Ghasem Ghorbani Nasrabadi; Esmaeil Dordipour; mojtaba Barani; Elham Malekzadeh; Abdolreza Gharanjiki
Abstract
Introduction Salinity is one of the most important environmental stresses limiting agricultural production in arid and semi-arid regions, which occupies a relatively large area of arable land. Nutrient availability is decreased in saline conditions in soil solution and plant nutrient balance is changed. ...
Read More
Introduction Salinity is one of the most important environmental stresses limiting agricultural production in arid and semi-arid regions, which occupies a relatively large area of arable land. Nutrient availability is decreased in saline conditions in soil solution and plant nutrient balance is changed. Nitrogen fertilizer management as an essential nutrient for plant growth is very important under salinity stress. Also, salicylic acid is a plant growth regulator involved in defense mechanisms of plants against biotic and abiotic stresses. Therefore, the aim of this study was to investigate the effect of salinity on the concentration of nutrients in wheat in response to salicylic acid consumption at different levels of nitrogen.Materials and Methods In order to investigate the effects of salicylic acid and nitrogen fertilizer application rates at different salinity levels on nutrient concentration of wheat cv. Morvarid, an experiment was conducted as a split plot factorial based on a randomized complete block design with four replications in the fields of Mazraeh-E-Nemooneh located in Anbarolum, Aq Qala city, Golestan province. The main factor included three soil salinity levels (3-4 below wheat tolerance threshold (control), 9-11 and 13-15 dS.m-1) and sub factors included two levels of salicylic acid (0 and 1.5 mM) and three levels of N fertilizer (from urea source, 46% N) were 1) N based on soil test recommendation, 2) 30% N more than soil test recommendation and 3) 30% N less than soil test recommendation, respectively. Salicylic acid was foliar applied twice for about 2 weeks in the tillering stage and 10 days after the second stage spraying, content in them was determined. Nitrogen treatments were applied in three stages - one third before planting with ammonium sulfate (21% N) and remains top-dressed with urea (46% N) at tillering and stem elongation stages. At the emergence stage of the cluster or the beginning of flowering of wheat, the amount of nitrogen in the flag leaf was measured. The concentrations of nitrogen, potassium and sodium in grain and straw were also measured by standard methods.Results and Discussion The results showed that by increasing salinity, the flag leaf N concentration, N and K concentration of wheat staw and seed decreased. However, Na concentration of straw and seeds increased. With increasing N and salicylic acid consumption, the concentration of N flag leaf, the seed and straw N and K concentrations increased, but the concentration of Na in seed and straw decreased.The interaction of salinity, salicylic acid and nitrogen on seed N and K concentrations and also on flag leaf N concentration was significant but there was no significant effect on other measured elements. Comparison of the mean of simple effects of salinity on the evaluated elements indicates a significant reduction of all studied elements due to salinity treatment. Also, comparison of the mean of simple effects of nitrogen fertilizer showed that all elements were affected by the treatment. The results of mean comparison showed a positive and significant effect of salicylic acid on the leaf N concentration of the flag leaf, so that the N concentration in the flag leaf in a 1.5 mM salicylic acid treatment was significantly increased compared to the non-use treatment.Conclusion according to the results, more nitrogen consumption at moderate salinity can have a positive effect on plant nutrition, and vice versa, at high salinity levels, it is better to reduce nitrogen consumption. The interactions of salicylic acid and nitrogen showed that in general nitrogen treatments with salicylic acid increased the N concentration of seed and straw. Nitrogen fertilization at higher and medium salinity levels increased the concentration of N and K in straw and seeds; However, at high salinity, less nitrogen fertilization improved the concentration of N and K. Also, nitrogen application with salicylic acid improved these traits under saline conditions. Therefore, the application of salicylic acid and nitrogen fertilizer management to some extent reduced the adverse effects of salinity up to moderate salinity levels and improved plant nutrition by increasing plant tolerance to salinity.Therefore, the application of salicylic acid and nitrogen fertilizer management to some extent reduced the adverse effects of salinity up to moderate salinity levels and improved plant nutrition by increasing plant tolerance to salinity.Key words: Salicylic acid, salinity stress, wheat, Nitrogen fertilizer management
Plant Nutrition, Soil Fertility and Fertilizers
Esmaeil Dordipour; Zeinab Bastamikojour; Mojtaba Baranimotlagh; Abdolreza Gharanjiki; Mohsen Olamaee
Abstract
Introduction The most important constraint in maize crop yield in developing contries worldwide, and especially among resource-poor farmers, is soil infertility. Therefore, maintaining soil quality can reduce the problems of land degradation that decreases soil fertility and rapidly declining production ...
Read More
Introduction The most important constraint in maize crop yield in developing contries worldwide, and especially among resource-poor farmers, is soil infertility. Therefore, maintaining soil quality can reduce the problems of land degradation that decreases soil fertility and rapidly declining production levels that occur in large parts of the world which needing the basic principles of good farming practice. For optimum plant growth, nutrients must be available in sufficient and balanced quantities. After nitrogen, phosphorus is the most limiting nutrient for crop yields, and is essential for maize growth and development. Large quantities of chemical fertilizers are used to replenish soil N and P, resulting in high costs and severe environmental contamination. Maize quantity and quality are increased by utilization of fertilizers, which has become the most important objective of these products worldwide. Phosphorus, is the second most important macronutrient required by the plants, next to nitrogen, and is reported to be a critical factor of many crop production systems due to its limited availability in soluble forms in the soils. The low availability of P to plants is because the vast majority of soil P is found in insoluble forms, and plants can only absorb P in two soluble forms, the monobasic (H2PO4-) and the dibasic (HPO42-) ions. Crop plants can therefore utilize only a fraction of applied phosphorus, which ultimately results in poor crop performance. To rectify this and to maintain soil fertility status, frequent application of chemical fertilizers is needed, though it is found to be a costly affair and also environmentally undesirable. Moreover, phosphorus (P) is an essential nutrientionl element for plant growth. Calcareous soils are frequently characterized by the low availability of P for plant uptake due to the low solubility of P compounds present in soils at high pH and the formation of relatively insoluble complexes, e.g., Ca-P. Many soils in Iran have received large amounts of P fertilizer and consequently contained a high level of available P. On the other hand, the root exudation of organic acids has been suggested to increase P availability in calcareous soils. The most common low-molecularweight organic acids (LMWOAs) identified in soils include oxalic, succinic, tartaric, fumaric, malic, and citric acids and are derived from the decomposition of soil organic matter in the upper soil horizons, microbial metabolites, canopy drip, and root exudation. The concentrations of organic acids in the rhizosphere or in soil solutions vary greatly and range from 10-2μM to over 80 mM. The ability of organic acids to release inorganic anions, such as P, has been reported and has been attributed to desorption of inorganic anions and solubilization of phosphate compounds. LMWOAs and their corresponding anions play a very important role to increase P bioavailability. Many studies have been conducted about the role of organic acids in increasing P availability, but these studies focused on acid soils in which Fe- or Al-bound P is the main P fraction. For calcareous soils where Ca-bound P is the main P fraction, questions that whether organic acids can mobilize P or not still exist. Although, a number of results show that addition of organic acids, especially citric and oxalic acids to soils can solubilize significant quantities of fixed P and reduce the sorption of newly applied fertilizer P. However, there are few studies on the transformations of P fractions induced by organic acids or organic anions, which are important for understanding the mobilization mechanisms of P and for exploring better ways of using different forms of P in soils. The objective of this study is to examine the effects of some organic acids and anions on the solubilization and plant uptake of soil P in some calcareous soils of Golestan province, Iran. Material and Methods For this purpose, a factorial pot experiment in a completely randomized design with three replications was conducted on maize. The first factor was comprised of 6 soil types from various areas of the province and the second factor was consisted of a combination of phosphorus fertilizer and organic acids (1) control, (2) 50 mg P kg-1, (3 and 4) 50 mmol kg-1 of organic acids (oxalic and malic acids), (5) P + oxalic acid and, (6) tomato fruit residue (25% w). After 10 weeks, plants were harvested and the parameters such as plant height, fresh and dry weights, phosphorus concentration and its uptake were determined. Results and Discussion Results indicated that soil type effect was statistically significant on the plant fresh and dry weights (P≤ 0.05), height, concentration and uptake of P (P≤ 0.01), respectively. Results also showed that the tomato fruit residue treatment in comparison with P fertilizer and malic acid treatments results in a significant increase in P taken up, and fresh and dry weights (P≤ 0.05). There was a significant difference between P fertilizer + oxalic acid and oxalic acid alone treatments in only plant height (P≤ 0.05). Also, no significant differences in terms of measured plant parameters were observed between malic acid and blank treatments (P≤ 0.05). Conclusion Application of tomato fruit residue rather than P fertilizer can help to take up residual soil P, to grow plants and to decrease of environmental pollution, and to be also affordable economically.
Plant Nutrition, Soil Fertility and Fertilizers
G. Roshani; A. Gharanjiki
Volume 37, Issue 2 , March 2015, , Pages 87-99
Abstract
The fertility maps are useful tools to know about the land resources. These maps are essential to do a correct fertilizer recommendation, monitoring the changes of soil fertility level and also to do prediction of toxicity or deficiency of necessary plants nutritional elements in the soil. The present ...
Read More
The fertility maps are useful tools to know about the land resources. These maps are essential to do a correct fertilizer recommendation, monitoring the changes of soil fertility level and also to do prediction of toxicity or deficiency of necessary plants nutritional elements in the soil. The present research was carried out to digital mapping of macro and micro elements as well as some important physical and chemical properties of the soil for agricultural service centers of Golestan province to optimize the use of chemical fertilizers in operating plan pattern. The studied areas were under irrigated and rain-fed wheat cultivation and the total surface area was about 520000 hectares. Using based maps with the scale of 1: 50,000, the area was divided into 5200 grids each having one kilometer square area. Using Global Positioning System (GPS) instrument a composite soil sample was taken from the center of any grid and analyzed for major macro- and micronutrients as well as physical and chemical properties of the soil namely; pH, EC,TNV, sand, silt and clay contents. At the time of sampling, some additional information like latitude, longitude, elevation, owner's name, date of sampling, kind of water resources, possibility of water logging, crop history (present and previous) was collected and recorded. After getting the laboratory results, for the above stated data sets, an electronic layer was created for any particular parameter and after doing interpolation, the layers were polygonized. Anisotropy of the data sets in different directions was evaluated by the help of variogram surface operation. Then spatial correlation of each data set was calculated. After variogram analysis, spatial variation of the data sets was studied and a suitable model was selected. Finally, through point interpolation using kriging technique, the digital map of each parameter was established.
