Iran Agricultural Research
Volume:33 Issue: 2, Winter and Spring 2015

Agricultural extension agents should provide dry land producers with appropriate education to make them more interested in learning about water use optimization. Therefore، it is recommended to accompany education with art. In this regard، a study، using the randomized experimental research design، was carried out among dry land grape producers in Herayjan village، Southwest Iran، using the Morgan table for 70 producers. They were randomly divided into 2 experimental and control groups. The post-test only one control group design was applied through exposing the experimental group to educational treatment accompanied by poetry and the control group to related education only. The results showed that the experimental group had higher mean scores for water use optimization. Therefore، it is suggested that the agricultural extension method can positively change the attitude of dry land grape producers towards water use optimization when the educational method makes use of the art of poetry.

Crop residue is applied to amend soil properties and increase crop yield. In this study، the effects of rapeseed residues and different rates of nitrogen on grain yield and yield components of sunflower and weed dry matter were investigated. The experiment was conducted at the Experimental Farm of College of Agriculture، Shiraz University، located at Badjgah، Shiraz، Iran in 2007-2008 and 2008-2009 growing seasons. Treatments were nitrogen levels (150، 300 and 450 kg urea ha-1) as main plot and rates of residue rapeseed (25%، 50%، 75%) and without residues included weed free (R0) and weedy check (R1) as sub plot. The experimental design was a split plot based on randomized complete block in four replications. Results showed that the lowest weed biomass، highest grain yield and yield components of sunflower were obtained at 150 and 450 kg N ha-1، respectively. Compared to weedy conditions، the lowest weed biomass (2847. 58 kg ha-1) and the highest yield (4087. 67 kg ha-1) of sunflower were obtained at 75 and 25 % residue، respectively. Optimum rates of nitrogen fertilizer and rapeseed residue to guarantee maximum grain yield and optimum suppression of weeds were 450 kg ha-1and 25%، respectively. Generally، to increase sunflower yield and suppress weeds، it is recommended to integrate cultural practices with use of 450 kg urea ha-1 fertilizers and left over 25% of rapeseed residue، was the best treatment.

Annual Medicago species (Medicago spp.) are native to the Mediterranean region and widely used in fields and pastures in Iran. There are several methods of sowing annual Medicago species، each with different effects on the performance. However، there is currently no sufficient information about the appropriate methods for sowing Medicago species. In order to evaluate methods of sowing (broadcast planting and row planting) on qualitative and quantitative traits of three annual Medicago species (M. rigidula، M. polymorpha and M. scutellata)، a 2-yr field study was conducted in Shiraz، Iran during the growing season 2010-2011. This study was carried out as a split plot experiment based on a randomized complete block (RCB) design with three replications. The results showed that there were no significant differences for most traits between the two years. Medicago planted in the row method had more root dry weight، ash، extract ether، natural detergent fiber (NDF) and nitrogen free extract (NFE). It was also demonstrated that shoot to root weight ratio، water content، organic matter، metabolic energy (ME) and digestibility (DE) were higher in Medicago plants that were planted by the broadcast method. All quantitative traits and ash of M. polymorpha were greater than those of the other two species. M. scutellata had higher percentage of organic matter، extract ether and crude fiber; M. rigidula also had a higher content of calcium، phosphorous، crude protein، NDF، NFE، ME and DE. Higher forage production was observed in M. polymorpha planted by the row method in both years، but this was especially evident in 2011. Overall، these results indicated that the row method was a more suitable method for planting M. polymorpha. Furthermore، broadcast planting was identified as a better method for planting M. scutellata and M. rigidula.

The information on the spatial properties of soil is vital to improve soil management and to increase the crop productivity. Geostatistical analysis technique is one of the most important methods for determining the spatial properties of soil. The aim of this study was to investigate spatial variability of soil chemical and physical attributes for field management in eastern Shiraz، Iran، in 2010. In the study area، for applying geostatistical analysis، eighty soil samples were taken randomly. The variability of saturation percentage (SP)، electrical conductivity (EC)، soil pH، sand%، silt%، clay%، nitrogen (N)، phosphorus (P) and potassium content (K) of the soil used to determine the spatial properties of soil by geostatistical analysis techniques. Soil properties were analyzed both geostatistically and statistically on the basis of the Semivariogram models. Thus، each soil parameter was used for different Semivariogram models such as spherical، circular and exponential because of their different spatial structures. The results showed that the best model to generate soil properties map was ordinary kriging with spherical and exponential Semivariogram models. The best model for soil pH، SP، K and N was the spherical model whereas for sand%، silt%، clay%، EC and P، the best model was the exponential model. Based on the models، the range of spatial dependency was found to vary within soil parameters. EC had the longest (134 meter) and pH had the shortest (19. 1 meter) range of spatial dependency. Additionally، spatial patterns may vary among soil parameters in the study area. Therefore، Semivariogram models can be useful tools to determine spatial variability of parameters، preparing soil map and field management strategy.

Efficient use of irrigation water for summer crops should be considered seriously due to rare occurrence of precipitation in summer. This research was focused on the assessment of water use efficiency for dominant crops of summer cropping pattern in the study area (i. e.، maize and rice) via considering water productivity (WP) with different water management scenarios at farm level at different climatic conditions. Results indicated that in most cases the maximum WP was not occurred at full irrigation scenario. With increasing irrigation application efficiency (Ea)، WP increased and the maximum WP shifted toward higher water reduction fraction (WRF). For maize، in deficit irrigation scheduling (DIS) methods with full irrigation at flowering stage، more deficit irrigation application was economically acceptable. For rice، with increasing Ea and WRF، WP increased and deficit irrigation at different growth stages was economically acceptable. Considering the real cost of water، economic water productivity ratio (EWPR) decreased greatly and in surface irrigation system، Ea should be increased and high WRF should be avoided (WRF should be lower than 0. 4). In solid-set sprinkler system، EWPR increased with increasing Ea and application of WRF higher than 0. 2 (0. 2-0. 6 for maize) was acceptable. Tape irrigation of maize was acceptable only for WRF less than 0. 2; also، 0. 2-0. 4 was acceptable for WRF by decreasing the Ea.

According to article 44 of the I. R. of Iran Constitution، the Iranian economy consists of three sectors; the state، the cooperative، and the private sectors. The aim of this study was to present a hierarchy of criteria for selecting the best economic sector for agricultural development. Analytic Hierarchy Process (AHP) was used to calculate the relative importance of either criteria or their alternatives (economic sectors) with regard to the aggregate opinions of experts. Using a structured questionnaire، data were obtained from experts in economic sciences، social sciences، agricultural extension and rural development (n=25) and analyzed using Expert Choice software. Results indicated that entrepreneurship، employment and social justice were the most important criteria to consider when selecting the best economic sector. Moreover، the study demonstrated that based on the criteria، the cooperative sector was the best and the optimum choice. Nevertheless، the gap between cooperative and private sectors was small.

To investigate the effects of bio-chemical and organic fertilizers on yield and seeds NPK contents of pumpkin (Cucurbita pepo var. styriaca)، an experiment was conducted at the Research Farm of Kurdistan University in 2009 growing season. Treatments were included 1) control، 2) seeds inoculated with free-living N fixing bacteria (NFB)، 3) seeds inoculated with phosphate-solubilizing bacteria (PSB)، 4) chemical fertilizer (C)، 5) organic fertilizer (O)، 6) NFB + PSB، 7) NFB+ 50% O، 8) NFB+ 50% C، 9) PSB + 50% O، 10) PSB + 50% C، 11) 50% O + 50% C، 12) NFB+ PSB + 50% O، 13) NFB+ PSB + 50% C، 14) NFB+ PSB + 50% O + 50%. The highest value of nitrogen concentration was observed in the NFB+ 50% C and NFB+ PSB+ 50%C treatments. The highest potassium concentration was found in the NFB+ 50% C treatment. The maximum phosphorous concentration was observed in PSB+ 50%C. The maximum seed yield was obtained from the treatment that pumpkin seeds inoculated with free-living N (NFB) and phosphate-solubilizing bacteria (PSB) + 50% organic fertilizer. The highest fruit yield was obtained from NFB+ PSB+ 50%C+ 50%O. It was concluded that application of biofertilizers in combination with 50% chemical and organic fertilizers، reduced the use of chemical fertilizers and produced higher seed and fruit yield.