Effect Of Controlled-release Fertilizer On Growth, Physiology, Nutrient Absorption And Nutrient Use Efficiency In Pepper

In an attempt to save cost in labor and fertilizer, increase fertilizer use efficiency, and provide a theory for the reasonable application of controlled-release fertilizer in vegetable production this project tested controlled-release fertilizer on the pepper variety “Longjiao No.5”. Pepper plants were cultivated in pots and in addition to the treatment plants were cultivated with no fertilizer(CK) and conventional fertilizer(CK1) as controls. The following parameters were monitored: pepper plant growth, dry matter accumulation amount and speed, NPK uptake amount and speed, the distribution of dry matter in each organ and change of each nutrient in substrate under different fertilizations(application of high nitrogen controlled-release fertilizer once and application of conventional fertilizer with “ basal fertilizer once and top dressing many times”). Results showed that:(1) Compared with CK, fertilizers could enhance the plant height, stem diameter, leaf area, dry matter of shoot and total plant and root activity. T3(Os-6) and T4(Os-7) reduced plant height by 19.3%~22.4% and 10.9%~17.4% than CK1. T3(Os-6) and T4(Os-7) significantly increased root activity after 120 days being planted.(2) Compared with the CK, fertilizers could increase the amount of dry matter accumulation, especially on amount of shoot. The rate of dry matter accumulation of T3(Os-6) and T4(Os-7) were 19.3%~30.5% and 20.8%~33.5% lower than CK1 during 120 days after being planted; but after 120 days, compared with CK1, dry matter accumulation of T3(Os-6) and T4(Os-7) was 3.9%-15.5% higher, and the rate of dry matter accumulation was 60.9%-63.6% higher. The max rate of dry matter accumulation was 26-28 d later than that of CK1. T3(Os-6) and T4(Os-7) increased dry matter accumulation of leaves during 30 days and branches accumulation after 120 days. T3(Os-6) and T4(Os-7) prolonged dry matter accumulating time by 9 days than CK1.(3) Compared with CK1, during 60 days after being panted, T3(Os-6) and T4(Os-7) decreased uptake speed of N,P,K by 34.4%~49.0%、59.6%~71.6%、42.5%~91.0%; but they increased the speed by 59.6%~66.6%、55.3%~58.0%、9.4%~47.6% after 60 days.(4) Compared with CK1, T3(Os-6) and T4(Os-7) decreased uptake amount of N,P,K in 90 days by 24.8%~39.2%、41.8%~50.8%、36.3%~43.4%; but the amount were 29.1% ~ 42.0% 、 8.0% ~ 24.0% 、 18.3% ~ 20.0% higher after 90 days. The highest maximum rate of NPK were prolonged by 27~29d、24~34d、7d than CK1. T3(Os-6) and T4(Os-7) increased distribution of NK in leaves and P in branches after 60 days.(5) T3(Os-6) and T4(Os-7) significantly promoted amount of total N, total K, alkali-hydrolyzale N, nitrate N, ammonium N and available K in the substrate, reduced amount of total P. The total amount of all kinds of available nutrient was 2~3 times higher than CK1. Meanwhile, substrate EC of T3(Os-6) and T4(Os-7) were significantly higher than CK1.