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Soil salinity and arbuscular mycorrhizal fungi (AMF) influence the soil hydrophobicity. An experiment was performed to determine the effects of soil salinity and AMF species on soil water repellency (SWR) under wheat (Triticum aestivumL.) crop. Six AMF treatments, including four exotic species (Rhizophagus irregularis, Funneliformis mosseaeandClaroideoglomus claroideum, a mix of three species), one mix native AMF species treatment and an AMF-free soil in combination with four salinity levels (1, 5, 10, and 15 dS m−1) were used. The soil repellency index (RI) increased with salinity increment ranging from 2.4 to 10.5. The mix of three exotic and native AMF treatments enhanced the RI significantly compared to AMF-free soil in all salinity levels with one exception for native treatment at 1 dS m−1. Among individual AMF species, theC. claroideumtreatment at 10 dS m−1increased the RI by 67% compared to AMF-free soil. The native AMF treatment was more efficient in root colonization, glomalin production and SWR development at 10 and 15 dS m−1, compared to exotic species. In addition to the net positive effect of salinity on SWR, the AMF influences on the RI were greatly dependent on salinity levels. [ABSTRACT FROM PUBLISHER]

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Integrated nutrient management is a major agronomic practice which brings together all methods to support plants nutritional requirement. However, the interaction of these methods together is very complex and needs to be studied in different climatic conditions. So, the effect of nitrogen fertilizer and Azospirillum lipoferum inoculation on maize (Zea mays L.) growth, yield and nutrients uptake was determined in this study. The hypothesis was that the bacterial inoculation decreases the need for N fertilizer application without reducing plant yield. Therefore, we carried out a factorial experiment in a randomized complete block design with three replications. Nitrogen at 0, 25, 50, 75 and 100 % concentrations of the recommended dose, i.e. 150 kg N ha-1 (based on the soil sample analysis) were applied with or without A. lipoferum inoculation. There was a significant effect of N and A. lipoferum inoculation on most of the variables. In most cases, there was no significant difference between the two highest doses, i.e. 75 % and 100 % of N. Most variables showed their highest value in the interaction of A. lipoferum ×100 % N. But, the value of most variables was the same as in uninoculated ×100 % N or inoculated ×50 % N. Azospirillum lipoferum inoculation could be an alternative to high N fertilizer rates, increasing soil fertility and maize yield in sustainable farming. In conclusion, 75 % of the recommended N application rate along with A. lipoferum inoculation has the best effect on the variables increasing grain yield by 136.5 %. [ABSTRACT FROM AUTHOR]

It has been previously indicated that arbuscular mycorrhizal (AM) fungi can enhance the bioremediation abilities of their host plant. Barley (Hordeum vulgareL.) is a crop plant with some unique physiological properties, such as tolerance to salinity. However, its tolerance to other stresses such as heavy metals must be tested. Accordingly, it was hypothesized that barley can be efficiently used to treat heavy metals in symbiotic and non-symbiotic association with AM fungi. In a greenhouse experiment barley plants were inoculated with the AM speciesGlomus mosseaeand grown in a soil polluted with cadmium (Cd), cobalt (Co), and lead (Pb). Relative to Cd and Co, mycorrhizal barley absorbed significantly higher amounts of Pb. AM species also significantly decreased Cd and Co uptake by barley indicating the alleviating effects ofG. mosseaeon the stress of such heavy metals. [ABSTRACT FROM AUTHOR]

In recent years, applying humic acid (HA) has been common in turfgrass management. A series of experiments were conducted to evaluate the effect of HA on qualitative and quantitative characteristics of “Speedygreen” perennial ryegrass (Lolium perenneL.). Different concentrations of HA (0, 100, 400, and 1000 mg L−1) were applied monthly as foliar application. Results showed that leaf phosphorus (P), potassium (K), and zinc (Zn) content, fresh and dry weight, chlorophyll content, and root fresh weights were not affected by HA. Meanwhile, HA improved the root and shoot development, except for root fresh weight. While just 100 mg L−1improved height, visual quality, nitrogen (N) content, roots length, and surface of roots, all of HA concentrations were effective on iron content. These results suggest that HA foliar application might be of benefit to enhance some nutrients uptake and root development of ryegrass possibly leading to improved drought resistance. [ABSTRACT FROM AUTHOR]

Nitraria schoberi plays an important role in restoration projects in arid areas of Iran. Improving the vegetative properties of this plant is critical to the success of these projects. This study was designed to achieve the best chemical, biological, and mechanical treatments to improve vegetative properties. The experiment was performed in a completely randomized design in two sections of cultivating trays and bags. Chemical treatments were 1000, 2000, and 3000 ppm salicylic acid and gibberellic acid. Biological treatments included Azotobacter chroococcum, Azospirillum lipoferum, Bacillus megaterium, Flavobacterium sp. and Pseudomonas flourescens. The 24 kHz wavelength of the ultrasonic device )for 5 minutes( formed a mechanical treatment. Germination percent, seed vigor index, root and shoot length, seedling growth, fresh and dry weight of root, shoot and leaf number in both cultivating trays and seedling bags, and leaf area in cultivation trays and shoot diameter in seedling bags measured. According to the results, all traits were significantly different in cultivating trays (p ≤ 0.01) except for germination percent and shoot length. In seedling bags, seed vigor index, root length, seedling growth, root and shoot fresh weight, shoot dry weight, leaf fresh and dry weight, shoot diameter, number of leaves, and root to shoot ratio showed significant differences. There was no statistically significant difference between germination percent, shoot length, and root dry weight. Maximum seed vigor index, root length, and leaf dry weight in both of the bags and trays were seen in 2000 ppm salicylic acid treatment. Also, fresh weight of root and shoot, root dry and fresh weight, and the number of leaves in cultivating tray and in seedling bag root to shoot ratio, shoot diameter, and seedling growth in salicylic acid treatment 2000 ppm was seen. The most leaf area was in 1000 ppm salicylic acid treatment. Azospirillum increased root, shoot and leaf fresh weight, leaf number and shoot dry weight in the seedling bag. Results indicated that salicylic acid priming and seed inoculation with Azospirillum are suitable for produce seedlings with better properties. [ABSTRACT FROM AUTHOR]