Saffron Agronomy and Technology

Abstract Evaluating and quantifying agricultural ecosystem services in saffron-based agroecosystems is essential for understanding their economic value and informing sustainable management. This study aimed to estimate and monetize multiple ecosystem services and disservices in saffron fields. Researchers collected primary data by using a structured questionnaire with saffron growers from selected counties in Khorasan Razavi and South Khorasan provinces (Mashhad, Torbat-e Jam, Torbat-e Heydarieh, Khalilabad, Bardeskan, Birjand, Zirkouh, and Boshruyeh), resulting in 120 completed questionnaires. The study estimated the value of five saffron ecosystem services—food production, oxygen production, biodiversity, conservation, and the absence of migration—and two disservices —greenhouse gas emissions and phosphorus and nitrogen leakage. Results showed that the total net value of ecosystem services in the studied fields was 39,353.6 US$/hectare per year. Prevention of rural migration, identified as a cultural service, was valued at 24,579.3 US$/hectare per year. Cultural and provisional services and biological diversity made up 62, 43, and 5.8% of the total ecosystem service value in saffron fields. These findings highlight the importance of assessing both ecosystem services and disservices in saffron agroecosystems to guide sustainable management and policy decisions.

Abstract Carbon footprint (CF) is the total amount of greenhouse gas emissions per unit of farmlands. Since the used inputs have an important role in greenhouse gas emissions, CF as an ecological indicator have been extensively applied for assessing the environmental externalities in agroecosystems. This study was conducted to estimate the CF and carbon efficiency (CE) of saffron production systems in North Khorasan, Razavi Khorasan and South Khorasan provinces. Also, life cycle assessment analysis is calculated for quantifying the impact of saffron farming activity on the environment. Studied indices were global warming potential (GWP), acidification potential )AP) and eutrophication potential in terrestrial (UPT) and aquatic (UPA) sub-categories, N2Odirect, N2Oindirect, N2O emissions affected as volatilization and leaching, carbon inputs (Ci), carbon outputs (Co), CF and CE. The results revealed that the lowest GWP for saffron production systems was related to south Khorasan with 339.43 kg CO2 equiv./ one kg flower yield. The minimum environmental index (EcoX) was recorded for south Khorasan (0.039 EcoX/ one kg flower yield). N2O emissions in South Khorasan, Razavi Khorasan and North Khorasan provinces were estimated with 95974.51, 199674.4 and 344723 kg N2O per one ha, respectively. The largest N2O emissions affected as leaching and volatilization were calculated for North Khorasan province (with 1.21 and 24.23 kg N2O per one ha, respectively). The maximum Ci and Co were related to North Khorasan province with 117986.52 and 15135.56 kg C per one ha, respectively. The largest CF and CE were computed for North Khorasan and south Khorasan provinces with 7.8 and 0.18, respectively. It concluded that adoption on conservation and reduced tillages, N2- fixing pulses, cover crops and green manures in rotations with saffron and increased nitrogen use efficiency as ecological approaches can optimize the system performance while reducing environmental externalities and the carbon footprint of the crop cultivation. So, with relevant agro-environmental policies in saffron production systems along with the adoption of improved agronomical practices increasing flower yield with no cost the environment can be achieved effectively, efficiently and economically.

Abstract Sustainable development of saffron production as one of the major and strategic goals of Iranian agriculture requires a well-defined and organized plan. Over the past half century saffron cultivation has increased 34-fold in Iran, more than any other crop. But the average yield did not follow this development and is reducing with slight negative slope; so, the average saffron production in Iran has reduced from 5.76 kg/ha in 1973 to 3.42 kg/ha in 2017. It is also estimated that there is a 90-70% yield gap in Iranian saffron farms. Saffron pests and diseases such as saffron mite (Rhizoglyphus robini), saffron corm rot, saffron dry rot (Burkholderia gladioli) and saffron viral diseases are also responsible for quantitative and qualitative reduction of saffron yields in farms. Saffron is propagated by its daughter corms, so increasing the yield of saffron is directly related to the quality of mother corm seed. This paper describes the criteria’s needs to generate and certify prebasic, mother corm and seed corm classes of saffron for standard saffron corm schedule. Production of standard pathogen-free seed corms as the only means of saffron propagation in nature is a prerequisite for any planning to increase saffron yield. Undoubtedly, application of standard free pathogen corms along with other ecological and physiological indices of saffron plant will increase yield and improve Sustainable development indicators.

Abstract Life cycle assessment (LCA) is a well-known and accurate methodology for comparison of environmental impacts of activities including different agricultural management systems. Since the used inputs have an important role in environmental pollution and greenhouse gas emissions, LCA have been extensively applied for crop species. This study was conducted to assess the environmental impact of saffron production systems based on field area (<0.5, 0.5-1 and >1 ha) in the Khorasan-e Razavi province using LCA methodology. The amounts of utilized agricultural inputs from the first year to the sixth year were collected by means of a questionnaire (13 fields from each area). In this regard, four phases, which are goal and scope definition, inventory analysis, impact assessment and interpretation, were designed to assess life cycle index with ISO14044 procedure. Functional unit were considered as one kg of flower. Three main categories as impacts on environment including global warming, acidification and eutrophication (terrestrial and aquatic) were defined. Finally, an index -called environmental index (EcoX) was calculated. Cronbach's alpha was used assessing the reliability of the questionnaire. The results showed that the Cronbach's alpha was computed with α=%84. The average values for global warming, acidification and eutrophication terrestrial and aquatic categories were calculated with115.41±53.41 kg CO2 equiv. / one kg flower yield, 0.35±0.16 kg SO2 equiv./ one kg flower yield, 0.58±0.27 kg NOx equiv./ one kg flower yield and 0.20±0.09 kg PO4 equiv./ one kg flower yield, respectively. The largest share of greenhouse gas emissions in the global warming category was related to CH4. The maximum emission of pollutants in acidification, eutrophication terrestrial and eutrophication aquatic categories was related to NH3. The results revealed that, field area affected the amounts of utilized agricultural inputs and environmental impacts as flower yield. Eutrophication and climate change categories had more sensitivity and affected as intensification based on field area. Therefore, one of the appropriate approaches to mitigate and decline the environmental impacts of agricultural production is achieving higher economical yield per unit of area by increasing resource use efficiency.

Abstract Studies that investigated the impact of organic fertilizers (manure, compost and biological fertilizers) and agronomical practices (density, method, date and depth of planting) on saffron yield have a long history in Iran. Due to the distribution and inconsistency in the results obtained from different studies, a meta-analytic approach was used in the current study. for this aim, 47 organic fertilizers studies and 44 agronomical practices studies were selected from 202 gathered studies and analyzed. The criteria for the selection of studies were the adequacy of data for the present meta-analysis. Among the individual fertilizer studies, manure fertilizer had the highest impact on saffron dry weight (g= 1.493) at 95% confidence interval. Average amount, 40 to 50ton/ha of cow manure, 20 to 30ton/ha of compost that is used as a combination with Biofertilizer (Nitroxin with Nitrogen-fixing bacteria) were more effective than higher amounts of these fertilizers will be alone. Among the agronomical practices studies, plant density had the highest and depth of planting had the lowest effect size on economical yield and number of flower. The optimal density for maximum yield was 50-100 corm per (m2), optimal consumed weight average 9-12 ton per hectare observed, optimal weight of any corm was 10-20 (g). Among planting methods, row-mass method was the best optimal (inter-planting was 20 cm and intra-planting 10 cm). The best planting dates was the end of May and the first decade of Jun. Optimal planting depth was 15-20cm. Homogeneity between organic fertilizers studies was accepted and the homogeneity between agronomical practices except depth of planting studies was accepted. This heterogeneity was caused by factors such as age of farms and different regions that had the most impact on heterogeneity and effect size. The present meta-analysis aims to provide a better understanding of agronomical and fertilizers management and offer the best possible management for this crop.

Abstract In order to determine the optimal use of corm size and density, an experiment was conducted by central composite design at the Research Station, the Ferdowsi University of Mashhad, Iran, during two growing seasons of 2008-2009 and 2009-2010. The treatments were designed based on low and high levels of corm size (3 and 7 g) and density (50 and 150 corm.m^-2). Central point in each treatment was repeated 5 times and a total of 13 experimental treatments were designed. Economic yield, corm diameter, number of daughter corms, number of mother corms, number of flowers and fresh weight of flowers were measured as dependent variables, and the response surface of these variables to experimental factors was estimated by the polynomial regression model. The results indicated a positive effect of corm size and density on economic yield, corm diameter, dry weight of tunic, number of daughter corms, number of mother corms, number of flowers and fresh weight of flowers. The optimum level of corm size and density were 7 g and 250 plant.m^-2, respectively.

Abstract Leaf area index, light extinction coefficient and radiation use efficiency are important eco-physiological characteristics for realization of crops growth, development and radiation absorption. In order to determine the leaf area index (LAI), light extinction coefficient (K) and radiation use efficiency (RUE) of saffron during the first and second growing seasons, four experiments were started in 2011 and ended in 2014, at the Research Farm of the Agriculture Faculty, the Ferdowsi University of Mashhad, Iran. Saffron corms with weights between 13 to15 g and density of 50 plant.m² were cultivated in 2011 and 2012. In all experimental years during the growing season, crop sampling was taken for required measurements including the leaf area index and shoot dry weight of saffron once every 14 days. The results showed that by increasing the age of saffron from 1 year to two years, the maximum LAI of saffron increased from 0.33 to 1.81, and light extinction coefficient decreased from 1.20 to 0.54. The increasing trend of LAI was coincident with fraction of absorbed radiation for all four years of the experiment. In the first and the second growing seasons, the amount of fraction of absorbed radiation gradually increased with increasing LAI and at 1083 and 1034 GDD reached its maximum value, respectively. In saffron farms when the plant was one year old and two years old, the mean value of RUE was 0.68 and 1.73 g.MJ^-1 PAR, respectively. These results indicate that by increasing the saffron age and LAI, the value of K decreases and consequently radiation absorption and use efficiency will‎ increase.