆盖稻草处理分别增产13.20%和19.79%,达极显著水平.因此,油菜免耕留茬直播并覆盖稻草是有效的轻简化栽培措施.     

不同秸秆还田方式及施肥对小麦复种小油菜经济效益的影响

为了减少小麦秸秆焚烧、控制污染和提高田间留茬的利用效率,采用二因素随机区组设计,在甘肃河西绿洲灌区通过大田试验,研究了小麦留高茬收割后立茬、粉碎、焚烧3种秸秆还田方式及化肥减量施用（参照N 180 kg/hm2、P2O5 90 kg/hm2）对春小麦复种油菜经济效益的影响。结果表明,3种秸秆还田的措施与传统低茬收割比较,小麦、油菜的产量均有显著提高,其中小麦单产以麦茬粉碎还田处理最高,复种油菜单产以秸秆焚烧还田最高,总产值、劳动生产率以高施肥、麦茬粉碎还田的处理最高,分别达26752元/hm2和59.45元/工日,纯收益、土地净产率和产出投入比以麦茬焚烧还田、化肥减量15%的处理最高,分别达20346元/hm2、11346元/hm2和1.76。化肥减量15%时,各高留茬秸秆还田处理间作物产量和经济效益指标之间没有显著差异,证明在合理的秸秆还田措施保证条件下,化肥较当前高施肥水平降低15%在生产中是可行的。从提高经济效益、生态效益和保护环境的综合因素分析,在小麦复种油菜生产中推荐的方案是小麦留茬20~25 cm收割,旋耕粉碎还田后复种油菜。     

小麦高留茬田间水分效应研究

通过小区和大田试验,研究了留茬、灭茬和烧茬三种处理土壤、近地层空气温湿度的变化,比较了三种处理夏玉米生长发育状况,分析了小麦高留茬的田间水分效应。结果表明,留茬明显降低了土壤温度,测定日0cm地表温度全天内留茬都处于最低,其中10时到14时降温效果最明显,土壤5~25cm平均温度分别较灭茬和烧茬低1.45℃和2.3℃;土壤0~70cm含水量自始至终留茬高于灭茬和烧茬;留茬对近地层空气湿度的影响主要在晚上,麦秆凝结的水汽增大了空气湿度,白天留茬高度内气温低湿度较大,留茬高度外气温高湿度较小（与灭茬和烧茬相比）。留茬对夏玉米生长发育的影响主要表现在中后期,试验结束时留茬株高、茎粗均高于灭茬和烧茬,表现出较大的后劲。     

不同收获方式对油菜子粒损失、含油量及种植效益的影响

以川油36、华海油1号为供试材料,以全人工收获为对照,分析脱粒机分段收获、机械联合收获对油菜收获损失率、菜子含油量及种植效益的影响。结果表明,两个品种不同收获方式的总损失率均表现为机械联合收获>脱粒机分段收获>全人工收获;两个品种全人工收获均以田间晾晒损失率最大,占总损失量的95%以上,脱拉机分段收获均以脱粒损失率最大,占总损失量的70%以上;机械联合收获均以自然脱拉损失率最小,但川油36以割台总损失率最大,占总损失的66.80%,华海油1号以清选、脱粒总损失率最大,占总损失的56.79%。机械联合收获降低了两个品种油菜子含油量,但种植效益均表现为机械联合收获>脱粒机分段收获>全人工收获。因此,在成都平原等适合大型机具操作的区域及田块,收获方式应首先考虑机械联合收获;在丘陵山区及部分不适合大型机具田间操作的小田块,可考虑选取小型油菜脱粒机进行分段收获。     

免耕不同处理对土壤养分、土壤酶活性及燕麦产量的影响

通过设置免耕高留茬高覆盖、免耕低留茬高覆盖、免耕高留茬低覆盖、免耕低留茬低覆盖和常规耕作5个处理,研究旱作免耕不同留茬覆盖处理对燕麦田土壤养分、土壤酶活性及燕麦产量的影响,以期为当地燕麦生产实施免耕技术提供理论依据。结果表明,免耕留茬覆盖各处理均能显著提高土壤耕层中有机质、全量养分及速效养分含量;随燕麦生育时期的推进,土壤酶活性呈先升后降的变化趋势,免耕留茬覆盖能显著提高土壤脲酶、碱性磷酸酶、蔗糖酶和过氧化氢酶活性,其活性大小均表现为：免耕留茬覆盖处理显著高于常规耕作,免耕高覆盖处理显著高于低覆盖,免耕高留茬高于低留茬;免耕留茬覆盖处理对提高燕麦产量作用显著,其中免耕高留茬高覆盖产量最高,为2 111.4kg/hm ²,较常规耕作增产18.6%,其产量表现为：高留茬高覆盖>低留茬高覆盖>高留茬低覆盖>低留茬低覆盖>常规耕作。     

不同秸秆还田方式及施肥对春小麦复种小油菜产量和资源利用率的影响

为了减少化肥投入,控制秸秆焚烧污染,探求作物秸秆有效还田的技术途径,采用二因素随机区组设计,在甘肃河西绿洲灌区通过大田试验,研究了小麦留高茬收割后立茬、粉碎、焚烧3种秸秆还田方式及化肥减量施用(参照N 180 kg/hm2、P2O5 90 kg/hm2)对春小麦复种油菜的产量以及资源利用率的影响。结果表明,3种秸秆还田的措施可提高籽粒产量和水、肥、光能利用率。其中小麦单产以高施肥、麦茬粉碎还田处理最高,复种油菜单产以秸秆焚烧还田、化肥减量15%处理最高,分别达7444 kg/hm2和997 kg/hm2。小麦水分利用率以麦茬粉碎还田、化肥减量15%处理最高,油菜水分利用率以秸秆焚烧还田、化肥减量15%处理最高,分别达1.75 kg/m3、0.50 kg/m3。全年光能利用率和生育期光能利用率均以高施肥、麦茬粉碎还田处理最高,分别为0.68%、1.56%。氮肥利用率和磷肥利用率均以麦茬粉碎还田、化肥减量15%处理最高,分别为53.20%、50.01%。化肥减量15%时,各高留茬秸秆还田处理间作物产量、光能利用率和氮磷肥利用率之间没有显著差异,说明在合理的秸秆还田措施保证条件下,化肥较当前高施肥水平降低15%在生产中是可行的。从经济效益、生态效益和保护环境方面综合分析,小麦留茬25 cm收割,旋耕粉碎还田后复种油菜是最佳方案。     

油菜钵苗移栽机取送苗系统设计与验证

目前国内移栽机以半自动移栽机为主,取苗阶段需人工投苗,栽植由机械部件来完成,生产效率低、劳动强度大,为此,设计试制了由顶苗机构、横向送苗机构、纵向送苗机构等组成的油菜钵苗取送苗系统,并通过调速电动机驱动进行台架试验。试验结果表明,顶苗频率对横向送苗精度影响不大,统计在顶苗频率为70株/min时,横向送苗单次平均进给误差为±1 mm,纵向送苗单次平均误差为±2 mm,取苗成功率达到95%以上,满足设计要求。该研究可为全自动油菜钵苗移栽机的设计提供参考。     

4SY-2.2型油菜割晒机设计与试验

针对现有油菜割晒机铺放质量差,导致后熟时间不可控、后续捡拾损失大的问题,设计4SY-2.2型油菜割晒机,可实现油菜的分禾、切割、输送和铺放作业。对油菜茎秆在铺放台上和离开铺放台的运动过程进行分析,给出油菜茎秆能顺利被推送、抛出铺放台的条件。对油菜茎秆离开铺放台后的运动分析可知,油菜的铺放角与油菜本身的生物学特征、割晒机的结构参数和割晒机的运动参数有关。田间试验表明,割晒机作业后形成的油菜铺条整齐性和一致性较好,测得铺放角平均值48.4°,铺放厚度平均值511.6 mm,铺放宽度平均值797.8 mm,割茬高度平均值365.5 mm,铺放质量满足后熟条件和后续捡拾的作业要求。     

Reducing potential gene escape in time by appropriate post-harvest tillage—Evidence from field experiments with oilseed rape at 10 sites in Europe

Persistence of oilseed rapeseed in soil can result in weed problems but also reduce oil quality of following rape crops or result in unwanted gene escape which is particularly relevant in the context of genetically modified oilseed rape. In this paper data from 13 field experiments at sites in England, Austria and Germany are presented where tillage operations were tested that potentially reduce the build-up of a seed bank. In the majority of experiments seed losses were artificially simulated by broadcasting ca. 10,000 freshly ripened rapeseed m⁻² onto cereal stubbles. Oilseed rapeseedlings in autumn, the seed bank in winter–spring and yields of the following crop winter wheat were assessed as a function of tillage regime. During summer and autumn 19–70% of the seeds germinated and emerged. This part of the population was killed by following tillage operations or herbicide applications. However, 0–29%, in moist years 0–5%, of the initially broadcasted seeds developed dormancy and remained ungerminated in the soil until the following winter–spring.

Delaying incorporation of the seeds by leaving the stubble untouched for up to 4 weeks resulted in a reduced seed bank in almost every case. Also, repeated stubble tillage compared to an early single stubble tillage operation resulted in a smaller seed bank. The type of primary tillage (ploughing versus non-inversion cultivation) had no clear effect. No relation was found between the number of seedlings in autumn and the size of the seed bank the following winter–spring. Grain yield of the following crop winter wheat was not adversely affected by delayed stubble tillage.

The results indicate that stubble tillage aiming at a reduced seed bank of oilseed rape should focus on conditions avoiding induction of secondary dormancy rather than improving germination conditions. This means that, under the climatic conditions of central and western Europe, the stubble should be left untouched for several weeks after harvest before starting the usual tillage sequence with stubble tillage and ploughing or a non-inversion tillage sequence.     

Will breeding for nitrogen use efficient crops lead to nitrogen use efficient cropping systems?: a simulation study of G×E×M interactions

The benefits of improving nitrogen use efficiency (NUE) in crops are typically studied through the performance of the individual crop. However, in order to increase yields in a sustainable way, improving NUE of the cropping systems must be the aim. We did a model simulation study to investigate how improvement of NUE traits of individual crops affects the succeeding crops and the NUE of the crop rotation. Based on experimental results parameterization was altered for different types of improved NUE in the EU-Rotate_N model, e.g. through higher N harvest index, reduced litter loss or improved root depth penetration rate. The different ways of improving NUE have different effects on the cropping system, affecting either N uptake, the ability of the crop to hold on to N already taken up, or the fraction of crop N being harvested. Due to the different modes of action, the model simulations show that these changes in NUE traits will also have different effects on N leaching loss and on N availability and N loss in the following years. Simulations also show that the effect of genotypes with improved NUE depend on environment and crop management. This is true for the improved crop itself and when its effect is analyzed for the whole cropping system. The environmental conditions, crop choices and management will all affect the fate of the N left in the soil, and whether this will contribute mainly to leaching loss or be used for production in later crops. As an example, increasing pre-crop fertilization was shown to affect the leaching after the following oilseed rape crop with up to 50 kg N ha^?1 taken up before it was lost to the environment when pre-crop fertilization as well as root depth penetration rate was high. All in all, the simulations illustrate the concept of NUE as the result of interactions between genotype, environment and crop management (G×E×M).     

机播深度对油菜生长特性、收获性状的影响

为寻求机播油菜最佳播种深度,提高油菜种植水平,在大田设置0、30~35、50~55、70~75和90~95mm5个播深种植试验区,分别测定不同试验区内油菜苗成活株、生长特性、收获性能等指标,借助DPSv6.5软件对测定的各性能指标进行分析。结果表明：油菜苗的各项指标和油菜的收获性能与播种深度存在相互关系,播深为70~75mm时,播种后72天,单位面积成活株为81.5株/m2,多次多点试验测定结果为主根系平均长度为63.62mm/株、根系干物质平均质量为0.0732g/株、植株分枝水平生长长度为21.62mm、分支数为6.89个/株、植株平均倒伏角为19.33°、收获产量为2524.8kg/hm²。结果显示：播深为70~75mm试验数据均优于其他播深。由此可得,在机械化直播油菜时,以播深70~75mm为宜。该研究结论为油菜播种机械结构设计及配套种植农艺条件提供理论依据。     

油菜割捆机打捆部件的设计与试验

为了解决收割冬油菜与栽插早稻的季节矛盾,提前腾地抢插早稻,设计了一种油菜打捆装置,将该装置配置在4SY-2.2型卧式油菜割晒机割台的左侧,组成油菜割捆机。该打捆装置主要由机架、集禾压缩机构、送绳机构、打结器、捆结离合器、推出机构等组成,通过对送绳机构、集禾机构、放捆机构进行设计计算,确定了打捆装置的主要参数。虚拟样机运动仿真分析表明送线机构、打结器、放捆机构动作配合协调,8.95s完成一个工作循环。利用打捆装置样机进行打捆试验,结果表明装置成捆率为95％,油菜捆平均直径为382mm,油菜秆含水率67.5％时每捆平均重量为5.08kg。本研究为油菜的分段收获提供一种新的方案和配套机具。     

Population dynamics of volunteer oilseed rape (Brassica napus L.) affected by tillage

Volunteer plants of oilseed rape (Brassica napus L.) from persistent seeds in soil can affect subsequent crops. Apart from the agricultural disadvantages, the environment and the marketing of the seeds may also be affected, particularly if plants with special ingredients or genetically modified (gm) plants are grown. In order to investigate the influence of soil cultivation and genotype on seed persistence and gene flow via volunteers, a field experiment was set up testing four tillage treatments and two cultivars in a split-plot design. The cultivars tested were near-isogenic to two gm cultivars. To simulate harvesting losses, 10 000 seeds m⁻² were broadcast on a soil in July. The subsequent tillage treatments were combinations of immediate or delayed stubble tillage by a rotary tiller, primary tillage with plough or cultivator, or zero tillage. Over the following year, the fate of the seeds was determined. Immediate stubble tillage with following cultivator or plough resulted in 586 resp. 246 seeds m⁻² in the soil seed bank. After delayed stubble tillage with following plough, 76 seeds m⁻² were found, and no soil seed bank was built up in the zero tillage treatment. Nevertheless, in the zero tillage treatment, several robust volunteer plants survived the herbicide application before the direct drilling in autumn until following spring. In the zero tillage treatment and in the cultivator treatment, 0.19 volunteers m⁻² resp. 0.06 volunteers m⁻² flowered simultaneously to ordinarily sown oilseed rape in the following crop of winter wheat and produced 73 resp. 18 seeds m⁻². Delayed stubble tillage reduced the risk of gene escape via the soil seed bank, while zero tillage resulted in the highest risk of gene escape by pollen and by production of a new generation of seeds. In terms of a labelling threshold for gm food this number of seeds would be below the threshold of 0.9% of transgenic parts in conventially bred food or feed.