نتایج جستجو برای: coarse grain soil

تعداد نتایج: 265184  

2005
H. B. Goosey A. W. Lenssen R. W. Kott

In dryland farming areas of Montana, annual precipitation is not sufficient for annual planting of cereal grains. Instead, a crop-summer fallow farming system is used to conserve soil moisture and increase available nitrogen for subsequent crop growth. Managing this summer fallow, either by mechanical means or with herbicides, is the highest variable cost associated with dryland grain productio...

2011
Alison G. Nelson Sylvie A. Quideau Brenda Frick Pierre J. Hucl Dil Thavarajah Jill Clapperton Dean M. Spaner

Micronutrient deficiencies in the diet of many people are common and wheat is a staple food crop, providing a carbohydrate and micronutrient source to a large percentage of the world’s population. We conducted a field study to compare five Canadian red spring wheat cultivars (released over the last century) grown under organic and conventional management systems for yield, grain micronutrient c...

2015
Xiuying Zhang Taiyang Zhong Lei Liu Xiaoying Ouyang Qian Qian

Food safety is a major concern for the Chinese public. This study collected 465 published papers on heavy metal pollution rates (the ratio of the samples exceeding the Grade II limits for Chinese soils, the Soil Environmental Quality Standard-1995) in farmland soil throughout China. The results showed that Cd had the highest pollution rate of 7.75%, followed by Hg, Cu, Ni and Zn, Pb and Cr had ...

2000
Anthony M. Whitbread Graeme J. Blair Rod D.B. Lefroy

Farming activities practiced on many Australian soils have resulted in substantial losses of soil organic matter (SOM), nutrient loss, soil structural degradation and declines in cereal yield and quality. Field trials, consisting of a legume or fallow phase followed by three wheat (Triticum aestivum L.) crops, were established on a degraded Ferric Luvisol (Red Earth) soil in New South Wales to ...

2016
Fan Wang Zhaohui Wang Changlin Kou Zhenghua Ma Dong Zhao Wenju Liang

The recycling of livestock manure in cropping systems is considered to enhance soil fertility and crop productivity. However, there have been no systematic long-term studies of the effects of manure application on soil and crop macro- and micro-nutrients, heavy metals, and crop yields in China, despite their great importance for sustainable crop production and food safety. Thus, we conducted fi...

Journal: :Science 2003
Jakob Schiøtz Karsten W Jacobsen

We used molecular dynamics simulations with system sizes up to 100 million atoms to simulate plastic deformation of nanocrystalline copper. By varying the grain size between 5 and 50 nanometers, we show that the flow stress and thus the strength exhibit a maximum at a grain size of 10 to 15 nanometers. This maximum is because of a shift in the microscopic deformation mechanism from dislocation-...

2001
J. Wu W. A. Norvell D. G. Hopkins

of North America. A total of about 1.5 million ha of durum is planted annually in the USA, with about 80% The accumulation of Cd in edible crops is undesirable because of concentrated in northern North Dakota. In some locapotential risks to human health. Agronomic efforts to lower Cd in foods will be more effective if we understand the extent and causes of spatial tions, durum wheat grain may e...

2013
X. J. Wang K. Jia L. Y. Liang

Degraded soils in Northwest China are mostly nonproductive due to imbalanced nutrient and inadequate water supply. The effects of manure application at three different rates (7.5, 15.0, and 22.5 t ha) combined with chemical fertilizers on soil water and Water-Use Efficiency in maize [compared with chemical fertilizers (control)], under semi-arid conditions in dark Loessial soil and over a perio...

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