Journal of Emergy, Life Cycle and System Analysis in Agriculture
Volume:2 Issue: 1, Summer- Autumn 2022

In recent years, the use of herbal compounds to control pests has been proposed as one of the alternative sources to chemical control because of their selectivity, readily biodegradable, and low impacts on non-target organisms and the environment. In this research, qualitative photochemistry and the insecticidal effect of ethanol extract of aerial parts (without flowers) of Pimpinella stocksii Boiss. (Apiaceae) on one-day old adult aphids (Aphis gossypii) in a completely randomized design with four replications for each concentration, have been investigated under laboratory conditions (25 ± 1°C, 65 ± 5 % R. H, photoperiod 16:8 L: D). The results showed that the mortality of the tested insect increased significantly by increasing concentrations from 7 to 425 µg/cm2. In the probit analysis, an ethanol extract of Pimpinella stocksii was found to be highly toxic to Aphis gossypii Glover, with a lethal concentration of 50 percent (LC50), equal to 82.57 µg/cm2. The mortality rate of one-day adult aphids treated with an ethanol extract of P. stocksii at concentrations ranging from 7 to 425 µg/cm2 ranged from 25 to 80 percent. Preliminary phytochemical analysis showed the presence of various bioactive and insecticidal constituents in P. stocksii, like glycosides (anthraquinones), flavonoids, steroids, saponins, and triterpenoid compounds. The purpose of the study is to conduct preliminary and qualitative identification of the active components of the Pimpinella stocksii extract as well as to investigate its insecticidal activity.

An experiment was conducted at the Faculty of Agriculture, Shahrood University, as a randomized complete block design with four replications to investigate the effect of ultrasonic waves and seed priming on some quality traits of cowpea under soil application of trifluralin. Nine treatments were: T1: control, T2: ultrasonic waves, T3: ultrasonic waves + reduced herbicide dose (1 L ha-1), T4: ultrasonic waves + recommended herbicide dose (2 L ha-1), T5: hydro-priming, T6: hydro-priming + reduced herbicide dose, T7: hydro-priming + recommended herbicide dose, T8: reduced herbicide dose, T9: recommended herbicide dose. The results showed that the effect of treatments was significant on all traits except leaf phosphorus. The maximum chlorophyll a (1.30 mg g-1 FW), carotenoid (1.82 mg g-1 FW), leaf relative water content (79.9 %), and leaf nitrogen (3.97%) were obtained in ultrasonic treatment, which resulted in a significant increase of 28.7, 22.1, 7.9, and 18.5 percent, respectively, in comparison to the control. In comparison to the ultrasonic treatment, ultrasonic waves + recommended herbicide dose reduced chlorophyll b, RWC, and leaf nitrogen by 29.3, 21.1, and 35.3 percent, respectively. In comparison to herbicide application alone, the combination of ultrasonic waves and the recommended herbicide dose reduced chlorophyll a and total chlorophyll by 29.7 and 22.2 percent, respectively. Overall, the results of the present study showed that pretreating cowpea seeds with ultrasonic waves could increase photosynthesis pigments, relative water content, and leaf N (in the absence of herbicide use).

Over 40% of agriculture on the planet is conducted on smallholder farms with low productivity but high production costs. As a result, governments have attempted to replace traditional farms with mechanized farms in recent years. The sustainability of three distinct production systems, namely traditional, semi-mechanized, and mechanized cultivation systems, were assessed using emergy approach in 2017-2018. These systems were practiced over areas of less than 2 ha, 2-10 ha, and more than 10 ha, respectively. The results indicated that the total emergy values for sugar beet production were 2.84E+16, 4.57E+16, and 6.21E+16 sej ha-1 yr-1, respectively, for traditional, semi-mechanized, and mechanized systems. Historically, the proportion of renewable natural inputs, non-renewable natural inputs, and purchased inputs in total input emergy was 8.88E+14, 8.88E+15, and 1.86E+16 sej ha-1 yr-1, respectively. However, the proportion of renewable natural inputs, non-renewable natural inputs, and purchased inputs was 9.06E+14, 2.56E+16, and 3.57E+16 sej ha-1 yr-1, respectively, in mechanized farms. As the rate of mechanization increased, the unit emergy value, renewable emergy ratio, emergy exchange ratio, emergy yield ratio, emergy input ratio, and environmental loading ratio increased by 11.5, 77, 13.7, 11.9, and 1.32 percent, respectively; while the renewable emergy ratio and environmental sustainability index decreased by 20.1 and 28.9 percent, respectively. In general, the results indicated that mechanization protected the environment more than traditional cultivation.

Thrips tabacci Lind. (Thysanoptera: Thripidae), the onion thrips, is one of the most damaging pests to onion fields. By using biotic or abiotic stimuli or growth regulators, it is possible to induce resistance, which activates the plant's natural defense. The effect of foliar application of two growth regulators, salicylic acid and potassium silicate, separately and in combination, on onion thrips population density, fresh weight, dry weight, chlorophyll concentration, and height of onion cultivars was investigated in the Jiroft region between 2016 and 2017. The experiment was conducted as a factorial design with 12 replications. Two onion cultivars (Gardesco and Milky Way F1), salicylic acid (0, 0.25, 0.5 mM), and potassium silicate (0, 1, 2 cc. lit-1) were used in three different concentrations. The analysis of variance revealed that the effect of biological fertilizer on thrips population density, fresh and dry weight, chlorophyll concentration, and the effect of onion cultivar on plant height and thrips population density were all statistically significant (Pvalue£0.01). Additionally, the interaction between fertilizer and cultivar was significant only for the pest population density parameter at the 1% level. The treatment with potassium silicate (2 cc. lit-1) resulted in the highest fresh and dry weight values, 363.29 and 120.25, respectively. Milky Way F1 plants were taller (41.16 cm) than Gardesco plants (37.10 cm). These findings indicate that salicylic acid and potassium silicate have the potential to significantly reduce the T. tabaci population

Green almonds are a seasonal treat, and mechanical harvesting of green almonds has the potential to increase their consumption while also introducing a new method of reducing almond processing costs and residue. The purpose of this study was to investigate the physical properties and mechanical behavior of green almonds of the Sahand variety. The physical properties measured were length, width, thickness, arithmetic and geometric mean diameters, which averaged 29.73, 20.23, 15.02, 21.66, and 20.81 mm, respectively. Additionally, the surface and projected areas, aspect ratio, sphericity, mass, volume, true density, and porosity were determined to be 1366.77 mm2, 473.59 mm2, 0.68, 0.70, 4.14 g, 3.78 cm3, 1.10 g/cm3, and 0.44. Almost all of the physical properties of green almonds studied were found to be correlated. Green almonds had a static friction coefficient of 0.519, 0.441, and 0.523 on MDF, galvanized iron, and rubber, respectively, and the static friction coefficients on MDF and rubber were not significantly different at the 1% confidence level. A uniaxial compression test was used to investigate the mechanical behavior of green almonds under compression. The tests were conducted in three directions (X, Y, and Z, which correspond to the length, width, and thickness of green almonds, respectively) and at three speeds (10, 15, and 20 mm/min). The results indicated that only direction had a significant effect on the mechanical test results and that green almonds can withstand greater deformation along their length before rapture.

The effect of drought stress induced by polyethylene glycol (PEG-6000) on the growth and mineral uptake of GF677 (peach and almond hybrid) rootstock was investigated in vitro using solid and liquid mediums. Plantlets of the GF677 rootstock were subcultured into the Murashige and Skoog (MS) proliferation medium containing 1 mg/l BA (6-Benzyladenine) and 0.1 mg/l NAA (naphthaline acetic acid) under four different drought stress conditions: 0 (control), 1, 2, and 3 percent polyethylene glycol. After six weeks, results indicated that the highest drought level reduced fresh weight, dry weight, shoot length, and proliferation rate, with the reduction being greater in the solid medium than in the liquid medium. Leaf abscission was greater in the solid medium than in the liquid medium. In the liquid medium, the GF677 rootstock absorbed more nitrogen (N) than in the solid medium. Drought stress had no effect on phosphorus (P) uptake. Potassium (K) uptake increased when drought levels were evaluated in both mediums, but was greater in the liquid medium than in the solid medium. Calcium (Ca), magnesium (Mg), and iron (Fe) uptake decreased in both mediums as drought levels increased. The GF677 rootstock was capable of uptake of N and K at a high concentration. Mineral uptake was greater in a liquid medium than in a solid medium. In conclusion, the GF677 rootstock exhibited a high capacity for N and K uptake under drought stress.

The critical period of weeds refers to the stage of the plant's growth cycle during which weeds must be controlled to avoid crop damage. Understanding the critical period of weed control is beneficial for both biological and economic reasons when making weed control decisions and scheduling. Field experiments were conducted in 2018 in Khorramabad, Iran to determine the critical period of weed control (CPWC) in rain-fed lentil. The treatments were divided into two series: weed interference with the crop from emergence to 10, 20, 30, 40, 50, or 70 days after emergence with a control treatment (weed infested), and weed-free treatments up to the aforementioned stages. The logistic and Gamprtz nonlinear models were used to determine the start and end of the critical period of weed control, respectively. Galium tricornutum, Turgenia latifolia, Cerastium dichotomum, and Lathyrus aphaca were the most significant weed species in the experiment due to their greater biomass and size. The results indicated that weed control and interference treatments significantly increased lentil yield. Grain yields were 471 and 187 kg ha-1 for weed-free and interference-control treatments, respectively. Thus, when compared to weed-free control, weed interference reduced grain yield by 60%. The critical period of weed control began and ended 43 and 26 days after emergence, respectively, based on acceptable yield reductions of 5% and 10%.

The drying characteristics of mallow (Malva sylvestris L.) in a microwave dryer were examined at different microwave power levels. To dry 30 g of mallow leaves, microwave power levels of 360, 450, 540, 720, and 900 W were used. The initial moisture content of samples was 6.31±0.01 g water/ g dry base. To determine the kinetic parameters, which were calculated by comparing the ratio of the difference between the initial and final moisture contents to the equilibrium moisture content, experimental data were fitted to seven distinct models. At various microwave power levels, the moisture diffusivity and energy consumption were measured. Based on the results, increasing microwave power from 360 to 900 W resulted in a drying time reduction between 14 and 5 minutes. A comparison of the proposed models demonstrated that the logarithmic model (MR= a.exp(-k.t)+b) provided the best fit because it had the highest coefficient of determination (R2), the lowest sum of squared errors (SSE), and the lowest root mean square error (RMSE). This model can therefore be used to estimate the moisture content of mallow leaves during microwave drying. Also, the maximum and minimum energy consumptions for drying with 360 W and 720 W microwaves were 84.0 and 67.5 W.h, respectively. Moreover, the effective diffusivity of mallow leaves varied from 1.098×10−10 to 3.532×10−10 m2/s for different microwave powers.

Excessive use of environmental resources and excessive consumption of chemicals have exacerbated environmental problems and harmed agroecosystem sustainability. As a result, it is beneficial to study energy consumption patterns and efficient energy use in agriculture, which is one of the fundamental principles of sustainable agriculture. The aim of this study was to assess the sustainability of rapeseed production (Brassica napus L.) in Gorgan county during the 2017-2018 crop year using emergy essessment. Sixty questionnaires were considered for this purpose. After establishing spatial and temporal boundaries and classifying resources into four categories: renewable environment, non-renewable environment, purchased renewable, and purchased non-renewable, and some emergy indices were calculated in rapeseed agroecosystems. The results indicated that the total emergy input for the rapeseed agroecosystems consumed a total of 6.39E+15 sej ha-1 yr-1. In rapeseed agroecosystems, dependence on market and non-renewable inputs was much higher than environmental and renewable inputs. With 59.94 percent of total emergy input in rapeseed agroecosystems, fossil fuels were the primary source of emergy. The transformity of rapeseed agroecosystems was 1.09E+05 sej J-1, the specific emergy was 3.09E+09 sej gr-1, the renewability was 12.46 percent, the emergy yield ratio was 1.22, the standard emergy investment ratio was 4.56, the modified emergy investment ratio was 9.23, the standard environmental loading ratio was 10.25, the modified environmental loading ratio was 7.02, the standard emergy sustainability index was 0.12, and the modified emergy sustainability index was 0.17. Based on the evaluation of emergy indices, the rapeseed agroecosystem has an acceptable crop production efficiency and resource consumption efficiency, and a significant potential for economic productivity increase. By implementing conservation tillage and modernizing machinery, will reduce our reliance on non-renewable and economic inputs, alleviate environmental pressure, and increase the agroecosystem's sustainability.

Bread wheat cultivars Chamran, Chamran2, and Sirvan are the dominant cultivars in Kerman province's warm regions. Due to their obsolescence and lack of purity, farmers are dissatisfied with the performance of common cultivars. Therefore, if the new cultivars outperform the conventional cultivars in terms of yield, they should be used to replace the conventional cultivars. The quantitative yield of 12 bread wheat cultivars was determined quantitatively in this experiment using a randomized complete block design with three replications. At a 5% probability level, the combined analysis of variance revealed that the year effect was significant for 1000-seed weight, plant height, and spike length. Additionally, at a 5% probability level, there is a significant difference between cultivars in terms of grain yield, 1000-seed weight, plant height, and spike length, indicating a genetic difference between cultivars. Sarang cultivar produced the most grain (7191.33) kg/ha, while the Chamran cultivar produced the least grain (6376.50 kg/ha). Sarang cultivar averaged 46.6 grams per 1000 seeds, while Shush cultivar averaged 35.1 grams per 1000 seeds. The Mehregan, Sirvan, and Tirgan cultivars, on the other hand, had the longest spikes at 10.16, 10.06, and 10 cm, respectively, while the Chamran2 cultivar had the shortest spikes at an average of 7.46 cm. The Chamran cultivar reached a height of 104.16 cm, while the Chamran2 and Aflac cultivars reached 94.33 and 94.16 cm, respectively. According to the findings of this study, Sarang, Shush, Khalil, and Tirgan wheat cultivars should be used in place of older and conventional cultivars in warm areas of Kerman province, depending on available facilities.

The need for a model for effective planning and management of water resources, particularly groundwater, is especially critical in light of water scarcity and aquifers. Given the importance of various factors in determining the amount of drop, this study used human and natural factors to predict the amount of aquifer drop in Qazvin. To accomplish this, the K-Means clustering algorithm was used first, followed by the tree algorithms CART, CHAID, C5.0, and QUEST to determine the optimal ratio between different fields. Accuracy values of 0.90, 0.96, 0.94, and 0.92 were obtained for the aforementioned tree algorithms. The values obtained for the CHAID algorithm's sensitivity, transparency, accuracy, precision, false-positive rate, false-negative rate, F-measure, geometric mean, and error rate demonstrate that this algorithm outperforms other algorithms. The amount of water in the irrigation network is the most influential human factor in model production, while the amount of temperature is the most influential natural factor. The proposed model enables more accurate prediction of aquifer changes and can be used by managers and farmers to improve aquifer management.

Non-renewable energy consumption in agriculture increased greenhouse gases (GHGs) emissions and global warming. The present study aimed to look at energy use, GHGs emissions and economic indicators in Azna, a city in Iran's Lorestan Province in 2019. For this purpose, data were collected applying questionnaires via face-to-face interviews. The TOPSIS method was used to find the most energy efficient and environmentally friendly crop. Investigated crops were irrigated and rain-fed wheat and barley, rapeseed, bean, potato, and sugar beet. The results revealed that sugar beet cultivation is not efficient in terms of energy consumption and global warming potential (GWP). The highest share of the total energy input was recorded for diesel fuel, N and P fertilizer with at least 80% for all crops. The maximum GHGs emission and GWP was observed in sugar beet and bean at 0.019 and 0.02, however, the lowest was recorded in rain-fed barely at 0.005. The highest relative proximity to the ideal and the shortest distance from the ideal were observed in rain-fed barley and wheat. In general, wheat and barley, especially when cultivated under rain-fed condition, had the highest cultivation priorities in the region, which can reduce environmental problems.

The orange pulvinaria scale, Pulvinaria aurantii Cockerell (Hemiptera: Coccidae), is one of the most significant citrus orchard pests in northern Iran. To assess the population fluctuations of this pest and its predator Cryptolaemus montrouzieri Mulsant in Tonekabon blood orange orchards, 80 leaves from 20 trees were randomly selected at each sampling time (with a maximum relative variation of 15%) and the number of each biological stage of the P. aurantii and its predatory ladybird were recorded per leaf. The average population of all biological stages of P. aurantii (ovisac, nymphal stages, and adult female insect) peaked on June 29 (30.05 per leaf) and September 14 (29.55 per leaf) in 2011, and on June 21 (30.09 per leaf) and September 6 (22.6 per leaf) in 2012. Similarly, the average population of all C. montrouzieri biological stages peaked on June 29 (0.34 per leaf), September 7 and 14 (0.45 per leaf), and June 21 (0.65 per leaf) and September 6 (1.00 per leaf) in 2011 and 2012, respectively. The population change curves indicated that increasing the population of ovisacs, 1st and 2nd instar nymphs of the pest attracted and increased the population of C. montrouzieri on infected trees, possibly due to the desirability of these biological stages of the pest to the predator. The present study revealed that in both years, the second generation of the pest is characterized by greater concordance and overlap between the populations of scale ovisacs and ladybird eggs. In 2011, C. montrouzieri prevented an increase in the population of P. aurantii second generation, and in 2012, due to a higher population density, it was able to significantly reduce the second generation population of this soft scale. Additionally, the regression between prey and predator populations was statistically significant, indicating a density-dependent response of the predator to the prey population.

The disparity in agricultural production unit performance is a critical and fundamental issue that necessitates the implementation of required programs and policies to ensure an equilibrium in the distribution of resources and seeds in order to increase efficiency. Enhancing efficiency can result in economic growth and development in the agricultural sector, as well as rural development. In recent years, the potato has been regarded as the dominant crop in Kabodarahang; policy formulation based on production efficiency has become a necessity, given the importance of production and the rational use of seeds in potato production. Thus, the efficiency, effectiveness, and productivity of production units were determined under uncertain conditions using various level-cut and fuzzy data envelopment analysis methods for potato farms in Kabodarahang; the most efficient units were selected. The result indicates that 14% of producers are efficient or near-efficient. Additionally, 75% of producers operate at a level of efficiency between 70% and 100%. In total, unit 6 is the most productive and stable of the other units. As a result, this unit is chosen as the best producer. Efficiency analysis at various levels reveals that producers operate at a high level of efficiency. Therefore, to increase production, manufacturing technology should be enhanced. Thus, politicians and policymakers should take into account new technologies for planting, growing, and harvesting.