Abstract:

To explore the effect of nitrogen application on yield and thousand-grain weight of flax, and provide a reference for flax nitrogen application management, a meta-analysis was conducted using 116 pieces of data from 21 papers collected up to 2023. The data were grouped according to the test year, test location, soil type, soil organic matter content, soil alkali hydrolyzed N content, soil available P content, soil available K content and soil pH value. The comprehensive effect of nitrogen application on flax yield and thousand-grain weight was explored, with no nitrogen fertilizer application serving as the control group. The research results indicated that when the nitrogen application was between 120-150 kg/hm², the effect values on flax yield (22.14%) and thousand-grain weight (4.55%) were the highest; the effect value of nitrogen application on flax yield (20.44%) was the highest from 2010 to 2013; the effect values of nitrogen application on Gansu flax yield (23.17%) and thousand-grain weight (5.23%) were the highest; the effect values of nitrogen application on flax yield (23.30%) and thousand-grain weight (5.63%) were the highest in sandy loam soil. When soil alkali hydrolyzed N content was >50 mg/kg, soil organic matter content was <10 g/kg, soil available P content was >25 mg/kg, soil available K content was 100-200 mg/kg, and soil pH value was 8-8.5, the nitrogen application of flax had the highest yield-increasing effect, which were 19.42%, 20.22%, 21.38%, 20.10% and 20.22%, respectively. When soil alkali hydrolyzed N content was <50 mg/kg, soil organic matter content was <10 g/kg, soil available P content was 15-25 mg/kg, soil available K content was 100-200 mg/kg, and soil pH value was 8-8.5, the nitrogen application had the highest effect on improving the thousand-grain weight of flax, which was 5.77%, 6.33%, 7.60%, 5.31% and 4.73%, respectively. When the nitrogen application rate was between 120-150 kg/hm², the increases in flax yield and thousand-grain weight were the highest. The research results of this experiment could provide a reference for increasing yield and thousand-grain weight of flax under different production conditions in the future.

Key words: flax, nitrogen application rate, yield, thousand-grain weight, Meta analysis