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Showing 5 results for Shekofteh
Study on the Effect of Drip Tape Placement and Fertilization Time on Yield of Potato in Jiroft Area
H. Shekofteh,
Volume 18, Issue 69 (fall 2014)
Abstract

In order to study the effect of depth of drip placement in soil in subsurface drip irrigation, and fertilization time during irrigation events, on tuber yield of potato, an experiment was carried out in Jiroft area in 1389. This experiment was in a completely randomized block design with four replications, with depth placement of drip tape as the main plot, and fertilization time as the sub-plot. Results showed that depth placement of drip tape had a significant effect on tuber yield, plant height, number of stems, stem diameter and dry plant weight at 1% level, number of tubers in plant, and wet plant weight and stolen height at 5% level. Fertilization time had a significant effect on tuber yield, stem diameter, stem number in plant, and plant height at 1% level and on dry plant weight and plant tuber number at 5% level. But, it did not show any significant effect on other attributes. Also, interactional effects of treatments were significant on tuber yield per plant, stem diameter, plant height, and number of tubers at 1% level, and on dry plant weight at 5% level, but the effect on other traits was not significant. According to the statistical results, the highest yield was obtained from the depth of 15 cm and middle time of fertilization.


Modeling Nitrate Leaching from a Potato Field Using Adaptive Network-Based Fuzzy Inference System Combined With Genetic Algorithm
H. Shekofteh, M. Afyuni, M. A. Hajabbasi, H. Nezamabadi-Pour, F. Abbasi, F. Sheikholeslam,
Volume 18, Issue 70 (winter 2015)
Abstract

The conventional application of nitrogen fertilizers via irrigation is likely to be responsible for the increased nitrate concentration in groundwater of areas dominated by irrigated agriculture. This requires appropriate water and nutrient management to minimize groundwater pollution and to maximize nutrient use efficiency and production. To fulfill these requirements, drip fertigation is an important alternative. Design and operation of drip fertigation system requires understanding of nutrient leaching behavior in cases of shallow rooted crops such as potatoes, which cannot extract nutrient from lower soil depth. This study deals with neuro-fuzzy modeling of nitrate leaching from a potato field under a drip fertigation system. In the first part of the study, a two-dimensional solute transport model (HYDRUS-2D) was used to simulate nitrate leaching from a sandy soil with varying emitter discharge rates and various amounts of fertilizer. The results from the modeling were used to train and validate an adaptive network-based fuzzy inference system (ANFIS) in order to estimate nitrate leaching. Radii of clusters in ANFIS were tuned and optimized by genetic algorithm. Relative mean absolute error percentage (RMAEP) and correlation coefficient (R) between measured and obtained data from HYDRUS were 0.64 and 0.99, respectively. Results showed that ANFIS can accurately predict nitrate leaching in soil. The proposed methodology can be used to reduce the effect of uncertainties in relation to field data.


Effect of Vermicompost, Pistachio Kernel and Shrimp Shell on Some Growth Parameters and Availability of Cd, Pb and Zn in Corn in a Polluted Soil
S. Molaei, H. Shirani, M. Hamidpour, H. Shekofteh , A. A. Besalatpour,
Volume 19, Issue 74 (Winter 2016)
Abstract

This experiment was conducted to evaluate the effect of vermicompost, pistachio kernel and shrimp shell on the immobilization and availability of Cd, Pb and Zn in corn in polluted soils. Treatments consisted of two levels of pistachio kernel, shrimp shell and vermicompost (5 and 10 % w/w). In control treatment, no amendment was added to the soil. The experiment was carried out as a completely randomized design with 3 replications. Plants grew for two months in the greenhouse. Then, all the plants were harvested and their shoots and roots were separated, washed with distilled water and oven dried at 65 °C to a constant mass. The measured characteristics were dry weight of shoots and roots, leaf area, greenness index, chlorophyll fluorescence, maximal quantum yield of PS  photochemistry (Fv/Fm), performance index (PI), and total concentrations of Cd , Pb and Zn in shoots and roots. Results showed that plant growth parameters (dry weight of shoots and roots, leaf area) and photosynthetic characteristics (chlorophyll fluorescence, Fv/Fm, and PI) were higher in plants grown in vermicompost and pistachio kernel treatments as compared to those grown in control. Plants died in shrimp shell treatment after two weeks. The concentration of Cd, Zn and Pb in shoots and roots of plants grown in vermicompost and pistachio kernel treatments were lower than those grown in control.


The Effect of Different Land Uses on Some Physical, Chemical and Biological Quality Indicators of Soil
H. Shekofteh, A. Masoudi, S. Shafie,
Volume 22, Issue 3 (Fall 2018)
Abstract
Soil quality is the permanent soil ability to function as a live system within ecosystem under different land uses. Investigating the impact of land use type on soil quality indicators could help to distinguish sustainable managements and therefore, to inhibit soil degradation. In order to evaluate the effect of different land uses on soil quality indicators, a research based on a randomized complete design in Rabor region, Kerman Province, Iran, was conducted. A total of 104 samples were taken from the soil surface (0-15 cm) of four land uses including: pasture (28 samples), forest (25 samples), agronomy (27 samples) and garden land use (24 samples). Soil quality indicators were measured as: soil organic matter, particulate organic matter, and bulk density, plant available water capacity, S index, cation exchange capacity (CEC), electrical conductivity (EC), soil pH, and phosphatase enzyme. According to the results, land use types had a significant effect on all indicators except S index at 1% probability level. The maximum amount of soil pH, bulk density and phosphatase enzyme was obtained from forest land use. On the other hand, the maximum amount of the other indicators was attained from the garden land use. Totally, garden land use, due to having high organic matter, could improve the soil quality. However, the pasture land use had the worst soil quality due to the weak cover and the low organic matter.

Identifying the Determinant Factors Influencing S Index in Calcereous Soils Using Anneling Simulated– Artificial Neural Network Hybrid Algorithm
F. Amirimijan, H. Shirani, I. Esfandiarpour, A. Besalatpour, H. Shekofteh,
Volume 23, Issue 3 (Fall 2019)
Abstract
Use of the curve gradient of the Soil Water Retention Curves (SWRC) in the inflection point (S Index) is one of the main indices for assessing the soil quality for management objectives in agricultural and garden lands. In this study Anneling Simulated – artificial neural network (SA-ANN) hybrid algorithm was used to identify the most effective soil features on estimation of S Index in Jiroft plain. For this purpose, 350 disturbed and undisturbed soils samples were collected from the agricultural and garden lands and then some physical and chemical soil properties including Sand, Silt, Clay percent, Electrical Conductivity at saturation, Bulk Density, total porosity, Organic Mater, and percent of equal Calcium Carbonate were measured. Moreover, the soil moisture amount was determined within the suctions of 0, 10, 30, 50, 100, 300, 500, 1000, 1500 KP using pressure plate. Then, the determinant features influencing the modeling of S Index were derived using SA-ANN hybrid algorithm. The results indicated that modeling precision increased by reducing the input variables. According to the sensitivity analysis, the Bulk Density had the highest sensitivity coefficient (sensitivity coefficient=0.5) and was identified as the determinant feature for modeling the S Index. So, since increasing the number of features does not necessarily increase the accuracy of modeling, reducing input features is due to cost reduction and time-consuming research.

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