introduction cultivated sunflower is one of the largest oilseed crops in the world. sunflower seed is the third largest source of vegetable oil worldwide, following soybean and canola. nitrogen is one of the most important elements for crops to achieve optimum yields and quality. phosphorus (p), next to nitrogen, is often the most limiting nutrient for crop and forage production. phosphorus ava...

The study was carried out to evaluate the effects of soil application of humic acid and calciumon morpho-physiological traits and Na+, Mg2+, Ca2+ uptake of Pistachio seedling (Akbari) grown under salt stress.  A completely randomized design was used with four replications in greenhouse conditions. The experimental treatment consisted of four levels of humic acid (Bis humic) (0, 4, 8 and 12 gr k...

The interactions between earthworms and microorganisms can produce significant quantities of plant growth hormones and humic acids which act as plant regulators. Experiments were designed to evaluate the effects of humic acids extracted from vermicompost and compare them with the action of commercial humic acid in combination with a commercial plant growth hormone, indole acetic acid (IAA) whic...

The aim of this work is to explore the suitability of the complementary use of mass spectra and the corresponding statistical analysis (principal components-Pareto analysis (PCA) and discriminant analysis (DA)) of these spectra to differentiate diverse humic samples as a function of their structural and conformational features. To this end, the mass spectra of humic samples belonging to the mai...

This study was carried out to evaluate the effect of soil application of humic acid on growth and physiological indices of pistachio seedlings ("Badami Zarand" rootstock) under drought stress. This experiment was arranged as a completely randomized design with three replications in greenhouse conditions. The experimental treatments consisted of humic acid (0, 30 and 60 gr in 4 kg-1 s...

objective:  in addition to the role of organic matter in plant nutrition, this material improves soil quality, physical structure, ventilation and water supply, and ease of penetration and expansion is rooted deep in the soil surface. effects of organic matter due to climatic factors, soil characteristics may vary from region to region, resulting in organic materials management must be given to...

The physiological and metabolic mechanisms behind the humic acid-mediated plant growth enhancement are discussed in detail. Experiments using cucumber (Cucumis sativus) plants show that the shoot growth enhancement caused by a structurally well-characterized humic acid with sedimentary origin is functionally associated with significant increases in abscisic acid (ABA) root concentration and roo...

Objective:  In addition to the role of organic matter in plant nutrition, this material improves soil quality, physical structure, ventilation and water supply, and ease of penetration and expansion is rooted deep in the soil surface. Effects of organic matter due to climatic factors, soil characteristics may vary from region to region, resulting in organic materials management must be given to...

We examined the molecular-level interactions of aromatic compounds with a humic acid that was extensively characterized with one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy. Interactions of target compounds were evaluated by monitoring their NMR relaxation properties. Solid-state NMR revealed that the humic sample contains paraffinic carbon (31%), substituted aliphatic ca...

The biological and chemical potential for electron shuttling via humic acids was evaluated by analyzing the depth distribution of humic-acid-reducing and iron-reducing bacteria in a freshwater sediment, and correlating it to the redox characteristics of humic acids and iron. Physicochemical analysis of profundal sediments of Lake Constance revealed a distinct stratification, with oxygen respira...