جستجوی مقالات مرتبط با کلیدواژه « Soil fertility » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

 Although man-made biochars positively affect soil properties and plant performance, their preparation and use, especially on a large scale, are costly. On the other hand, mineral biochar can be considered an alternative method. However, there is no information about the effect of this type of biochar and its method of use on soil characteristics and plant performance.

 Effect of levels of 0 (control), 5, 12, and 25% of mineral biochar (obtained from the mine of Koohbanan city, Kerman province) in three forms of use (including mixed with surface soil, mixed with deep bottom soil, and mixed with total volume soil) on the vegetative performance of bush Fortuynia bungei, shrub Calligonum comosum and tree Ziziphus spina-christi were evaluated in a completely randomized factorial design in the nursery during four months. Cultivation operations in two stages included the germination section (without biochar) and studying the treatments' effects on the species' vegetative characteristics. The seeds were planted in pots containing 100 grams of sand. After sprouting the seedlings and their three to five leaves, one seedling was selected from each pot and transferred to larger pots containing biochar. The amount of water required was determined based on the measurement of soil field capacity. Seedling characteristics were measured at 20-day intervals for four months, and biomass production was measured at the end of the experimental period. At the end of the test period, some soil properties were examined, including organic carbon, total nitrogen, absorbable phosphorus, absorbable potassium, acidity, and electrical conductivity.

 The application of different levels and the manner of using biochar to the evaluated characteristics showed that the most noticeable effect was related to the level of biochar. In other words, although using biochar or the cultivated species resulted in varying results, the amount of biochar had the greatest effect on the evaluated characteristics. The findings showed the effect of higher levels of biochar and the mixture of biochar with the total soil volume on plant species performance (Sig.0.005). Also, the species performed differently, so C. comosum had the highest growth height (65 cm), and F. bungei had the lowest growth height (19 cm). The method of using biochar also had a significant effect on plant biomass, so the highest biomass was related to F. bungei (9.2 grams) under the influence of 25% biochar mixed with the entire soil profile. The levels of biochar or plant species alone affected soil properties. However, the combined effect of the species and the level of biochar used on soil properties was not noticeable. With the application of 25% of biochar, nitrogen (from 0.14 to 0.25%), organic matter (0.88 to 4.1%), and electrical conductivity (0.76 to 1.33 dS/m) showed the most changes (Sig.<0.001).

 By increasing biochar levels, improved soil properties and plant performance were observed. On the other hand, biochar application affects plant performance depending on species. The method of using biochar also significantly changed the performance of cultivated plants so that, considering the economic discussion of using biochar, its mixture with the entire soil profile leads to higher production than mixing biochar with surface or deep soil. However, more studies are needed regarding biochar's effect on soil properties and plant performance.

Biological control of erosion in sloping lands and recognizing the effects of plant species, which are used for rangeland improvement, is the most effective and sustainable method for stabilizing and controlling soil fertility in rangeland.Variations of plants composition cause extensive changes in the soil so that in the short term return to the original state is limited .The interactions of plant species on soil have been studied in various research.Tree species with creating litter, have positive effects on physical and chemical properties of soil, and their loss due to various factors leads to a decrease in soil quality characteristics. The aim of this study is investigation the effects of plant species  planted to improve and rehabilitation slope lands on recovering of soil characteristics of Kakhk watershed.

Kakhk watershed with 37.2 Km2 area in northeastern of Iran is located between 58° 31ʹ 12ʺ to 58° 37ʹ 08ʺ E longitude and 34° 02ʹ 13ʺ to 34° 05ʹ 04ʺ N latitude. The average annual rainfall of the basin is 243 mm. The project of improving and rehabilitating the destroyed lands and pastures in this watershed including sub-projects of planting fruit tree and non-fruit trees, shrub planting, range seeding, seeding, and mount culture Which started in 1993 and has continued until 2006. Slope, direction of slope, altitude, and geology maps of the basin was prepared with GIS software and by overlying them homogeneous work unit maps was obtained.Sampling sites were selected under similar condition of geology and topography. Soil sampling was done randomly and systematically from 0-30 and 30-60 cm depth of understory soil of Prunus amygdalus, Pinus eldarica, Rhus Coriaria and bare area (control treatment). soil texture by hydrometric method, amount of organic matter by Valky block method, pH of saturated soil extract with pH meter, electrical conductivity of saturated soil extract with EC meter, total nitrogen by Kjeldahl method, absorbable phosphorus by Olsen method, lime, potassium, and Bicarbonate of soil samples was measured in soil science laboratory. One-way analysis of variance was used to compare between several independent groups.Also, the comparison of means and differences between groups was investigated using LSD and Dunnett t3 test.

The highest percentage of Nitrogen (0.054), Potassium (270 mg/kg), Phosphorus (6.6 mg/kg), and the percentage of organic matter (0.96) were observed in understory soil of R.coriaria and the highest percentage of lime (7.91) was observed in P. eldarica understory soil. Their lowest values were 0.017, 96.33, 1.92, 0.3, and 2.87, respectively, in the soil of control area. The analysis of variance results showed that there was no significant difference at the level of 5% between the amount of acidity, salinity in all soil depth, and bicarbonate in depth of 30-60 and 0-60 centimeters of soil in different treatments. The percent of sand, silt, and clay also have a significant difference at the level of 5% between treatments in total soil depth (0-60 cm). The average amount of Nitrogen and organic matter of control area in depth of 0-30 cm have a significant difference at a 5% level with P. Amygdalus, P. Eldarica, R. Coriaria treatments. There are a significant difference at a 5% level between the average of potassium (137.67 mg/kg), organic matter (0.55 %), and lime (8.04 %) in understory soil (0-30cm) of P. Eldarica treatment with R.Coriaria region (278.67 mg/kg, 1.07 % and 4.38% respectively) and only in term of lime have a significant difference with P. Amygdalus treatment. The mean of phosphorus (6.26 mg/kg) and organic matter (0.84%) in P.Amygdalus treatment are significantly different from the control area (1.82 mg/kg and 0.32% respectively) but not significantly different with P.Eldarica and R. Coriaria. The soil of 0 to 30 cm depth in the R.Coriaria cultivation area was the most different from the control area in terms of studied chemical parameters. The average amount of Nitrogen, potassium, phosphorus, organic matter and silt  of control area in depthes of 30 to 60 cm showed a significant difference at 5% level with P. Amygdalus, R. Coriaria treatments. Soil pH and EC in none of the treatments and studied depths did not show a significant difference with the soil in the control area at the level of 5%.

The results of this research showed the planting of different trees species in Kakhk watershed has been causes changes in some physical and chemical properties of soil.The R. Coriaria and P. Amyigdalus species more than P. Eldarica provide soil fertility by increasing the minerals Such potassium, nitrogen, phosphorus and organic matter in the their understory soil without significant increasing unhelpful indicators such as salinity. Since Rh.coriaria has better ability for establish and growth in the slopping lands, so it can be used as a suitable species to repairing and rehabilitation of destroyed mountain pastures in Gonabad County.

In congruence with the idea of sustainable development, integrated soil fertility and plant nutrition management has received global attention. The challenges facing soil fertility and plant nutrition in Iran include low soil organic carbon and nutrient contents, imbalanced plant nutrition, low nutrient efficiency, ineffective soil fertility system, environmental stresses, non-efficient fertilizer application, and inadequate knowledge transfer to users. Under these conditions, recommending proper fertilizers will be a multi-faceted and complex task. The development of a framework that incorporates all the factors involved into a single management package is the prerequisite to the integrated soil fertility and plant nutrition management as a smart system for applying an optimal assortment of chemical, organic, and biological sources of nutrients well adapted to environmental and local conditions and aimed at optimized exploitation of inherent soil capacities in a cropping system while sparing negative effects on soil ecological services. The desired integrated management system must be capable of duly accounting for all the components including plant variety; chemical, organic, and biological fertilizers; cropping system; climatic and soil conditions; and socio-economic parameters. The present study introduces the following three steps to achieve an integrated management system: 1) participation of all the stakeholders in the design, prioritization, implementation, and monitoring processes; 2) integrated use of chemical, organic, and bio-fertilizers in terms of amounts, timing, and method of application well adapted to the nutritional requirements of the plant varieties grown in the established cropping system with due consideration of environmental stresses; and 3) dissemination of localized knowledge and know-how of the integrated management system with the help of local extensionists and volunteer farmers from a pilot farm for replication and achievement of the expected outcomes in other farming sites.

In many areas of Iran wher water is scarce, including the western Khorasan, people have understood the importance of water and soil resources. They have made great efforts to protect them, and they also gained valuable experiences. The use of these experiences in the construction of the Bandsars allowed optimizing the water and soil resources and the localization of  watershed management operations which will improve the effectiveness of those operations. The bandsars cause the sedimentation of suspended particles by controlling the flow rate, and consequency, in addition to the increase in soil fertility, improve the recharge of groundwater, vegetation cover and desertification control. This research studies the effect of the use of flood in bandsars,  located in the south of the city of Sabzevar on soil fertility using both field and laboratory methods. To achieve this, 5 Bandsars sites were selected in the study area, and in each site 3 soil profiles inside the bandsars and also 3 profiles outside the Bandsars with 60 cm depth were digged. The soil samples were collected from three depths of 0-20, 20-40 and 40-60 cm. Soil samples were transported to the laboratory and the amount of organic mater, N, P and K were measured. Results were analysed using t as well as Dankan tests. Results showed that the values of the fertilizing elements such as organic mater, N, P are different between inside and outside the bandsars, and are higher inside the bandsars comparing to the related outside areas. Although this difference is not statistically significant in some cases, it can be concluded that Bandsars improved soil fertility.

Insects are the most abundant organisms associated with plants and soil. Mass rearing of insects to supply animal feed has provided access to insect frass as a new source of organic fertilizer. The chemical composition of insect frass (i.e., proper amounts of organic nitrogen, soluble carbon, and nutritional elements as well as a low carbon to nitrogen ratio) and its physical properties (fine size and layered structure) have given rise to an increasing interest in their potential use for enhancing soil fertility and developing novel organic products. In addition to its being a rich source of plant nutrients, insect frass not only contains beneficial microorganisms such as some species of Bacillus and Pseudomonas bacteria but is also the only source of chitin available top plants to improve their resistance to biotic (insects and nematodes) and abiotic (drought and salinity) stresses. Current studies in the field are focused on the two industrial insects of black soldier fly (Hermetia illucens) and mealworm (Tenebrio molitor). The results have shown that application of 5-10 tons of frass from these two insects per hectare of farm soil increases the yield, both in quantity and quality, in such important crops as rapeseed, barley, rye grass, corn, and sugar beet. Given the nationwide rise in the mass rearing of industrial insects, it is instructive to accelerate the development of appropriate methods and standards for their application as a fertilizer.

Enhancements in crop yield and quality depend on proper use of chemical fertilizers, the most important tool for which is a comprehensive understanding and accurate knowledge of the fertility status of the soil under cultivation. The present study presents a review of the fertility of soils under wheat cultivation in Qazvin Plain in an attempt to formulate extension guidelines for facing the challenges due to soil limitations hindering satisfactory wheat yield. For this purpose, use was made of 43120 soil analytical data obtained from 2695 samples collected from Qazvin Plain to study the 12 soil physicochemical properties of soil texture, pH, and EC as well as lime, organic carbon, phosphorus, potassium, iron, copper, manganese, and boron contents. The results showed that, while a major portion of the soils studied was loam, more than 78% were alkaline in nature with pH values of 7 to 8. Also, the soils were found to suffer from such limitations as deficient available K, manganese, copper, and boron. Given an electrical conductivity of less than 2 dS m-1 obtained for the soil saturation extract, 47.1% of the soils in the plain were identified as non-saline. Calcium carbonate accounted for more than 96% of the soils as affected by lime. Moreover, the soils were drastically deficient in organic content as revealed by the organic carbon index that indicated an organic carbon content of less than 1% in 93.5% of the soils examined. Critical phosphorus and potassium levels were measured at 15 and 300 mg kg-1, respectively, indicating 27% of the soils in need of phosphorus fertilizer application but more than 80% in no need of potassium fertilizers. The critical levels of iron, zinc, manganese, boron, and copper were measured at 5, 1, 5, 1, and 1mg kg-1, respectively, such that about 74% of the studied areas suffered from iron deficiency, 64% from zinc deficiency, 17% from manganese deficiency, 27% from boron deficiency, and about 30% from copper deficiency. Thus, soil micronutrients were not uniformly distributed across the wheat farms. It is, therefore, essential to formulate recommendations duly based on plant needs and to avoid uniform application of the same fertilizers on all soils with different deficiencies in order to achieve desirable yields at lower production costs.

Given the role of rangelands in soil conservation and soil fertility, strengthening the soil of rangelands could be achieved by range management plans (RMP). Therefore, in this research, 15 summer rangelands and 16 winter rangelands with RMP were investigated to determine the effects of range management plans on some soil properties. In each rangeland with RMP and in each vegetation type, three soil profiles were dug and soil samples were collected at two different depths. Beside each rangeland with a RMP, a rangeland with a same vegetation type and without RMP was selected for comparison and sampling was conducted. Organic matter, nitrogen, potassium, and phosphorus were measured in the laboratory. The data from two different range management types were analyzed in an independent sample T test using SPSS software. The results showed that, in summer rangelands, range management plans could increase the amount of some factors like phosphorus, nitrogen, and organic matter, while it had no significant impact on some other factors, including the amount of potassium and increasing the depth of horizon A. However, in the winter rangelands, the plans had no significant effect on strengthening the soil of rangelands and it seems that due to the slow changes of soil in arid areas, more time is needed to make significant changes in the soil.

Flood plalins are usually affected by the quantity and quality of the suspended load of the floodwater that inundates those areas. This is made possible by pumping the turbid water for irrigating the cropland adjacent to the river. This study was performed to assess the effects of addition of the suspended load carried by the Hirmand River on some physico-chemical properties of the farm fields irrigated by the pumped turbid water. It was observed that there was no statistically significant difference in the sand percentage, pH and Ca and Mg concentration between the irrigated and the control area. However, K, C, N, organic matter content and water saturation percentage showed a highly significant difference (p<0.01) between the two treatments. Moreover, SAR, ESP, and P concentration and silt and clay content of the irrigated area showed higher quantities at the (P<0.05) significance difference. Soil texture changed from loamy sand in the control area to loamy in the irrigated cropland. The turbid water irrigation of the sandy flood plain of the Hirmand River has improved most of the physico-chemical characteristics of the cropped area. Therefore, this irrigation method may be termed a desertification control technology.

Diamonium phosphate is the basic fertilizer commonly applied to sugarcane cultivations. Under the climatic conditions in southern Khuzestan with its calcareous soils, a lot of the fertilizer nitrogen may become unavailable to the plant due to its loss as gaseous ammonia. This study was carried out to explore the effects of soil, time lapse, and weather conditions on nitrogen losses emitted in the form of gas. For this purpose, an experiment was conducted using plots in two sugarcane fields with different soil textures (Clay and Silty Clay Sand). To each plot, 300 kg ha-1 of diamonium phosphate fertilizer was applied along sugarcane furrows (soil surface) using the stripping method. Samples of the fertilizer spread in the plots were taken over a period of six weeks to measure residual nitrogen in the samples. Soil samples were also taken before and after fertilizer application to determine soil physicochemical characteristics. The results obtained were analyzed in a randomized complete block design and the mean of treatments were compared using the Duncan method. No significant differences in gaseous nitrogen losses from diamonium phosphate fertilizer were observed between the soil of a silty clay loam texture and that with a clay texture. Time lapse and temperature changes, however, showed significant effects (α= 1%), with the highest nitrogen loss recorded from the third week onwards. It was concluded that shorter time intervals between fertilizer application (base fertilizer) and sugarcane cultivation might help prevent high nitrogen losses and improve upon fertilizer effects.

Flood spreading has been identified as an effective method to improve soil fertility, recharging groundwater, restoring vegetation condition and combating desertification. Identifying the rate of changes under this treatment has great value for restoration programs. The purpose of this study was to study the effects of flood irrigation on the soil properties in Band-E-Alikhan area in Varamin. The study area is located in south part of Varamin, north of Masileh Plain and Salt Lake coast in Qom. Mixed soil samples were collected from the first, middle and the last plots established along the five transects with 50 meters length in both treated and control sites. Soil samples were also collected and compared from under canopy and bare soils in flood spreading area. Results of T test showed that the average percentage of organic carbon, nitrogen, phosphorus, potassium and saturated water content and silt were increased and electrical conductivity, soil bulk density and clay content were decreased in flood spreading area compared to control site. Results also indicated that electrical conductivity, nitrogen, phosphorus, potassium, saturated water content, sand and clay content were increased and silt percentage was decreased under plant canopy compared to the bare soil areas. Therefore, it can be stated that establishing flood spreading system in the region has gradually increased the soil fertility.