Showing 4 results for Rezvani
M.r. Rezvani, A. Golian, F. Eftekhari Shahroudi, H. Nassiri Moghaddam,
Volume 4, Issue 1 (spring 2000)
Abstract
An experiment with 720 pullets was conducted to investigate the effect of dietary energy levels of pullet and dietary energy and fat of laying ration on subsequent performance parameters during 14-20 and 22-44 weeks of age. In the first period, white leghorn pullets were fed with two diets of low and high density energy (2600 and 3200 Kcal ME/kg). In the lating period (second period), birds, in each treatment of pullet period, were fed with six diets containing three levels of low, medium and high energy (2600, 2750 and 2900 kcal/kg) at two levels of supplemental fat (zero and 2%). All diets were formulated to meet minimum NRC (1994) requirements of amino acids and protein. This experiment was done in randomized complete block designs with 5 replicates. The levels of energy in the growing period did not affect egg production, egg weight, daily feed intake, feed conversion rate and age of pubertal maturity in laying period, but pullets fed with high energy diet had significantly higher weights as compared to low energy diet in the beginning of laying period. In the laying period, the use of supplemental fat (2%) improved egg production and egg weight, but feed intake and feed conversion rate were not affected. Means of feed conversion rate, feed intake and egg production during laying period in low energy diet were greater than those as compared to high energy diet, but egg weight was not affected by energy level of diets. Low energy intake to protein intake ratio in low energy diet versus high energy diet may be a reason for greater egg production in lower energy than in higher energy diets.
A Khodashenas, A Koocheki, P Rezvani Moghadam, A Lakzian , M Nassiri Mahallati,
Volume 14, Issue 52 (sumer 2010)
Abstract
Among the biodiversity of soil microorganisms, bacteria have the basic role in soil functions. In order to determine the diversity and abundance of soil bacteria in arid regions, and also to study the effect of agricultural practices on them, a study was conducted in winter wheat fields on Shirvan, Mashhad and Gonabad. In each region, high and low input fields of winter wheat and a natural system for comparison were selected. Use of agricultural inputs was criteria for selection of low and high input fields in each region. Soil sampling was done on fields and natural systems and organic matter content, abundance and diversity of soil bacteria were measured in soil samples. Species richness and abundance of soil bacteria was affected by region and so that natural system of Gonabad has the minimum of species richness among the studied systems and the differences of other systems was not significant. Abundance of soil bacteria in 1 g dry soil was maximum in Gonabad and minimum in Shirvan. Abundance of soil bacteria was affected by organic matter and in low and high input systems of Gonabad and low input system of Mashhad was greater than other systems. Overall, 19 species of bacteria that belonged to 4 genus were detected. Results showed that species richness and abundance of soil bacteria in studied systems were relatively low and agricultural practices have not significant impact on these organisms, so that species richness and abundance of soil bacteria were improved in agricultural systems of Mashhad and Gonabad. Pattern of bacterial diversity showed that regional and agricultural stresses were affected on bacterial function so that in high level of stresses, species richness decreased and function of soil bacteria was restricted to decomposition of organic matter. Therefore, organic matter of soil must be increased and agricultural stresses must be decreased to improve of soil bacterial functions.
A. Heidari, A. Hemmat, S.m Rezvani,
Volume 18, Issue 67 (Spring 2014)
Abstract
efficiency was investigated during a 2-year period (2009-2010) in a silty clay loam soil in Tajarak Research Station
(Kaboudarahang Township), Hamedan. The experimental design was a strip-plot within a randomized complete blocks
design. The horizontal band, the irrigation water rate after flowering, included full and deficit irrigation (100% and 75%
potato water requirement) and the vertical band, kind of inter-planting row tillage including 1- subsoiling to 30-35 cm
soil depth, 2- chiseling to 20-25 cm soil depth, 3- sweeping to 5 cm soil depth and 4- no-till. During the growing
season, soil mechanical resistance (cone index) in two stages and water infiltration into the soil were measured. At the
end of the growth season (harvesting time), potato yield quantity and quality were measured. Result showed that the
effect of inter-row tillage on soil mechanical resistance was significant. Subsoiling and chiseling had lower soil
mechanical resistance and higher water permeability between treatments, respectively. The effect of inter-row tillage on
potato yield was significant so subsoiling and chiseling had a higher potato yield between treatments, respectively. The
effect of irrigation water rate on potato yield was not significant. The effect of inter-row tillage on water use efficiency
wasn’t significant.
M. Rezvani, M. Shafiezadeh,
Volume 19, Issue 71 (spring 2015)
Abstract
Nowadays, due to the effective role of nitrogen fertilizer in growth, yield and crop quality, farmers apply large amount of chemical fertilizers. High application of nitrogen fertilizers has caused soil and water pollution and environmental dangers, higher nitrate accumulation in plant, and different disease risks in human and livestock. In order to investigate the effects of nitrogen and cycocel application effects on soil nitrate pollution and agronomic traits of rice, an experiment was arranged in split plot based on a completely randomized block design with three replicates at Sari region (north of Iran) in 2010. The main factor was nitrogen in four levels and cycocel was considered as a sub factor in three levels. Results showed that maximum and minimum plant height and fourth internodes bending moment were obtained in 0 and 150 kg N ha-1, respectively. Higher filled spikelet percentage per panicle, grain yield and harvest index were obtained in 100 kg N ha-1 application. Application of N up to 150 kg N ha-1 increased soil nitrate by 44.7 percent. As cycocel application decreased, the plant height and panicle length were reduced, but tiller number per plant, filled spikelet percentage per panicle, and grain yield were increased.
