Winter Runoff of Nitrogen and Phosphorus from a Rotational Pen Design with Suckler Cows

来源 :农业科学(英文) | 被引量 : 0次 | 上传用户:tank2203555
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Keeping beef cattle outdoors during winter reduces costs and improves animal welfare, but increases the risk of nitrogen (N) and phosphorus (P) runoff losses. This study evaluated a rotational pen design on grassland with two groups of suckler cows given
其他文献
In main foxtail millet growing regions of China, natural disasters happen frequently, causing losses in production and finance. Therefore, it is urgently needed
This study aimed to observe the response of 32 rice accessions to attack of sugarcane borer (Diatraea saccharalis Fabr., 1794). Twenty larvae were placed on the
在湖泊环境的研究中,采到保持原状的沉积物-水界面样品是一项基本工作。根据国外有关资料,在前期研制的沉积物-水界面采样装置的基础上,研制成功了一种新型湖泊沉积物-水界面取样器
Use of individual plants as experimental units may be necessary when resources are limited, but inter-plant variation risks obscuring differences among treatmen
50多年来,对地球内部100~500km深处的地震的认识还一直是个谜。在此深度,预料岩石可能因塑性流动而不是脆性破裂或断层表面摩擦滑动而变形的。实验室实验以及对地震活动消亡带
北京发现的微熔融石(microtektite)与月球上的玻璃小球和地球上的玄武岩的化学成分比较结果表明,它们之间的差异很大,彼此之间没有任何必然的联系,排除了北京微熔融石是地球上玄武
在马里兰州,美国鹅掌楸(Liriodendron tulipifera L.)的生长年轮看来保留了填土中地下水污染的化学记录。在填土下坡,树木生长年轮中铁和氯的高浓度带,在时间上与填土中预计
Bacterial wilt, caused by Ralstonia solanacearum, is a major tomato disease in tropical and sub-tropical regions. It is difficult to be managed, since no single
The Phaseolus vulgaris L. is one of the traditional and most important leguminous crops in the Island of Madeira. The island’s bioclimatic tiers, agro-ecologic
对铌的分析化学的兴趣并没有减弱,有关的论著很多证明了这一点。收集了大量70-80年代有关铌分析的资料,做了系统的分类、整理和分析工作,并总结成本文,以对测铌方法作系统的介绍和评论