青海省农作物品种选育及品种志编撰

概述了改革开放30年来,青海省农作物育种工作的主要成就,育种目标和育种技术的演变特征;详细叙述了《青海省农作物品种志》(1983-2005)编撰的技术路线及图像处理、电子系统开发、资料采集等关键技术和思路,为更好了解和使用《青海省农作物品种志》提供参考。     

《植物育种学》教学质量提升探索

根据社会发展对植物育种人才的要求,分析了《植物育种学》教学中存在的问题,总结了华南农业大学《植物育种学》教学团队在教学开展中的一些经验,提出了进一步改进的建议。     

种衣剂在小麦上的应用效果初报

就17%多·克·酮小麦种衣剂对幼苗生长的调控作用以及田间防治甘肃省小麦主要病害的实际应用效果进行了试验研究。盆栽试验结果表明,17%多·克·酮种衣剂安全的药种比为1:50,在此包衣比例下,不仅可提高出苗率,对植株生长无不良影响,而且能使植株根系活力显著增强,叶片叶绿素含量明显提高,生长后期抗倒伏能力增强;田间小区试验结果表明,对早期小麦条锈病的防效可达76.2%、小麦白粉病可达77.0%,对土传性小麦全蚀病的防效可达到82.1%,冬麦区小麦产量提高6.8%,春麦区小麦产量提高10.9%。     

研究作物群体结构及生态因子时空分布的新方法——三维切片法

本文介绍了三维切片法的原理，用于切片的框架制作 ，操作方法和资料处理及表达方法。     

Evaporation from a Clay Soil Covered with a Surface Mulch - Three Lysimeter Studies

Cultivation systems with mulching have been successfully tested in spring cereals for several years in Sweden. The water conserving effect of the mulch was considered to be important in these field experiments. Three experiments with lysimeters were conducted in this study to investigate the effect on evaporation of a) different amounts of mulch, b) different types of mulch and c) different frequencies of rain in combination with mulching. The lysimeters contained undisturbed soil cores from a heavy clay soil. The protection against evaporation was largest at the beginning of soil drying. It increased with increasing amounts of mulch, but there were no differences in protection between the various kinds of mulch tested. Accumulated evaporation was 12, 14 and 30% lower in the mulched compared to bare soil after 28 days with no rain, infrequent rain and frequent rain respectively. The implications for designing a cultivation system with mulching are discussed as well as its potential in different weathers.     

Water retention and hydraulic conductivity of a loamy sand soil as influenced by crop rotation and fertilization

Measurements are reported of soil organic carbon content, dry bulk density, water retention characteristics, and saturated hydraulic conductivity of a sandy loam soil with two different crop rotations and two levels of fertilization. The water retention characteristics were fitted to the van Genuchten equation. Values of unsaturated hydraulic conductivity were estimated by calculation. It was found that crop rotation has much larger effects on these soil physical properties than fertilization. Water retention and hydraulic conductivity are greater when mustard, and clover with grass are included in the crop rotation, but only at water contents greater than 0,10 and 0, 13 kg kg^?1respectívely.     

巴彦淖尔地区主要作物生产成本与收益分析

针对巴彦淖尔地区6种主要作物(小麦、玉米、花葵、油葵、籽瓜、白瓜籽)的生产成本、收益、净收益、产出投入比的变化进行了对比分析,结果表明:巴彦淖尔地区主要作物的生产成本总体上均呈略有增长的趋势,变化幅度不大,其中,花葵和生产成本最高,玉米其次,籽瓜最少;主要作物净收益差异极显著,其中,花葵净收益最高,白瓜籽其次,小麦最低;主要作物产出投入比差异显著,其中,白瓜籽产出投入比最高,花葵其次,小麦最低。6种主要作物中,花葵和白瓜籽的生产效益较高,小麦效益则最低。提出了选择优质高产品种、加大财政投入力度、强化科技支撑作用、适当地调整作物结构等提高作物生产收益的相关措施。     

Effects of Crop Density and Irrigation Management on Water Productivity of Rice Production in Northern Iran: Field and Modeling Approach

Freshwater availability for irrigation decreases because of increasing demand from urban and industrial areas, degrading irrigation infrastructure, and water quality. The demanding for high production of rice with less water use is crucial for food supply. In this research, a field experiment was conducted during 2001 and 2002 to determine the effect of crop density on water productivity of rice crop. The study was carried out in a split-plot design with three plant spacings as subplots (20 cm × 20 cm, 15 cm × 15 cm, and 10 cm × 20 cm) and four different irrigation regimes (continuous submergence as the control and 100%, 75%, and 50% evaporation of pan) as main plots. To model the various water productivity components, the ORYZA2000 model was used. The comparison of model results with observed data was performed using different statistical methods. The results showed that the irrigation by 75% evaporation from pan evaporation and 20 cm × 20 cm crop size are the optimum irrigation method and crop density management.     

Bacillus asahii comes to the fore in organic manure fertilized alkaline soils

Organic manure (OM) fertilization has a profound impact on agroecosystems. However, little is known about temporal responses and roles of the specific soil microbial guilds involved in the increases of soil fertility and crop yield triggered by OM fertilization. To unravel these interactions, a series of fresh and archived soil samples from a fertilization experiment started in 1989 in North China Plain (NCP) was systematically investigated. Molecular assays of contemporary fresh samples unravel that Bacillus asahii responded most distinctly to OM fertilization, while no shifts in microbial community structure were observed between chemical fertilizations and the control without fertilization; a series of archived soil samples from 1989 to 2009 reveal that the indigenous B. asahii took 2–4 years to become specifically dominant and its ratio fluctuated between 40% and 72% during 20 years. Culture-dependent assessments of isolated B. asahii strain further indicate that its rise subsequently played a key role in the increases of both crop yield and soil fertility, especially via accelerating carbon and phosphorus cycling. This insight deepens our understanding of how OM impacts agroecosystems through soil microbial processes, and highlights the possibility of using archived microbial information as a reference to develop an efficient and sustainable agricultural strategy.