EFFECTS OF DRIPPER DISCHARGE AND IRRIGATION FREQUENCY ON GROWTH AND YIELD OF MAIZE IN LOESS PLATEAU OF NORTHWEST CHINA

摘要

A field experiment was conducted at the Changwu Experimental Station in Changwu County, Shaanxi Province, innorthwestern China from 2010 to 2011 with four treatments and six replicates in a randomized complete block design todetermine appropriate dripper discharge and irrigation frequency for maize (Zea mays, L.) irrigated by drip irrigated system.Dripper discharge was applied to maize 1L/h of dripper discharge, 2 days irrigation frequency and 100% of evaporationfrom a class a pan (T1), 2, 3 and 4 L/h corresponding to 4, 6 and 8 days irrigation frequency, and deficit irrigation waterlevels was 90%, 80% and 70% of evaporation (T2, T3 and T4), respectively. The results indicated that longest root, rootactivity, plant height, leaf area, biomass and grain yields values were highest in T1 in both years. The highest grain yieldwas obtained of 8.78 and 8.84 t ha-1 under T1 in both years, and the minimum yield was obtained with 8.15 and 7.78 t ha-1under T4 in 2010 and 2011, respectively. The maximum irrigation water use efficiency (IWUE) was 3.247 and 3.283 kg m-3in both years under T4. Despite the reduction of growth and grain yield in T3, the dripper discharge was 3L/h, 6 daysirrigation frequency and 80% of evaporation was still high and acceptable for maize production and irrigation water useefficiency in Loess Plateau of Northwest China.