The relation between crop yield, nutrient uptake, nutrient surplus and nutrient application.

This study reexamines the hypothesis that if the availabilities of several limiting nutrients are raised simulthaneously and proportionally, the nutrients are most productive at high, rather than low input rates. It was concluded that in most cases rather the opposite hold

The tetrahedron of knowledge acquisition : A meta-model of the relations among observation, conceptualization, evaluation and action in the research on socio-ecological systems

This paper presents a meta-model which integrates different approaches in the research on socio-ecological systems. The relations between hypothetical-deductive, empirical-inductive and interpretive-phenomenological holistic research approaches are visualized schematically together with their interrelations with the real system. All the relations shown are describe