IRANIAN JOURNAL OF RANGE AND DESERT RESEARCH
Year:2001 | Volume:- | Issue:4|Papers Count:5

Five annual Medicago species: M. minima, M.polymorpha, M.radiata, M. rigidula and M.turbinata were compared for drymatter and pod production in rainfed area. They were sown at spring and autumn in a split-plot design with. four replication. Main plots were seasons and subplots were annual Medicago species. M. radiata and M. ligidula produced more herbage and pods than the other species in both spring and autumn cultivation. However, the yield was higher in spring than autumn in all the Medicago species. Herbage production for Medicago radiata in spring cultivation 684.5 and inautumn 528 kg/ha. The other species were inferior in herbage production than M. radiata. Pod production in all the M. species had the same trend as herbage production and in M.radiata was the highest. All the M. species had more pod than hay which is in agreement with Mac Arthur (1962) idea. M.radiata and M. ligidula may be the best species of the annual medics for herbage and pod production in rainfed areas of Uromieh.

This research was conducted in order to distinguish the high yielding alfalfa, cultivars and for offering a distinct fertilizing formula, using split plot statistical design with four replications. Main factor was alfalfa by four cultivars (local of Salmas - Bonab Abi , Krysari , and Native) and six minor factor was fertilizer (P205), by six levels based on effective ingredients including zero, 15, 25, 35, 45, and 55kg/ha. The experiment was conducted in the dry - land condition of Meshgin village located at Km. 50, north - west of Zanjan, with average rainfall of 372 mm; since 1371, lasting for 5 years.Hay yield and height of the cultivars were measured from the 2nd year and means were compared statistically by Duncan method. In spite of non significant difference between main treatments, the local cultivar (Native) produced the highest amount of yield, totally 1959 kg/ha. during the whole period of experiment, and other mentioned cultivars i.e. Salmas, Krisari and Bonab Abi had average yield of 1630, 1491, 1441 kg/ha respectively. It is not worthy that, yield of main factor during whole years were followed the same rank, with the exception of year 1373, there were statistically significant difference (P<0.05), and complex analysis of variance resulted significant difference (P<0.01) between minor treatments (application of fertilizers). In response to different fertilizer levels, the most amount of hay yield for fertilizer b5 (45kg/ha effective ingredient) during the whole period of the experiment with average yied of 1871 kg/ha and the least amount of hay yield was related to fertilizer b1 (without fertilizer) during the whole period (except 1372), with average yield of 1462 kg/ha. Regarding the difference between the means of interaction effects (AB), (P<0.05) combination of local cultivar of alfalfa (native) with fertilizer response of b5 (45 kg/ha. effective ingredient) i.e, a4b5 with the average yield of 2204 kg/ha. was introduced as the most productive cultivar and fertilizer administration expected for native cultivar of alfalfa, This is advised for extension of cultivation in vast areas of dry lands in the region, it is one of the main results of the current research. There were significant differences between the yields of hay during the years, so that the 2nd year (1374), was the most productive year, averaging 2963 kg/ha. From the view point of the height, the local Salmas and native cultivars by 53cm height, and Bonab-Abi and Krysari by 49cm height were the taller and shorter cultivars. Actually the taller cultivars were those which produced higher yield. The most growth of tall cultivars was related to the year 1375 (3d year of harvesting) with 64cm height and the least amount was related to year 1376 with 38cm height.

Due to low emergence of alfalfa seedlings Intercropping of Lucerne and barley is common in clay soils. Barley seeds are bigger than alfalfa seed and sowing them together induced better emergence of alfalfa seedlings. An experiment was conducted in Homand Rangeland station in 1988 to examine the effect of barley seeds on alfalfa seedlings emergence. A completed Blook Design with four replication was used. The rates of barley seeds were 0-25-50-75-100 Kg/ha and the amount of the alfalfa seeds was 10 kg/ha Intercropped with barley seeds.The results showed that Zero and 50 Kg/ha barley seeds Intercropped with alfalfa seeds and significant effect on alfalfa seedlings with 10 Kg/ha seeds emergence. Intercropping of 50 Kg/ha and 0 Kg/ha barley seeds produced 1494.5 Kg/ha, 1429.8 kg/ha herbage respectively. In conclusion the intercropping of barley seeds and alfalfa seeds had significant effect on alfalfa seedling emergence.

Dagh and Kavir are two faces of palaya in desert geomorphology. Since Literally there has not been any proper definition of the word Kavir and Dagh, it is difficult to distinguish between these two types of desert morphology. However the differences between these two features of desert can be explained mainly by the differences appeared in the chemical soil properties between this two formations. As defined, generally the Dagh and Kavir is the lowest terrain, which formed by streams or drying lakes. When streams or the occasional torrents of water produced by rains move down the mountains, they are heavily loaded with sediment. These streams and run off spread over the gentle slopes and finally accumulate over the extensive area at lowest terrain patterns. As time passes, with on going evaporation of water and depositional processes Dagh and Kavir are formed. The only distinction between Dagh and Kavir is the accumulation of precipitated salts in Kavir formation. Though the aim of this paper is not to distinguish the differences between this two features of desert in details, in fact this paper reports the results of the soil characteristics of four Dagh located in the central desert of Iran, firstly to clarify the distinction between Dagh and Kavir and secondly investigate the utilization of Dagh for agricultural purposes. The soil analysis of these two features showed that the total dissolved salt was the main distinctive factors between Dagh and Kavir. Dagh’s soils consist of heavy soil texture and Kavir's soil was associated with high saline and alkaline salts. In same parts of Dagh areas, farmers use the land for cultivation of different crops and orchards mainly pistachio in the cold desert and date palm in temperate and semi arid zones. The local farmers also practiced reclamation of the Dagh heavy-soil texture with application of sand particles. Sand dune, which spreads extensively over the desert area, is the main source of sand particles. Dune particles analysis also showed that there is no any limitation for pistachio seedlings in terms of sensitivity to soil salinity. Application of coarse sand particles in Dagh areas appeared to be a good technique for utilization of those areas for pistachio plantation.

Stalinization and alkalization is one of the most important fertility soil degradation processes in semiarid and arid regions. For mapping and monitoring the spatial distribution of salt-affected soils using remotely sensing data, is paramount importance. Salt-affected soils, in general, showed relatively higher spectral response in the visible and near-infrared regions of the spectum as compared to normal non-saline soils. Further strongly saline-sodic soils were found to have a higher spectral response as compared to moderately saline-sodic soils. The salt-affected soils mainly. Consist of three catogories, viz, saline, sodic and saline-sodic soils. This paper tries to show important points of applying remote sensing in classification of salinity and analyze the result of today researches. At this study remote sensing technology in mapping and monitoring salt-affected soils have shown great promise of enhanced speed, accuracy and cost effectiveness. Of course, problems such as variation in the sun elevation angle, soil moisture, the type and abundance of salt-tolerant vegetation cover, topsoil textures and topsoil properties are the main causes of spectral confusions.