Effect Of Combined Application Of Humic Acid And Controlled-release Nitrogen Fertilizer On The Yield And Quality Of Garlic

Humic acid combined with controlled release N fertilizer and controlled release N fertilizer could effectively improve the fertilizer utilization rate.Increase the nutrient supply time,meet the demand for fertilizer in the whole growth period of garlic,and improve the yield and quality of garlic;To solve the problem of concentrated nutrient release of common fertilizer and excessive application of base fertilizer easily resulting in fertilizer loss and unable to meet the nutrient supply of garlic in the later growth period;To reduce the adverse ecological effects of fertilization on soil;To reduce economic and labor input and provide a theoretical basis for the use of long-acting fertilizer on garlic,this study was conducted.In this study,’Jinxiang Garlic’was used as the test material,through the fertilization method of humic acid and different ratios of controlled-release nitrogen fertilizer（N-P₂O₅-K₂O=18-10-20）,a randomized block experiment design was adopted and routines were set.Fertilization is control（CK）,controlled-release nitrogen fertilizer 27.8%（T2）,controlled-release nitrogen fertilizer 50%（T3）,and controlled-release nitrogen fertilizer 72.2%（T4）;on this basis,60kg/hm2 humic acid treatment is added,conventional fertilization+humus Acid（T1）,controlled-release nitrogen fertilizer 27.8%+humic acid（T5）,controlled-release nitrogen fertilizer 50%+humic acid（T6）,controlled-release nitrogen fertilizer 72.2%+humic acid（T7）eight kinds of fertilization treatments,to study different proportions of control The effects of combined application of nitrogen-release fertilizer,humic acid and controlled-release nitrogen fertilizer in different proportions on garlic growth characteristics,yield,quality and soil nutrient changes,aiming to reveal the effect of controlled-release nitrogen fertilizer and controlled-release nitrogen fertilizer on garlic during the entire growth and development process.According to the response mechanism of acid,the optimal controlled-release nitrogen fertilizer dosage and the optimal compound ratio of humic acid and controlled-release nitrogen fertilizer for garlic planting were screened out,which is the reasonable application and application of controlled-release nitrogen fertilizer,humic acid and controlled-release nitrogen fertilizer on garlic.Promotion provides theoretical reference.The main research results are as follows:1.Combined application of controlled release nitrogen fertilizer,humic acid and controlled release nitrogen fertilizer can improve the plant height,stem diameter,leaf number,chlorophyll content and root activity of garlic plants.With the increase of the proportion of controlled release nitrogen fertilizer,the effect increased significantly.Grow in the whole process,compared with conventional fertilization CK,72.2%controlled release nitrogen fertilizer,humic acid,and 72.2%of controlled release nitrogen fertilizer NPK treatment in bulbil flower bud differentiation stage,bulb)issue of the chlorophyll content and root activity were significantly higher than that of conventional fertilization treatment,leaf photosynthetic capability and root activity of strong,suggests that plant metabolism,can for garlic plant manufacturing,to absorb more nutrients.2.Combined application of controlled-release nitrogen fertilizer,humic acid and controlled-release nitrogen fertilizer can increase the yield of garlic bolts and bulbs.With the increase of the proportion of controlled release nitrogen fertilizer,the effect of increasing yield increased.In the controlled release N treatment,72.2%controlled release N fertilizer had the best effect.Compared with CK,the bulb and garlic crop yield of 72.2%controlled release N fertilizer increased by 19.5%and 15.3%,respectively,and bulb single weight and transverse diameter increased by 30%and 14.2%,respectively.The weight and length of garlic bolts were increased by 16.2%and 20.4%,respectively.In the combined treatment of humic acid and controlled release nitrogen fertilizer,the combined treatment of humic acid and 72.2%controlled release nitrogen fertilizer had the best effect.Compared with CK,the yield of garlic bulbs and garlic bolts treated with humic acid and 72.2%controlled release nitrogen fertilizer increased by 22.4%and 18.7%,respectively.Bulb single weight and transverse diameter were increased by 34.1%and 16.8%,respectively.The weight and length of garlic bolts were increased by 20.9%and 25.2%,respectively.Compared with 72.2%controlled release N fertilizer and 72.2%controlled release N fertilizer,the yield of garlic bulb and garlic crop increased by 2.5%and 2.9%,respectively.Bulb single weight and transverse diameter were increased by 3.1%and 2.3%,respectively.The weight and length of garlic bolts were increased by 4.0%and 3.9%,respectively.These results indicated that the combined application of humic acid and controlled release N was better than the same proportion of controlled release N,and the interaction between humic acid and controlled release N was obvious.3.Combined application of controlled-release nitrogen fertilizer,humic acid and controlled-release nitrogen fertilizer can improve the quality of garlic bulbs,and increase the contents of soluble sugar,soluble protein,free amino acid,VC and allicin in garlic bulbs.With the proportion of controlled release nitrogen fertilizer increasing,the quality of garlic was significantly improved.Compared with CK,72.2%controlled release N treatment increased 27.5%,10.9%,22.6%,15.9%and 30.1%,respectively,and the effect was the best in controlled release N treatment.The combined application of humic acid and 72.2%controlled release nitrogen fertilizer increased 34.5%,18.9%,24.7%,24.4%and 39.4%,respectively,compared with CK,and the effect was the best among all treatments.Humic acid combined with 72.2%controlled release N fertilizer was superior to 72.2%controlled release N fertilizer in improving garlic bulb quality.4.Combined application of controlled-release nitrogen fertilizer,humic acid and controlled-release nitrogen fertilizer can improve soil physical and chemical properties.With the increase of the proportion of controlled release nitrogen fertilizer,the contents of nitrate nitrogen and ammonia nitrogen in soil increased significantly.Compared with conventional fertilization,controlled release nitrogen fertilizer was beneficial to increase the contents of nitrate nitrogen and ammonia nitrogen in soil,and 72.2%controlled release nitrogen fertilizer had the best effect,which increased by 32.8%and 28.1%,respectively,compared with conventional fertilization.The contents of available phosphorus,available potassium and organic matter were not significantly affected.With the increase of the proportion of controlled release nitrogen fertilizer,the contents of nitrate nitrogen and ammonia nitrogen were significantly increased,the contents of available phosphorus and available potassium were also increased,which were 38%,32.1%,2.5%and 3.2%,respectively,and had no significant effect on the change of soil organic matter content.Humic acid combined with 72.2%controlled release N fertilizer was superior to 72.2%controlled release N fertilizer in improving garlic bulb quality.There was an interaction between humic acid and controlled release N fertilizer in improving soil physical and chemical properties.