Effects of Applying Humic Fertilizers on Tea's Yield , Nutritional Quality and Soil Fertility in a Tea Garden

Abstract

A field trial with 2 kinds of humic fertilizers (i.e., humic and weathered coal) being added to the balance use of nitrogenous, phosphorus and potassium fertilizers for 3 years was carried out to test effects of tea's yield, nutritional quality and soil fertility in a tea garden. And 4 treatments were designed, i.e., (1) Chemical fertilizers (N 103 kg·hm -2 ·a -1 , P2O5 34 kg·hm -2 ·a -1 and K2O 34 kg·hm -2 ·a -1 , following was the same); (2) Chemical fertilizers (same as (1))+Humic (2000 kg·hm -2 ·a -1 ), (3) Chemical fertilizers (same as (1))+weathered coal(1500 kg·hm -2 ·a -1 ), (4) Chemical fertilizers (same as (1))+ Humic acid(1000 kg·hm -2 ·a -1 )+ weathered coal(750 kg·hm -2 ·a -1 ). Results show that, under the condition of humic fertilizers being used in tea garden, tea's yield and tea polyphenols were increased by 3.19%~14.24% and 5.21%~10.73%, respectively; Soil pH, organic matter, total nitrogen, total phosphorus, total potassium, alkali-hydrolyzable nitrogen, available phosphorus and potassium were increased by 2.97%~18.61%, 8.86%~27.22%, 9.80%~45.10%, 6.12%~40.82%, 4.52%~40.16%, 8.81%~45.75%, 0.62%~67.55% and 5.56%~36.09%, respectively. Whereas, effects of increasing tea's yield, tea polyphenols and soil alkali-hydrolyzable nitrogen by treatment of chemical fertilizer + humic + weathered coal were better than other treatments; Effects of increasing soil organic matter, total nitrogen, total phosphorus, total potassium, available phosphorus and potassium by treatment of chemical fertilizer + humic acid were better than other treatments; And the effect of enhancing soil pH by treatment of chemical fertilizer + weathered coal was better than other treatments.