Nosratollah Najafi; Rashed Ahmadinezhad; Naser Aliasgharzad; Shahin Oustan
Abstract
Introduction: Chemical fertilizers can supply all the nutrients required by plants, but their high consumptions cause environmental pollution and increased agricultural production costs. Organic fertilizers can improve the biological, physical, and chemical properties of soil and improve soil fertility ...
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Introduction: Chemical fertilizers can supply all the nutrients required by plants, but their high consumptions cause environmental pollution and increased agricultural production costs. Organic fertilizers can improve the biological, physical, and chemical properties of soil and improve soil fertility and productivity. However, these fertilizers alone cannot provide all the requirements of plants for different nutrients. In addition, these fertilizers are not sufficiently available to farmers everywhere. So, in order to increase effectiveness of organic and chemical fertilizers, to decrease environmental pollutions and to achieve sustainable agriculture, integrated application of organic and chemical fertilizers is recommended. Nitrogen (N), phosphorus (P) and potassium (K) are essential elements for plant nutrition and growth. Wheat as a strategic crop is the most important cereal and plays a very important role in human and animal nutrition and health. The deficiencies of N, P and K in the most agricultural soils often reduce the growth and yield of wheat. Therefore, the appropriate concentrations of these nutrients in wheat seed, leaf and stem are important not only for the optimum growth of the wheat plant and its quality improvement but also for the health of humans and animals.
Materials and Methods: This research work was carried out to study the effects of combining farmyard manure (FYM), municipal solid waste compost (MSWC) and municipal sewage sludge compost (MSSC) with different levels of urea on seed, leaf and stem yields of wheat (Triticum aestivum L.) cultivar Alvand and concentrations of N, P and K in seed, leaf and stem in a randomized complete blocks design with 15 treatments and three replications under field conditions at Khalatposhan Agricultural Research Station, University of Tabriz, Tabriz, Iran. The treatments included were: 1) control (without fertilizers), 2) 150 kg urea/ha, 3) 300 kg urea/ha, 4) 30 ton MSWC/ha, 5) 30 ton MSWC/ha + 150 kg urea/ha, 6) 60 ton MSWC/ha, 7) 60 ton MSWC/ha + 150 kg urea/ha, 8) 30 ton MSSC/ha, 9) 30 ton MSSC/ha + 150 kg urea/ha, 10) 60 ton MSSC/ha, 11) 60 ton MSSC/ha + 150 kg urea/ha, 12) 30 ton FYM/ha, 13) 30 ton FYM/ha + 150 kg urea/ha, 14) 60 ton FYM/ha, 15) 60 ton FYM/ha + 150 kg urea/ha. The size of each plot was 2.0m × 1.9m. At the end of growth period, the plants were harvested and different sections of wheat plant (seed, leaf and stem) were separated and the yield of each section was determined. The concentration of N in seed, leaf and stem were then measured by Kjeldahl method. After dry ashing of the seed, leaf and stem samples, the concentrations of P and K in their extracts were measured by spectrophotometer and flame photometer instruments, respectively.
Results and Discussion: The results showed that application of 300 kg urea/ha increased the wheat grain yield and concentrations of N, P and K in seed, leaf and stem but it decreased the stem yield. Application of 150 kg urea/ha had no significant effect on the leaf yield but its integration with 60 ton MSWC/ha significantly increased the leaf yield of wheat. The combining of 150 kg urea with 30 and 60 ton FYM, MSWC and MSSC per hectare increased yields of wheat stem and seed and their N and P concentrations as compared with the control and application of solely organic fertilizers. The use of FYM, MSWC and MSSC significantly increased the wheat grain yield and concentrations of N, P and K in seed, leaf and stem relative to the control but their effects on yields of leaf and stem depended on the type and rate of organic fertilizer. The highest yields of grain, stem and leaf and the highest concentrations of N, P and K in wheat grain, stem and leaf were observed under combined application of 150 kg urea and 60 ton FYM, MSWC and MSSC per hectare. The minimum yields of seed, leaf and stem and the minimum concentrations of N, P and K in different organs of wheat plant were observed in the control treatment. The average wheat yield component was in the order of seed > stem > leaf. The mean concentrations of N, P and K in different sections of wheat were in the order of seed > leaf > stem, seed > leaf > stem and stem > leaf > seed, respectively. The grain yield of wheat had positive and significant correlations (p<0.01) with concentrations of N, P and K in different organs of wheat, which indicates the role of N, P and K nutrition of wheat plant in increasing its seed yield.
Conclusions: The wheat seed had higher concentrations of N and P and lower concentration of K compared to leaf and stem. In general, in order to decrease nitrogen fertilizers use, enhance N, P and K nutrition of wheat plant, improve wheat seed quality, decline environmental pollution and increase wheat yield, application of 150 kg urea and 60 ton manure per hectare is recommended. However, if there is not enough manure, 150 kg urea and 60 ton municipal solid waste compost or municipal sewage sludge compost per hectare can be applied at similar conditions.
Hojat Dialami
Abstract
Introduction: Date palm is considered as one of the important fruit trees in Iran. According to agriculture statistic book of Iran (2015-2016), mature date plantation area and production of Iran are 230000 hectares and more than 1000000 tons, respectively. This crop usually is planted in south of Iran ...
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Introduction: Date palm is considered as one of the important fruit trees in Iran. According to agriculture statistic book of Iran (2015-2016), mature date plantation area and production of Iran are 230000 hectares and more than 1000000 tons, respectively. This crop usually is planted in south of Iran where the soils are calcareous with high pH. The high soil pH causes reduction of nutrient elements absorption and yield. Thus, finding a solution for this problem is necessary. The investigations indicate that application of elemental sulfur along with Thiobacillus inoculant in soil reduces local pH in rhizosphere area due to sulfur oxidation. The reduced pH of calcareous soil can increase the availability of other essential nutrients resulting in an increase in the nutrient uptake by plants. In addition, uncontrolled use of chemical fertilizers destroys soil structure and decreases organic matter resulting in a more dense soil. This research was conducted to assess the effects of sulfur along with manure on yield improvement and fruit quality as well as the consumption amount of chemical fertilizers.
Materials and Methods: In order to evaluate the effect of elemental sulfur along with Thiobacilli bacteria and manure on quantitative and qualitative characteristics of date fruit, an experiment was carried out in randomized completed block design (RCBD) with six treatments and four replications on 24 fruitful, 25 years old date palm (cv. Barhee), in Ahwaz (Khuzestan Province). The treatments were: T1= Control (without any fertilizer), T2= (application of chemical fertilizer based on soil test for each date palm), T3= (application of 30 kg manure based on general recommendation for each date palm), T4= T3 + (application of elemental sulfur mixed with Thiobacillus inoculant) as 5% of manure, T5= T3 + (application of elemental sulfur mixed with Thiobacillus inoculant) as 10% of manure and T6= T3 (application of elemental sulfur mixed with Thiobacillus inoculant) as 15% of manure. Before the treatments application, soil and water were sampled and analyzed. In second treatment, macronutrient chemical fertilizers were also applied. Source of nitrogen, phosphorus and potassium were urea, triple super phosphate and potassium sulfate, respectively. The nitrogen fertilizer was split and applied in February and May (the next year). Furthermore, all phosphorus and potassium fertilizers were used in February. These treatments were carried out along with manure (30 kg) and chemical micronutrient fertilizers applied based on general recommendation (i.e. 150 g of zinc sulfate, iron sulfate, copper sulfate and manganese sulfate). In third treatment, manure (30 kg) was applied based on general recommendation for each date palm. In T4, T5 and T5 treatments, 500g of Thiobacillus inoculant was mixed with 25 kg of elemental sulfur and then consumed base on 5, 10 and 15% of manure, respectively. All treatments were undertaken during winter by local placement method (Chalkood). Agro-technical practices such as pollination, thinning and irrigation were done according to local practice. Each year, in May, 20-25 leaflets from middle of leaf in second row were picked up, and their mineral nutrients were analyzed. At harvesting time, yield, average of weight, length, diameter and volume of fresh fruit, weight of stone and weight ratio of fruit pulp to its stone, pH, acidity, brix, total and reducing sugars in fruits were determined. The obtained data were analyzed with MSTATC statistical program and mean comparison was conducted using the Duncan’s Multiple rang test.
Results and Discussion: The results showed that using sulfur along with Thiobacillus bacteria and manure had significant effect on leaf phosphorus concentration at the 1% level and on yield and some quantitative characteristics such as weight, length, diameter, volume and pulp weight of fruit fresh and concentration of nitrogen at the 5% level. Sulfur application did not, however, significantly affect the leaf potassium concentration, stone weight, weight ratio of fruit pulp to its stone, pH, acidity, brix, reducing sugar and total sugar of fruit. As a result, application of 1500 g elemental sulfur (mixed with Thiobacillus inoculant) along with 30 kg manure for each date palm is recommended to improve yield and fruit quality and to reduce chemical fertilizer application.
majid forouhar; Reza Khorassani; Amir Fotovat; Hossein Shariatmadari; Kazem Khavazi
Abstract
Introduction: Global warming is strongly linked to the increase in greenhouse gas emissions to the atmosphere. One of the most efficient ways to reduce the amount of atmospheric CO2 is to produce a lot of biomass and convert the biomass into a biochar. Biochar is an organic carbon-rich solid that can ...
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Introduction: Global warming is strongly linked to the increase in greenhouse gas emissions to the atmosphere. One of the most efficient ways to reduce the amount of atmospheric CO2 is to produce a lot of biomass and convert the biomass into a biochar. Biochar is an organic carbon-rich solid that can be obtained from pyrolysis of various organic materials. In other words, biochar can be produced via thermal degradation of many organic materials such as vegetation biomass, animal waste, sewage sludge, etc. in absence or lack of oxygen. Biochar is more resistant to microbial degradation than its feedstock and has a mean resistance time of several decades. In connection with the use of biochar, the most researches have been done in non-fertile and highly weathered soils. The most significant effects of biochar application, have been also observed in strongly acidic soils. In many arid and semi-arid regions of the world, including Iran, the soil organic matter content is low. The lack of organic resources and their instability in the soil are considered as some of the most important challenges in improving soil fertility and plant growth and yield. To improve soil fertility by using insufficient existing organic resources, stabilizing organic matter by converting it into the biochar can be a fundamental strategy. If this strategy is applied in our country with calcareous soils, it is necessary to study the effects of different biochars on calcareous soils from different aspects .In this regard, in the present study, the effect of three types of biochar in a calcareous soil has been investigated in comparison with their feedstock.
Materials and Methods: The effects of three types of biochar and their feedstock in a calcareous soil were investigated in a 6-months period of incubation. A completely randomized design in the form of split plot experiment, was carried out. The main plots were consisted of Control, Municipal Waste Compost (MWC) and its biochar (BMWC), Sewage Sludge (SS) and its biochar (BSS) and Cow Manure (CM) and its biochar (BCW). The sub plots consisted of five sampling times as 10, 30, 60, 120 and 180 days after the beginning of incubation. Application rate of each treatment per kilogram of soil was calculated based on having the same weight of organic carbon content. So that all treatments contained 2.2 grams of organic carbon. After mixing the treatment with soil and adjusting the humidity to the moisture content of the field capacity (FC), they were transferred to the cans (with 3 holes embedded on their doors) and kept at 25°C in the incubator. During the 6-month incubation period, soil moisture was set at FC levels at intervals of two to three days. Sub samples were taken at five times. After air drying the sub samples, the chemical parameters such as EC of 1:2.5 extract, pH of 1:2.5 suspension, available phosphorus (extracted with sodium bicarbonate 0.5N) and available potassium (extracted with ammonium acetate 1N) were measured. After data collection, statistical analysis was performed using SAS software.
Results and Discussion: The soil texture was sandy loam with 21% of clay, 7% of silt and 72% of sand. Soil CaCO3 content and soil organic carbon content was 16% and 0.23% respectively. Available forms of potassium and phosphorous in soil were 76 and 6.3 mg kg-1, respectively. According to the results, under the influence of each treatment, the variation of soil available P, showed a significant increasing trend with the time. Changes in available potassium and soil pH were not significant over the time. Variation of soil salinity with time although showed an increasing trend but was not significant. Comparison of the effects of treatments showed that both biochars and their feedstock could significantly increase the available phosphorus and potassium in soil. In this regard, the effect of biochars was more pronounced than their feedstock. Among the feedstock, ranking for enhancing effect on available P, was SS > CM > MWC and among the biochars, it was BCM > BSS > BMWC. Ranking for enhancing effect on available K, was CM > MWC > SS and BCM > BMWC > BSS among the feedstock and biochars respectively. The increase in available phosphorus and potassium due to the use of biochars were much higher than that of total phosphorus and total potassium added by biochars. The soil pH decreased as a result of the application of each treatment compared to control. In this regard, the significant difference between biochars and their feedstock were not seen. Probable presence of some amounts of pyrogenic carbon with biochars can be one of the reasons for soil pH reduction. Electrical conductivity of 1:2.5 extract of soil was increased by all treatments compared to the control. Except for BSS, two other biochars significantly increased soil salinity more than their feedstock. This increasing effect on soil salinity can be partially due to the existence of some amount of ash accompanied with biochars.
Conclusions: Application of biochars derived from cow manure, sewage sludge or municipal waste compost in this experimental conditions, led to a significant increase in the amount of available phosphorus and potassium in soil compared to control and their feedstock. Therefore, the use of these biochars can have a high potential for reducing the consumption of some chemical fertilizers. From this point of view, the order of the superiority of the coal was as follows: biochar of cow manure > biochar of municipal waste compost> biochar of sewage sludge. The conversion of any of these feedstock to biochar did not have an effect on their potential for soil pH changes. Except for biochar of sewage sludge, in two other biochar, the potential for increasing soil salinity was higher than the feedstock. Considering that the durability of biochar in soil is much higher than that of its feedstock, it is possible to use suitable biochars such as those examined in this study as a great potential for the sustainable improvement of soil fertility and for reducing the use of chemical fertilizers in our country's agriculture. This requires extensive field researches for other soil properties in different soil and water conditions, with different kinds of biochars and crops.
A. Abtahi; M. Hoodaji; M. Afyuni
Abstract
The objectives of this research were to study the effect of three kinds of biosolids applications such as urban compost, sewage sludge, cow manure and chemical fertilizers (sulphates of Zn, Fe) concentration on soil and corn plant. Two calcareous soils having different textures (sandy loam and clay loam) ...
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The objectives of this research were to study the effect of three kinds of biosolids applications such as urban compost, sewage sludge, cow manure and chemical fertilizers (sulphates of Zn, Fe) concentration on soil and corn plant. Two calcareous soils having different textures (sandy loam and clay loam) were used in order to study the uptake of the above zinc and iron by corn. This study was carried out in pots in a greenhouse using a factorial experiment design which was block completely randomized and each treatment was replicated three times. The levels of biosolids used were 0, 25, 50 Mg ha-1 and chemical fertilizers applied were as (Zn and Fe) sulphates. Seventy five days after corn seeds were sown; young plants at 4 to 5 leaf stage were harvested and made ready for chemical analyses. Results of the soil analysis showed that in sewage sludge treatment (50 Mg ha-1) the CEC, and the DTPA extractable (Zn and Fe) increased significantly compared to control and other treatments in soils. Cow manure treatment (50 Mg ha-1) had a significant effect on OM, and EC. Result of the plant analysis showed that in the sewage sludge treatment the concentration of Zn in the roots, and the concentrations of Zn, Fe in the shoots increased significantly. In general, corn yields increased significantly in the sewage sludge treatment compared to the other treatments in clay loam soils. Generally, the results of this study showed that biosolid application including sewage sludge increased concentration of micronutrients (Zn and Fe) in soil and corn plant.
N. Najafi; S. Mardomi; Sh. Oustan
Abstract
In a greenhouse experiment, the effects of waterlogging, sewage sludge and manure on the uptake and concentrations of P, K, Ca, Mg and Na in root and shoot of sunflower (Helianthus annuus L.) were investigated. A factorial experiment based on completely randomized design with three replications including ...
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In a greenhouse experiment, the effects of waterlogging, sewage sludge and manure on the uptake and concentrations of P, K, Ca, Mg and Na in root and shoot of sunflower (Helianthus annuus L.) were investigated. A factorial experiment based on completely randomized design with three replications including duration of waterlogging at five levels (0, 2, 4, 8, 22 days), source of organic fertilizer at two levels (manure and sewage sludge) and each at three levels (0, 15, 30 grams per kg of soil) was conducted. The results showed that by increasing the duration of soil waterlogging, the P and K uptake and concentration in shoot and root, the concentration of Ca and Na in root, the Mg concentration in shoot, the uptake of Ca and Mg in root and the uptake and concentration of Na in shoot increased but P uptake and concentration in root and K uptake in root and shoot decreased again. By increasing the duration of soil waterlogging, the uptake and concentration of Ca in shoot decreased but the Ca concentration in shoot increased again. The effect of soil waterlogging on the Mg uptake in shoot was not significant. By application of sewage sludge and manure and increasing their amounts, the uptake and concentration of P in shoot and root, the uptake of Ca in shoot and root and the uptake and concentration of Na in shoot increased. The K uptake and concentration in shoot increased by application of manure and increasing its level while decreased by application of sewage sludge. The effect of soil waterlogging on the macronutrients and sodium uptake and concentrations in root and shoot was dependent on the source and amount of organic fertilizer and vice versa. The results demonstrated that even short periods of soil waterlogging (2 days) had considerable long-term effect on the concentrations of elements in plant. Generally, sunflower plant accumulated P, Mg and Na in root and Ca in shoot while the K concentration in root did not differ with shoot significantly.
