不同供氮水平下施硅对辣椒产量与营养品质及其养分吸收利用的影响

为探究不同供氮水平下施硅对辣椒产量、果实品质及养分吸收利用的影响,以辣椒品种‘奥黛丽’为试验材料,采用基质栽培,设置正常施氮肥（1.0N：260.9 kg/667 m2）、氮肥减施40%（0.6N：149.1 kg/667 m2）、氮肥减施60%（0.4N：104.3 kg/667 m2）、不施氮肥（0N：0 kg/667 m2）4个不同供氮（基施）水平和2个硅肥（根施）水平（0 mmol/L、1.5 mmol/L）,研究不同供氮水平下硅对辣椒产量、品质及氮肥利用效率的影响效应,并筛选出最佳施肥处理,旨在为辣椒的增产提质提供理论基础和技术参考。结果表明：（1）0.6N供氮水平较1.0N、0.4N和0N供氮水平下的辣椒果实产量分别提高了7.18%、74.14%和87.99%,施硅处理后则进一步促进了果实产量,其中0.6N供氮水平下施硅较正常供氮量下的辣椒果实产量提高了15.33%;（2）0.6N供氮水平更有利于促进辣椒果实中可溶性糖、还原糖、可溶性蛋白、维生素C含量的提高和可滴定酸、NO3?含量的降低,施硅后不同供氮水平下辣椒果实品质均显著提高;（3）0.6N供氮水平更有利于辣椒果实矿质元素的积累与土壤氮肥利用率的提高,其中0.6N供氮水平较1.0N供氮水平下的氮肥利用率与氮肥农学效率分别显著提高了97.57%和69.20%,施硅处理后不同供氮水平下辣椒果实矿质元素含量与土壤氮肥利用率均显著提高;（4）通过对辣椒产量及果实品质指标的主成分分析,结果表明,0.6N+Si处理下的综合得分最高,即氮肥减施40%配施1.5 mmol/L的外源硅肥对辣椒产量、品质及氮肥的吸收利用促进效果最佳。

Effect of silicon application on fruit quality and yield of pepper at different levels of nitrogen supply

As one of the essential elements for the growth and development of crops, nitrogen is involved in the synthesis of various nitrogenous organic substances in plants and plays an important role in their growth and development. Therefore, it is important to study the optimal application of nitrogen fertilizer for high quality and high yield of pepper and soil protection of farmland. To investigate the effect of silicon application on yield, fruit quality and nutrient uptake and utilization of pepper at different levels of nitrogen supply, the pepper variety "Audrey" was used as the test material and was grown in substrate with normal nitrogen fertilization (1.0N: 260.9 kg/667 m2), reduced nitrogen fertilization by 40% (0.6N: 149.1 kg/667 m2), reduced nitrogen fertilization by 60% (0.4N: 104.3 kg/667 m2), and no nitrogen fertilization (0N: 0 kg/667 m2)., and two levels of silica fertilizer (0 mmol/L, 1.5 mmol/L), to study the effect of silicon on nitrogen uptake and utilization and fruit quality of pepper crop under different levels of nitrogen supply, and to screen out the best fertilization treatment, aiming to provide a theoretical basis and technical reference for increasing yield and improving quality of facility pepper. The results showed that: (1) Fruit yield of pepper at 0.6N N supply level increased by 7.18%, 74.14% and 87.99% compared to that at 1.0N, 0.4N and 0N N supply levels, respectively, and silicon application further promoted fruit yield, where silicon application at 0.6N N supply level increased fruit yield of pepper by 15.33% compared to that at normal N supply level. (2) The 0.6N nitrogen supply level was more favorable to promote the increase of soluble sugar, reducing sugar, soluble protein and vitamin C content and decrease of titratable acid and NO3- content in pepper fruits, and the soluble sugar, reducing sugar, soluble protein and vitamin C content in pepper fruits at 0.4N and 0N nitrogen supply levels were significantly lower than those at 1.0N and 0.6N levels, and the quality of pepper fruits was significantly improved after silicon application. The fruit quality of pepper at different levels of N supply was significantly improved. (3) The 0.6N N supply level was more beneficial to the accumulation of mineral elements in pepper fruits and the improvement of soil N fertilizer utilization, in which the N fertilizer utilization and N fertilizer agronomic efficiency were significantly increased by 97.57% and 69.20%, respectively, under 0.6N supply level compared with 1.0N supply level, and the mineral elements content of pepper fruits and soil N fertilizer utilization were significantly increased under different N supply levels after silicon application. (4) The results of principal component analysis of pepper yield and fruit quality indicators showed that the highest overall score was obtained under 0.6N+Si treatment, other words, the application of exogenous silicon fertilizer of 1.5 mmol/L with 40% reduction of N fertilizer had the best effect on N fertilizer uptake and utilization, fruit mineral element accumulation, fruit quality and yield of pepper.