| Chili pepper is widely cultivated all over the country because of its rich content of vitamin C and is one of the vegetables widely eaten in people’s life all year round.Pepper in the process of growth of water,temperature,humidity and other conditions are relatively high requirements.In order to avoid the reduction of pepper production and ensure the quality and yield of pepper,the common practice today is to apply fertilizers and pesticides to prevent the occurrence of diseases.However,the long-term use of chemical fertilizers and pesticides has changed the physical and chemical properties of soil to a certain extent,destroyed the original soil micro-environment,caused land pollution,broke the ecological balance,and was not conducive to the sustainable development of agriculture.Therefore,the reduction of chemical fertilizers and pesticides has become the only way to promote the green development of agriculture,change the way of agricultural economic development,improve the ecological environment,ensure the safety of agricultural products,and achieve the sustainable development of agriculture and ecology.The application of Bacillus subtilis as organic microbial fertilizer in agriculture has attracted extensive attention of Chinese scholars in recent years.Taking potted pepper as the research object,this paper studied the effects of different treatments on the growth of pepper,soil physical and chemical properties and soil enzyme activities by applying different fertilizer amounts with Bacillus subtilis respectively,and selected the optimum application amount from them,thus providing theoretical and data basis for the optimum application amount of Bacillus subtilis and fertilizer to peppers.The findings are as follows:1.Physical and chemical properties of soil:During the entire growth cycle of pepper,The treatment of 80%,100%fertilizer dose with bacillus subtilis and 100%fertilizer dose alone that its soil EC value is between 0.4（mS/cm）and 0.5（mS/cm）,and they are in the range of EC values 0.25（mS/cm）-0.63（mS/cm）suitable for pepper growth.The 80%fertilizer dose with bacillus subtilis treatment,fixed 15-90 days soil pH between 6.49-6.68,more stable than other treatments.The overall trend of the increase in the amount of available nitrogen and potassium per treatment in the soil was consistent.The content of available phosphorus in soil treated with 100%chemical fertilizer and Bacillus subtilis was the highest,but there was no significant difference between 80%and 100%chemical fertilizer and Bacillus subtilis,63.35（mg/kg）and 63.21（mg/kg）,respectively,and there was little difference among treatments except blank control,which indicated that the content of available phosphorus in soil was not significantly affected by different fertilizer application rates.2.Soil enzyme activity:The changes of soil urease,alkaline phosphatase and sucrose enzyme activity were consistent.It showed the interaction between urease,alkaline phosphatase and sucrose enzyme in soil.Among them,the enzyme activity of80%fertilizer dose with bacillus subtilis treatment was 4.1667(NH3-N mg·g-1),1.8014(酚mg·g-1),and 5.2538(glucose mg·g-1).3.The change trend of plant height and stem diameter of the treatments with different fertilizer amount and Bacillus subtilis was"S"type.The growth trend of plant height was the most obvious in chemical fertilizer treatment.The plant height was 61.73 cm in 90 days after planting,but showed the instability of growth.The growth of plant height was very slow in 45-60 days after planting,and showed a trend of excessive growth in 60-90 days.The treatment of 80%fertilizer dose with bacillus subtilis that increase in stem diameter is most obvious,and the stem thickness is 10.35cm.Treatments of different fertilizer quantity that were no significant difference in leaf diameter,longitudinal diameter and leaf number.But,80%,100%fertilizer dose with bacillus subtilis were superior to 100%fertilizer dose alone in terms of leaf fresh weight,leaf area,root length,root volume,etc.It shows that the application of bacillus subtilis can improve the plant morphology and promote the better growth of the plant.4.Plant physiological indicators and nutrient indicators:When the light intensity is high,the treatment of 100%fertilizer dose with bacillus subtilis that its chlorophyll content is as high as 63.27 SPAD,which produces light inhibition and inhibits plant growth to a certain extent.The treatment of 80%,100%fertilizer doses with bacillus subtilis that root activity is significantly better than other treatments,which are1244.3(μg·g-1·h-1),1016.9(μg·g-1·h-1).The treatment of 80%fertilizer dose with bacillus subtilis is higher than other treatments in photosynthetic parameters of pepper leaves,Net photosynthetic rate（Pn）is 17.63(μmol·m-2·s-1),Porosity（Gs）is 176.25(mmol·m-2·s-1),Transpiration rate（Tr）is 2.69(mmol·m-2·s-1).The treatments of80%,100%fertilizer dose with bacillus subtilis and 100%fertilizer dose alone,the total N,P,and K contents of their plants are significantly higher than the remaining treatment.Among them,the total N,P,and K contents of the treatment of 80%fertilizer dose with bacillus subtilis treated plants were the highest,but the total P content was less different.5.Production and quality of pepper:The single fruit weight of the treatment of100%fertilizer dose with bacillus subtilis that is up to 142.60 g.The treatment of80%fertilizer dose with bacillus subtilis is superior to 100%fertilizer dose alone and other treatments in the number of plant results,total output,soluble sugar content,vitamin C content,etc..The results show that the application of chemical fertilizer and the combined use of bacillus subtilis can increase the soil nutrient absorption ability of pepper plants,which can promote the increase of pepper production and improve the fruit quality of pepper. |
