中南地区甜玉米丰产栽培技术     

戴翠容 《湖南农机》2007,(11):6

本文从土地选择、品种选择、怖种与育苗、田间管理、病虫害防治、适时收获等六个方面,总结了中南地区甜玉米的丰产栽培技术.  相似文献   

Effect of drying on soil strength and corn emergence     

H. O. Fapohunda  W. D. Kemper  D. F. Heerman 《Irrigation Science》1985,6(3):149-158

Summary Laboratory studies were conducted to evaluate the effects of drying on soil strength and corn emergence (Zea mays L.). Corn was germinated in Billings silty clay under a bank of heat lamps which operated 9, 14, 19, or 24 h per day. Soil strength (modules of rupture), soil moisture content and emergence were measured daily.The relationship of soil strength to corn seedling emergence as influenced by the four light and heat durations and bare and mulched soil surfaces was determined. As soil strength increased emergence decreased until it ceased at soil strengths of about 80 kPa. Strength of this soil had a high negative correlation with soil water content and increased with time. Mulching decreased initial rate of drying, decreased crust strength, and improved corn emergence. The 14-hour light and heat treatment resulted in the highest corn emergence.Contribution from Colorado State Experiment Station, USDA-ARS Snake River Conservation Research Center, and USDA-ARS Fort Collins, respectively  相似文献   

The effect of salinity on corn yield using the CERES-maize model     

José Beltrão  Jiftah Ben Asher 《Irrigation and Drainage Systems》1997,11(1):15-28

In most cases, when calculating soil water availability, only thewater content is considered. The effect of salinity on the wiltingpoint is neglected. The objective of this work is to use asimulation model (CERES-maize) in order to predict cornyields as a function of water salinity under severalenvironmental, agrotechnical, and plant characteristics. A modelis presented in which the wilting point is a function of the soilsalt content. At high salinity, the water content at wilting pointis higher than at low salinity, resulting in an insufficient amountof available water and, therefore, a reduced yield. The modelwas used to simulate several theoretical and experimentalsituations for forage corn and grain corn. Simulation resultsshowed that nitrogen fertilization increases the salinity thresholdvalue and the yield sensitivity (rate of yield reduction per unitof salinity). The also showed that forage corn is more sensitiveto salinity than grain corn. If the soil is not leached, a heaviersoil texture has a higher salinity threshold value. On the otherhand, if the soil is leached, the soil texture has no influence onthe salinity threshold value and the yield is less sensitive tosalinity in sandy soils. The determination coefficient (r²= 0.75) indicated that the results of the simulations were in goodagreement with the field data.  相似文献   

平面弹性欠驱动并联机构刚度特性分析   总被引：2，自引：0，他引：2  

耿明超  赵铁石  杨建涛  边辉  赵延治 《农业机械学报》2015,46(5):365-371

根据多维运动模拟的需求,提出一种包含螺旋圆弹簧(圆柱形螺旋弹簧)的欠驱动运动模拟台。利用螺旋圆弹簧的轴向和横向刚度约束运动模拟台的工作空间,通过两个驱动分支和动力耦合实现其3个自由度的运动。将螺旋圆弹簧等效为RePeRe弹性运动支链,进而将并联运动模拟台等效为2RPR/2RePeRe弹性欠驱动机构,并利用Grassmann线几何分析该机构的输入选取原则。基于旋量及其迁移公式,建立等效机构的运动学模型。借助于影响系数和虚功原理,对该弹性欠驱动机构进行静力学分析,得到其静力学约束方程。最后,建立了该机构的连续非线性柔度模型,并以此为基础得到其方向刚度模型。  相似文献   

变截面板簧轧机电液伺服系统性能分析     

李素玲  刘军营 《农业机械学报》2007,38(9):171-174

设计了变截面板簧轧机电液伺服系统,该系统采用了工控机和PLC组成的两级计算机控制方式。建立了由电液伺服阀、伺服液压缸和轧辊组成的伺服控制系统数学模型。在分析系统的稳态性能和动态性能基础上,采用PID校正方式,进一步增大了系统的剪切频率,缩短了调节时间,降低了稳态误差。结果表明轧机电液伺服系统的稳定性好、控制精度高,达到了设计目的。  相似文献   

穗茎兼收型玉米联合收获机的发展现状与展望   总被引：1，自引：0，他引：1  

杜翠红  张道林  李秀亭  张喜瑞 《农机化研究》2006,(10):11-13,24

随着我国农业结构的调整和畜牧业的发展，穗茎兼收型玉米联合收获机成为发展热点。为此，总结了该种机型的发展现状，简单介绍了几种较成熟机型的性能及特点。基于现状，论述了穗茎兼收型玉米联合收获机的发展趋势，并指出该种机型具有广阔的发展前景。  相似文献   

一年两作地区玉米直播机械化技术可行性研究     

侯方安  刘永刚  陈海燕 《中国农机化》2005,(4):12-14

在山东一年两作的玉米播种中多年来一直沿用了麦田套种的习惯，成为机械化技术的大面积高效率应用的一个障碍。本文在总结山东省各地实践验的基础上，从机械技术的发展、玉米品种的培育和气候变迁等方面研究了实行玉米直播机械化技术的可行性，以期对于适宜地区的玉米生产提供参考。  相似文献   

玉米收获机的发展前景分析     

李有田 《中国农机化》2005,(5):34-36

通过对我国玉米产区的耕作习惯、经济基础、技术水平、自然特点等因素进行分析．指出中国的玉米收获机械化道路不是死胡同，是有光明前途的。当前乡镇经济的发展，使得农村的经济实力得到增强．富裕起来的农民只要看到玉米种植的综合效益，肯定会在农机上投入资金。  相似文献   

利用近红外光谱技术快速分析全株玉米青贮营养成分     

王新基  郭涛  潘发明  李飞 《家畜生态学报》2021,32(1):52-55

研究旨在利用近红外光谱技术(near infrared reflectance spectroscopy,NIRS)建立全株玉米青贮6种营养成分的近红外预测模型,为生产实践中合理利用全株玉米青贮饲料资源提供理论依据.选取玉米青贮样品64份作为定标集,16份作为验证集.利用NIRS结合改良偏最小二乘法(modified ...  相似文献   

应用DTOPSIS分析法评价青贮玉米新品种   总被引：1，自引：0，他引：1  

陈凤金  麻翠丽 《河北农业科学》2006,10(1):48-51

采用DTOPSIS分析法,以2004年国家北方青贮玉米品种区域试验结果为依据,对参试青贮玉米品种进行了评价.结果表明:DH5554品种评价值最高,为0.932 5;其次为精饲736和晋单42品种,评价值分别为0.865 6和0.861 4,适合北方种植,与当前生产表现一致.  相似文献