Effects Of Partial Substitution Of Chemical Fertilizer By Bio-fertilizer On Growth Physiology And Nutrient Utilization Of Pepper By Substrate Cultivation

With the increasing amount of fertilizer application in agricultural production in China,numerous problems including environmental pollution and waste of resources have been common phenomena.In recent years,more and more studies have shown that the combination of biological fertilizers and chemical fertilizers is beneficial to the growth and development of crops.We tested the effect of different fertilizers on the performance of‘Longjiao No.5'pepper variety,The six?6?treatments applied were:no fertilizer as control group?CK?,100%chemical fertilizer?T1?,chemical fertilizer reduction by 20%+600kg/667m² biological fertilizer?T2?,chemical fertilizer reduction by 20%+300 kg/667m²biological fertilizer?T3?,chemical fertilizer reduction by 30%+600 kg/667m² biological fertilizer?T4?and chemical fertilizer reduction by 30%+300 kg/667m² biological fertilizer?T5?.In order to provide a theoretical reference for the reduction of chemical fertilizer in the cultivation of pepper,the effects of fertilization on growth and development,photosynthetic fluorescence characteristics,nutrient absorption and utilization,yield and quality of pepper were studied in a substrate medium.The main results are as follows:1.Under the conditions of chemical fertilizer reduction of 20%,the combined application of 300-600kg/667m² of bio fertilizer treatments?T2,T3?significantly improved the chlorophyll a content,chlorophyll a+b content,stomatal conductance?Gs?of pepper plants during the full fruiting period?90d?and significantly improved the actual photochemical efficiency of leaf photosystem II??PS??at the later stage of fruiting period?120d?compared with single application of chemical fertilizer treatment?T1?.T2,T3 treatments significantly reduced the intercellular CO₂ concentration?Ci?,which could effectively enhance the photosynthetic capacity of the pepper leaves.Under the conditions of chemical fertilizer reduction of 30%,the combined application of 300-600kg/667m² of bio fertilizer treatments?T4,T5?significantly reduced the plant height,root activity,chlorophyll content and the photosynthetic capacity of the pepper plants at the later stage of fruiting period compared with the T1 treatment.2.At the full fruiting period,the uptake of nitrogen and potassium in pepper plants of T2treatment significantly increased by 6.0%and 6.1%compared with T1,the uptake of nitrogen in pepper plants of T2,T3 treatments increased by 10.1%and 1.8%compared with T1;the uptake of phosphorus of T4,T5 treatments were significantly reduced,but the distribution ratio of phosphorus in pepper fruits were significantly increased.3.The utilization rate of nitrogen fertilizer of T2 treatment significantly increased compared with T1,the utilization rates of phosphorus and potassium fertilizer had no significant difference between T2,T3 treatments and T1;the utilization rates of nitrogen and phosphorus of T4,T5 treatments were significantly decreased compared with T1.4.The fruit number per plant of T2,T3 treatments were increased by 5.88%and 3.21%compared with T1,the yield increased by 8.1%and 0.4%.5.The vitamin C contents of T2,T3 treatments increased by 1.7%and 0.9%compared with T1,the contents of soluble sugar and soluble protein had no significant difference between T2,T3 treatments and T1.In conclusion,under the conditions of this experiment,20%of fertilizer reduction can be replaced by 300-600kg/667m² bio fertilizer.This fertilizer application scheme can effectively promote the growth of pepper plants and increase the photosynthetic capacity of pepper leaves,simultaneously this treatment can increase the yield and fruits quality compared with the single application of chemical fertilizer.