in this study, effect of irrigation duration on concentration of some macro and micro nutrient elements in ‘thompson navel’ orange leaves grafted on three rootstocks was evaluated as a factorial experiment in completely randomized block design. factors included rootstocks in three levels (poncirus trifoliata, citrus aurantium and troyer citrange (citrus sinensis ´ poncitus trifoliata)) and irri...

salinity is one of the most limitation factors for crop production in agricultural systems due to the toxic effects and preventing water and nutrients absorption, in this research the efficiency of four strains of fluorescent pseudomonads on concentration of nutrient elements in rice was determined, under saline conditions. a pot experiment was carried out based on the factorial completely rand...

Plankton--nutrient interaction models with both instantaneous and delayed nutrient recycling are considered. The system consists of three components: autotrophic phytoplankton, herbivorous zooplankton and dissolved limiting nutrient. Local stability of the equilibria is analysed. It is shown that the positive equilibrium loses its stability when the nutrient input concentration passes through a...

The rapid growth of aquaculture is accompanied by increased discharge of nutrient-rich wastewaters into rivers and coastal waters leading to eutrophication and deterioration of water quality. Seaweeds are suitable candidates to reduce dissolved inorganic nutrient concentration discharged through aquaculture effluent, and can improve water quality and allow for sustainable aquaculture. In this s...

The rapid growth of aquaculture is accompanied by increased discharge of nutrient-rich wastewaters into rivers and coastal waters leading to eutrophication and deterioration of water quality. Seaweeds are suitable candidates to reduce dissolved inorganic nutrient concentration discharged through aquaculture effluent, and can improve water quality and allow for sustainable aquaculture. In this s...

Decision support for nutrient application remains an enigma if based on soil nutrient analysis. If the crop could be used as an auxiliary indicator, the plant nutrient status during different growth stages could complement the soil test, improving the fertilizer recommendation. Nutrient absorption and partitioning in the plant are here studied and described with mathematical models. The objecti...

[1] We use both theory and ocean biogeochemistry models to examine the role of the soft-tissue biological pump in controlling atmospheric CO2. We demonstrate that atmospheric CO2 can be simply related to the amount of inorganic carbon stored in the ocean by the soft-tissue pump, which we term (OCSsoft). OCSsoft is linearly related to the inventory of remineralized nutrient, which in turn is jus...

the effects of salinity and supplied calcium chloride on growth and leaf ions concentration of tomato (lycopersicon esculentum l.) were investigated in gorgan, iran. a factorial experiment was conducted based on rcbd with four nacl levels (0, 50, 100, and 150 mm) and four cacl2 levels (0, 100, 200 and 300 mg l-1). data of growth, yield and leaf’s ca, k, and na content were subjected to analyze ...

A method based on the rate of depletion of a nutrient from solution was developed to characterize nutrient flux of plant roots. Nutrient concentration of the solution was measured at a series of time intervals to describe the complete depletion curve. An integrated rate equation, based on a Michaelis-Menten model, was developed and fit to the data of the depletion curve using a least-square pro...