نشریه مدیریت خاک و تولید پایدار
سال نهم شماره 3 (پیاپی 29، پاییز 1398)

The assessment of soil quality for agricultural land is essential for the economic successes and sustainability of the environment in developing countries. Currently, many types of methods with different factors are used to evaluate soil quality. Soil quality evaluation is an indicator of sustainable agriculture and optimized application of utilization of natural resources. Moreover, the Bardsir city is one of the most important regions of Rose (Rosa Damasceneea Mill) in Kerman province and Iran. In this research, soil quality were evaluated in a part of the cultivated land of Rose using integrated soil quality index (IQI) and Nemoro soil quality index (NQI) in combination with two of data sets, total data set (TDS) and minimum data set (MDS) for 0-25 and 25-50 cm depth.

In this research, a farm with an area of 30 hectares was selected in Bardsir city, Kerman province. Then, 100 locations were sampled to determine soil characteristics (0-25 and 25-50 cm), then in each location, the yield was determined. Among the total characteristics of soil quality, the most important of characteristics were determined Using principal component analysis (PCA). The results showed that in the topsoil and subsoil, minimum data set were organic matter, sand, Mn, calcium carbonate equivalent, Zn, Cu and sand, K, calcium carbonate equivalent, Zn, P, fragments and Mn, respectively.

The results showed that at the 0-25 cm, the correlation between IQITDS and IQIMDS and between NQITDS and NQIMDS were 0.85 and 0.79, respectively. Also, at the depth of 25-50 cm, the correlation between IQITDS and IQIMDS and between NQITDS and NQIMDS were 0.75 and 0.77, respectively. The geostatistical analysis of soil quality indices showed that all of the studied soil parameters and Rose yield have spherical model and strong to medium spatial structure. The range of variograms is varied from 119.33 m for IQITDS in the subsoil to 151.8 m for NQITDS in the topsoil. Besides, the range of variogram for Rose yield was 122.16 m. The correlation between kriging maps of Rose yield and soil quality indices showed that the highest correlation was found between the yield and the IQITDS index at both studied depths. The results of correlation between soil quality indices and Rose yield showed that the IQITDS index has a higher correlation with yield than other indices.

These results demonstrated that the IQI index, especially in the TDS set, has a better performance for assessing the soil quality in the study area. Because of the relatively good correlation between this set and MDS, the TDS set is better to determine soil quality indices; this result may be attributed to use MDS to determine the soil quality indices with proper accuracy. However, if the purpose of soil quality assessment is to achieve the optimal yield, the use of IQITDS index, due to its greater correlation with the Rose yield, has a better performance.

The shortage of phosphorus is one of the major problems of calcareous soils. One of the most effective and economical ways to increase phosphorus availability is through the addition of organic fertilizers. Vermicompost is the most desirable organic material and bio fertilizers, but the high usage of vermicompost to achieve optimal performance and the presence of organic insoluble phosphates are limited the use of vermicompost. One of the best way is that enriched vermicompost with plant growth-promoting bacteria, especially phosphate solubilizing bacteria.

Vermicompost sample was produced in Vermicompost Research Center of Tehran University. 18 isolates with ability of organic and inorganic phosphate solubilizing were isolated. Finally, two isolates 53 and 22 which had high solubilizing capacity of inorganic and organic insoluble phosphate were purified and identified. An incubation experiment was conducted in the Split plot design based on time to investigate the enrichment of vermicompost with phosphate solubilizing bacteria on available phosphorus, pH, microbial respiration, alkaline phosphatase and dehydrogenase enzyme activity in pots with 4 kg of soil consist of 5 treatments, including T1: vermicompost (6%) + B53; T2: vermicompost (6%) + B22; T3: positive control (Triple superphosphate fertilizer at 50 mg/kg); T4: vermicompost (6%) and T5: negative control (soil without vermicompost and bacteria), in 3 replicates. The treatments were incubated for 30 days and after incubation, the effect of treatments on phosphorus availability, pH and biological indices was measured.

The results of the 16S rRNA gene sequence identified isolate 22 as Serratia marcescens with 99% similarity and isolate 53 as Pseudomonas aeruqinosa with 98% similarity. the use of vermicompost enriched with phosphate solubilizing bacteria (T1 and T2) increased available phosphorus (59.2% and 100%), microbial respiration (58% and 61%), Alkaline phosphatase activity (34 and 41%) and dehydrogenase activity (102.6% and 13.7%) significantly compared to control treatment (T4), but reduced pH (4.7% and 4.4%). According to the results, bacterial enriched treatment Serratia marcescens (T2) was more able to increase phosphorus and biological indices.

The application of vermicompost enriched with phosphate solubilizing bacteria (T1 and T2) cusses increase of the available phosphorus, microbial respiration, alkaline phosphatase enzyme activity and dehydrogenase activity and soil pH reduction. The treatment enriched with Serratia marcescens (T2) had more ability to increasing phosphorus availability and biological index. The results showed that vermicompost enrichment with phosphate solubilizing bacteria can be a suitable alternative for reducing the use of phosphate fertilizers and as a suitable strategy for better vermicompost management in calcareous soils in the future.

Wheat is one of the most important food crops. In modern agriculture, Due to the increasing human population and the detrimental effects of chemical fertilizer such as environmental pollution and concerns about human health, adapting suitable alternatives like production of bio-fertilizers which have none of these dangerous effects would be necessary. Plant growth-promoting fungi and bacteria used in bio-fertilizers are the beneficial microorganisms that can enhance plant growth, yield and resistance to biotic and abiotic stresses directly or indirectly through a wide variety of mechanisms. Although bio-fertilizers have become more noticeable in recent years, the lack of accurate identification of microorganisms used in the production of these fertilizers is one of the problems of bio-fertilizers in Iran. Failure to accurate identification of species is due to deficiencies in morphological or biochemical methods in fungi and bacteria. Therefore, the purpose of this study was to identify of fungal and bacterial isolates molecularly and also to investigate the effect of these isolates alone and in combination with arbuscular mycorrhizal fungus on some growth characteristics of the wheat plant.

After the preparation of fungal and bacterial isolates from the Soil and Water Research Institute, which are known as plant growth promoting microorganisms, accurate identification of each isolate was performed based on morphological and molecular methods. Extraction of genomic DNA in arbuscular mycorrhizal fungus was done by single-spore method and in other bacterial and fungal isolates by CTAB method. Amplification of 16S rDNA region in bacterial isolates, TEF-1α and ITS1-5.8S-ITS2 regions in Trichoderma species, ITS1-5.8S-ITS2 region in Serendipita indica and SSU-ITS1-5.8S-ITS2- LSU region by nested PCR method in the arbuscular mycorrhizal fungus was performed. To investigate the effect of fungal and bacterial isolates alone or in combination with arbuscular mycorrhizal fungus in a greenhouse, their effect on wheat growth indices such as plant height, shoot and root dry weight, head height and weight and dry weights of seeds were measured.

Based on morphological and molecular investigation, three species of Bacillus including Bacillus velezensis, B. pumilus, and B. subtilis and three species of Trichoderma including Trichoderma atroviride, T. longibrachiatum, and T. harzianum and S. indica and Rhizophagus irregularis were identified. T. harzianum + R. irregularis and T. longibrachiatum showed the maximum dry weight and head weight. T. longibrachiatum + R. irregularis and T. atroviride showed the highest effect on plant height. Pots treated with T. harzianum + R. irregularis, T. harzianum, T. atroviride, and S. indica+ R. irregularis showed the highest weight of seeds compared to control plants.

The result showed that the effect of fungal treatments such as T. harzianum + R. irregularis and Trichoderma spp. on growth characteristics of wheat was significant. According to the results of this study, the use of an appropriate combination of inoculants and the preparation of primary formulations for use in farm experiments is proposed to increase the availability of nutrients and improve the growth of wheat plants. Keywords: Arbuscular mycorrhizal fungus, Bacillus, Plant growth promoting fungi, Trichoderma

Root stabilization of toxic metals by mycorrhizal plants is one of the protective mechanisms of symbiotic arbuscular mycorrhizal (AM) fungi in response to metal stress. Role of the glomalin as a specific glycoprotein of spore and hyphal cell wall of AM fungi can be remarkable in sequestration of toxic metals and reduction of stress effects on host plant. Considering this hypothesize, the study was conducted to investigate the role of glomalin produced by Rhizophagus irregularis fungus symbiosis of clover plant in root stabilization of Pb.

A pot culture experiment was performed as completely randomized block design by two factors including AM fungus (inoculated with R. irregularis and non-inoculated) and four levels of Pb+2 (0, 150, 300 and 450 µM) with five replications. For glomalin extraction, root samples were autoclaved at 121˚C with 50 mM sodium citrate buffer for 1 hr in three cycles. Glomalin concentration in the extracted samples were determined by ELISA method using monoclonal antibody 32B11. After precipitation of the glomalin and its digestion in concentrated nitric acid, Pb-sequestrated by the glomalin were measured. Shoot and root dry weights, root colonization percentage, shoot and root P and Pb contents, and plant uptake, extraction and translocation efficiency of Pb were assessed.

Shoot and root dry weights of mycorrhizal (M) and non-mycorrhizal (NM) plants were decreased by increasing of Pb levels. At the levels of 150, 300 and 450 μm Pb, shoot and root dry weights were decreased by 11.2%, 12.9%, 18.3% and 7.5%, 18.1%, 36.7% compared to the control (0 μm Pb), respectively. Shoot and root dry weights of M plants were increased by 24.9% and 43.2% compared to the NM ones. P contents of shoot and root were affected by AM fungus, so that the shoot and root P contents of M plants were increased by 32.2% and 45.8 % compared to the NM ones. At different levels of Pb, shoot and root Pb contents in M plants significantly were higher than NM ones. Maximum contents of Pb of shoot and root were recorded at level of 450 µM Pb in M plants which were increased by 46.5% and 80.7% compared to the NM ones at the same level. At the levels of 150, 300 and 450 µM Pb, the uptake efficiency of Pb in M plants was increased by 8%, 14.5% and 80.7% compared to the NM ones at the same levels. Based on ANOVA results, Pb-extraction and translocation efficiency were affected by Pb treatments. Pb-extraction efficiency of plants was increased as Pb concentration increased, so that the content of Pb-extraction efficiency at 450 µM of Pb was increased by 69.3% and 27.8% compared to the 150 and 300 µM of Pb, respectively. Plant Pb-translocation efficiency from root to shoot was decreased as Pb concentration increased. The percentage of root colonization was increased as the Pb concentration increased up to 300 µM Pb and then was slightly decreased as the level of Pb rose from 300 to 450 µM, but there was no significant difference between the levels of 150, 300 and 450 µM Pb. Glomalin production in root and Pb sequestrated by glomalin was significantly increased as Pb concentration increased.

Root colonization of clover plant by R. irreqularis led to improved growth and phosphorus nutrition of M plants compared to the NM ones, under Pb stress condition. Pb uptake was greater in roots than in shoots, therefore the clover plants played a more effective role in root stabilisation of Pb.

Two problems of increasing costs and environment effects have enhanced the important of nutrition temporal management and its effects on productivity. In typical agricultural activities, inputs such as chemical fertilizers, plant pesticides and water are used uniformly and without regard to their actual needs in farms and orchards. However, given the high emphasis on the quality and efficiency of food production, it is necessary to use inputs based on actual needs in terms of time and place.

In this study, at first, the scientific points of view were determined related to deficiency and toxicity symptums and time management of nutrition. Then, growers' attitude and behavior regarding temporal management of this input was evaluated. Comparing growers' knowledge with experts' idea, the pistachio producers' number related to temporal management of nutrition and was calculated. Using questionnaire method, data was collected. Pistachio producers of Anar and Rafsanjan cities in Kerman province were study population. Using stratified random sampling method, a sample of 100 farmers was selected. As, more than one orchard were considered for each grower, final sample size was 286. Also, for measuring the effects of socio economic factors on growers' knowledge and also the effects of growers' knowledge on pistachio yield, Pearson correlation, variance analysis and regression methods were used.

The results showed that average of farmers' knowledge regards to temporal management of nutrition and recognizing the symptums of deficiency and toxicity nutrients is low and is very different among pistachio producers. Among the three indicators of deficiency and toxicity of elements, the time of elements application during the year and based on the plant growth stage, farmer's knowledge about the application time of the elements during the year was the best and about plant growth index was the worst condition. Also, among the elements studied, nitrogen is the best, followed by phosphorus and potassium.The results, also, showed that research and extension activities have had the significant effect on increasing knowledge of input temporal management. Also, knowledge of nutrition temporal management has increased land productivity. In this regard, one number increasing in farmers' knowledge will enhance pistachio yields, 21.32 kilogram per hectare. In other words, a person who receives 20, his yield is 426 kilogram per hectare more than a person who receive zero.

The knowledge of farmers and the impact of this knowledge on productivity of fertilizer use can be increased with the quantitative and qualitative increase in education and extension, raising the quality level of human resources employed in agriculture, improving water and soil conservation guidelines and reforming the rules for paying subsidies.

Wind erosion is a serious problem in many parts of the world, especially in arid and semi-arid regions and it is an important factor in soil degradation and loss. In most area, conservation operations against the wind erosion are appropriate practices.There are two main strategies to combat wind erosion. These first strategy is to increase the strength of erodible bed against erosive factorsand second one is to reduce the force of erosive factors. Seedling is the more effective solution to reduce speed of wind, to combat wind erosion and to stabilize the drifting sands. Therefore, the objective of this research was to study the effect of mechanical and biological management practices on the amount of wind sediment in Tal-Hamid area, which is located in Tabas (Khorasan Razavi province, Iran).

In order to determine the role of each management practices on wind erosion and its control, sediment traps were established at different distance between conservational practices at 0.5, 1 and 1.5 meters from the surface of the earth. Conservational treatments included T1 (4 rows seedlings of Haloxylon persicum and 3 rows native plant of Stipagrostis) T2 (fence and sand channel), T3 (one row of Hammada Salicornica, 3 rows seedlings of Haloxylon persicum, and one row Stipagrostis), and T4 (moat and Railroad tie). Also, a control sediment trap was regarded in adjacent area without any conservational practices. The management practices had been performed for 3 years. After then sediment traps were established in December 2015, and according to wheatear information, after each wind storm (two times in each month) the trapped sediments were collected and weighted in established sediment traps for each treatments from January to June 2016 (spring and winter seasons).

The results showed that all conservational practices were effective to reduce amount of sediment and the effect of T1 and T2 in reduction the wind sediment was considerably greater than other treatments. The more reduction of sediment load was found at height less than 0.5 m, therefore it can be concluded that the biological and mechanical practices could considerably prevent the saltation movement of sand particles. The wind sediment during the spring (due to lower moisture content and greater wind speed) was more than the winter. In addition, among the conservational treatments, the lowest value of wind sediments was related to mechanical management practices (fence and channel) and the highest amount of wind sediments was related to biological management practices (four rows of Haloxylon, and native plant i.e. Stipagrostis) in both seasons, because T4 and T3 are the first hedges against wind direction and they are located behind T2, and considerably have decreased the speed of wind, therefore when low speed wind reach to T2 its speed and energy is low. As a result of this, the sediment load In T2 was the lowest.

In general, biological and mechanical management practices decreased considerably the amount of wind sediment compared to the control. In spite of common viewpoint, the biological management practices may decrease the wind erosion, but due to unsuitable growth of Haloxylon seedlings and plants as a result of drought duration and deficiency of water, their efficiency in reduction of wind speed and energy especially T1 and T3 was not more than mechanical management practices (T2). It seems that during 3 years Haloxylon seedlings have not been grown sufficiently, and if they grow for long time, they can decrease the wind erosion considerably. According to results of this research, application both simultaneous biological and mechanical practices are needed to control wind erosion in arid regions such as Tabas.

Increase of water holding capacity induced by polymers has been developed in arid and semi-arid regions. The effect of polymers on increasing water holding capacity and the effect of selected polymers on some growth characteristics of corn plant under drought stress was carried out in both experimental and greenhouse condition, respectively.

The present research included two complementary parts performed in laboratory and greenhouse. First, the effect of 11 polymer treatments (polymer type and concentration) including Karacoat 1and 3 %, Acrylic 1 and 3 %, Polyvinyl acetate 1 and 3 %, Superab 0.5 and 1 %, Stockosorb 0.5 and 1 % and control without polymer on moisture changes of two soils (loamy sand and sand) during 11 times (0, 12 h, 1, 2, 4, 6, 8, 10, 12, 16, 20 day) were studied in laboratory and 4 best polymer treatments were selected for greenhouse cultivation. In greenhouse, the effect of polymer treatments (Karacoat 1and 3 %, Stockosorb 0.5 and 1 % and control without polymer) under drought stress (30, 50 and 80 % field capacity) on some growth characteristics of corn plant (leaf number, height, wet and dry weight of stem and wet and dry weight of root) were studied separately in loamy sand and sandy soils.

Results showed that increase of moisture in both treated soils was higher than control and from this point of view, water soluble polymer-Karacoat 3 % (18.5 % compared to loamy sand control and 35.9 % compared to sandy control) and Stockosorb 1 % hydrogel (95.8 % compared to loamy sand control and 3.4 times compared to sandy control) were more powerful. Mean moisture after 20 days for water soluble polymers and Superab hydrogel was higher in loamy sand than sandy soil. But, Stockosorb 1 % hydrogel was more effective in sandy soil (16.1 % increase compared to loamy sand soil). With increasing polymer concentration, the moisture content of polymer treated soil samples increased. To increasing water holding capacity Stockosorb 1% hydrogel in loamy sand (0-12 day) and sandy (0-16 day) soils was more successful than other polymer treatments. Both water holding capacity during the time and final moisture content in sandy soil treated with polymers were more than loamy sand soil. Leaf number, stem height, wet and dry weight of stem and dry weight of root in corn plant were reduced under drought stress. In contrast, height, wet and dry weight of corn stem were better in stockosorb hydrogel 1 % treatment. Wet weight of corn stem in loamy sand soil under drought stress was significantly affected (P < 0.01) by stockosorb hydrogel. Stockosorb 1% hydrogel increased wet weight of stem 59.29, 82.41 percent and 3.82 time in low, medium and severe stress compared to control, respectively.

According to the results karacoat 3 % and stockosorb 1 % are recommended for increasing moisture and water holding capacity of coarse texture soils. Moreover, polymer materials with properties such as useful longevity, high efficiency at low concentrations, and local application in the root zone of trees could provide ideal condition for plant which growth in soils with low water holding capacity. In addition, they are ideal for drought condition that is common in arid and semi-arid regions where rain is low and evaporation is high.

The salt-affected soils are widely distributed in arid and semi-arid areas including Iran. In the soils affected by excessive salt, physical, chemical and biological changes in coupling with the low levels of organic matter (OM) resulting from the weak growth of plants, cause the deficiency of such nutrients as nitrogen (N) on the one hand and ionic toxicity (sodium and chlorine) on the other hand. The lack of vegetation in arid and saline areas results in the return of small amount of plant residues, so that the content of soil organic matter and thus the amount of nitrogen and other elements is reduced. One of the ways to increase the vitality and efficiency of elements in saline conditions for plants is to use organic fertilizers. Therefore, the aim of this study was to investigate the effects of organic carbon and salinity levels on nitrogen and carbon mineralization and nutrient concentrations in soil.

An completely randomized design (CRD) experiment was conducted to investigate the effect of organic carbon levels from the source of cow manure on the mineralization of carbon and nitrogen and nutrient concentrations in soil salinity conditions in a completely randomized design (CRD) by factorial arrangement with three replications. Organic carbon factor included (0, 1.5 and 3% organic carbon) and salinity factor consisted of 1.5, 4.5 and 9 dS/m. To create salinity levels a combination of MgSO4.7H2O, NaCl, Na2SO4 and CaCl2 was used in the ratio of 42.82, 0.91, 36.20, and 36.91, respectively. The treated soils were incubated at 25 °C under 70% field capacity for 70-day period. To determine the nitrification rate (Rn), the ammonium and nitrate concentrations were monitored during the incubation period at 0, 2, 4, 6, 8, and 10 weeks since the time of incubation. To address the carbon mineralization rate, the soil basal respiration was determined weekly since the beginning of the experiment. At the end of the experiment, the macro and micro nutrient status was determined in the treated soils.

The results showed that both salinity and organic matter application significantly affected the basal respiration, concentration of ammonium, nitrate, K, Ca, Mg, Na, Cl, Fe (P<0.01). Salinity increased soil Ca and Mg concentration. Organic carbon treatments have a significant effect on soil total nitrogen and soil organic carbon. The interactional effect of organic matter and salinity was significant on the basal respiration concentration of ammonium and nitrate and K, Na, Cl, Fe. Salinity in 9 dS.m-1 level compare to 1.5 dS.m-1 decreased basal respiration, NH4+ and NO3- concentration by 47%, 27% and 76% respectively. The basal respiration in 3% of soil organic carbon treatment, higher by 24% compared to control treatment (without organic matter addition). Furthermore, the ammonium and nitrate production after 70 days in 3% of soil organic carbon treatment, was 10% and 37% more than control.

Salinity had a negative effect on the process of carbon and nitrogen mineralization. The use of organic compounds, by creating a balance in nutrient status, could create more favorable conditions for the processes of mineralization of carbon and nitrogen. Organic compounds may have an easy source of carbon, which, if placed on the soil, stimulate and increase microbial activity, increase the mineralization of carbon and nitrogen to some extent.

Use of plant genotypes which are efficient in uptake and utilization of nutrients, is an approach that applied for many years but its importance is more realized. In recent years, plant genotypes that are efficient in using of nutrients attracted more attention and use of them is new approach in low external input agriculture in order to increase efficiency of fertilizers. Iron and zinc are essential macronutrient for plants that are also important in human nutrition. The purpose of this study was to identify the efficient genotypes on use efficiency of iron and zinc that can achieve biofortification of iron and zinc in wheat products.

The trial conducted as a factorial experiment in a completely randomized design with three replications in order to investigate use efficiency of iron and zinc in bread wheat genotypes. The experimental factors consisted of 12 wheat genotypes and 4 levels of fertilizer. Wheat genotypes were N87-20, Morvarid, Gonbad, Falat, Tajan, Line90-7, Line91-17, Aftab, Ghabus, Kouhdasht, Karim and Line17. Fertilizer treatments were completely nutrient solution, iron deficiency, zinc deficiency and iron and zinc deficiency. Zinc used as ZnSO4 at zero (deficiency level) and 1µM (sufficient level) and iron used as sequestrine at 1µM (deficiency level) and 100µM (sufficient level).

the results showed that shoot and iron and zinc uptake of shoot significantly reduced due to iron and zinc deficiency, but use efficiency of iron and zinc increased. Deficiency of iron and zinc together reduced more parameters rather than deficiency of each alone, but increased theirs use efficiency. Iron use efficiency of Line90-7 was the best and Line17 and Kouhdasht had the worst. The highest use efficiency of zinc has seen in line17 and lowest one was for Kouhdasht, Tajan, Karim and Ghabus. Classification of genotypes by Gill method based on dry matter weight and use efficiency of iron and zinc in shoot showed Line90-7 and N87-20 were high responsive to iron and zinc respectively and Line90-7 and Line17 were high efficient to iron and zinc respectively. Classification also showed that the Tajan and N87-20 were the best and Line17 and Kouhdasht were poor in uptake and use of iron and zinc and production of dry matter.

The results of this study showed that Tajan and N87-20 genotypes were responsive to iron and zinc fertilizers and had the highest efficiency in using iron and zinc and producing dry matter. Therefore, in order to reduce the cost and environmental effects of chemical fertilizers, we suggest these cultivars for field trials both in fertile and low output lands (iron and zinc deficiency).