جستجوی مقالات مرتبط با کلیدواژه « امنیت غذایی » در نشریات گروه « اکولوژی »

Among the approaches that have received attention in recent years to sustain agroecosystems is the identification and employment of traditional/indigenous/local knowledge and strategies of smallholder farmers around the world to solve the basic challenges of these ecosystems regarding food production. In this regard, the role and function of biodiversity as the main component of indigenous knowledge is of particular importance. At the same time, with the expansion of new agricultural solutions, the use of these farmers' approaches has decreased over time and, in some cases, has completely disappeared. Therefore, this study was conducted with the aim of identifying the indigenous methods used in the agricultural ecosystems of the Sabzevar region and their role in increasing biodiversity. Biodiversity loss has been a major concern to humans, especially during the last quarter of the previous century. Nowadays, various efforts to protect agricultural biodiversity are emerging that seem not enough. Biodiversity in agricultural ecosystems causes effective control of weeds, pests and diseases and greater resistance to changing environmental conditions and leads to better management of agricultural systems and increased food security. Additionally, biodiversity is carefully managed and nurtured to interface with hydrological and nutrient cycling to provide for ecosystem resilience, food security and diversity, and risk minimization. Although potentially less important in the short term, biodiversity, encompassing variation from within species to across landscapes, may be crucial for the longer-term resilience of ecosystem functions and the services that they underpin. Accordingly, in this research, the methods employed by local farmers to increase biodiversity were investigated.
In order to evaluate the usefulness of indigenous knowledge for assessing trends in biodiversity, a case study was undertaken in two counties, Sheshtamad and Sabzevar, in Razavi Khorasan province. This involved the use of participatory rural appraisal (PRA) techniques, including semi-structured interviews and transect walks. To study local methods employed by farmers, 453 farmers were interviewed and questions were asked to the farmers about the number of crop species and the amount of use of methods to increase biodiversity such as rotation, fallow, mixed cropping, etc.
The results showed that agricultural systems in these areas have shifted from livelihood systems to market-based systems. Local farmers in these areas used a variety of methods such as using different crops from different families, intercropping, rotation, fallow, seed exchange, integration of livestock with cropping and horticulture to increase diversity in their farms. The main common products in these two cities were plants such as wheat, barley, cotton, alfalfa and pistachios. Most of the plants used in the cultivation pattern of farmers in these cities were related to plant families such as Poaceae, Fabaceae, Malvaceae, Asteraceae, Cucurbitaceae, Amaranthaceae and Rosaceae, which had a different contribution in the cultivation pattern of the studied villages. There was a significant difference between the villages, districts and two counties in terms of the plant species and plant families used. In all the studied villages, farmers employed more than one method to increase the diversity of their farms. The fosterage of livestock and horticulture plus to cropping in these agroecosystems led to greater economic security for farmers, in particular in adverse weather conditions. In general, the results showed that rural development has led to a reduction in the use of traditional knowledge/local methods only in limited cases, and the employing of local methods in some cases has increased the net income of farmers from wheat farming systems.
The results approved that the farmers in these areas used different crops from different families and groups and also used methods such as intercropping, rotation, integration of livestock with cropping, fallow and seed exchange to increase the biodiversity in the three levels of species, function and ecosystem in the agroecosystems of these regions. Increasing biodiversity in agroecosystems is very important and significant issue, especially in arid and semiarid areas, because improved biodiversity in these areas can increase food and economic security to some extent. Diversification could become an essential tool for sustaining production and ecosystem services in croplands, rangelands and production forests.

According to the predictions outlined in global warming models, Iran, especially the plains of the central plateau, has been dealing with increasing temperatures and decreasing rainfall. These changes have had harmful effects on agricultural production and the overall sustainability of agriculture and the environment due to ongoing drought conditions. This study utilizes a model to estimate the risk of agricultural drought based on the principles of information diffusion theory. The goal is to assess the likelihood of agricultural drought occurring in the plains of Shazand, Khomein, and Saveh. By using agricultural data and meteorological information, three main aspects were taken into consideration: the susceptibility of environments prone to disasters, the ability to withstand risk, and the collective exposure to risk. To measure the risk of agricultural drought, three indicators were selected: the vulnerability of the area to drought, the percentage of abnormal rainfall, and the frequency of disaster occurrences. The results of the investigation revealed that the assessments of risk, when viewed from the perspective of disaster-prone environments, hazards, and the population exposed to risk, were significantly elevated. Concerning the susceptibility of disaster-prone environments, the examined plains show a concentrated range between severe and extremely severe sensitivities, with values ranging from 0.6 to 0.9. When considering the precariousness of the risk, these regions are facing a notably high level of vulnerability to drought. In evaluating the overall risk, the incidence of drought-related disasters in these areas exceeds 0.5 on the scale. Consequently, the associated probability of such risks materializing is estimated at intervals of approximately 4.8, 3.2, and 1.2 years for the Shazand, Khomein, and Saveh plains, respectively.

Rice (Oryza sativa L.) as the second most important crop globally and provides 80% calorie and 5% protein requirement of people is Southeast Asia. After wheat, the rice is main food of the Iranian people. This plant is cultivated in 15 provinces of the country on an area of about 600,000 hectares. Up to 1961 rice production in Iran was able to answer the internal rice requirement but at present due to population increase and economic enhancement compared to previous decades, production is less than requirement amount so there are so much importing rice the moment. Water is most limiting factor for rice production in Iran. Among other crops, rice with consumption of 80% of Southeast Asia use the highest share of water. About 70% of share of 25% global regular water is consumed by agriculture and 25-30% of has been in use for rice production. Rice is a large water consumer and its yield quite depends on climate and thus deficit water as a consequence of it. The main tendency of the Iranian people is, to consume quality rice cultivars such as Hashemi, Sadri, Ali Kazemi, Sadri Domsiah. They have a long slender grain and a head rice recovery (HRR) of 60 to 63 percent, an intermediate amylose content (AC), aroma and elongation qualities. However water is the main limitation of rice cultivation in Iran and management of water supply, distribution and consumption along with proper yield, has a major role in the continuation of rice production in Iran. So selection of cultivars compatible with intermittent irrigation management and at the same time, relatively good quality and higher yield, increases Physical productivity of water and farmers incomes. 

This experiment was conducted as split-plot based on complete block design with three replications in Rice Research Center in 2014 and 2015. The employed treatments consisted of five irrigation levels (permanent flood, and rotational by 5, 8, 10 and every 15 days) and four cultivars (Khazar, Gilane, Hashemi, and 8431) as main and sub-factors, respectively. After transplanting, for the first 15 days no irrigation was applied till fully established of plants. At raining situations, water level was determined before rainfall to prevent more water than was already determined as treatment. Main ground was two times ploughed.  Transplanting was done on 15 April using transplants with 20-25 cm length and have 4 to 5 leaves. Before transferring the transplants, the transplanted ground was irrigated for easier pull out of transplants and no damage imposed to roots. Trains including leaf and stem dry weight, leaf area index (LAI), crop growth rate (CGR), net assimilation rate (NAR), leaf area ratio (LAR), relative growth rate (RGR) and specific leaf area (SLA) were measured at booting stage.

Study results showed that the interaction of irrigation and cultivar was significant (p < /em>≤0.01) for leaf and stem dry weight, LDW, TDW, and NAR.  In addition, LAI, LWR were also significant (p < /em>≤0.01) for irrigation treatment. Daily irrigation resulted in highest yield and at no stress condition (daily irrigation) the cultivar 8431 and Hashemi showed the highest and lowest growth respectively. Under 5 and 8 days interval irrigation the cultivar 8431 showed that highest tolerance to water stress while Hashemi was the weakest ne. Under intensive stress (irrigation levels of 10 and 15 days) Khazar showed the highest tolerance but Gilane showed the least tolerance. Therefore, knowledge of various cultivars response is quite vital for any management to achieve the highest yield at water-limited conditions.

This study showed that permanent flood water is the ideal condition for rice to produce the highest yield. As time interval of irrigation increased rice plants yield decreased. Under optimum condition, Hashemi showed the poorest cultivar while 8431 cultivar showed superior across all cultivars. Similar results obtained at irrigation intervals of 5 and 8 days.

Potato (Solanum tuberosum L.) accounts for the largest share in production of food products after wheat, rice and corn, which plays an important role in the nutrition and food basket of the world. Currently, the issue of food security and supplying is very important in different parts of the world and thus prediction of its demand that is increasing. Also, growing population will intensify this issue too. A key strategy to overcome the nutritional challenge of the growing population of the world is eliminating the gap between the current achievement in farms and the yield which can be achieved by using the best cultivars compatible with the environment and the best water, soil and plant management methods.

In this study, potential yield of potato was estimated using the SSM-iCrop2. then the production and yield gap of potato were investigated with two methods of Global Yield Gap Atlas (GYGA) and Arc GIS software by interpolation method for Golestan province. For this aim, the information of potato cultivation management in the province level and the daily data of 23 synoptic weather station as well as their soil data were used. Meanwhile, potential yield gap analysis protocol (GYGA protocol) was used to identify the main weather stations named reference weather stations (RWSs) and climates where potato is planted in Golestan province. Potential yield of potato was estimated within the area covered by each RWS, and then scaled up to the province level. In order to implement the interpolation method in ArcGIS software, initially, potential yield of 23 stations in the Golestan province was estimated. Afterwards, the potential and actual yield in the whole province was estimated using Kriging and IDW methods, respectively.

According to the Agricultural Jihad Report, the actual yield of Golestan province (a ten-year average) was reported as 22 t.ha-1, while the actual yield calculated based on the interpolation method was estimated equal to 22 t.ha-1. However, the actual yield calculated using the global yield gap atlas (GYGA) method was estimated as 20 t.ha-1. Heigh yield of potato in the province was reported by farmers up to 55 tons, which was considered as potential in the province to be compared with GYGA and interpolation methods, so that in the GYGA method, 52 t.ha-1 and in the interpolation method, finding was 42 t.ha-1. yield gap and relative yield in the GYGA method (33 t.ha-1 and 38 percent), and interpolation (20 t.ha-1 and 52 percent) were obtained. Also, in GYGA method, the values ​​were estimated using only two stations, but in the interpolation method the province's yield was estimated using 23 stations and daily meteorological data. The GYGA protocol is a bottom-up approach used by Hochman et al. (2016) to assess the variation of national yield from climatic zoning to analyze similar agro-cluster groups. So far, several studies have been done using this protocol. Gobbett et al. (2017) showed that wheat lands in Australia are located in six key climatic regions. They selected 22 reference stations in this area and calculated the limited water potential yield using the APSIM model (for the years of 1996 to 2010).

The results showed that both Global yield gap Atlas (GYGA) and interpolation method had accurate estimation of actual and potential production and yield, but those values obtained using statistics and 23 weather stations in the interpolation method, and using just 2 weather station (Hashemabad and Gorgan stations) in the Global Atlas method. As previously mentioned, the GYGA method is designed to estimate the yield gap at the national level, which can calculate the potential yield, production, and yield gap in a wide range even with the least amount of information. One of the advantages of GYGA protocol is that the results obtained at any point in the world are comparable to other areas and cultivations of that particular product. Based on the comparison made in this study, it was concluded that the Global yield gap Atlas method should be used to estimate the yield of the country.

Rice (Oryza sative L.) is an essential crop among cereals and shared a significant component in the global human diet, especially in developing countries. About 80% of water consumption in Asia is for the agriculture sector, and half of it would be used for rice production. Rice needs roughly 8000 to 1000 m3 of water per hectare and 1Kg of its dry matter needs to 700 liters of water. Rice farmers tend to keep their farms flooded continuously to make sure the product is more productive by too much water storage and, in this way, prevent against weeds. Up to the year 2050, rice production should increase by 50%, which requires improved cultivars and enhanced field management. For achieving high crop yield, applying fertilizers to maintain high soil fertility is quite necessary. Nitrogen is one of the main crop’s nutrient requirements and is a limiting factor for rice production. Nitrogen fertilizer affects the accumulation of dry matter and its allocation in different parts of the plants. The difference in the accumulation of dry matter in response to nitrogen arises from the difference in the amount of active radiation received by photosynthesis of vegetative canopy and plant efficiency in the use of solar radiation. Nitrogen deficiency reduces leaf growth, and leaves become less colorful since the amount of chlorophyll in the leaves decreases, accelerates aging leaves, therefore, reduce the amount of solar radiation, and it reduces the accumulation of dry matter in plants, finally. Nitrogen, plays an important and direct role in the development of grains by increasing the level of enzymes and enzyme activity, and this increases the transfer and processing of sucrose to seeds. Many studies have shown that increasing nitrogen up to a threshold has highly increased rice grain yield. Growth analysis indices are essential to realize how the crop yield may change in response to management and environmental factors. Therefore the application of appropriate management factors that have a positive effect on growth indices can enhance grain yield.

This study was conducted as split-plot based on a randomized complete block design in Rice Research Center of Rasht in 2014-2015 and 2015-2016. Irrigation with five levels (daily irrigation, rotational irrigation with 5, 8, 10, and 15 days interval) as main plot and nitrogen at six levels (0.0, 30, 45, 60, 75, and 90 kg.ha-1) as subplot were considered in this experiment. At flowering and harvest leaf and dry stem matter was measured. Then leaf area index (LAI), Crop Growth Rate (CGR), Net Assimilation Rate (NAR), Leaf Area Ratio (LAR), Relative Growth Rate (RGR) and Specific Leaf Area (SLA) were calculated.

Our results showed that the interaction of irrigation and nitrogen significantly (P≤0.01) affects stem and leaf dry matter, LAI, and NAR. Irrigation was significantly (P≤0.01) effective on CGR. Among irrigation levels, daily irrigation resulted in the highest LAI and NAR. Our results indicated that daily and every five days irrigation and considering almost no difference between 75 and 90 kg.ha-1 nitrogen, then 75 kg.ha-1 urea can be suggested as the optimum fertilization value. However, at higher irrigation intervals, 90 kg.ha-1 nitrogen would be recommended. Daily irrigation and 90 kg.ha-1nitrogen showed the highest water consumption (6663 m3.ha-1), but 15 days irrigation interval and 0.0 kg.ha-1nitrogen showed the lowest water consumption (4691 m3.ha-1). It seems that low rate release nitrogen fertilizers, along with suitable irrigation practice, would be the optimum management to achieve high yield and lowest possible irrigation water consumption.

The results of this study showed that applying nitrogen and irrigation increased LAI and crop productivity indices, which resulted in higher biomass yield production. Among irrigation levels, daily irrigation resulted in the highest LAI and CGR. Under daily irrigation and five days of interval irrigation, the application of 75 kg.ha-1 nitrogen can be recommended. Although there was not a significant difference between 70 and 95 kg.ha-1 nitroge, but due to environmental concerns, 75 kg.ha-1was recommended.

In the foreseeable future, plants are still the most important source of human food supply, and given the rapid rise in demand for food in developing countries, the demand for food will increase sharply over the next 20 years. Compression is the most important factor in increasing agricultural production. One of the useful indicators in determining the compression rate is the use of agronomic index. In Nepal, an applied definition has been used to compress agriculture, which includes increasing the number of crops per unit area in a crop season, along with the trend of chemical changes to improve plant performance. One of the important indicators used by many researchers is made by Boserup (1966). In this definition, agricultural compression  means increasing the cultivation of crops in a given period in an agricultural system., The idea of increasing the frequency of planting important crops originated in agriculture prior to industrialization and was the only way to increase crop production in one year. This concept later became more comprehensive by other researchers by adding the differences in the length of sowing and planting of crops. In a number of studies, the frequency of products indicating the amount of land use has been used as a compression index.

In order to study the trend of changes in crop density, agronomy and stability in agricultural production, statistical data of 15 agricultural variables including crop area and rainfall in different provinces of the country for the period of 50 years from 1961 to 2011 have been obtained from the Statistical Yearbook, databases The Ministry of Agriculture, the Center for Statistics of Iran and the FAO Database.
Agronomic index was used to study the land use status of arable land and an aspect of compression including land cover with one-year cultivars.

Based on the average, total agricultural density in 1971, 2004 and 2011were 9.26, 8.48 and 8.80, respectively, and the mean of three years was 8.94 months. The lowest index of agricultural density index in 1350 belonged to southern coastal provinces (Hormozgan and Bushehr) and Mazandaran with average of 6.98 and 7.33 months, respectively. In 2004 Guilan and Mazandaran provinces had the least index of 4 and 62.5 months, and in 2011 the lowest rate of this indicator was in Gilan and southern coastal provinces, with a period of coverage of 63.6 and 5.3 months, respectively. Considering that in most regions of the country more than half of the cultivated area is allocated to wheat, and also wheat remains on the ground  longer than the other crops, therefore, wheat cultivation owns the most important share  in the determination of the index of agronomic agglomeration (or crop cover). On the other hand, in the northwestern regions due to climatic conditions and colder periods of time, cereals especially wheat remail on the ground longer ,so the main reason for the higher index of agronomy in these areas is that wheat is present at the surface of earth. The study of agronomy in the country's arable crops showed that, contrary to expectation, in areas with higher rainfall the duration of land cover is less and soil remains without cultivation a long time in the year, due to the cultivation of crops such as rice. Therefore, changing the pattern of planting is essential in these areas .

The results of this study showed that due to the dominance of cereal cultivation in cropping pattern, crop density was affected by the cropping area of ​​these plants. Food security is one of the basic needs and increasing the production per unit area isone of the important ways to achieve it.  So, changing the pattern or planting system is necessary in areas where compression is low.

The concept of ecological footprint was first proposed by Rees (1992) and further developed by Wackernagel and Yount (2000). This is an index based on the land area needed for basic requirements and also the waste disposal of an individual in a specific geographic location and usually calculated on the basis of area per capita which is normally global hectare (Gha) per capita. Based on the report of World Wildlife Found, total world ecological footprint for the year 2010 has been estimated to be 18.2 billion global hectares (Gha) with a per capita 2.7 Gha. This index is reciprocal of carrying capacity.
During the last two decades ecological footprint accounting is used widely for evaluation of ecosystems sustainability. However, limited information is available about ecological footprint of Iran and its components. In this research the state of production and consumption of different food stuffs and ecological footprint of food were calculated for Iran and the results are compared with other countries.

Data was collected for different group of agriculture foods including cereals, oil crops, pulses, dairy products, meat, fruits and vegetables from Ministry of Jihad Agriculture, Ministry of Commerce and also from other published data in official databases in the country. Calculation was made by the method provided in the literature.
Based on these factors ecological foodprint for each food product (efi) on the bases of Gha can be calculated from equation 1.
Equation (1)
In which efi: is the foodprint for product i, Ai: is the land area required for the same product i and fe,i: is the conversion factor for product i (Gha per ha).
Calculation of foodprint
Equation (2)
Equation (3)
Where EF is total ecological footprint (Gha), ef: per capita ecological footprint in terms of Gha and N: total population of the country.

The amount of total food production and consumption in 2013 were estimated as 89.5 and 94.6 Mg, respectively with self-sufficiency coefficient (production: consumption ratio) of 0.87. Self-sufficiency of cereals, oil crops and sugar crops were calculated as 0.69, 0.12 and 0.48, respectively that shows these food groups are highly import-dependent. However, production of vegetables and fruits exceeded their consumption and for other food items consumption was balanced by production. Ecological footprint of food estimated as 0.88 Gha/person and increased to 1.04 ha/person when calculated based on local hectares. Component analysis showed that this difference was due to lower efficiency of cereal and meat and dairy production systems of the country compared to world averages. Meat and dairy products accounted for 48% of food footprint of Iran and 33% of this footprint was due to cereals. Based on our results, Iranian food footprint is higher than Asia (0.7 Gh/person) and is almost the same as the world average (0.9 Gh/peron). Moreover, footprint of food is increased over the country by 76% during years 2000-2013 and this trend could led to severe environmental consequences.

Except for vegetable oils, sugar and cereals, the production and consumption of other groups of food materials are in balance, even for some groups such as fruits and vegetables. There is a small surplus in production over consumption for some extent dairy products. Foodprint for Iran is higher than the value for Asia and is similar to average for the world. In general, foodprint differs significantly amongst the nation and as expected this value is higher in those countries with higher consumption of meat. Higher demand for consumption of meat has caused an increase in indirect consumption of cereals for meat production. It should be noted that since foodprint is based on global hectare, comparison between countries and regions are simply possible. In fact if yield of a crop at national level is increased but world mean yield does not change, foodprint based on global hectare remains unchanged but if it is calculated on the bases of local hectare, foodprint will decrease. Therefore, system efficiency can be evaluated at national level, by comparison of foodprint at two different scales of global hectare and local hectare.

This research (14920.1) was funded by vice chancellor for research of Ferdowsi University of Mashhad, which is hereby acknowledged.