Agroforestry is a young science in need of theories and methods providing predictive understanding. The present study is an attempt to contribute to the development of a general agroforestry theory and accessory methods. A tree-environment-crop interaction equation is derived in which the overall tree effect on crop production is explained as a balance of (positive and negative) relative net tr...

Water Footprint Assessment is a fast-growing field of research, but as yet little attention has been paid to the uncertainties involved. This study investigates the sensitivity of and uncertainty in crop water footprint (in m3 t−1) estimates related to uncertainties in important input variables. The study focuses on the green (from rainfall) and blue (from irrigation) water footprint of produci...

1. Eruptions occur when a species appears in unusually high densities within and often outside of its normal range. We used 30 years of Christmas Bird Counts combined with cone/seed-crop data on boreal coniferous trees, breeding bird surveys, and weather records to test correlates of winter eruptions by 11 species of primarily boreal North American seed-eating birds. 2. Eruptions of six species...

The large-scale burning of crop residues in the North China Plain (NCP), one of the most densely populated world regions, was recently recognized to cause severe air pollution and harmful health effects. A reliable quantification of the magnitude of these fires is needed to assess regional air quality. Here, we use an eight-year record (2005-2012) of formaldehyde measurements from space to cons...

 In order to evaluate the effects of cover crops on reduced weed biomass in hybrid sunflower an experiment was carried in the research stations, Natural Resources Medicinal Plants (Samian_Ardabile) with 3 replicates in 1390-1391. The first factor was considered three type of cover crops, winter rye, spring barley, winter wheat with 2 control treatment, second factor was mulch management at two ...

the comparative advantage of iran kiwi production and the effects of governmental applied policies on the production process of kiwi fruit investigated over the period 1998-2003 by using policy analysis matrix. iran has had comparative advantage in the production of this crop, but the profitability of this crop has been decreased in 1998-2003. the amount of domestic resource cost index has incr...

 In order to evaluate the effects of cover crops on reduced weed biomass in hybrid sunflower an experiment was carried in the research stations, Natural Resources Medicinal Plants (Samian_Ardabile) with 3 replicates in 1390-1391. The first factor was considered three type of cover crops, winter rye, spring barley, winter wheat with 2 control treatment, second factor was mulch management at two ...