Tillage selection is just one of the issues that farmers must address when making crop production decisions. Among the factors that will influence the choice of tillage for a given field is the condition of the residue and soil in the field; the residue management practices needed to meet conservation plan specifications; the tools, time, and money that are available; the need to incorporate am...

Environmental Science Research Laboratory, Central Research Institute of Electric Power Industry, 1646 Abiko, Abiko, Chiba 270-1194, Japan Faculty of Environmental Earth Science, Hokkaido University and CREST-JST, North 10 West 5, Kita-ku, Sapporo, Hokkaido 060-0810, Japan Graduate School of Environmental Science, Hokkaido University, North 10 West 5, Kita-ku, Sapporo, Hokkaido 060-0810, Japan ...

We used a fully factorial experimental design to examine the simultaneous effects of light availability, absolute nutrient (nitrogen and phosphorus) availability, relative N : P availability, and trophic structure on zooplankton community composition and the abundance and stoichiometry of algal producers. During May–June 2000, we created gradients of light and nutrient supply and predation risk...

Rising levels of CO2 in the atmosphere have led to increased CO2 concentrations in the oceans. This enhanced carbon availability to the marine primary producers has the potential to change their nutrient stoichiometry, and higher carbon-to-nutrient ratios are expected. As a result, the quality of the primary producers as food for herbivores may change. Here, we present experimental work showing...

Phosphorus (P) is a macro mineral in broiler nutrition. In growing broilers, besides its requirement for proper bone development, it is also involved in almost all metabolic processes. Poor P availability results in decreased productivity and poor health status.Phosphorus availability from plant derived feeds is affected by an anti-nutritional factor “phytate”, which forms a variety of insolubl...

Human activity is currently changing our environment rapidly, with predicted temperature increases of 1-5°C over the coming century and increased nitrogen and phosphorus inputs in aquatic ecosystems. In the shallow parts of these ecosystems, submerged aquatic plants enhance water clarity by resource competition with phytoplankton, provide habitat, and serve as a food source for other organisms....

Food consists of a complex group of substances that differ in chemical composition and physical structure. Collectively these substances form a matrix and it is the behaviour of this matrix which determines the digestibility, the rate and extent of nutrient release, from a food during normal gut transit. In the process of digestion both chemical and physical degradation of food occurs. Chemical...

We studied the interacting roles of nutrient availability and herbivory in determining the macroalgal community in a rocky littoral environment. We conducted a factorial field experiment where we manipulated nutrient levels and herbivory at two sublittoral depths and measured macroalgal colonization and the following young assemblage during the growing season. At the community level, grazing re...