in this study, nutrition, nutrient return and nutrient retranslocation were compared between two stands of alnus subcordata (n-fixing tree) and taxodium distichum (coniferous deciduous tree), planted on a weak drained soil in north of iran (tashbandan, amol). in each tree stand, n, p, k, ca and mg concentration of fresh and senescent leaves and soil were measured. the concentrations of n and mg...

The size of a minimum realizer of a partial order is called the dimension of that partial order. Here we initiate the study of minimal realizers which are not minimum. As an aid to the study of such realizers, we associate to each minimal realizer certain critical digraphs. We characterize all such critical digraphs for the antichain on n elements, and consequently deduce that for n > 4, the ma...

Conventional procedures are inadequate for optimizing the concentrations ofnutrients to increase the sugar yield. In this study, an artificial neural network(ANN) was used to optimize the Ca, Mg, N, K and Na content of the storage rootto increase sugar yield (Y) by increasing both sugar content (SC) and root yield(T). Data from three field experiments were used to produce a wide range ofvariati...

in order to study the effect of intercropping of corn with bean and bitter vetch and farmyard manure (fym) on corn nutrition, a factorial experiment was carried out on the basis of randomized complete blocks design with three replications. the factors were types of intercropping systems at levels of sole bean, bean+corn, sole bitter vetch, bitter vetch+corn, sole corn, and fym at levels of 0, 3...

no on-site sanitation system treats both urine and faecal matter in one process. a laboratory scale biological filter was fed with high concentration of urea (4 g n/l) and 17.1 g cod/l to determine if it will be possible to treat liquid that leach from a ventilated improved pit latrine. the hlr in the proposed biological filter system was calculated to be ca 36 l/m2/d, significantly lower than ...