Effect of Boron and Magnesium Fertilization on Tea Yield,Quality and Soil Fertility of Red-soil Tea Plantations

Deficiency on available boron and magnesium in the red-soil among the tea plantations in South China is common.This study attempted to determine the optimal application of boron and magnesium fertilizers to remedy the shortage.Using application of a chemical fertilizer(CF)as control,a 3-year field trial on 3treatments,i.e.,(a)CF and boron(CF+B),(b)CF and magnesium(CF+Mg)and(c)CF,boron and magnesium(CF+B+Mg),was conducted.Yield,quality and mineral nutrient absorption of the tea as well as fertility of the red-soil were monitored.Compared with control,the 3treatments increased the yield by 7.86%-14.03%,free amino acids by18.63%-35.29%,tea polyphenols by 4.15%-7.91%,water extracts by 5.53%-10.42%,and theine by10.73%-24.52%.The ratio of tea polyphenols to free amino acidsdecreased by 12.20%-20.24%;while the contents of B,Mg,nitrogen,potassium and phosphorus were raised by15.99%-36.34%,7.63%-19.08%,6.12%-12.39%,2.42%-13.87% and 2.92%-7.60%,respectively.The minerals in the soil,including the available B,Mg,phosphorus and potassium,increased by 133.33%-273.33%,6.63%-34.65%,20.29%-58.60% and 15.38%-32.83%,respectively.On the other hand,the pH,organic matters,total nitrogen,phosphorus,potassium and alkali-hydrolyzable nitrogenin the soil showed no significant differences.It appeared that the fertilization with CF combined with B and Mg was comparatively superior in enhancing the yield,quality and mineral nutrient absorption of the tea.