Effects of Different Fertilizer Treatments on Yield and Quality of Chinese Cabbage under Optimal Irrigation System

Based on results of water demand test results，water and fertilizer tests were carried out to explore effects of water and fertilizer on the yield，water productivity and quality of Chinese cabbage in the alpine region of northwest Hebei Province.According to water requirement of Chinese cabbage at different growth stages，two-factor completely randomized trial of water and fertilizer was conducted in 2018，irrigation quota was 210、180 and 150 m3/hm2 respectively，and fertilizer amount was 100%，85% and 55%.In 2019，four fertilizer levels of 100%，85%，70% and 55% were set to test and verify effects.Results showed that yield，water productivity and quality of Chinese cabbage were affected to different degree by different fertilizer rates.Variation laws of yield and water productivity were the same，both increased at first and then decreased with the increase of fertilizer rate.Nitrate content of Chinese cabbage was significantly affected by amount of fertilizer amount.With increase of fertilizer amount，content of nitrate increased，showing a positive correlation.Under low irrigation level，vitamin C content increased with increase of fertilizer amount.Content of vitamin C increased with decrease of fertilizer amount under adequate irrigation.In the study area，suitable irrigation quota was 1 100~1 300 m3/hm2 and fertilizer amount was 450~550 kg/hm2 in the whole growth period of Chinese cabbage.