水分亏缺对覆膜玉米生长发育及产量的影响

通过系统的覆膜玉米亏水灌溉试验 ,研究了不同生育期内不同程度的水分亏缺对覆膜玉米生长发育、光合作用、产量及水分利用效率等的影响。结果表明 ,拔节期受旱对玉米株高及叶面积指数影响最大 ,抽雄后的水分亏缺对玉米生长发育影响不明显。各处理产量资料表明 ,覆膜春玉米的需水临界期为抽雄开花期 ,此期轻度的水分亏缺可造成产量大幅度下降 :灌浆期较抽雄开花期玉米产量对水分亏缺敏感程度低 ,但在这个阶段的水分亏缺也可使玉米减产 ;拔节期玉米产量对水分胁迫敏感程度较差 ,该阶段为对玉米进行水分亏缺处理的适宜时期     

不同节水灌溉技术的节水机理试验研究

根据甘肃省特殊自然地理条件，对于喷灌、滴灌、渗灌及波涌灌几种方式下，小麦和玉米两种作物的灌溉节水机理进行了对比试验研究，分析了不同节水灌溉方式下这两种作物的节水性和生育动态。试验结果表明，在降雨、灌溉水量和前期土壤特性一定的情况下，在喷灌、滴灌、渗灌及波涌灌几种节水灌溉技术中，渗灌的节水性最好，依次为滴灌、喷灌、波涌灌。小麦和玉米在渗灌条件下产量比滴灌、喷灌和波涌灌都高，小麦渗灌产量比滴灌增加7．6％，比喷灌增加13．1％，比波涌灌增加22．4％。玉米渗灌产量比滴灌增加1．3％．比喷道增加6．3％。     

中南地区甜玉米丰产栽培技术

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.     

Effect of drying on soil strength and corn emergence

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     

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

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.     

一年两作地区玉米直播机械化技术可行性研究

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。     

玉米收获机的发展前景分析

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。     

利用近红外光谱技术快速分析全株玉米青贮营养成分

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 ...     

应用DTOPSIS分析法评价青贮玉米新品种

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.     

饲粮中糙米替代玉米的比例对饲料制粒性能的影响

为考察糙米替代玉米对饲料制粒性能的影响,按糙米替代比例设计6种饲粮进行饲料制粒参数测定,6种饲粮分别为Ⅰ型(玉米100%)、Ⅱ型(玉米75% 糙米25%)、Ⅲ型(玉米50% 糙米50%)、Ⅳ型(玉米25% 糙米75%)、Ⅴ型(糙米100% 2%植物油)和Ⅵ型(糙米100% 3%植物油).结果表明,饲粮中添加一定比例的糙米来替代玉米,有利于改善饲料制粒性能,饲粮中随糙米添加比例的增加,制粒机的生产率与颗粒饲料的硬度显著提高,水稳定性明显增强,粉化率显著降低,但密度、体积质量无显著影响.适宜的替代比例为75%.