جستجوی مقالات مرتبط با کلیدواژه « چای » در نشریات گروه « آب و خاک »

Shortage and improper distribution of rainfall in tea growing period are important growth limiting factors in tea fields in Northern part of Iran. If there is not any other limited factors, supplemental irrigation by sprinkler can increase tea yield. This study was carried out in order to investigate the optimum sprinkler irrigation interval on yield and water use efficiency of tea. The experiment was conducted on a CRBD with three replications during tea planting period of 2002-04 in Fouman tea research station. The irrigation treatments were 4, 8, 12 and 16 day irrigation intervals along with rainfed treatment as control. Results showed that control and 4 day interval treatment with 1483 and 3443 kg/ha had the lowest and highest yield respectively, and 8, 12 and 16 day irrigation intervals were in next grade, respectively. In term of water use efficiency, control and 4 day treatment in dry period with 0.34 & 0.67 kg (made tea)/m3 of used water had the maximum and the minimum water use efficiency. Irrigation water use efficiency in growing period for 4, 8, 12 and 16 day treatments were 0.66, 0.55, 0.48 and 0.36 kg/m3, respectively. Since very short period of dry season in the last year of the experience(2004), no significant difference was observed in yield.

In tea plantation regions of northern part of the country, application of supplemental irrigation during dry periods (lacking rainfalls) in conjuction with proper nitrogen fertilizer application can significantly improve tea yield per unit of plantation area. In order to quantify the effectiveness of proper irrigation and nitrogen management on tea, the response of tea to various levels of irrigation and nitrogen applications was studied in Fouman suburb of Guilan province. Tea crop production function and its crop coefficient (KC) were determined. A line source sprinkler irrigation was used for creatiating a variable irrigation application and a split-split-plot statistical design was used. Irrigation treatments consisted of full irrigation (I4), deficit irrigation (I3, I2 and I1) and no irrigation(I0). Nitrogen application treatments were N1, N2 and N3 (100, 180 and 360 kg/ha) in three replications randomly arranged as main plots, while irrigation treatments as sub plots were not randomized. During the growing period, soil moisture up to the depth of 90 cm was determined gravimetrically and actual crop water use was calculated from mass balance equation weekly. Reference evapotranspiration (ETo) was estimated by Penman-Montieth equation and was used to estimate tea crop coefficient. During growing period, the actual tea water use of I4 and I0 were computed to be 457 and 256 mm. Tea crop coefficient during dry period (June, July and Augest) ranged from 0.8 to 0.9. Crop resistance factor (Ky) for tea was found to be 1.37. Results indicated that optimum rate of nitrogen (180 kg/ha) along with supplemental irrigation, increased yield and water use efficiency (WUE). Futhermore, supplemental irrigation increased yield and WUE more than nitrogen application. In I0 and I1 treatments, application of 100 kg/ha nitrogen resulted the highest yield and WUE.