Characterization of Leaf Photosynthetic Properties for No-Tillage Rice

A study was conducted to determine the influence of no-tillage cultivation on leaf photosynthesis of rice plants under field conditions. Experiments with the treatments, no-tillage and conventional tillage were carried out at three locations （Jiaxing, Hangzhou and Xiaoshan, Zhejiang Province, China） for two years （2005 and 2006）. Grain yield was constant in Jiaxing, but slightly higher in Hangzhou and Xiaoshan under no-tillage cultivation than that under conventional cultivation. In comparison with the conventional cultivation, no-tillage cultivation showed less biomass accumulation before heading and higher capacity of matter production during grain filling. A significantly higher leaf net photosynthetic rate was observed for the plants under no-tillage than for those under conventional tillage. The fluorescence parameter （Fv/Fm） in leaf did not show any difference between the two cultivations. The effect of cultivation management on transpiration rate （Tr） and SPAD value of rice leaf was dependent on the location and year.

Effects of Subsoiling on Soil Moisture Under No-Tillage for Two Years

In order to improve the water use efficiency under conservation tillage, the effects of subsoiling on soil moisture under notillage were studied. An experiment of 40 cm subsoiling in a field kept under no-tillage for 2 years was operated from 2005 to 2006. Based on the data of the soil moisture and crop yield, the physical basis of subsoiling for water conservation and yield increase was analyzed. The results showed that the soil water storage under subsoiling, from the soil surface to a depth of 100 cm was more than that under no-tillage for the growth season. In the 0-100 cm soil depth, the soil moisture in 50-100 cm depth under subsoiling was more compared with no-tillage, which increased when it＇s drought and decreased when it＇s rainy with the increase in soil depth. Compared with no-tillage, subsoiling could reduce the water consumption of oats in the 0-50 cm depth and increase the water consumption in the 50-100 cm depth. Also, subsoiling increased the yield by 18.29% and the water use efficiency by 16.8% in a two-year average. The effects of subsoiling on water conservation and yield increase were affected by precipitation, and a well-proportioned rainfall was better to increase yield and water use efficiency. Meanwhile, subsoiling decreased bulk density, which increased with the available precipitation. Subsoiling under no-tillage is the effective rotation tillage to contain more soil moisture and improve water use efficiency in ecotone of North China.

Inter-annual changes in the aggregate-size distribution and associated carbon of soil and their effects on the straw-derived carbon incorporation under long-term no-tillage

Converting from conventional tillage to no-tillage influences the soil aggregate-size distribution and thus soil organic carbon （SOC） stabilization. However, the dynamics of soil aggregation and the straw-derived carbon （C） incorporation within aggregate fractions are not well understood. An experiment was established in 2004 to test the effects of two treatments, no-tillage with residue （NT） and conventional tillage without residue （CT）, on the soil aggregate-size distribution and SOC stabilization in a continuous maize （Zea mays L.） cropping system located in the semiarid region of northern China. Soil samples were collected from the 0-10 cm layer in 2008, 2010 and 2015, and were separated into four aggregate-size classes （〉2, 0.25-2, 0.053-0.25, and 〈0.053 mm） by wet-sieving. In each year, NT soil had a higher proportion of macroaggregates （i.e., 〉2 and 0.25-2 mm） and associated SOC concentration compared with CT. Additionally, to compare straw-derived C incorporation within NT and CT aggregate fractions, ^13C-labeled straw was incubated with intact NT and CT soils. After 90 days, the highest proportion of 13C-labeled straw-derived C was observed in the 〉2 mm fraction, and this proportion was lower in NT than that in CT soil. Overall, we conclude that long-term continuous NT increased the proportion of macroaggregates and the C concentration within macroaggregates, and the physical protection provided by NT is beneficial for soil C sequestration in the continuous maize cropping system in semiarid regions of northern China.

Effect of experimental warming on soil respiration under conventional tillage and no-tillage farmland in the North China Plain

Understanding the response of soil respiration to global warming in agro-ecosystem is crucial for simulating terrestrial carbon （C） cycle. We conducted an infrared warming experiment under conventional tillage （CT） and no-tillage （NT） farmland for winter wheat and summer maize rotation system in North China Plain （NCP）. Treatments include CT with and without warming （CTW and CTN）, NT with and without warming （NTW and NTN）. The results indicated that warming had no sig- nificant effect on soil moisture in irrigated farmland of NCP （P〉0.05）. The elevated average soil temperature of 1.1-116℃ in crop growing periods could increase annual soil CO2 emission by 10.3% in CT filed （P〉0.05）, but significantly increase it by 12.7% in NT field （P〈0.05）, respectively. The disturbances such as plowing, irrigation and precipitation resulted in the obvious soil CO2 emission peaks, which contributed 36.6-40.8% of annual soil cumulative CO2 emission. Warming would enhance these soil CO2 emission peaks; it might be associated with the warming-induced increase of autotrophic respiration and heterotrophic respiration. Compared with un-warming treatments, dissolved organic carbon （DOC） and soil microbial biomass carbon （MBC） in warming treatments were significantly increased by 11.6-23.4 and 12.9-23.6%, respectively, indicating that the positive responses of DOC and MBC to warming in both of two tillage systems. Our study highlights that climate warming may have positive effects on soil C release in NCP in association with response of labile C substrate to warming.

Growth Characteristics and Yield of Late-Season Rice under No-tillage and Non-flooded Cultivation with Straw Mulching

A long-term field experiment （started at 2003） was conducted to determine the effects of different dce cultivation methods on growth characteristics and grain yield of late-season rice under double-rice cropping system in seasonal drought region of southeast China （Yujiang County, Jiangxi Province）. The rice cultivation methods included no-tillage and flooded rice cultivation （N-F）, no-tillage and non-flooded rice cultivation with straw mulching （N-SM）, and no-tillage and non-flooded rice cultivation without straw mulching （N-ZM）. There was no significant difference in rice grain yield between the N-SM and N-F treatments. However, the rice grain yields in the N-SM and N-F treatments were significantly higher than that in the N-ZM treatment. The late-season rice plants in the N-SM treatment had significantly higher numbers of effective panicles and total grains per hill compared with those in the N-ZM treatment. The above-ground dry matter of late-season rice was similar between the N-SM and N-F treatments. Compared with the N-F treatment, the N-ZM and N-SM treatments significantly decreased the leaf area at the heading stage. Moreover, the N-SM treatment could significantly increase total root length and root tip number at the grain-filling stage compared with the N-ZM treatment.

Suppression of weeds and weed seeds in the soil by stubbles and no-tillage in an arid maize-winter wheat-common vetch rotation on the Loess Plateau of China

Reduced tillage provides ecological and economic benefits to arable land on the Loess Plateau of China, where soil erosion has long been a serious problem and soil water availability is largely restricted. However, high abundances of weeds in reduced tillage systems cause significant yield losses. In this study, we explored the effects of no-tillage and stubble retention on the number and density of weeds and weed seeds in a 12-year maize-winter wheat-common vetch rotation on the Loess Plateau. Four treatments including conventional tillage, no-tillage, conventional tillage＋stubble retention and no-tillage＋stubble retention were designed and applied. We found that no-tillage increased the number of weed species and weed density in most of the crops, while stubble retention decreased weed density in maize and tended to suppress weeds in both no-tillage treatments（no-tillage and no-tillage＋stubble retention）. No-tillage led to an increase in the number of weed species in the weed seedbank and tended to increase seed density during the spring growth of winter wheat, but it decreased seed density during post-vetch fallow. Stubble retention tended to reduce seed density during the spring growth of winter wheat and post-vetch fallow. We concluded that no-tillage can promote weeds in the experimental crop rotation, while stubble retention suppresses weeds in untilled fields. The combined effects of stubble retention and no-tillage on weed suppression varied among the three crops. Based on these results, we recommend stubble retention in untilled legume-crop rotations on the Loess Plateau to improve the control of weeds.

Long-Term No-Tillage Direct Seeding Mode for Water-Saving and Drought-Resistance Rice Production in Rice-Rapeseed Rotation System

To study the effects of long-term no-tillage direct seeding mode on rice yield and the soil physiochemical property in a rice-rapeseed rotation system, a comparative experiment with a water-saving and drought-resistance rice （WDR） variety and a double low rapeseed variety as materials was conducted under no-tillage direct seeding （NTDS） mode and conventional tillage direct seeding （CTDS） mode for four years, using the CTDS mode as the control. Compared with the CTDS mode, the actual rice yield of WDR decreased by 8.10% at the first year, whereas the plant height, spikelet number per panicle, spikelet fertility, 1000-grain weight, grain yield, actual yield, and harvest index increased with no-tillage years, which led to the actual yield increase by 6.49% at the fourth year. Correlation analysis showed that the panicle length was significantly related to the actual yield of WDR. Compared with the CTDS mode in terms of the soil properties, the pH value of the NTDS mode decreased every year, whereas the contents of soil organic matter and total N of the NTDS mode increased. In the 0-5 cm layer of the NTDS mode, the soil bulk decreased, whereas the contents of soil organic matter, total N, and available N increased. In the 5-20 cm layer of the NTDS mode, the available N and K decreased, whereas the soil bulk, contents of soil organic matter, and total N increased. In summary, the NTDS mode increased the rice yield, and could improve the paddy soil fertility of the top layer.

No-tillage effects on grain yield and nitrogen requirements in hybrid rice transplanted with single seedlings: Results of a long-term experiment

This study was conducted to determine whether,and if so how,the grain yield and nitrogen(N) requirements of hybrid rice transplanted as single seedlings are affected by no-tillage(NT) practices.A fixed field experiment was done at the Experimental Farm of Hunan Agricultural University in Changsha,Hunan Province,China,from 2004 to 2014.Grain yield and yield attributes(panicle number per m2,spikelet number per panicle,spikelet filling percentage,grain weight,total biomass,and harvest index) were evaluated as well as the N-use characteristics(total N uptake,internal N-use efficiency,and N requirements) of hybrid rice transplanted as single seedlings comparing NT with conventional tillage(CT).A significant finding was that there were no significant differences in grain yield,yield attributes,and N-use characteristics between CT and NT.Averaged across the 11 years,grain yield and N requirements were 9.51 t ha^(-1) and 20.2 kg t^(-1) under CT and 9.33 t ha^(-1) and 20.0 kg t^(-1) under NT,respectively.There were significant yearly variations in grain yield,yield attributes,and N-use characteristics observed under both CT and NT.The yearly variation in grain yield was related to simultaneous changes in spikelet number per panicle,grain weight,total biomass,and harvest index.Also,it was found that grain yield was positively correlated with internal N-use efficiency but negatively correlated with N requirements.It is concluded that grain yield and N requirements in hybrid rice when transplanted as single seedlings are not affected adversely by NT.The results of this study suggest that(1) compatible relationships among yield attributes can be established in hybrid rice that is transplanted as single seedlings,and(2) higher grain yield and higher N-use efficiency can be concurrently achieved in hybrid rice transplanted as single seedlings.

Physiological Mechanism of High and Stable Yield of No-tillage Cast-transplanted Rice

Four years' successive comparative experiments showed that no-tillage cast-transplanted rice (NTCTR), compared with conventional tillage cast-transplanted rice (CK), grew slower and produced less tillers at the early growing stage; but, it had shorter ineffective tillering time, less nutrition consumption, stronger individual growth and more uniform growth between individuals and the colony. These characteristics contribute to the increase not only in the productive tiller percentage but also in the ear quality. Furthermore, the flag leaf of NTCTR had higher photosynthetic rate during the filling stage and no early senescence phenomenon at the late stage, which facilitated the accumulation and the transportation of carbohydrates and improved grain setting rate.

Effects of Five Years Adoption of No-Tillage Systems for Vegetables Crops in Soil Organic Matter Contents

Vegetables productions systems are done normally with intense soil tillage causing a strong decline of soil quality. Use of conservation systems can be an alternative to recover this quality. In order to evaluate the effects of such systems on soil organic matter, an experiment has been conducted in randomized blocks design and factorial scheme 3 × 2: three soil management systems (no-tillage;reduced tillage and conventional tillage) and two cover crops (maize single;and intercropping maize with gray velvet bean—Stizolobium niveum);and repeated measures over time. Soil samples were collected before the implementation of the experiment and at the end of each crop cycle until the fifth crop cycle. Carbon associated with humic substances is also determined in 0 - 5 cm, 5 - 10 cm and 10 - 30 cm at the end of the last crop cycle. The SOM content was higher in RT (48.34 g·kg-1) than in the CT (39.48 g·kg-1) at the end of the fifth crop cycle. SOM content in NT (44.92 g·kg-1) was statistically equal to RT and CT, during the same period. In 0 - 5 cm, carbon contents associated to the humic substances present the same behavior of SOM contents in 0 - 10 cm. Probably these results are associated with the capacity of each system to improve superficial contents of SOM stable fractions. It follows that the conservation systems used are alternatives to the cultivation vegetables in order to improve soil organic matter contents.

盐碱地肥沃耕层构建水肥盐综合调控机理与技术研究进展

盐碱地是我国重要的后备耕地资源,我国历来高度重视盐碱地的改良和利用工作,但目前盐碱区淡水资源短缺严重制约了盐碱地的改良利用。如何在水资源约束下,优化调控土壤水肥盐动态是当前盐碱地可持续利用中亟待解决的关键科学问题。近年来,大量研究利用有机培肥、耕作、节水灌溉、田间覆盖、咸水利用等农艺措施,在盐碱地建立“控盐、保肥、保水”的肥沃耕作层,显著改变了水肥盐在土壤-植物-大气连续体中的运移过程,实现了盐碱地质量和产能快速提升,上述内容也日益成为盐碱地改良利用中的重要研究方向。本文系统总结了盐碱地改良和肥沃耕层构建等方面的研究进展,并针对盐碱地肥沃耕层构建下土壤水肥盐综合调控及其与植物生长的协同关系等进行了展望,以期为盐碱地可持续改良利用提供参考。

不同耕作方式对砂姜黑土孔隙结构特征的影响

砂姜黑土黏闭僵硬问题突出,耕作是改良其结构的重要措施之一。基于安徽龙亢农场砂姜黑土耕作试验基地,采集免耕(No-tillage,NT)、旋耕(Rotarytillage,RT)和深翻(Deepploughing,DP)处理的原状土柱(高20cm,直径10cm),利用X射线CT扫描技术和ImageJ软件等对土壤孔隙结构进行三维重建和可视化处理,定量分析不同耕作方式对土壤孔隙度、孔径大小分布、孔隙形态特征、网络特征以及土壤饱和导水率的影响。结果表明:(1)与免耕相比,旋耕和深翻下土壤的大孔隙度分别增加了192.7%和261.1%(P<0.05);与旋耕相比,深翻下土壤大孔隙度增加了23.4%;(2)相较于免耕,旋耕和深翻显著增加了土壤孔隙的水力半径、紧密度、分形维数和全局连通性(P<0.05),显著降低了各向异性程度和欧拉数(P<0.05),土壤饱和导水率得到显著提升,且深翻的改良效果总体优于旋耕;(3)相关分析表明土壤饱和导水率与除水力半径外的孔隙结构特征参数均存在显著相关(P<0.05),其中与连通性最大孔隙度的相关性最高(r=0.833**,P<0.01)。综上所述,深翻扩大了土壤孔隙的水力半径,改善了连通性,提升了复杂程度,从而构建了相对良好的土壤孔隙形态和网络结构,提高了导水能力,消减砂姜黑土结构性障碍效果显著。

耕翻深度对阴山北麓地区马铃薯根系生长及土壤酶活性的影响

为探究耕翻深度对阴山北麓地区马铃薯根系生长及土壤酶活性的影响,分析了4个耕翻深度20 cm(D_(20),CK)、30 cm(D_(30))、40 cm(D_(40))、50 cm(D_(50))对马铃薯根干物质积累量、根系活力以及土壤过氧化氢酶、碱性磷酸酶、脲酶、蔗糖酶活性的影响。结果表明:较D_(20)和D_(30)处理,深翻D_(40)和D_(50)处理可显著提高根系活力,促进淀粉积累期马铃薯根系干物质积累,分别提高了75.2%~292.1%和23.4%~30.2%。通过土壤酶活性分析,深翻(D_(30)、D_(40)、D_(50)处理)对马铃薯田中过氧化氢酶、蔗糖酶活性影响不明显,但对碱性磷酸酶与脲酶活性影响较大。深翻可提高马铃薯全生育期0~20 cm土层及苗期20~60 cm土层中碱性磷酸酶活性,其中在块茎膨大期至淀粉积累期0~20 cm土层与苗期40~60 cm土层中D_(40)和D_(50)处理影响显著。深翻D_(30)、D_(40)、D_(50)处理分别显著提高了0~20 cm土层中整个生育期、块茎膨大期和淀粉积累期、淀粉积累期的脲酶活性;同时还提高了20~60 cm土层中脲酶活性,其中D_(40)和D_(50)处理显著提高了33.8%~80.0%。综上所述,深翻30 cm仍旧是马铃薯根系生长的胁迫深度,深翻40 cm对促进马铃薯根系生长、提高马铃薯田土壤碱性磷酸酶与脲酶活性效果最佳。

不同耕翻深度对土壤养分及水稻产量的影响

[目的]了解不同耕翻深度对引黄灌区农田土壤蓄水保墒、养分及作物产量的影响,探寻能充分营造水、肥、气等水稻良好生长环境的合理耕翻深度,以期为引黄灌区水稻合理耕层构建及作物高产栽培提供理论参考。[方法]采用完全随机设计,设置3个耕翻深度处理,分别为耕翻22~25 cm、耕翻30~32 cm、耕翻38~42 cm,研究不同耕翻深度对土壤容重、含水率、土壤养分、水稻产量的影响。[结果]在不同耕翻深度下土壤含水率整体表现在耕翻30~32 cm处理下较高;土壤容重在0~10 cm土层下以耕翻22~25 cm处理较低,在20~40 cm土层下以耕翻30~32、38~42 cm处理较低,且耕翻30~32 cm处理显著低于38~42 cm处理;有机质、有效磷和速效钾含量在0~20 cm土层以耕翻30~32 cm处理较高,在20~40 cm土层以耕翻38~42 cm处理较高;水稻产量耕翻30~32 cm处理显著高于耕翻22~25和38~42 cm处理;通过主成分综合评价得到耕翻30~32 cm处理>耕翻38~42 cm>耕翻22~25 cm。[结论]不同耕翻深度可影响耕层土壤结构及土壤养分,进而影响土壤的蓄水保温效应,促进作物生长和产量提高,在该地土壤条件下耕翻30~32 cm处理对土壤的综合改善效果最佳,水稻产量较高。

花生连作土壤土层置换式深翻犁的设计与试验

针对目前花生连作导致花生减产的问题,设计研制了土层置换式深翻犁。重点对土层置换式深翻犁的翻转机构进行机械设计和运动分析,对犁体曲面进行了理论分析和受力分析。为验证土层置换式深翻犁的作业性能,以犁铧安装角、耕宽、作业速度为试验因素,以耕深变异系数、植被残茬覆盖率和翻垡率为性能评价指标,进行三因素二次旋转正交组合田间预试验,得到各因素的响应曲面模型,分析了各因素对性能的影响,并以耕深变异系数最低、植被残茬覆盖率最高和翻垡率最高为目标对各因素进行优化。最优结果为:犁铧安装角为25.58°、耕宽为526.01mm、作业速度为5.82 km/h时,耕深变异系数为3.35%、植被残差覆盖率为93.95%、翻垡率为94.39%。以最优结果为基础,对作业速度设置5个梯度进行田间验证试验。验证试验结果表明,当土层置换式深翻犁以最优犁铧安装角、耕宽作业时,各个速度梯度下耕深变异系数均小于4%、残茬覆盖率均大于90%、翻垡率均大于90%,满足翻转犁作业质量要求。连续两年应用土层置换式深翻犁对连作花生地进行增产效果试验,试验结果表明,2022年花生产量比对照组增产21.2%,2023年增产16.9%,增产效果显著。本研究可为连作花生大面积单产提升提供技术支持。

基于离散元的棉田仿生减阻犁体设计与试验

针对当前铧式犁在棉田土壤犁耕作业过程中易黏附、阻力大、能耗高等问题,立足两种典型棉田土壤,以犁体、棉田土壤和两者之间的相互作用为研究对象,提出犁体曲面模型优化和表面结构仿生相结合的方法。以穿山甲体表的鳞片三角圆弧状结构和蜣螂体表的凸包结构相结合作为仿生原型,研制一种棉田仿生脱附减阻犁体,分别对两种棉田土壤的物理和化学特性进行试验测定并建立离散元模型。进行传统犁体与仿生犁体的耕作过程仿真与试验,在1号土样中仿生犁体相对传统犁体减阻5.4%,土壤减粘性能提升44.15%;在2号土样中仿生犁体相对传统犁体减阻7.8%,土壤减粘性能提升45.49%,研究结果表明仿生犁体对棉田土壤减粘降阻效果明显。

汉晋南朝南方地区铁犁牛耕的形制演化和推广使用

通过整理目前所见汉晋南朝南方地区出土的铁犁和牛耕画像石以及内部配置铁犁牛耕的水田模型,佐之必要的文献资料,本文对汉晋南朝南方地区铁犁牛耕的形制演化和推广使用情况进行分析。研究发现:南方地区铁犁牛耕技术历经两汉时期的“二牛抬杠”式长辕犁到两晋南朝时期的“单牛挽拉”式短辕犁的形制演化过程,呈现出曲轭、绳索牵引耕犁等“软配套”技术特征,有利于南方水田耕作。南方地区铁犁牛耕推广程度有限且存在区域差异,并以豪强庄园地主为使用主体。汉晋南朝南方耕犁与唐代曲辕犁和农业组织方式的关系值得进一步探讨。

旱地小麦产量和水分利用对翻耕时间和降水量及其分布的响应

【目的】针对山西省麦区降水年际变化大,休闲期降水占比高、生育期降水少且分布不均,造成雨养旱地小麦年季间产量波动大、降水水分利用率(WUE)低等问题,探寻不同降水年型下旱地麦田休闲期翻耕时间对土壤蓄水量和产量的影响,为山西南部旱地小麦根据降水型“定产”提供理论依据。【方法】2010—2021年度,通过田间区组试验,设8月10日(P1)、8月20日(P2)和8月30日(P3)左右3个翻耕时间,研究翻耕时间、降水量及其分布对旱地小麦产量、休闲期土壤蓄水特性和生育期耗水及相关性的影响。【结果】(1)旱地小麦产量受降水年型、休闲期和生育期降水共同影响,且年型>休闲期>生育期。试验年度平均产量2400.0—6298.0 kg·hm^(-2),年季间变异系数为29.8%,其中丰水年(2012、2014和2015年度)、平水年(2011和2013年度)和枯水年(2010、2016、2019、2020和2021年度)平均产量分别为5524.6、3048.2和4088.7 kg·hm^(-2);休闲期降水量和生育期降水分布主要通过成穗数和穗粒数影响产量,年度和3—4月降水多则产量明显增加;翻耕时间对旱地小麦产量影响与休闲期降水分布密切相关,7—8月降水多,P1产量高,9月降水多,则P2或P3产量高。(2)降水量及其分布和翻耕时间共同影响播种前和收获期土壤蓄水特性。休闲期降水主要影响播种前和收获期下层(100—200 cm)土壤蓄水量;休闲期丰水型播前上层(0—100 cm)和下层土壤蓄水量相近或略低,平水型和枯水型则下层低于上层,分别比上层低6.17%和24.66%;7月降水多有利于下层土壤多蓄水,8—9月降水多有利于上层土壤多蓄水;生育期降水主要影响收获期上层土壤蓄水量,尤其是5月降水;播种前和收获期上层土壤平均蓄水量P2最高,收获期下层和0—200 cm土壤平均蓄水量P2或P3最高。(3)耕作时间和降水量对生育期耗水量和水分利用率影响相对较小,年度降水多则旱地小麦生育期耗水多,3月降水对生育期耗水量影响大。【结论】休闲期降水量及其分布影响旱地小麦播前0—200 cm土壤蓄水量,并与3—4月份降水量共同作用影响成穗数、穗粒数和旱地小麦产量,且水分利用率与旱地小麦产量间呈显著正相关。山西南部7—8月降水多旱地麦田于8月10日前后翻耕,降水少时则翻耕时间推迟10—20 d,可增加播种前土壤蓄水量使旱地小麦实现增产。

犁体阻力离散元仿真分析

为验证离散元法分析犁体耕作阻力的可靠性,利用离散元仿真对犁体阻力进行分析。通过多组参数的仿真试验,获得在不同含水率土壤条件下进行不同耕深的犁体牵引阻力数据。结果表明,犁体的土壤耕作阻力随着土壤含水率与耕深的增大而增大,与田间耕作结果一致,证明了离散元法分析犁体土壤耕作阻力的可行性,为犁铧的耕作模拟仿真研究提供一定参考。

Reducing Operation Emissions and Improving Work Efficiency Using a Pure Electric Wheel Drive Tractor

In response to the problems of excessive greenhouse-gas and particulate emissions and the low traction efficiency of conventional diesel tractors in the field,a purely electric wheel-side drive tractor was studied,including an electric motor drive system,a battery ballast system,and an electro–hydraulic suspension system.This paper develops a dynamics model of an electric tractor-ploughing unit under complex soil conditions,leading to the proposal of an active control method for drive wheel torque and a joint control method for the traction force of the suspension system and the front-and rear-axle loads of a tractor.Finally,the tractor is prototyped and assembled,and ploughing tests are carried out.The ploughing results show that the active torque-distribution control method proposed in this study reduces the tractor slip by 14.83%and increases the traction efficiency by 10.28%compared with the average torquedistribution mode.Compared with the conventional traction control mode,the joint control method for traction and ballast proposed in this paper results in a 3.7%increase in traction efficiency,a 15.05%decrease in slip,and a 4.9%reduction in total drive motor energy consumption.This study will help to improve the operation quality and traction efficiency of electric tractors in complex soil conditions.