among the agricultural important factors, inputs are the most significant in agricultural production. this article aimed to examine the impact of government subsidy policies on production of one of the most strategic products, namely on production of one of the most strategic products, namely maize, in iran. to achieve this goal, panel data for the nine provinces of iran's major producers of ma...

test day milk records of a holstein dairy farm collected during years 2004 to 2006 on 142 cows in the 1st lactation vs. 140 cows in the 2nd lactation were used in this research. there were real milk yields of cows available in each part of lactation in this farm making it possible to compare functions based on the new criteria (squared error of estimation). five functions were compared to estim...

abstract             (co) variance components of milk, fat and protein yield of 11368 first lactation iranian holstein dairy cow were estimated by single trait random regression test-day models and restricted maximum likelihood (reml) method. in this study the homogeneous residual variance was assumed throughout lactation. estimated heritability for 305-day production traits ranged from 0.25 to...

considering iran geographical location, water is the most limited factor in agriculture section. therefore, it would be logical to consider water as one of the most significant criteria in selection of cultivation model. the purpose of this study is assigning cultivation pattern based on economic value of water in gotvand township in agronomic year 2008-2009. so it was necessary to computes the...

abstract in order to optimize the water management in agriculture in semi arid and arid conditions water-salinity function should be evaluated. in order to evaluate salinity and deficit irrigation two experiments were conducted in 2008 and 2009. kochia was grown with six levels of saline water (1.5, 7, 14, 21, 28, and 35 ds/m) and three levels of applied water (25, 75, and 125 percent of the wa...

production is hard to achieve by increasing cropping area due to limited water resources. so, increased yield per unit area may be the solution to increase production. investigating productivity of production factors is very important in this context. the objective of this study is to measure the productivity of production factors in sugar beet production in fars province. the data needed for t...

abstract intensive and inefficient use of energy leads to degradation of natural resources and environmental problems. this study evaluated the relationship between the energy of consumed inputs and yield of tomato, cucumber and melon using the cobb–douglas production function. the data were collected from 90 farmers in firoozabad using a questionnaire. the farmers were chosen by simple random ...

introduction: lactation yield and persistency are two economic important traits in dairy cow. the production level of a dairy cow is determined by a joint effect of genetic and environmental factors.the main factors determining the total amount of milk production are milk yield at the peak of lactation and persistency as well as length of lactation period. persistency are defined as a extent to...

workers who carry out manual rebar tying tasks are exposed to muscular-skeletal injuries associated with the use of manual tools and the movements associated with them (force, repetitiveness and awkward wrist postures). this paper presents a background on musculoskeletal injuries directly linked to manual and mechanical rebar tying method is conducted. the objective of this study is to compare ...

given the strategic remarkable rank of pistachio in non-oil exports, inputs’ management in its production is so important. as the scarcest input in agricultural sector, water is considered to be among the most important inputs of pistachio production.water inadequate supply and limate conditions increase water demand in pistachio growing areas. it is necessary to determine the real value or pri...