Evaluation of spatial variability of the integral energy of plant available water and its influential properties in paddy soil

Paddy and Water Environment - Plant Available Water is the main concept for describing the existing water content in a soil profile. Along with this concept, Integral Energy shows the energy...     

Droplet-vitrification cryotherapy and thermotherapy as efficient tools for the eradication of apple chlorotic leaf spot virus and apple stem grooving virus from virus-infected quince in vitro cultures

European Journal of Plant Pathology - Viral diseases affect quince plant productivity and fruit quality. This study evaluated the effectiveness of droplet-vitrification cryotherapy and...     

Effects of spatial,temporal, and spectral resolutions on the estimation of wheat and barley leaf area index using multi- and hyper-spectral data (case study: Karaj,Iran)

Precision Agriculture - Leaf area index (LAI) is a key parameter for the calculation of crop biophysical and biochemical processes. Therefore, the accurate estimates of LAI has been always of great...     

Crop photosynthetic response to light quality and light intensity

Under natural conditions, plants constantly encounter various biotic and abiotic factors, which can potentially restrict plant growth and development and even limit crop productivity. Among various abiotic factors affecting plant photosynthesis, light serves as an important factor that drives carbon metabolism in plants and supports life on earth. The two components of light(light quality and light intensity) greatly affect plant photosynthesis and other plant's morphological, physiological and biochemical parameters. The response of plants to different spectral radiations and intensities differs in various species and also depends on growing conditions. To date, much research has been conducted regarding how different spectral radiations of varying intensity can affect plant growth and development. This review is an effort to briefly summarize the available information on the effects of light components on various plant parameters such as stem and leaf morphology and anatomy, stomatal development, photosynthetic apparatus, pigment composition, reactive oxygen species(ROS) production, antioxidants, and hormone production.     

Simultaneous synthesis of nano ZnO and surface modification of polyester fabric

In this study, synthesis of zinc oxide nanoparticles was carried out along with the hydrolysis of polyester fabric using sodium hydroxide to increase the surface activity and enhance the nanoparticles adsorption. The polyester fabrics were treated with zinc acetate and sodium hydroxide at different bath conditions, ultrasound and stirrer, resulting in formation of ZnO nanospheres and ZnO nanorods. The presence of zinc oxide with different shapes on the surface of the polyester fabrics was confirmed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Also, the X-ray diffraction patterns established the composition of wurtzite structure of zinc oxide. The self-cleaning property of treated polyester fabrics was evaluated through discoloring dye stain under sunlight irradiation. The antibacterial activities of the samples against two common pathogenic bacteria including Escherichia coli and Staphylococcus aureus were also assessed. The results indicated that the photocatalytic and antibacterial activities of the ultrasound treated polyester fabrics were superior compared to the stirrer treated samples.     

EFFECT OF HUMIC ACID APPLICATION ON CADMIUM ACCUMULATION BY LETTUCE LEAVES

The objectives of this study were to determine the effects of nitrogen (N) forms and deficient and toxic rates of boron (B) on the growth, NO₃ accumulation, membrane permeability, mineral nutrition, and nitrogen use efficiency (NUE) of bunch onion (Allium cepa L. var. Radar) plants. Therefore, 20% of NO₃ in reference nutrient solution was replaced by NH₄, urea, or mixed amino acids (AA). To each of these solutions 3, 30, or 300 mmol m^?3 B was added. Fresh and dry weights were the same in the reference and mixed AA treatments, but NH₄ and urea decreased these growth parameters as compared to the reference. Mixed AA decreased the NO₃-N content while urea increased it, and NH₄ treatment yielded similar NO₃-N content as compared to the reference. The nitrogen content of plants was increased by NO₃ replacement with either NH₄ and, urea or mixed AA. At the 300 mmol m^?3 B rate, B content of plants was decreased by NH₄ and urea, but increased by the mixed AA treatment. Membrane permeability was increased by NH₄?replacement of NO₃. Nitrogen use efficiency was found the highest in the reference treatment. Nitrogen and NO₃-N contents were increased by the 300 mmol m^?3 B rate. Increasing B in nutrient solution increased the B contents of plants. Mixed AA treatment decreased the phosphorus (P) content of plants. Potassium (K) and chloride (Cl) contents of plants were decreased in the NH₄ treatment where B was applied at the 3 mmol m^?3 rate. These results suggest that bunch onion growers may reduce NO₃ content in onion tops by partially replacing NO₃ with amino acids without reducing yield.     

Efficacy of starter N fertilizer and rhizobia inoculant in dry pea (Pisum sativum Linn.) production in a semi-arid temperate environment

ABSTRACT

Uncertainties exist about the importance of rhizobia inoculant and starter nitrogen (N) application in dry pea (Pisum sativum L.) production. Three field experiments were conducted to evaluate how rhizobia inoculant and starter N fertilizer affect pea seed yield and protein concentration in a semi-arid environment in central Montana. Commercial rhizobia inoculant was mixed with seed prior to planting at the manufacturer’s recommended rate. Starter N fertilizers were applied into the same furrow as seed at 0, 22, 44 and 88 kg ha^?1 as urea, slow-release polymer-coated N fertilizer (ESN), and a combination of both. The application of rhizobia inoculant had no or a very small beneficial effect on pea yield in lands with a previous history of peas. In a land without pea history, application of rhizobia increased pea seed yield by 16%. The positive effect of starter N was only pronounced when initial soil N was low (≤ 10 kg ha^?1 nitrate-nitrogen), which increased net return by up to US$ 42 ha^?1. In this condition, application of slow-release N outperformed urea. However, application of starter N (especially with urea) had a negative effect on pea establishment, vigor and seed yield when soil initial N was high (≥ 44 kg ha^?1 NO₃-N). The results indicate that the rate, placement and form of the starter N must be optimized to benefit pea yield and protein without detrimental effects on germination and nodulation. Moreover, application of starter N must be guided by the soil nitrate content.     

Factors Influencing Consumers' Attitudes Toward Organic Agricultural Products

The purpose of this study was to determine the factors influencing consumers' attitudes toward organic agricultural products. The study is correlational research. Results of regression analysis indicated that the variables of health awareness, knowledge of organic products, and consumers' motivations and age explained 32% of the changes in attitudes about organic products. The authors therefore recommend educational initiatives to increase knowledge and awareness and influence attitudes and consumption habits.     

Impact of land-use management on nitrogen transformation in a mountain forest ecosystem in the north of Iran

Soil inorganic N is one of the most important soil quality indexes, which may be influenced by land-use change. The historical conversion of land-use from native vegetation to agriculture resulted in sharp declines in soil N dynamics. This study was conducted to determine the soil inorganic N concentrations and net N mineralization rate in four common types of land-uses in the mountain forest area in the north of Iran, namely arable land, pine plantation, ash plantation, and beech stand. The soil samples were taken from top mineral soil layer (5cm) in each site randomly (n=6) during August- September 2010. Beech stand and ash plantation showed significantly higher total nitrogen compared with arable land and pine plantation, while extractable NH 4 + -N concentration was significantly greater in Beech stand compare to arable soils (p<0.05). No significantly difference was found in Net N mineralization, net nitrification and net ammonification rates among different land-uses. Results showed that net N mineralization and ammonification were occurred just in the soil of Ash plantation during the incubation time. Our findings suggested that conversion of Hyrcanian forests areas to pine plantation and agricultural land can disrupt soil natural activities and affect extremely soil quality.