نوع مقاله : مقاله پژوهشی
نویسندگان
1 مربی پژوهش مرکز تحقیقات کشاورزی و منابع طبیعی خراسان رضوی
2 مربی پژوهش بخش تحقیقات اصلاح و تهیه نهال و بذرخراسان رضوی
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Cotton, as one of the most important industrial crops, grows in different climatic conditions. Determination of cotton water requirements (ET) is important in the light of frequent water shortage and drought in the country and inadequate precipitation during growing season. This investigation was conducted in Kashmar Research Station, Using a drainage type Lysimeter(2 * 2 * 1.5m) surrounded by 40 * 40m cotton crop to eliminate the oasis effects such as heat transfer. Before planting, soil samples were collected for chemical and physical analysis and soil moisture characteristics such as FC, PWP were determined .Fertilizers were applied according to Soil and Water Research Institute recommendations. Irrigations were done when readily available soil water was depleted. The amount of applied water was calculated according to the below equation so that 10% drainage water were collected. Inflow and drainage water were measured. Evapotranspiration was calculated based on soil water balance equation as below :ETc = I + P ± dw – D, where: ETc = Evapotranspiration (mm) , P = precipitation (mm) , I = irrigation depth(mm), D=Drainage water depth(mm) and dw= soil moisture variations between two irrigations that was assumed (0) zero. Results showed that mean cotton evapotranspiration for four years of experiment was equal to 1183mm, while this was predicted 1000.4mm according to Penman-Monteith equation.
کلیدواژهها [English]
)