Polysulphate Tea Trial in Vietnam
15
Lam Dong district, Vietnam 2015
15
Key Conclusions
Polysulphate enhances the volume and quality of tea buds. Overall, Polysulphate increased farmers’ profit by up to 13%. For both cultivars, CT2 was significantly more profitable than CT1, and CT3 more than CT2. These results suggest that the common tea fertilization practice (CT1) in these regions of Vietnam may be considerably improved by using Polysulphate.
Objective
The experiment examined the benefits of Polysulphate as a potential additive to compound NPK fertilizers, as part of an alternative fertilization program for the tea (Camillia sinensis) industry in the Lam Dong district in Vietnam.
Trial Details
Trial station
Lam Dong district, Vietnam
Crop
Tea
Product
Granular Polysulphate
Assessments
Bud density, bud weight, bud length, tea bud yield, and tea quality parameters
Treatments
Three fertilizer treatments were tested at 2 sites of 7-year-old tea plantations of 2 varieties of tea (Kim Tuyen and TB14) between April and December 2015. The 1st treatment (CT1) was the farmers’ standard fertilizer practice, the 2nd treatment (CT2) used locally available commercial compound fertilizer, and the 3rd treatment (CT3) was the same as CT2 but fortified with Polysulphate.
Fertilizer | Bao Loc (cv. Kim Tuyén) | Bao Lam (cv. TB14) | |||||
---|---|---|---|---|---|---|---|
CT1 (Control) | CT2 (Phu My Fertilizer) | CT3 (Phu My Fertilizer + Polysulphate) | CT1 (Control) | CT2 (Phu My Fertilizer) | CT3 (Phu My Fertilizer + Polysulphate) |
||
kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | ||
Polysulphate | 0 | 0 | 200 | 0 | 0 | 150 | |
NPKS (16-16-8-13) | 0 | 800 | 800 | 0 | 400 | 400 | |
NPK (15-15-15) | 0 | 1,000 | 1,000 | 0 | 500 | 500 | |
NPK (25-9-9) | 0 | 1,500 | 1,500 | 0 | 750 | 750 | |
NPK (27-6-6) | 0 | 1,500 | 1,500 | 0 | 750 | 750 | |
Urea | 3,200 | 900 | 900 | 1,600 | 450 | 450 | |
Fused Ca-Mg-P | 3,353 | 0 | 0 | 1,677 | 0 | 0 | |
KCl | 832 | 100 | 53 | 466 | 100 | 65 |
Treatments
Three fertilizer treatments were tested at 2 sites of 7-year-old tea plantations of 2 varieties of tea (Kim Tuyen and TB14) between April and December 2015. The 1st treatment (CT1) was the farmers’ standard fertilizer practice, the 2nd treatment (CT2) used locally available commercial compound fertilizer, and the 3rd treatment (CT3) was the same as CT2 but fortified with Polysulphate.
Fertilizer | Bao Loc (cv. Kim Tuyén) | Bao Lam (cv. TB14) | |||||
---|---|---|---|---|---|---|---|
CT1 (Control) | CT2 (Phu My Fertilizer) | CT3 (Phu My Fertilizer + Polysulphate) | CT1 (Control) | CT2 (Phu My Fertilizer) | CT3 (Phu My Fertilizer + Polysulphate) |
||
kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | ||
Polysulphate | 0 | 0 | 200 | 0 | 0 | 150 | |
NPKS (16-16-8-13) | 0 | 800 | 800 | 0 | 400 | 400 | |
NPK (15-15-15) | 0 | 1,000 | 1,000 | 0 | 500 | 500 | |
NPK (25-9-9) | 0 | 1,500 | 1,500 | 0 | 750 | 750 | |
NPK (27-6-6) | 0 | 1,500 | 1,500 | 0 | 750 | 750 | |
Urea | 3,200 | 900 | 900 | 1,600 | 450 | 450 | |
Fused Ca-Mg-P | 3,353 | 0 | 0 | 1,677 | 0 | 0 | |
KCl | 832 | 100 | 53 | 466 | 100 | 65 |
Results
Polysulphate, added to a systematic NPK fertilization program for tea plants grown on reddish brown soil in Lam Dong, Vietnam, enhanced the density, weight, and size of tea buds, thus increasing tea productivity of both varieties of tea by 14.1-15.3%. Polysulphate also improved tea quality parameters such as dry matter content and the concentration of soluble substances, tannins, and caffeine, which are important for flavor in tea.
Research Partner: Petrovietnam Fertilizer and Chemicals Corporation (PVFCCo), Vietnam.
From research funded by the International Potash Institute www.ipipotash.org