Fertilizer And Mulch Film-saving And Quality-improving Effects Of Magnesiun,Boron And Controlled-release Formala Fertilizers On High-altitude Chinese Cabbage And Pepper

High-altitude vegetable is an important part in summer and autumn vegetable market in our country.The production and environmental problems caused by long-term unscientific fertilization and continuous film mulching cultivation are getting worse and worse,which seriously impede the green and efficient development of high-altitude vegetable.In this study,we took high-altitude Chinese cabbage and pepper through field trials to investigate the effects of magnesium,boron and controlled-release formula fertilizer on yield,quality,fertilizer recovery efficiency,economic benefits,and the physical and chemical properties of soil,so as to supply technical support for green,clean and effective production of high-altitude vegetables.The main findings are as follows:（1）Applying controlled-release formula fertilizer can significantly reduce the amount and cost in fertilizer and mulch film of two crops of Chinese cabbage with a film,increase the commercial yield of Chinese cabbage,improve quality and increase fertilizer recovery efficiency.Compared with farmers’conventional fertilization（CN）,applying controlled-release formula fertilizer（T1）reduced total nutrients input by 34.7%and mulch film input by 50%.While it increased the commercial yield of two crops of Chinese cabbage by 1.86%,reduced the nitrate content by 29.4%～33.6%,and increased the vitamin C,soluble protein and soluble sugar contents by 5.59%～10.4%,12.3%～22.3%and 7.24%～143%.It also increased the fertilizer recovery efficiency of N,P and K by 19.7%,27.5%and 14.9%respectively,as well as increased the net income by16,900 yuan per hectare.And all the differences reached significant levels.Applying controlled-release formula fertilizer with 600 kg/hm²of organic fertilizer（T2）not only ensured yield and income of Chines cabbage,but also improved the quality.Reducing10%of N in T2 treatment（it called T3）could get better effect.Compared with farmers’conventional fertilization（CN）,T3 treatment increased the commercial yield of two crops of Chinese cabbage by 6.93%,decreased the nitrate content by 45.4%～56.6%,increased the vitamin C,soluble protein and soluble sugar contents by 12.0%～22.6%,41.9%～50.9%and 32.1%～223%,respectively.It also increased the net income by 25,700 yuan per hectare.（2）Applying controlled-release formula fertilizer can significantly increase the nitrogen content and mitigate acidification of 0-20 cm top soil,as well as reduce the risk of NO₃^--N leaching with organic fertilizer.Compared with farmers’conventional fertilization（CN）,applying controlled-release formula fertilizer（T1）increased the total nitrogen content and NO₃^--N content of the 0-20 cm top soil by 8.44%and 23.8%,increased EC by 29.4%,increased p H by 0.16 units,respectively.Applying controlled-release formula fertilizer with 600 kg/hm²of organic fertilizer（T2）increased the total nitrogen content and NO₃^--N content of the 0-20 cm top soil by 5.19%and 11.3%respectively,increased EC by 47.6%,increased p H by 0.44 units.It also reduced the NO₃^--N content of the 20-40 cm deep soil by 47.9%,and all the differences reached Reducing 10%of N in T2 treatment（T3）got better effect in reducing the risk of NO₃^--N leaching.（3）Proper application of magnesium fertilizer can significantly increase the commercial yield of Chinese cabbage,improve the quality,and increase fertilizer recovery efficiency.Compared with farmers’conventional fertilization（CN）,adding 8.70～26.1 kg/hm²Mg O（T1,T2 and T3）improved the quality of Chinese cabbage,but decreased the commercial yield by 3.60%～9.35%.Applying formulated fertilizer with600 kg/hm²organic fertilizer and 17.4 kg/hm²Mg O（T4）increased the commercial yield of Chinese cabbage by 8.43%,decreased the nitrate content by 43.8%,increased vitamin C,soluble protein and soluble sugar contents by 35.8%,68.7%and 52.5%respectively,as well as increased the fertilizer recovery efficiency of N,P and K by 10.6%,22.7%and17.7%respectively.And the differences all reached significant levels.（4）Proper application of boron fertilizer or magnesium fertilizer can significantly increase the yield of pepper,improve the quality and promote nutrients uptake.Compared with farmers’conventional fertilization（CN）,adding 2.67 kg/hm²B or 5.34 kg/hm²B（T1and T2）increased the yield of pepper by 37.9%and 67.9%,increased vitamin C,soluble protein and soluble sugar contents of different fruiting periods by 7.96%～14.2%,23.1%～36.0%and 23.4%～34.7%,as well as increased the fertilizer recovery efficiency of N,P and K by 15.8%～25.2%,2.84%～7.94%and 27.5%～39.6%,respectively,with significant differences.Adding 17.4 kg/hm²Mg O（T3）,increased the yield of pepper by47.9%,increased vitamin C,soluble protein and soluble sugar contents of different fruiting periods by 13.4%～15.4%,38.4%～50.6%and 4.08%～15.2%,and also increased fertilizer recovery efficiency of N,P and K by 17.4%,3.82%and 28.1%,respectively,with significant differences.