جستجوی مقالات مرتبط با کلیدواژه « عناصر غذایی کم مصرف » در نشریات گروه « آب و خاک »

Determining the relative distribution of each chemical form of the elements and their relationship with the physical, chemical, and clay mineralogical properties of soils can help researchers to achieve the sustainable agricultural management. The present study was conducted to evaluate the chemical forms of four micronutrients (Zn, Cu, Fe and Mn) in some surface and subsurface soils of Kohgiluyeh and Boyer Ahmad province and their relationship with the physical, chemical and mineralogical properties of the soils. The results showed that the exchangeable and sorbed chemical forms of the studied elements were very low and negligible, but the residual, carbonate, and organic forms had the highest to lowest values of the chemical forms of these elements, respectively. Examination of the correlation of the chemical forms of these elements with soil properties showed the effective correlation of organic carbon values with the Zn chemical forms; also, there was a correlation between clay, silt, cation exchange capacity and calcium carbonate and the chemical forms of Cu, Fe and Mn. The correlation between the quantities of clay minerals and the chemical forms of these elements showed that the amounts of different forms of the studied elements were directly related to 2:1 clay silicate minerals (especially vermiculite). Evaluation of Fe and Mn chemical forms  also showed that the amounts of these elements were higher in the  soils with developed profiles (Alfisol and Mollisol), the  wetter climate and zeric moisture regime rather  than in soils with non-developed profiles (Entisols and Inceptisols) and a drier climate and a ustic moisture regime. In general, the results showed that variations of soil forming factors such as climate (as well as the  total amount of each micronutrients), could be effective on the chemical forms of micronutrients (especially on Mn and Fe);  these can be effective in the management of weakly to highly-developed soils orders.

The diagnosis and recommendation integrated system (DRIS) and deviation of optimal percentage (DOP) methods are used for interpreting the results of leaf analysis. In the present study, leaf samples from 98 wheat fields were collected in Moghan region of Ardebil province in 2014-2015. The nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), zinc (Zn), iron (Fe), manganese (Mn), copper (Cu) and boron (B) concentrations were determined. The wheat fields were grouped into high- and low-yielding subpopulation by using mean ± SD; then, the DOP and DRIS indexes were calculated. Based on the DOP and DRIS indices, the nutrient requirement order were determined as: Zn> Cu> Fe> Mn> P> N> K = Ca> Mg> B, and Zn> Mn = Fe = Cu> N = P> B > K> Mg > Ca, respectively. These results showed that there was a high degree of similarity between the two methods in interpreting the results of leaf analysis. After identifying the negative indices of some micronutrients (Zn, Fe, Mn, and Cu), a factorial field validation experiment was conducted with foliar application of Fe, Zn, Cu, and Mn using a randomized complete block design with three replications in two separate fields, with a total number of 96 plots, in 2015-2016. The results of the validation experiment showed marked decrease in the DRIS and DOP indices, indicating a more balanced concentration of nutrients. The order of the nutrients requirement in the DRIS method was Mg> P> N = K> Fe = B> Mn = Zn> Ca = Cu and in the DOP method Mg > N > Mn > P > K = Fe = Cu > Zn = B > Ca, which indicated the correct diagnosis of micronutrients deficiency by both studied methods. Micronutrients treatment in the validation test led to 28% increase in yield by balancing the nutrients. Since micronutrients, especially Zn, ranked the first priority of the deficiency for wheat in Moghan area, micronutrients should be used along with the phosphorus and nitrogen fertilizers.

An experiment was conducted to evaluate the effect of arbuscular mycorrhizal fungi (AMF) and vermicompost on biological yield، stem height، spike length، and concentration and uptake of zinc (Zn)، iron (Fe)، manganese (Mn) and copper (Cu) in straw of two wheat cultivars as a factorial experiment arranged in a completely randomized design (CRD) with three replications under greenhouse conditions. Treatments included two levels of AMF (with and without AMF)، two levels of vermicompost (0 and 1%، w/w)، and two wheat cultivars (Shiraz and Bahar). Results showed that maximum biological yield، stem height and spike length obtained by application of vermicompost (without AMF) in Bahar cultivar. Biological yield، spike length، Zn and Mn concentrations، and total uptake of Zn، Fe، Mn and Cu significantly affected by vermicompost application. Maximum concentration and uptake of Zn observed in AMF treatments (without vermicompost) in Bahar cultivar. Mn uptake was increased when vermicompost and AMF were applied to soil samples but it was decreased when AMF was not applied. Biological yield، stem height، concentration and uptake of Zn and Mn were higher in Bahar cultivar compared to Shiraz cultivar. It might be concluded that biological fertilizers increased the wheat yield which is a strategic product. Yield and micronutrients uptake in Bahar cultivar were higher than Shiraz ones.

Appropriate nutrition is necessary for obtaining high quality crop. In this research، the effect of different NH4+ / NH4+ + NO3- ratios on vegetative growth and N، K، Ca، Mg، and Fe concentration in apple seedling leaf was studied. The NH4+ / NH4+ + NO3- ratios were (0. 03، 0. 07، 0. 10، 0. 14، and 0. 04 meq L-1). Nutrient solution pH was adjusted at 6. 5 ± 0. 1. The experimental design was randomized complete block and was performed in three replicates. The results of the evaluation indicated that the increase in ammonium concentration caused significant (at 5% level) increase in leaf area، stem length، branches current year length، moisture content، and iron concentration of leaf. However، stem diameter، calcium، potassium، and magnesium concentration of leaf showed significant decrease with increasing concentration of ammonium. Number and diameter of current year branches as well as total nitrogen concentration did not show significant differences under different NH4+ / NH4+ + NO3- ratios.

A hydroponics experiment was conducted to compare effect of Fe-deficiency on concentration, uptake, translocation of Fe, Zn, Mn in some plants. A completely randomized block design in triplicates was conducted in research greenhouse. Seven plants with different Fe-efficiency contained two bread wheat genotypes (Triticum aestivium L. CVs. Backcross Roshan and Qods), triticale (X. Triticosecale Cv eleanor), dent corn (Zea Mays L. CV. S.C704) and two safflower (Carthamus tinctorius L. CVs Arak2811 and Koose) were grown in a nutrient solution at two Fe levels of 5 and 50 µM Fe EDTA. The most tolerant and the most sensitive of plants to Fe-deficiency were bread wheat (Qods genotype) with 125% Fe-efficiency and safflower (Arak2811) with 3.5% Fe-efficiency, respectively. A significant and positive correlation was found between the Fe-efficiency and Zn, Fe and Mn contents and root to shoot translocation of Fe among the studied crops. Large variation was found among the studied crops in shoot and root Zn, Fe and Mn content. The Qods and cross back Roshan wheat genotypes accumulated greater Zn, Fe and Mn in their shoots compared to other genotypes. Higher uptake and root to shoot translocation of microelements in the Fe-efficiency genotypes is an important aspect for biofertilization programs with the aim of improving crop quality.