Research Paper
Karim Shahbazi; Hossin Besharati
Abstract
This study was carried out in order to develop a soil fertility database and to assess agricultural soil fertility of country. To this end, 315000 soil test data (more than 50000 soil samples) that provided by laboratories of soil and water research centers in 30 provinces of Iran between 2002 and 2012 ...
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This study was carried out in order to develop a soil fertility database and to assess agricultural soil fertility of country. To this end, 315000 soil test data (more than 50000 soil samples) that provided by laboratories of soil and water research centers in 30 provinces of Iran between 2002 and 2012 was collected. Results revealed that amount of plant available phosphorus and potassium of 71.8% and 21.0% of agricultural soils are less than critical levels of these two elements( P=15 , K= 180 mg kg-1) respectively. Organic Carbon content of 63.2 % of collected soil samples was less than 1% which shows poor organic matter status of agricultural soils of country. The results also showed that among the micronutrients, Zinc and Iron were the most commonly deficient in agricultural soils in which 56% and 40% of soil samples were below the 0.75 mg kg-1 zinc and 4.5 mg kg-1 iron respectively. Moreover, 87% of collected soil samples have more than 5% calcium carbonate equivalent which means majority of agricultural soils of Iran are affected by calcium carbonate. In addition, 80% of soils have pH levels between 7.5 and 8.5 and 95% of them are alkaline (pH>7). The majority of soil texture classes were loam (21%) and clay loam (16%).
Research Paper
Abbas Aghakhani; Mohammad Feizi; Mahmood Solhi; Mojtaba Ramezani Etedali
Abstract
Today, shortage of fresh water especially in arid and semi-arid regions has caused several difficulties. Whatever more than 70 percent of the earth is water, but also high salinity of water resources, caused serious restrictions for human to use these resources. Therefore, desalination has attracted ...
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Today, shortage of fresh water especially in arid and semi-arid regions has caused several difficulties. Whatever more than 70 percent of the earth is water, but also high salinity of water resources, caused serious restrictions for human to use these resources. Therefore, desalination has attracted all attentions more than any time. Between different water consumers in the country, agriculture with consumption of more than 90 percent of the country water recourses has devoted the highest portion, but unfortunately, in the most part of the country, shortage of fresh water resources for agriculture feel, yet. So, in this article, attempted to explain different desalination methods in the world, briefly and finally, necessity, importance and application restrictions of these methods in the country, is investigated.
Research Paper
Hoshang Khosravi
Abstract
To date there is not progress commercially production and large scale application of PGPR in agriculture. One reason for limited commercial use of PGPR is variability, inconsistency and irreproduciblility of results between laboratory, greenhouse, and field trials. These problems with PGPR arises from ...
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To date there is not progress commercially production and large scale application of PGPR in agriculture. One reason for limited commercial use of PGPR is variability, inconsistency and irreproduciblility of results between laboratory, greenhouse, and field trials. These problems with PGPR arises from variation in crops and cultivars, the physical, chemical and biological composition of soils, the content of soil organic matter, competition of indigenous microorganisms, soil moisture content, climate, or perhaps an incomplete understanding of the other mechanisms of PGPR that can affect on plants growth. Therefore, it is difficult to evaluate recommendable numbers of microorganisms in PGPR inocula and the appropriate time, place and application methods. On the other hand, low cost of chemical fertilizers in Iran has precluded any serious consideration to the extension of PGPR application in Iran. The documented reports of PGPR application in Iran indicated that more trials are conducted in invitro, greenhouse and out of farm. Being decentralized research, low content of soil organic matter, the problems with industrial commercialization, being non-targeted chemical fertilizer subsidies, indecisiveness and uncertainty to ensure effectiveness of PGPR in all times and places, lack of inappropriate communication between the research sector, production and extension and the absence of proper mechanisms for supervision and quality control of commercial inoculants are some of the most important challenges with PGPR application in Iran. In other hand there are strengths, because there are many students that interested in studying trends in soil biology and there are many training center for this students in Iran. However, because of national archives including fifth development plan and 20-year outlook there is a clear vision about development of biofertilizers in Iran.
Research Paper
Peyman Keshavarz
Abstract
Use of nitrogen fertilizers has contributed much to the remarkable increase in food production that has occurred during the past 50 years. However, environmental and economic challenges due to nitrogen application in agricultural have increased regard to nitrogen use efficiency (NUE). Studies conducted ...
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Use of nitrogen fertilizers has contributed much to the remarkable increase in food production that has occurred during the past 50 years. However, environmental and economic challenges due to nitrogen application in agricultural have increased regard to nitrogen use efficiency (NUE). Studies conducted around the world shows that only half of nitrogen fertilizer inputs is taken up by crops. Unfortunately, in Iran, very little information exists about NUE on a large scale for cereal. However, look at the statistics of nitrogenous fertilizers it can be found that overuse of fertilizers may be due to their low efficiency. Therefore, to estimate of NUE during 10 years (1378-87) was used from partial factor productivity (PFP) for this purpose. The results show that, PFP was 38 kg kg-1 and less than 6 units global average (44 kg kg-1). Obviously PFP must be increased by about 8% in the year until the year 1400 at least it equal global average. Thus, it seems that nitrogen fertilizer management methods at the farm scale are the need to review, to reduce nitrogen losses to the environment. In this regard, improving farm management practices, experiences of other countries and using advanced technologies highly will help. Because most technologies have synergistic effects on plant response to nitrogen, hence they must be applied in an integrated manner.
Research Paper
Hamed Rezaei
Abstract
Consumption of manure from livestock and human health aspect and their utilization as fuel,animal feed and fertilizer are important. Due to the domination of livestock farming system, limited number of animals and lack of chemical fertilizer in the traditional agriculture, consumption of animal manure ...
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Consumption of manure from livestock and human health aspect and their utilization as fuel,animal feed and fertilizer are important. Due to the domination of livestock farming system, limited number of animals and lack of chemical fertilizer in the traditional agriculture, consumption of animal manure in the agricultural land of country was in an efficient way. Introduction of chemical fertilizers with their rapid impact have caused to the reduction of animal manure consumption. By emerge of chemical fertilizer’s side effects, restriction of their supply and better understanding of animal manure effects on soil fertility, application of manure has been increased recently. To apply research results of manure consumption on soil fertility and crop production in the field and take them into future research program this research was carried out. The result showed that most of past research has examined the effects of animal manure on crop yield and physical, chemical, and biological characteristics of soils. One main task of future research is to find a ways to increase supply nutrient efficiency of livestock manure consumption in the Integrated Soil Fertility Management (ISFM) paradigm. This research review revealed that collection, translocation and processing of manure to be ready for the consumption in the field were ignored in the research agenda.So, it is essential for soil and animal scientists to work jointly to select best possible options for efficient manure management. Due to decrease of greenhouse gas emissions, water and soil pollution this research strategy will satisfy stakeholders who are interested to protect environment.
Research Paper
Teymoor Sohrabi molayousef; Vahid Karami; Mohammad Ali Asgharzadeh
Abstract
The effective management of available water for irrigation in arid region like Iran has become increasingly important due to limited water supply. The need for irrigation water allocation in water limiting condition caused to use GIS in order to manage information optimally and to have easy access. In ...
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The effective management of available water for irrigation in arid region like Iran has become increasingly important due to limited water supply. The need for irrigation water allocation in water limiting condition caused to use GIS in order to manage information optimally and to have easy access. In the present study, the objective was to develop a planning support system to be adaptable to the existing condition of water delivery and distribution and operational systems of irrigation networks in which to determine irrigation timing and amount of water that is needed to be available for the planted crops. This model was written in Visual Basic language and in using data banks it takes advantage of ACCESS software and execution is performed in ArcGIS 9.3 environment. To calculate irrigation water needed to be allocated to every irrigation block, four steps were designed to be taken into account in the model. The steps include crop and soil parameters, first order canal capacity parameters, and second and third order canal capacity and gates parameters. Finally, model evaluates irrigations was done for each crop in each block.
Research Paper
Yahya Parvizi; Manouchehr Gorji
Abstract
Soil organic carbon is a key factor in productivity and quality of soil and environment particularly in semi arid regions. In this article, the role of farm soil organic matter management in soil and in land is discussed. The variability of soil organic carbon in drylands is mainly controlled by tillage ...
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Soil organic carbon is a key factor in productivity and quality of soil and environment particularly in semi arid regions. In this article, the role of farm soil organic matter management in soil and in land is discussed. The variability of soil organic carbon in drylands is mainly controlled by tillage and crop residue management. Results of this study indicated that usage of correct tillage method and residue management can sequester about 35 ton of atmospheric carbon per hectare of drylands in semiarid regions.
Research Paper
Ali Akbar Azizizohan; Mohammad Passandideh
Abstract
Iran is a major producer of saffron in the world. About 255 tons of saffron is produced on 70 thousands hectares of land, of which 125 tons are exported. Production is practiced on small holding, using traditional cultivation practices. One of the major problems associated with saffron cultivation is ...
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Iran is a major producer of saffron in the world. About 255 tons of saffron is produced on 70 thousands hectares of land, of which 125 tons are exported. Production is practiced on small holding, using traditional cultivation practices. One of the major problems associated with saffron cultivation is soil fertility depletion during the first cultivation period, the effects of which extends for a time period equivalent to three times of the first cultivation period. This will adversely affects the sustainability of saffron production in areas most suited to saffronThree hypotheses have been proposed as the possible causes of this phenomenon: 1) changes in soil physico-chemical properties, 2) changes in biochemical conditions of the soil and 3) major changes in the population of the soil microorganisms. A few researches dealt with this problem suggest that soil morphological, physico-chemical and genetic properties do not change after one period of saffron cultivation. In addition, no micronutrient limitations were observed in the soil after harvesting the crop. Production of allelopatic compounds is probably the main reason for soil familiar to satisfy crop needs. One study evaluated soil leaching after harvesting the crop saffron cultivation, with the hypothesis that allelopatic compounds may have been produced, and that it is possible to remove them by leaching. The results were relatively successful.