土壤压实度测量系统研究进展

随着农业机械功率的不断增加和机具下地次数的增多,土壤压实的问题愈加明显.为了定量获得土壤压实特性,研究人员开发了各种各样的土壤压实度测量系统.分析了土壤压实产生原因、危害,重点对国内外压实度测量系统的研究现状进行了综述,指出通过测试土壤阻力获得其三维的分布特性是土壤压实测量的发展趋势.     

农田原状土壤压实测试系统的设计及操作方法

使用土压力传感器监测土壤压实状况的优势是可以直观反映土体内的应力过程,但是传统的操作方法费时费力,因此设计一种全新的农田原状土应力测试系统,该系统以30°倾斜角打洞埋设土压力传感器,并配合平板下陷同步测试地表下陷位移、平板加载力及土体内的应力传递。在水稻土中的应用结果表明,系统的设计参数合理,最大限度地减小了原位土壤的扰动,土压力传感器的安放深度以及测试结果都达到了预期效果,能够满足短时间内进行多点测试的要求。     

中型拖拉机压实对测试截面土壤坚实度和含水率的影响

以黑龙江省黑土区垄作旱田为研究对象,采用中型拖拉机开展压实试验,提出一种农业机械压实后土壤坚实度和含水率试验数据测试创新方法,对科学合理使用农业机械、保持和提升黑土区耕地生产能力具有重要理论和实际意义.设压实1～5次及对照(CK)6种处理,测试时,在压实辙印垂直方向以辙印中点为中心取7个测点(每测点间隔10 cm),测...     

作物对土壤压实胁迫响应研究进展

作物要获得优质高产,不仅需要适宜的水肥条件还需要适宜的土壤结构。而土壤压实后容重升高导致土壤理化性状和土壤微生物种类及结构发生改变,影响土壤养分的有效性,造成多数土壤酶活性、土壤生物数量降低,使植物生长发育受阻、生物产量降低,进而影响作物的正常生长发育。本文综述了土壤压实胁迫形成的原因和其对土壤环境、作物的危害,及作物生理对土壤压实胁迫的响应机理等方面研究进展,并在此基础上对土壤压实胁迫下一步的研究方向进行了展望。     

土壤压实节水对水稻生长及土壤生态的影响

2006年,在沿江地区进行了水稻土壤压实节水试验.结果表明:在高渗透沙壤土地区,实施压实节水灌溉技术,节约灌溉用水24.1%,增产10.1%;实施该技术,对水稻不同生育期土壤真菌、细菌和放线菌的数量没有显著影响;采用压实节水的耕作层土壤,其脲酶活性在水稻拔节期均高于对照;在水稻抽穗期,根系氧化力显著提高.     

黄土高原南部3种农田土壤剖面坚实度的变化规律

为了揭示黄土高原南部地区不同质地类型土壤剖面坚实度的变化及其与土壤含水率的定量关系,以黄墡土、土娄土、裸露在地表的粘化层耕作剖面为研究对象,定位观测其0~45 cm土壤坚实度与含水率的变化。结果表明,黄墡土、土娄土、裸露在地表粘化层耕作剖面的犁底层平均坚实度均大于耕层,犁底层平均坚实度较耕层分别高194.8%,87.3%,10.4%;剖面土壤质地越粘其平均坚实度越大;土壤坚实度与含水率呈负相关关系;土壤坚实度变化速率为0时,以上3种土壤剖面临界含水率分别为0.1712,0.1757,0.1835;质地不同的土壤剖面坚实度时空变化特征有差异,其中黄墡土剖面0~20 cm土层土壤坚实度为350~500 kPa,受土壤含水率变化的影响较小;20~30 cm土层土壤的坚实度为500~1400 kPa,不易受外界环境影响;30 cm以下土层土壤坚实度为700~1600 kPa,受土壤含水率变化影响较大。土娄土剖面0~40 cm土层土壤坚实度为600~1200 kPa,受含水率变化影响较大;40 cm以下土层土壤坚实度稳定在1 800 kPa左右。粘化层剖面0~15 cm土层土壤坚实度在2000 kPa左右,受环境影响较大,15 cm以下土层土壤坚实度稳定在1800 kPa,受含水率变化影响较小。     

模拟农业机械对土壤压实的试验研究

[目的]进行模拟农业机械对土壤压实的实验,为研究农业机械对土壤造成的压实破坏提供理论依据。[方法]重塑含水率(级差为3%)和体积密度(级差为0.2 g/cm3)不同的水稻土和黄棕壤,利用土壤固结仪对其进行模拟压实,分析压实对土壤容重、饱和持水率和应力传递系数的影响。[结果]随着含水率的增加,压实对土壤的影响逐渐加重,且当土壤含水率在16%~22%时压实对土壤产生的破坏较为严重。土壤抗压实能力随体积密度的增加而增加。相同含水率和体积密度土壤应力传递系数不变,即传递至土壤底层应力σz与土壤表面施加力σ0呈相对稳定的线性关系。[结论]机械压实会使土壤容重增加,饱和持水率降低。随着土壤含水率的减少和体积密度的增加,压实对土壤的影响减弱。土壤应力传递系数与土壤类型、含水率、体积密度等有关。对于给定状态的土壤,其土壤应力传递系数不变。     

某高速公路基层压实度施工质量动态控制

对某高速公路全线73.899 km中第Ⅰ标段做级配碎石底基层、水泥稳定碎石上下基层的压实度施工质量动态控制.旨在通过动态控制及时发现施工过程中出现的问题,针对存在的问题,分析其原因并提出解决方案,至于解决办法是否有效,通过动态控制图予以检验.     

压实度和含水率对冻土性质的影响

本文通过试验研究了压实度和含水率对冻土性质的影响.研究表明:相同的冻结温度下,如果保持压实度不变,随着含水率的增加土样的冻胀率也一直增加,且最佳含水率是影响土样冻胀率变化趋势的分界点；如果保持含水率不变,随着压实度的增加土样冻胀率呈减小的趋势,且变化幅度也在减小.粘性冻土的无侧限抗压强度随着含水率和压实度的增加而呈现上升的趋势,且粘性冻土的冻胀率和抗压强度与其含水率及压实度之间存在明显的函数关系.     

基于PDA的小麦测土配方施肥信息移动查询系统

在原有的基于GIS的县域小麦测土配方施肥系统的基础上,采用TCP/IP通信机制,PDA终端通过GPS接入内部网络,通过Web Service提供数据服务,实现对土壤信息和施肥决策的移动查询.     

基于RFID的养猪管理与监控系统设计与实现

主要讨论了如何在PDA上结合RFID读写模块实现一个数据采集管理监控系统,阐述了该系统硬件设备的构成和软件开发的流程,以及API调用、通信接口实现和数据库同步等关键问题,最后对该系统进行了界面演示.     

基于PDA操作的智能用电监察系统

利用PDA对便携式工频电量监察设备进行在线测量和控制。测试数据可视化显示，并与MIS系统进行连接，使电能计量的检测更加方便和实用。基于Linux内核编写USB驱动程序使数据的传输更加快捷方便。     

Remote real-time monitoring soil water potential system based on GSM

Aiming at the limitation of traditional measuring soil water potential, the paper presents an information system based GSM to real-time monitor data coming from multiple data sources. The monitoring system, which consisted of monitoring center, GSM transmission channel and data detection terminal, was given. The detection terminal included the measuring station and TS-2 negative pressure meter, which was applied to measure soil water potential. Nowadays the system has been successfully applied to drip irrigation in the cotton field on farm in Xinjiang region. The system provides a feasible technology frame-work for collecting and processing wide geographical distribution data in farmland.     

一种多点土壤电导率实时监测系统的研制

为获取建立溶质运移模型所需的土壤溶质浓度参数,根据土壤溶液电导率与溶液浓度c的线性关系,应用电流电压四端法,研制出一种多点土壤电导率实时监测系统。该系统硬件部分自行设计的四针微型探头可减小对溶质运移的扰动,且可高密度分布在土壤中;连接8路电导率探头和1路温度探头的高精度数据采集器DAB能够实现8通道土壤电导率测量及温度辅助测量,并可通过485总线接口实现系统规模的扩展。采用VC开发的监测显示平台能够完成采集器参数设置,数据采集、显示与存储功能。通过对采集器通道和探头的标定,有效解决了多点土壤电导率实时监测的一致性问题。标定试验结果表明,数据采集器8通道电导测量值与标准电导的相关系数为0.999 5,表明通道标定后有效提高了其测量准确度,减小了各通道测量差异;通道标定后采集器各通道测量的标准溶液电导G与其电导率σ具有良好的线性关系,但不同电导率条件下探头的测量结果存在较为明显的偏差,说明探头制作过程引起的结构差异不可忽略,进而采用分段标定方法对每一个探头的结构常数进行标定。     

Procedures of soil farming allowing reduction of compaction

Evaluation of new technologies using guidance systems is very important and can help producers with choosing the right equipment for their applications. Without using satellite navigation during field operations, there is a tendency for passes to overlap. That results in waste of fuel and pesticides, longer working times and also environmental damage. When utilising satellite guidance for field operations, there is a close connection with controlled traffic farming (CTF) as well. CTF is currently a quite quickly developing farming system based on fixed layout of machinery passes across a field. Tracks precisely set out for a machine’s tyres in the field could be a tool for minimising soil compaction risk which is another threat to the environment. The purpose of this paper was to evaluate the accuracy of currently available guidance systems for agricultural machines. Real pass-to-pass errors (omissions and overlaps) in a field were measured. Consequently, comparison between observed guidance systems was made regarding final working accuracy. Further, intensity of machinery passes, percentage of wheeled area and repeated passes in fields were monitored. These measurements were made in fields under real operating conditions using a conventional tillage system with ploughing and also a conservation tillage system, both systems with randomly organized traffic. Finally, the same parameters were monitored in fields where fixed machinery tracks were used for all operations and passes but only under a conservation tillage system. Pass-to-pass accuracy was measured for the evaluation of different guidance systems. Size of missed areas or overlaps was evaluated statistically. Concerning intensity of machinery passes and total field area affected by machinery passes, the following facts were found out. The experiments with randomized traffic showed a significant difference of the parameters mentioned above between a conventional tillage system with ploughing and a conservation tillage system. Wheeled area was 86 and 64%, respectively which proves benefits of conservation tillage. The experiments with a fixed track system showed that the total run-over area by machinery tyres decreased even more (up to 31%) in comparison to randomized traffic in a field (only fields under conservation tillage system were monitored and evaluated). The following statements based on our results can be made. The navigation and therefore possibility for better accuracy of machinery passes in fields together with permanent machinery tracks utilization could help with soil condition improvement and also energy savings which would result from that. The CTF system will help with further development of a system for soil compaction protection which is currently a real necessity.     

新型土壤孔隙水压力检测系统的研制与建模

分析了土壤含水率和孔隙水压力测量的应用领域和研究现状;阐述了建立二者之间数学模型的意义;介绍了目前国内外几种常用的测量方法、测量手段和相关仪器设备,并对比了他们之间的优缺点.介绍了系统各部分的功能结构、测量原理和数据分析过程.在分析结果数据、仪器监测数据和前期结论的基础上,得出了一种算法,根据该算法编写了软件,实践证明...     

小麦收割机对免耕地土壤压实的试验研究

用4GG—170型收割机和新疆—2号联合收割机在免耕麦茬地上压地1~10次,测定土壤容重和土壤硬度随碾压次数的变化情况.结果表明,两种收割机型对土壤的压实程度有显著性差异.新疆—2号联合收割机使土壤硬度、土壤容重和孔隙度的变化程度大于前悬挂4GG—170型收割机;新疆—2号联合收割机对土壤硬度的影响超过了30 cm;新疆—2号联合收割机对土壤3~5次碾压程度相当于4GG—17型收割机碾压10次以上.     

土壤pH值速测方法的改进

对土壤pH值速测的混合指示剂比色法进行了改进。结果表明 :改良法与比色法测定结果相比 ,更接近电位法测定结果 ;比色法、改良法的测定结果与电位法的测定结果的相关系数分别为 0 984 4和0 9990。改良法解决了比色法存在的 4个问题 ,即取样数量、水土比、指示剂数量的定性、比色受土壤颜色影响 ,从而提高了测定的准确性。