Precision Agriculture
ُseyyed Mohammad Mousavai; Hojat Emami; Gholam Hosain Haghnia
Abstract
Extended abstractIntroductionKnowledge about the soil quality in agriculatral lands and natural resources is essential for achievement the best management and maximum economic efficiency. The land use change is the important human activity in environmental ecosystems, which effect on some soil processes ...
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Extended abstractIntroductionKnowledge about the soil quality in agriculatral lands and natural resources is essential for achievement the best management and maximum economic efficiency. The land use change is the important human activity in environmental ecosystems, which effect on some soil processes such as microbial activity, mineralization of carbon and nitrogen content. In addition, land use has an important role on temporal and spatial variation of soil properties and quality. Agricultural practices may affect positive or negative effect on soil quality. Intensive cultivation of plants decreases soil physical and quality, as a result of this yield of plants, production efficiency and environment quality decrease. In this research, the effect of three land uses on soil physical, fertility and quality properties were studied. Materials and methodsThe studied area (Hossein abad) is located 30 km far from the northern Nehbandan town (South Khorasan, Iran).To study the effect of land uses change on soil properties were selected three land uses including pomegranate (Punica granatum ), olive (Olea europaea) and wheat (Triticum aestivum ). The 45 soil samples (15 samples from each land use) were taken from surface soil (0-30 cm). Then some soil physical and fertility properties which affect the soil quality were measured and the effect of land use change from wheat cultivation to olive and pomegranate gardens during the recent 20 years were studied. In addition, soil quality in each land use was determined based on cornel university test. To compare soil properties and quality, the randomized complete block design was applied.Results and discussionThe results showed that land use change had a significant effect on organic carbon, mean weight diameter of aggregates (MWD), water stable aggregates (WSA), macro nutrients (N, P, and K), and some micro nutrients (Fe and Mn) (P < 0.001). Comparison of means demonstrated that the difference between organic carbon content in olive and pomegranate land uses was not significant, and the content of OC in both land uses was significantly higher than wheat land use. Olive and pomegranate land uses cause to stability of soil structure increase, probably due to reduction the traffic of wheals and also somewhat increasing the organic carbon as a result of littering. Therefore, the MWD in olive land use was significantly higher than two land uses and the lowest value was obtained in what land use. Also, the value of WSA in three land uses was significantly different (P < 0.05) and their content in olive and wheat land uses were the maximum and minimum, respectively. The concentration of total nitrogen in pomegranate land use was more significant than two other land uses (P < 0.05). But the concentration of phosphorous (P), potassium (K), Fe and Mn in wheat land use was the highest content and significantly greater than other two land uses. Despite the concentrations of P, K, and Fe nutrients in pomegranate land use were the lowest value, but, there were no significant difference between the concentration of them in olive and pomegranate land uses. It seems that this variation especially P and Fe is probably due to pH and the Ca and Mg concentration and creation insoluble component of Fe, Mn and P in these land uses.According to the results of cornel university test, soil quality in garden land uses was decreased and the range of soil quality score was varied from 49.5 (olive) to 61.2 (wheat). Among the soil properties affecting the soil quality, fertility and chemical properties such as electrical conductivity (EC), absorption sodium ratio (SAR) and somewhat pH of soil saturated extract decreased the soil quality in olive land use. Also, OM, Fe, Zn, and Mn decreased the soil quality in 3 land uses, of course in olive and pomegranate land uses, micro nutrients (Fe and Mn) had the more effect on decreasing the soil quality compared to wheat land use. In addition, bulk density (Bd), mean weight diameter of aggregates (MWD), aeration porosity (AC), P, K, and Cu contents increased soil quality in all 3 land uses.ConclusionIn general, when wheat land use change to olive and pomegranate land uses decreased some soil properties and quality in arid area of Nehbandan, probably due to low quality of irrigation water.
Alireza Abdollahpour; Mojtaba Baranimotlagh; Amir Bostani; Farshad Kiani; Farhad Khormali; REZA GHORBANINASRABADI
Abstract
Introduction Globally, deforestation is the dominant land use change process and has severe effects on soil biogeochemical properties. Large areas of the north facing slopes of the Alborz mountain range in northern Iran are covered by extensive loess deposits. Loess often contain little clay results ...
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Introduction Globally, deforestation is the dominant land use change process and has severe effects on soil biogeochemical properties. Large areas of the north facing slopes of the Alborz mountain range in northern Iran are covered by extensive loess deposits. Loess often contain little clay results in a loss of SOC under cultivation. Deforestation and cultivation on the loess hillslopes in northern Iran have resulted in a deterioration of soil quality, particularly significant reduction in SOC. Loess lands of Golestan province in northern Iran is densely being cultivated following deforestation. Labile fractions of soil organic matter (SOM), rather than total SOM, have been used as sensitive indicators of soils' quality and response to agricultural management changes. Several physical, chemical, and biological methods have been used to distinguish between labile (or biologically active) and recalcitrant pools of SOM. So, this research aims to investigate the effect of land use change from pristine and undisturbed forest as a reference to other land uses on soil organic carbon components and fractions as an important indicator in the sustainable soil management system and maintaining fertility and controlling soil erosion. Also, the effect of these land use changes on total carbon, soil organic carbon, and finally on the physical and chemical components of soil organic carbon.Materials and Methods The study area is the Toshan watershed, which is located in the northwest of the city of Gorgan (Golestan province) in the north of Iran. Four major and dominant types of land use were considered in the study area, including a) garden (olive), b) agricultural (cotton), c) virgin or untouched forest, d) abandoned (raspberry). Soil carbon fractionation was done by two physical methods (soil aggregate fractionation method) and chemical method (hydrolysis of organic matter with hot water). The selection of soils in different land uses was such that they have similar initial conditions and therefore the change in soil carbon in each use is related to the change in land use. The obtained data were analyzed based on the factorial design in the form of completely randomized design and using SAS software.Results and Discussion The results showed that the highest amount of total carbon and soil organic carbon was observed in the forest treatment and in the first depth (6.02% and 3.5%, respectively), which had a significant difference compared to other land use treatments studied. The results showed that despite the absence of a significant difference between the two depths, the amount of stable organic carbon increased with increasing soil depth in agricultural and abandoned uses. The forest land use had the highest amount of stable organic carbon at the depth of 0-10 cm at the rate of 2.51%, followed by garden treatment at the same depth. The lowest amount of stable organic carbon was recorded in the abandoned land use treatment. The highest amount of organic carbon dissolved in water at both investigated depths was obtained in the forest management treatments and then in the abandoned management. While no significant difference was observed between the two investigated depths in the abandoned land use. A significant decrease in organic carbon fractions that can be extracted with hot water was observed in abandoned and agricultural uses, as well as their increase in forest land uses. After the forest land use, the olive garden land use had the highest amount of total and organic carbon, however, there was no significant difference between the agricultural and abandoned treatments. In forest and garden treatments, the amount of stable carbon at a depth of 0-10 cm is significantly higher than the amount of stable organic carbon at a depth of 10-20 cm. In the garden use treatment, the amount of organic carbon in the soil at a depth of 10-20 cm showed a significant increase of 35% compared to the first depth.Conclusion A significant decrease in organic carbon fractions that can be extracted with hot water was observed in abandoned and agricultural uses, as well as their increase in forest uses. In total, the results showed that the carbon of labile fraction was more responsive to the type of land use than other fractions, and among the different methods of carbon fractionation, physical methods showed a clearer response to land use change.
Plant Nutrition, Soil Fertility and Fertilizers
Masuod Shahrokhi; Saeid Shafiei; Hosein Shekofteh; Shapour Kouhestani
Abstract
Introduction: The quality of irrigation water has an important effect on the growth and concentrations of nutrients. The application of boron-rich irrigation water is a global issue and the most important boron pollution source in the environment. Poor water quality unavoidably leads to decreased growth ...
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Introduction: The quality of irrigation water has an important effect on the growth and concentrations of nutrients. The application of boron-rich irrigation water is a global issue and the most important boron pollution source in the environment. Poor water quality unavoidably leads to decreased growth of plants. One of the problems of irrigation in tropical regions is the high concentration of boron element in water and its concentration in irrigation water increases every year. In dry areas where agriculture takes place, boron is often found in high concentrations along with saline soils and salty waters. Boron stress occurs widely and limits plant growth and crop productivity worldwide. Boron is in the form of boric acid in the soil solution and it is washed from the soil in heavy rains, but it is not washed enough when it rains, and by accumulating in the soil, it poisons the plant and prevents its growth. Therefore, in arid and semi-arid areas, irrigation with groundwater that has a high boron content reduces crop growth. Therefore, this experiment aimed to evaluate the effect of activated carbon on nutrient concentrations by tomatoes, cucumbers, and eggplants under the boron stress of irrigation water. Materials and methods: To evaluate the effects of activated carbon on the concentrations and translocation of boron in the plant a factorial experiment with a completely randomized design and three replications was performed in the greenhouse conditions. Treatments included three plants (tomato, cucumber, and eggplant), three levels of boron concentration in irrigation water (0.03, 2.5, and 5 mg l-1) from a boric acid source, and four levels of activated carbon (0, 1, 2, and 3% soil). To prepare seedlings, first, a sufficient number of healthy seeds were selected and for better germination, they were placed in wet napkins for one day and night. Then the seeds were planted in seedling trays with coco peat substrate. In this stage, watering was done once every two days until finally, after 30 days and when the seedlings reached the four-leaf stage and the true leaves appeared, the plants were ready to be transferred to the pots. For cultivation, each of the plastic pots was filled with 3 kg of sampled soil, which was mixed with a proportion of activated carbon according to the type of treatment. Then, in the middle of each pot, several seedlings of the same size were planted. Then the pots were placed in the greenhouse according to the plan. The experiment was conducted with 36 experimental treatments in three replications and a total of 108 experimental units. The soil used was prepared with geographical coordinates (longitude 57˚ 37ʹ and latitude 28˚ 42ʹ) and depth of 0-30 cm and was classified according to the American classification system Sand, mixed, hyperthermic typical Torriorthents. During the growing period, the plants were irrigated daily according to the farm capacity (FC). The day temperature of 25 – 30 °C, the night temperature of 15 – 20 °C, and the relative humidity was 50 – 70%.Results and discussion: The results indicate that the main effects of boron and activated carbon levels had a significant effect (p < 0.01) on the concentration of iron, zinc, manganese, and copper in the aerial parts of the plant. With the amount of boron increased in the treatments, the amount of copper and iron in the aerial parts increased while the amount of manganese and zinc decreased. Regarding the effect of activated carbon, the results showed that by increasing the amount of activated carbon in the treatments, the amount of copper, manganese, and zinc decreased. In contrast, the amount of iron has increased. The highest concentration of iron in the aerial parts (219.6 mg kg-1) belonged to the level of 3% of activated carbon. Also, with the increase in activated carbon in the treatments, concentrations and accumulation of boron in the aerial parts decreased. The highest concentration of boron in the aerial parts (31.77 mg kg-1) was obtained in the cucumber and the level of 0% activated carbon, and the lowest concentration (5.75 mg kg-1) was obtained in eggplant and the level of 3% activated carbon.Conclusions: It is concluded that the use of activated carbon under boron stress conditions can reduce the concentrations and toxicity of boron in plants.
