酸模叶蓼田间发生量与油菜籽产量损失关系的初步研究

酸模叶蓼（Polygonum lapatifolium)一年生双子叶杂草，是青海川水地区农田主要杂草之一，田间发生量（鲜重）与油菜产量存在显著负相关关系，r=-0.9303，回归方程Y^=2407.1-0.1413x；酸模叶蓼的发生，导致田间油菜角果数的减少，两者存在极显著负相关关系，r=-0.9726^**，回归方程Y^＝241.38－0.0138x。     

湖北省分地区水灾损失等级划分初探

建立了湖北省分地区水灾损失灾度等级的划分标准。基于模糊模式识别理论，按最大隶属原则和择近原则对灾度等级进行了模糊综合评判。     

降低饲料生产成本,提高企业利润

改革开放以来,我国的畜牧业有了很大的发展,缩小了与世界先进水平的差距,其中“公司+农户”的联合养殖模式发挥了重要作用。我国加入WTO以后,享有了平等的进出口权利,为畜牧业的进一步发展提供了有利条件。但由于各个国家存在利己和贸易保护主义,相继提高了进口产品的质量指标,设置了许多技术壁垒,这对我国的畜产品的出口是一个严峻的考验。畜产品的安全问题显得尤为突出,畜产品因药物残留问题导致不能出口。在国内如北京、上海等城市对农产品也相继实行了产品准入制度,严把畜产品质量关。在这种新形式下,传统的“公司+农户”的联合模式严…     

Sediment Load in Runoff Under Laboratory and Field Simulated Rainfall

Soil erosion is one of the most important problems in the Loess Plateau of China affecting sustainable agriculture. Near Luoyang (Henan Province, China), field plots were constructed to measure soil erosion rates under conventional tillage practices using field-simulated rainfall.Field rainfall experiments were carried out to compare previous results from laboratory rainfall simulations on the same soil for interrill conditions. Although in the laboratory experiments, a strong correlation was found betweenthe stream power of the runoff water and the unit sediment load, this sediment transport equation overestimated the field rainfall simulation results. Another sediment transport equation derived by Nearing et al. for rill erosion was in better agreement with the results of the field experiments, although it also overestimated these values. The measured sediment load values during the field rainfall simulations were also lower than those found during field experiments on the same soil but with a loosened surface layer. This difference indicates the importance of soil physical condition of surfce like soil structure and aggregate size, which may contribute to the discrepancy between the field and laboratory experiment results.     

蚕头损失是造成高县养蚕单产低的主要因素

近年来，高县蚕桑生产发展呈现良好势态，发种、产茧逐年增加，2002年全县发种15．5万张，产茧8．12万担，位列全省第二位。尽管“三大”科技推广力度不断加大，但养蚕单产仍较低，自1996年以来，全县平均单产始终徘徊在22公斤左右，1996年最低，全县平均单产仅15．7公斤。     

鲜食葡萄贮藏期真菌性病害防治要点

葡萄灰霉病又叫葡萄灰腐病，病原为灰葡萄孢，是目前发生较严重的病害，在所有贮藏病害中，造成的损失最为严重。     

饲料损耗的确意味着营养损失

改进饲养方式和提高设备利用率并不是猪场降低饲料损耗所需考虑的仅有方面。