Conservation tillage is a technology regarding sustainable agricultural development, which features less or no tillage and crop stubble covering and has brought significant economic, environmental, and social benefits to China’s agricultural production. As agricultural production in China develops toward the directions of large scale, high efficiency, and intelligence, promoting the development of conservation tillage becomes conducive to cultivated land protection, grain supply security, and agricultural technology improvement. This study reviews the development process of conservation tillage in China from the aspects of research and development of conservation tillage technologies and equipment, demonstration and ability construction, and utilization of black soil in Northeast China. It also summarizes the development status of conservation tillage technologies and equipment in China, involving representative technical models and key machines for surface straw and stubble treatment, shallow soil tillage, and no- or less-tillage sowing. The major factors that affect the development of conservation tillage in China are analyzed, including suitable model and equipment, support of laws and policies, and drive of large-scale planting households. Furthermore, suggestions are proposed to promote the rapid and stable development of conservation tillage in China. First, a national science and technology innovation platform should be built and high-standard demonstration projects should be implemented by counties. Second, national action plans on conservation tillage should be implemented to strengthen policy guidance. Third, publicity of conservation tillage should be further strengthened.

一、我国蔗糖产业逐年萎缩,甘蔗生产人工成本高企是主要原因 我国甘蔗种植区域主要集中在广西、云南、广东和海南4省(区).根据国家统计局数据, 2019/2020年全国甘蔗种植面积1931万亩,甘蔗产量10482万吨,蔗糖产量1072万吨,其中广西甘蔗种植面积、甘蔗产量、糖产量分别占到全国的68％、70％、63％以上.

The mode transformation of agricultural production is a common concern for China and worldwide.Currently, the level of mechanization has been significantly promoted for the agriculture sector in China and smart production becomes an inevitable trend for modern agriculture.Smart agriculture regards data, knowledge, and intelligent equipment as the core elements and integrates modern science and technology with agriculture to realize digital perception, intelligent decision-making, precise operation, and smart management in the entire process of agricultural production, thereby greatly improving labor productivity, resource utilization rate, and land output rate.This article presents the current status of agricultural production in China using rice production as an example, and analyzes the necessity, opportunities, challenges, directions, and route for the intelligent transformation of China's agriculture.Furthermore, we propose policy suggestions to promote the intelligent development of China's agricultural production, including (1) strengthening the research and innovation system for agricultural machinery, (2) improving the agricultural machinery promotion system, (3) optimizing the socialized service system for agricultural machinery, and (4) accelerating the construction of smart agriculture demonstration zones.

分析了我国现有"剥叶去梢"整秆式联合收获机存在的问题,介绍了带叶带梢整秆甘蔗进糖厂压榨试验出现的入榨作业故障率高、生产能力下降、出榨糖汁质量达不到标准要求的情况.通过对比分析,在发挥割铺机高效低成本的基础上,配套可实现田间净秆除杂的剥叶机,提出了推广"整秆割堆+田间除杂"分步式机械化收获方式的建议.

介绍了"十三五"期间以及"十四五"开局之年我国甘蔗机收情况,从劳动力短缺、机收综合效益、农机农艺融合、糖企-机企-蔗农系统协调和糖企的核心作用等方面分析了我国甘蔗机收推进缓慢的原因,提出建立以糖厂为核心的"糖机农"融合机制,加快加深农机农艺融合,提高农机适用性和可靠性,是打破我国甘蔗机收发展缓慢的有力抓手.

分区域、分产业、分品种、分环节分析我国棉油糖蔬果茶药等8个主要经济作物生产机械化发展新情况、存在的短板不足,提出当前和今后一段时期的主攻方向和主推技术.结果 表明,与2020年相比,预计2021年棉花、油菜、花生、甘蔗、蔬菜、茶叶、中药材综合机械化率分别提高2.7个百分点、3.4个百分点、3.6个百分点、1.9个百分点、4个百分点、1.8个百分点、2.5个百分点,仅有林果提高不到1个百分点.需关注的问题主要有,全国还有超过1000 khm2的棉花、超过1000 khm2的甘蔗、超过1800 khm2的花生未实现机收,超过4200 khm2的南方冬闲田需要扩种油菜;蔬果茶药生产机械化还处于起步阶段,无机可用、有机不好用的问题还比较突出;南方与丘陵山区农田条件不宜机,传统种植模式不宜机,国产机具作业质量和可靠性有待提升;棉花花生残膜污染严重.提出当前和今后一段时期各经济作物机械化主攻方向和主推技术,如国产采棉机质量提升与残膜高效回收,油菜宜机化品种选育与联合机械作业,夏花生免膜种植与高效清洁收获,甘蔗低含杂收获与制糖工艺改制,典型蔬菜品种标准化种植与高效收获,果园茶园宜机化标准建园和管理,中药材重点品种生产机械定制化研发等.

糖料甘蔗是我国南方重要的经济作物之一,甘蔗产业的可持续发展关系到我国食糖的战略安全.本文建议以《国务院关于加快推进农业机械化和农机装备产业转型升级的指导意见》(国发〔2018〕42号)为依据制定我国甘蔗机械化"十四五"发展规划目标.从种植业生产系统、甘蔗糖业系统、甘蔗生产系统和甘蔗收获系统4个层次分析了甘蔗产业可持续发展与甘蔗生产机械化应注重解决的问题.提出应以全程机械化为手段,推进甘蔗间套种技术,稳定高地租下的甘蔗种植面积;以甘蔗糖业副产品综合利用和产业链延伸促进当地的经济发展和甘蔗糖业的可持续发展;通过"二步法"糖企配置和糖厂原料蔗除杂装置应用实现机收蔗无障碍进厂;通过构建"糖企—机企—农企"系统运行机制实现甘蔗糖业系统协调运行;以蔗田规划、农机农艺融合等措施保障甘蔗全程机械作业顺利实施;以农企、机企适度规模经营促进甘蔗生产良性发展等几个方面推进甘蔗生产机械化和甘蔗产业可持续发展.

自2017年农业部等四部委联合推进甘蔗全程机械化“五大行动”实施以来,经过三年的努力,甘蔗机械化基本解决了“无机可用”的问题,工作重心由解决收获机械短缺转变为协调产业链各方利益.换句话说,当前的主要矛盾是,在糖企与农户、机收服务组织之间,建立新的利益分配关系,即化解“工、农、服”之间的矛盾,“工”为糖企,“农”为蔗农,“服”指机收服务组织.

甘蔗是我国制糖的主要原料,目前甘蔗生产机械化水平远远落后于其他主要农作物,因此甘蔗生产机械化发展得到国家高度重视.本文从甘蔗生产机械化水平和所需主要机具发展情况等方面综述了我国甘蔗生产全程机械化的发展现状,指出我国的甘蔗种植区域主要是丘陵山区,应以发展中型全程机械化为主、大型全程机械化为辅.分析了甘蔗全程机械化发展迟缓的原因,对如何协调利益共同体、推进农机农艺融合技术研发和试验示范、建立适用的土地流转制度、加强完善社会化服务体系建设等问题提出了建议.

广东是农业大省,近年来随着人口增加和农村经济快速发展,农业面源污染形势十分严峻.广东省承担的世界银行农业面源污染治理项目中的水稻保护性耕作项目,设计免耕和少耕机插秧、免耕和少耕直播4种主要模式,投入50多台(套)农业机械,经过7个试验点5年的试验,结果表明,在全程机械化条件下的保护性耕作,通过采用先进适用的农业机械,农机农艺结合,合理使用化肥农药,减少作业量、人工以及化肥农药等物资投入,可达到减少面源污染的目的,提高农业生产效益.广东开展水稻保护性耕作有重要意义.

为了研究扶蔗机构的工作性能,优化扶蔗器结构参数设计,建立了运动学模型.使用SolidWorks,设计两段圆锥式螺旋扶蔗机构虚拟样机,应用ADAMS仿真工具,进行了运动学及力学仿真试验及高速摄影试验验证.结果表明:输送段安装角为30°～60°范围内,甘蔗不跌落;输送段安装角为60°,甘蔗扶起到最高点为4.1s,效率最高;螺旋倾角为45°时,甘蔗均匀受到螺旋叶片的作用力,无跌落现象;螺距有效范围为270～290mm,螺距为285mm时,受力情况以及扶起变化最稳定,扶起效果最好.

为了更好地研究甘蔗收获机的功率消耗,利用ADAMS软件针对甘蔗收获机关键部件—物流排杂装置进行了虚拟试验和验证试验,该装置主要由喂入、上输送、下前输送、剥叶和下后输送滚筒等组成.在最佳参数组合下以扭矩为试验指标,分别进行了喂入、输送、剥叶、风机外圈和杂质分离等滚筒转速的单因素试验,虚拟试验结果表明,各对滚筒的扭矩分别为127.51 N·m、103.61 N·m,根据虚拟试验结果进行了验证试验,验证试验结果表明,剥叶滚筒转速为1 300r/min时,扭矩为14 N·m.其余滚筒转速为100r/min时,喂入滚筒扭矩为9N·m,上输送滚筒扭矩为9N·m;下前输送滚筒扭矩为13N·m;下后输送滚筒扭矩为65N·m.在各部件中,剥叶滚筒所受的扭矩最大,与虚拟试验结果一致.

目前甘蔗种植时的作业质量、作业行距主要依靠机手经验控制,易造成行距不均匀及漏播等问题.为提高甘蔗田间种植均匀性,在甘蔗种植机上安装GPS信号接收机及光幕传感器,开发了甘蔗种植机田间作业监测系统,实时监测甘蔗田间作业行内漏播及种植机作业的行间均匀性.为测试定位数据的准确性和稳定性进行了标定试验,试验结果表明,定位数据的横向跟踪误差最大值平均为0.030 7 m,平均值为0.010 6 m,标准差为0.010 1 m,满足甘蔗种植辅助导航的精度要求.田间试验表明,该系统漏播率与实际漏播率基本一致,单芽段甘蔗种植机在转速40 r/min、车速2.26 km/h时的播种均匀性最好.该系统可进行路径规划,实时监测车辆动态、回放作业路径和种植质量图,对甘蔗种植管理提供可靠依据.

颗粒悬浮速度是选用风力清选与除杂方法的主要依据.切段甘蔗混合物主要包含蔗段、蔗梢和蔗叶,通过自制的测量装置,对这3种成分的悬浮速度进行分析与测量.结果表明:蔗叶悬浮速度随着长度增加、含水量升高及宽度增加而提高;蔗梢的悬浮速度与蔗段的悬浮速度存在交叉,通过风力除杂只能去掉蔗叶和部分蔗梢.试验结果可为切段式甘蔗联合收割机的除杂系统设计提供一定的理论参考.

通过自制的测试装置,借助高速摄像对垂直管流中的蔗叶松弛时间进行研究.结果表明,蔗叶松弛时间随蔗叶长度增加逐渐降低,随气流速度的增大,蔗叶松弛时间逐渐减小.

Positioning of rice seedlings is an important step of mechanical intra-row weeding.Aiming to minimize the positioning errors based on canopy of rice,a system that could capture RGB images of rice stem base on the side view was built to position the rice seedlings according to edge fitting in separated region of the stem base.Firstly,relevant factors,including the morphology of rice seedlings,the installation parameters of camera on the side-view and affecting image quality were analyzed,and a method of grabbing image under shading conditions was proposed,contributing to a system with shading device.The original RGB images were distinguished from soil by analyzing the excessive green (2G-R-B) rice seedlings index images.The Otsu algorithm method was employed to transform a gray image to a binary image,and then the binary images were smoothed by morphological operation to remove noise for subsequent analysis.After that the edges of stem base were extracted by the Canny operator,and the fitting region of edges was set up.A method was presented in fitting region based on edge fitting in nonseparated region of the stem base.However,the results showed that this positioning method was not accurate because of effect of unsmooth and unilateral sloping edges of stem base.Therefore,the fitting region was separated into three subintervals where the edges of stem base were fitted by the Hough transform.The center of rice seedlings was gained by the center coordinates of the mid-line fitted by the mean of midpoint coordinates of fitting edges.The positioning experiments of rice seedlings in terms of stem base and the canopy were carried out respectively.The results of positioning based on stem base showed that the positioning errors were less than 7.0 mm,and the positioning errors were 6.9 mm,5.9 mm and 6.3 mm under the condition of including water and 6.8 mm,5.8 mm and 6.5 mm under the anhydrous condition on the 10th,15th and 20th day after transplanting,respectively.The results of positioning based on canopy showed that the positioning errors were above 8.0 mm,and the positioning errors were 8.2 mm,11.3 mm and 15.4 mm under the condition of including water and 9.0 mm,10.7 mm and 16.1 mm under the anhydrous condition on the 10th,15th and 20th day after transplanting,respectively.The results suggested that the innovative positioning method that based on edge fitting in separated region of the stem base of rice seedlings met the technical requirement of mechanical weeding in terms of high precision and long applicable period.

In order to settle the current problems in sugarcane mechanic field transportation, road transportation and dis-charge at sugar refinery mill system,such as unreasonable scheduling and vehicle configuration,and serious affect the de-velopment of sugarcane mechanization,taking Guangqian company of Zhanjiang state farms as an example, building opti-mization model with non-linear programming,and simulating by extend Sim software. After the logistics system optimized, the results show,it achieved good results in saving transport vehicle investment,reduce transport costs and shorten the sugar harvest time,and promoting the development of mechanization of sugarcane harvesting.

甘蔗尾茎的物理力学特性对于解决甘蔗断尾位置难以控制、断尾误差大这一关键技术难点具有重要意义，促进了甘蔗收获机械化的发展。利用自制的夹具，采用悬臂梁弯曲方法研究甘蔗尾茎在弯曲载荷下的力学特性。试验结果表明，蔗尾节位对抗弯强度、弯曲弹性模量的影响极显著，抗弯强度、弯曲弹性模量均随节位数值的增大而增大，由中部向尾部顶端生长点方向减小，呈二次曲线高度正相关关系；蔗尾生长点以下1～5节与6～9节的抗弯强度差异极显著，在1～5节处施加弯曲载荷，蔗茎容易断裂，断面光滑整齐；蔗尾生长点以下第5节处的抗弯强度平均值为9．40 MPa，标准误差为0．46 MPa，弯曲弹性模量平均值为55．85 MPa，标准误差为4．86 MPa。

针对整秆式联合收获机机械收获后甘蔗夹杂物中青叶多、茎秆尾梢部分过长等问题，对国内外甘蔗尾梢部位确定及断尾机构现状进行深入分析，分析表明，断尾位置控制、紧密包裹尾部叶鞘的撕裂剥除是当前阻碍断尾除叶技术发展的2个关键技术难点，确定符合农艺要求又适合机械断尾的断尾位置，设计相应的断尾机构，对推动甘蔗收获机的发展有着积极和重要的意义。

In order to obtain the mechanical characteristic parameters of sugarcane tail stalk, tensile and compression tests were conducted in the accurate micro-controlled electronic universal testing machine.The results indicated that sug-arcane tail node had extremely significant effects on the tensile strength and the compressive strength which decreased from the middle to the tail apical growing points, the results also showed that the average values of tensile strength of 1~3 nodes below the tail apical growing points were 1.44,2.87,4.72MPa,respectively, and their average values of tensile modulus of elasticity were 22.02,27.60,37.09MPa, respectively;It was quadratic function negative correlation between the diameter and the tensile strength of each nodes in the tail, and the tensile strength decreases with the increase of di-ameter;their average values of compressive strength were 4.04,5.22,6.66MPa, respectively, average values of com-pression modulus of elasticity were 23.93,25.37,24.12MPa, respectively, it was power function positive correlation be-tween the diameter and the maximum compression load of each nodes in the tail,and with the increase of diameter, the maximum compression load increases.The conclusions provide the theoretical foundation to design tail -breaking mecha-nism of sugarcane harvester and establish mathematical model for dynamic simulation.