June 2012 issue
[3(2) 2012]

Southern Cross Publishing Group© 2012

June 2012 issue | Australian Journal of Agricultural Engineering
Effects of humic acid on decrease of phosphorus usage in forage maize var. KSC704 (Zea mays L.)

H. Rezazadeh, S.K. Khorasani, R.S.A. Haghighi

Department of Agriculture, Islamic Azad University, Mashhad, Iran
Khorasan Razavi Agricultural and Natural Resources Research Centre, Mashhad, Iran
Department of Agronomy and Plant Breeding, Islamic Azad University, Mashhad, Iran, P.O. Box 91735 -413


This study was conducted on the effects of humic acid on yield and the yield components of Forage Corn (Zea mays L. Var. KSC704) in Chenaran, Mashhad, Iran on 2010. The evaluation process was based on 3 levels of phosphorus (0, 100, 200 kg/ha) and 4 levels of humic acid usage consisting of control (without humic acid), seedling, flowering, seedling and flowering as factorial experiments based on RCBD with 3 replications. The results showed that using different levels of Phosphorus had significant effects on de-husked ear, cob weight and harvest index of forage Corn (P=0.05). Furthermore, the levels of humic acid on corn dry material, de-husked ear, cob weight /ha, row no. and forage harvest index (HI) was significant at 5% level. Moreover, consumption of 100 kg/ha Phosphorus led to the highest yield of dry material (24937 kg/ha). After using humic acid in flowering, the forage dry material increased to 31035 kg/ha. The result of this study showed that level of organic matter and phosphorus content of soil were low and high, respectively. Thus, the low level of organic matter and high soil phosphorus can be lead to forage yield decrease, therefore it is necessary low levels of the phosphorus fertilizer usage. Therefore, farmers should be aware of improved usage of phosphorus fertilizer. Also, we concluded the consumption of humic acid in seedling and flowering stages of maize var. KSC704 could be raised up forage yield and reduce the chemical pollution of soil.

Pages 34-38 | Full Text PDF
Comparison of multiple linear regressions and artificial intelligence-based modeling techniques for prediction the soil cation exchange capacity of Aridisols and Entisols in a semi-arid region

Yusef Kianpoor Kalkhajeh, Ruhollah Rezaie Arshad, Hadi Amerikhah, Moslem Sami

Department of Soil Science, Faculty of Agriculture, Shahid Chamran University, Ahvaz, Iran
Department of Agricultural Machinery, Faculty of Agriculture, Shahid Chamran University, Ahvaz, Iran


The cation exchange capacity (CEC) of the soil is a basic chemical property, as it has been approved that the spatial distribution of CEC is important for decisions concerning pollution prevention and crop management. Since laboratory procedures for estimating CEC are cumbersome and time-consuming, it is essential to develop an indirect approach such as pedo-transfer functions (PTFs) for prediction this parameter from more readily available soil data. The aim of this study was to compare multiple linear regressions (MLR), adaptive neuro-fuzzy inference system (ANFIS) and artificial neural network (ANN) including multi-layer perceptron (MLP) and radial basis function (RBF) models to develop PTFs for predicting CEC of Aridisols and Entisols in Khuzestan province, southwest Iran. Five soil parameters including bulk density, calcium carbonate, organic carbon, clay and silt were considered as input variables for proposed models. The prediction capability of the models was evaluated by means of comparison with observed data through various descriptive statistical indicators including mean square error (MSE) and determination coefficient (R2) values. Results revealed that the MLP model (R2=0.83, MSE=0.008) had the most reliable prediction when compared with the other models. Also results indicated that the ANFIS model (R2=0.50, MSE=0.009) had approximately similar accuracy with those of MLR (R2=0.51, MSE=1.21), while, their prediction performance was less than RBF (R2=0.74, MSE=0.034) model. However, regarding to obtained statistical indicators, ANNs especially MLP model provide new methodology with acceptable accuracy to estimate the CEC of Aridisols and Entisols that diminished the engineering effort, time and funds.

Pages 39-46 | Full Text PDF
Seed yield and yield components of intercropped barley (Hordeum vulgare L.) and annual medic (Medicago scutellata L.)

Amir Sadeghpour, Emad Jahanzad

Department of Plant, Soil, and Insect Sciences, University of Massachusetts, Amherst, MA 01003-9294, USA


Seed availability of annual medic (Medicago scutellata L.), an annual legume which performs well in various forage cropping systems, is a major challenge for livestock producers in Iran. This study was conducted at the experimental farm of University of Tehran to determine if intercropping annual medic with barley (Hordeum Vulgare L.) can produce supplement medic seeds while barley grain yield as the main crop is not compromised in 2007 growing season. A randomized complete block design with eight cropping ratios comprising of one row of barley: one row of annual medic (1B:1M), 2B:2M, 4B:4M, 6B:6M, 6B:2M, 4B,2M, 2B,4M, and 2B:6M along with sole culture of barley and annual medic was studied. The overall results as indicated by Land Equivalent Ratio (LER) revealed that regardless of ratios, the grain yield of barley when intercropped with medic was lowered. The total seed yield of both crops however, was improved in some of the intercropping ratios when compared to the monoculture of either crop. The land equivalent ratio (LER) of the cropping ratio of 2H:2M was 1.32 which is an indication of 32 percent yield advantage over the sole cropping of the two crops. The results of this study indicated that although intercropping of annual medic with barley, using 6B:2M replacement series yielded 259 kg ha-1 less grain compared to barley sole cropping but it produced a 365 kg ha-1 annual medic seed which has significantly higher market value than barley. 

Pages 47-50 | Full Text PDF
Evaluation of the performance of a three-dimensional vibrating test rig for cleaning stumps

Erik Anerud, Raida Jirjis and Girma Gebresenbet

Department of Energy and Technology, Swedish University of Agricultural Science, Box 7032, SE-75007 Uppsala, Sweden


It has been shown that vibrating devices can successfully be used for separation and removal of unwanted/contaminant material, for both laboratory and full-scale industrial purposes. The presence of impurities on energy-rich softwood stumps is a major drawback when using stumps as fuel, since it leads to high ash content. Vibration methods can be an efficient approach to remove excess impurities and achieve acceptable ash content. Stumps are usually shaken in connection with harvesting and stored afterwards to facilitate the removal of contaminants. The required storage duration can lead to high dry matter losses and a faster and efficient cleaning method such as vibration is highly desirable. This study evaluated the performance of an adjustable three-dimensional vibrating test rig designed to assess the cleaning efficiency of vibration-based methods. Vibrating parameters such as acceleration amplitude, frequency and displacement of the test rig were determined for 12-24 mm distance between eccentric weight centre of mass and the rotating shaft of electric motors at rotation velocity 19.16-29.17 Hz. The acceleration amplitude ranged from 1.38 to 5.71 g. The parameters could be repeated irrespective of direction and number of vibration directions. The test rig was therefore considered to be a reliable tool for determining and evaluating the efficiency of vibration in removing contaminants from stumps.

Pages 51-58 | Full Text PDF
Effects of weed control methods on yield and yield components of Iranian rice

H. Yousefnia pasha, R. Tabatabae koloor, S.J. Hashemi

Department of Agricultural Machinery, Sari Agricultural Sciences and Natural Resources University, Sari, Mazandaran, Iran


In order to study the effects of several weed control methods on yield and yield components of rice, a field experiment was carried out in Northern part of Iran during 2011. The experiments were set up as randomized complete block design with three replications and seven treatments including hand weeding twice (T1), powered weeding twice (T2), powered weeding + hand weeding once (T3), cono-weeder weeding twice (T4), herbicide application + hand weeding once (T5), control treatment (T6) and herbicide application once (T7). Results showed that all the treatments had significant effect (P<0.01) on the grain yield, biological yield, fertile tillers, panicle number per square meter, grain number per panicle, filled grain number per panicle and unfilled grain number per panicle, while the treatments effect on weight of thousand seeds was not significant. In general, among treatments, herbicide application + hand weeding once (T5) had the highest grain yield (4584 kg ha-1), while control treatment (T6) because of the high unfilled grain per panicle and less panicle number per square meter had the lowest grain yield (2505 kg ha-1). Among the mentioned traits, unfilled grain number per panicle had negative and significant correlation (-0.47*) with grain yield. Panicle number per square meter had very high and positive correlation (0.94**) with grain and biological yield. As
a result, panicle number per square meter is considered as the most important and the most effective trait in increasing grain yield.                                                                                                                                                   

Pages 59-64 | Full Text PDF
Some moisture dependent thermal properties of Cashew kernel (Anarcardium occidentale L.)

Ato Bart-Plange, Ahmad Addo, Francis Kumi, Abubakar Kamil Piegu

Department of Agricultural Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
Department of Agricultural Engnieering, University of Cape Coast, Cape Coast, Ghana


Thermal properties of crops are very important in the  design of drying, processing and storage equipment. The availability of such relevant information on cashew nutwill aid in the design and manufacture of equipment for postharvest operations. The thermal conductivity, specific heat capacity and thermal diffusivity of cashew kernel were evaluated as a function of moisture content. Specific heat was measured by the method of mixtures while the thermal conductivity was measured by the line heat source probe method. Thermal diffusivity was calculated from the experimental results obtained from specific heat, thermal conductivity and bulk density. The bulk density for nut and kernel decreased from 625.62 to 592.42kg/m3 and 559.60 to 505.06kg/m3 respectively with increasing moisture content from 5.0% to 9.0% w.b. Specific heat increased linearly from 1586 to1756J/kgC with increasing moisutre content. The thermal conductivity ranged from 0.2103 to 0.2296W/mK and thermal diffusivity varied from   2.36910-7 to 2.58810-7m2/s. Specific heat, thermal conductivity and thermal diffusivity were found to increase linearly with increasing moisture content from 5.0 to9.0% w.b.

Pages 65-69 | Full Text PDF
Designing vertical and horizontal frame structure for slope protection

Md. Toriqul Islam, Md. Zakaria Hossain, Masaaki Ishida

Department of Sustainable Social Systems, Mie University, Japan
Department of Environmental Sci. and Tech., Mie University, Japan


Composite frame structure, a reinforced cementitious composite, attains its optimal reinforcing capability for land reinforcement applications owing to its synergetic action from two components of wire mesh and mortar. This paper presents some field performance on the composite technology for vertical and horizontal frame structures reinforced with woven square mesh. Design and fabrication of composite technology for land slope protection are depicted in this paper that can be applied in Japan and other countries of the world. The selected structures that have been identified for land slope protection are skeletal frame of soil anchoring, land reinforcements, hill cover and slope surface lining. Design sketches of various composites along with fabrication procedure are depicted. Some examples of  practical applications of this composite technology have been demonstrated using simple techniques. Based on the cost of required materials and labor, the cost of fabrication per unit area of composite structure has been calculated. It is concluded that the required cost of the composite frame structure was US$ 60 per square meter. New concept depicted in this paper is applicable for the construction of strong, durable and cost-effective frame structures for land slope protection.

Pages 70-74 | Full Text PDF