Effect Of Nitrogenous Fertilizer Levels On Growth Physiology And Nutrient Utilization Of Pepper

In order to prove the suitable amount of nitrogen growth of pe pper, pot experiments were condueted to study the effect of different nitrogen levels on growth, photosynthetic characteristics, dry matter accumulation, nutrient distribution, fertilizer utilization rate, yield and quality of pepper. The five treatments were applied: control(CK) ie no manure, and T1~T4 were manure treatments with 30%, 40%, 50% and 60% nitrogen levels respectively.1. Nitrogen treatments significantly increased plant height and stem diameter and also enhanced the root vigor during the late growth period. After 40 days establishment, nitrate reductase in pepper leaves(N R) were significantly higher than that in CK. After 70 days, leaf chlorophyll content increased and improved the photosynthesis, in T3, in the peak period(engraftment after 70~100d) and root activity was significantly higher than that of other treatments. The T3 also increased the leaf chlorophyll content, photosynthesis rate(Pn), stomatal conductance(Cs), transpiration rate(Tr) and maximal photochemical efficiency of PSⅡ(Fv / Fm) and the actual photochemical efficiency of PSII and photochemical quenching coefficient(qp), reduced Intercellular CO2 concentration(C i) and non-photochemical coefficent(NPQ), improved leaf photosynthetic function, enhanced the CO2 assimilation rate and decreased energy non-photochemical dissipation in fluorescence emission and heat dissipation.2. Nitrogen treatments at each stage improved pepper dry matter accumulation rate, nutrient absorption and distribution and nutrient absorption rate. The T3 gave significantly higher values than the other treatments, The period of rapid growth are all from the beginning of fruiting period( planted 70 days)and the peak period reached the peak. From the nutrient distribution, pepper on nitrogen, potassium demand is far greater than phosphorus. More than 50% of the nitrogen, phosphorus, potassium concentration in fruit, and nutrient uptake by nitrogen treatments was significantly higher than that of CK. In the peak period, Nutrient uptake and uptake rate were T3>T4>T2>T1>CK. The N partial factor productivity, N agronomy efficiency and physiological efficiency of applied N were downtrend when the amount of nitrogen was increased. T3 treatment of nitrogen, phosphorus and potassium utilization efficiency was significantly higher than other treatments, by 37.1%, 28.5% and 24.9% respectively.3. The fruit number per plant, yield, soluble protein content and soluble sugar content were higher than CK treatment. The T3 had the highest yield and best quality. With the increase in nitrogen, the yield was first increased and then decreased, The stimulation ratio respectively reached 77.4%, 112.1%, 185.0% and 145.0%. The mean fruit weight and vitamin C content was significantly higher in T3 than other treatments. The T1, T2 and T4 had similar vitamin C content with CK. By the two curve simulation, get the mathematical model between the amount of nitrogen fertilizer and yield, Y=-2.167x2+149.269x+1687.711, R2=0.907**, When the nitrogen amount of X was 34.44kg/667m2, the yield of Y reached the maximum, 4252.2kg/667m2.Based on the various parameters studied, T3 was the optimal nitrogen level for improved growth and development of papper.