| The hot pepper has the characteristics of long growth period and high demand for nutrients.In the usual production system basal fertilizer,usually topdressing nitrogenous fertilizer are applied to improve yield,However,this practice has disadvantages including nutrient loss through leaching and ammonia volatilization loss,The practice does not usually supply adefuete nutrients for sood pepper performance over the long growth period.It increases nitrate content in pepper fruits,reduces the quality of the fruits and it is harmful,bring harm to human health.The controlled release fertilizer has high efficiency,high utilization rate of nutrients,and the nutrient release is in accordance with the crop requriment.This experiment is based on previous screening experiment,on the ‘Longjiao No.5'pepper as test material,The treatment were no fertilizer as control(CK),the common chemical fertilizer(CF),controlled release fertilizer(CRF,N,P,K,N and CF in the same reduction),10%controlled release fertilizer(CRF10),and N 20% reduction of controlled release fertilizer(CRF20).The effects of the treatments on growth,yield,quality,fertilizer use efficiency,soil enzyme activity and nutrient content were studied in a pot experiment.The aim was to provide theoretical basis for the application of controlled release fertilizers in the production of pepper.The research findings were as follows:1.After 70 days,the growth rate of the each fertilizer treatment was obvious,the plant height,stem diameter and dry matter accumulation were significantly higher than CK,Among them,the fertilizer treatment CRF had the best effect,followed by CF and CRF10;It enhanced flowering,leaf photosynthetic capacity,compared with the other treatments.The CRF treatment significantly improved the pepper chlorophyll a,chlorophyll b,chlorophyll a+b,Pn,Tr,Gs,Fv/Fm,and q P with PSII and reduced Ci,NPQ.The results indicated that CRF treatment was more effective in improveing photosynthetic capacity and CO2 assimilation rate.2.CRF treatment also significantly increased the accumulation of N,P,K,and nutrient distribution in fruits;The accumulation and distribution of nitrogen,phosphorus and potassium in each organ were fruits > stem > leaf > root;The nitrogen use efficiency of CRF treatment was 6.4%,20.56% higher compared with CRF10 and CF,respectively.The CRF also gave highest utilization rate of P(29.36%)and K(29%).3.The effective nutrients of each controlled release fertilizer were the maximum at40~70 d,and the nutrient release is in accordance with the law of pepper uptake.Moreover,CRF treatment was in the maximum for a long time,which provided sufficient N,P,Knutrients for the growth and development of pepper;However,the effective nutrient content of the medium treated with the same amount of nitrogen fertilizer was low and the leaching loss was large.The activity of catalase,urease and invertase decreased with a decrease in controlled release nitrogen fertilizer.4.Compared with other fertilization treatments,CRF treatment significantly increased the mean fruit weight and yield.The yield was 4983.8kg/667m~2,rate of growth is147.8%.The yields of CRF10 and CF were 4441.5 kg/667m~2 and 4525.8 kg/667m~2,respectively,but there was no significant difference between the two.The nitrate content increased with the increase in nitrogen application rate,but did not exceed the national standard.CRF increased soluble sugar,soluble protein and Vitamin C in the pepper fruits compared with other treatments.In a conclusion,the controlled release fertilizer can replace the common chemical fertilizer at the same nitrogen application level,at the same time,it can promote the growth of the pepper plant,increase the yield and improve the quality of the fruit;More than 10% of nitrogen decreased the growth vigor of pepper,resulting in the decrease of yield and fruit quality,Therefore,CRF treatment can be used as reference for controlling the amount of controlled release nitrogen fertilizer. |
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