Effect of reducing chemical fertilizer and applying microbial one on the growth and yield of Carthamus tinctorius L. under mulch drip irrigation

【Objective】 To study the effect of chemical fertilizer reduction combined with microbial fertilizer on the growth and development of Carthamus tinctorius L.. 【Methods】 From 2020 to 2021, a two-year located fertilization experiment was arranged in Yumin County, Tacheng Prefecture, Xinjiang. The split plot experiment design was adopted, and six treatments were set up: (1)CK:no fertilization;(2) CF:compound fertilizer of 20 kg/667m²;(3)OF:microbial bacterial fertilizer of 20 kg/667m²;(4) CF+25M:chemical fertilizer of 15 kg/667m²(chemical fertilizer reduction of 25%)+microbial bacterial fertilizer of 5 kg/667m²;(5) CF+37.5M:chemical fertilizer of 12.5 kg/667m²(chemical fertilizer decreased by 37.5%)+microbial bacterial fertilizer of 7.5 kg/667m²;(6) CF+50M:chemical fertilizer of 10 kg/667m²(chemical fertilizer decreased by 50%)+microbial bacterial fertilizer of 10 kg/667m². During the experiment, the effects of different fertilization treatments on the agronomic characters, dry matter accumulation and distribution, and yield formation of Carthamus tinctorius L. were studied. 【Results】 The results showed that CF+25M and CF+37.5M treatments were more conducive to the growth and development of Carthamus tinctorius L. than CF treatment, which could significantly increase the plant height, number of branches, number of leaves and chlorophyll content of Carthamus tinctorius L., promote the accumulation of dry matter of Carthamus tinctorius L., regulate the distribution of dry matter, coordinate and improve the yield components of Carthamus tinctorius L., thereby increasing the yield of Carthamus tinctorius L. filament and seed. Among them, the comprehensive performance of Carthamus tinctorius L. under CF+37.5M treatment was the best. The number of fruit balls per plant, 1,000 grain weight, filament yield and grain yield of Carthamus tinctorius L. under CF+37.5M treatment were significantly increased by 87.85%, 12.29%, 11.42% and 15.78%, respectively, compared with CF treatment. In addition, the plant height, root length and chlorophyll content of Carthamus tinctorius L. reached the highest level under CF+37.5M treatment. 【Conclusion】 Proper reduction of chemical fertilizer and application of microbial fertilizer (37.5% reduction of chemical fertilizer, 12.5 kg/667m² of chemical fertilizer+7.5 kg/667m² of microbial fertilizer) is an environmental protection fertilization scheme that can effectively reduce the application amount of chemical fertilizer. It can promote the growth and development of Carthamus tinctorius L. root system, improve the fertilizer utilization rate, so as to increase the dry matter accumulation of Carthamus tinctorius L., coordinate the yield composition of Carthamus tinctorius L..