Y.T. Liu, Y.C. Kuo, G.D. Wu & L.B. Li ORGANIC COMPOUND FERTILIZER FROM ETHANOL DISTILLERY SLOPS Y.T. Liu, Y.C. Kuo, G.D. Wu & L.B. Li Taiwan Sugar Research Institute 0, Tainan 701 I ABSTRACT Liquid and solid organic compound fertilizers were made from concentrated ethanol distillery slops and applied to the short-term crops (lettuce and tomato) in order to obtain test results in a short time. Chemical compound fertilizer or distillery slops powder alone was not as effective as a combination of the chemical fertilizer and distillery slops, which had a remarkable effect on plant growth, productivity and quality. Keywords: Sugarcane, organic compound fertilizer, ethanol distillery slops, lettuce, tomatoes, Taiwan. INTRODUCTION The ethanol fermentation industry produces large amounts of distillery slops (13 111 ethanol produced) with a very high BOD content (> 40,000 ppm, Paturou 1982). Its disposal poses a serious disposal problem. Several years ago at the Shin-Ying by-products factory of the Taiwan Sugar Corporation (TSC), distillery slops were first providd as a raw material in feed yeast production, then the slops from the yeast plant were treated by anaerobic digestion, followed by aerobic digestion (activated sludge method) (Lu & Wang 1986). The colored materials derived from cane molasses could not be decomposed effectively by microorganisms, resulting in low transparency of the treated water;,and the COD was high because of high sulfite compounds in the slops. Given the high cost of feed yeast production, the factory was closed. Subsequently, the slops were transported to the cane plantation and sprayed on the field as a To minimize transportation cost's, an evaporation process was finally adopted. A Japanese firm (Katakura - Chikalin) used the concentrated distillery slops as liquid organic fertilizer for Sc-ing remarkable results (Weng 1990). We made liquid and solid organic compound fertilizer with the distillery slops and obtained satisfactory results. MATERIALS AND METHODS Chemical analyses M o l distillery slops came from the Shin-Ying ethanol distillery, which used cane molasses. The slops, concentrated slops and organic compound fertilizers were sent to the TSRI chemical analyses center. Components of ethanol distillery slops. Sugarcane cells contain a lot of sucrose and other essential cell life materials such as nucleic acids, proteins, enzymes, vitamins and minerals. After milling and squeezing, the cells were dissolved in mixed juice, and sucrose was separated by crystallization from other materials. The remaining noncrystalizing materials were in the form of cane molasses (about 50 % sugars as TS and 35 % of other materials), which was used as the only raw material for ethanol fermentation. After inoculating yeast in the cane molasses broth, most of thq sugar was fermented as ethanol and separated from other nonvolatile material by distillation. This nonvolatile material is referred to as slops, which contain yeast metabolites, yeast cells, nucleic acids, proteins, vitamins and minerals (Table 1). As shown in Table 1, the ethanol distillery slops contained 12-15 % dissolved materials, rich in K, Ca, Mg, Fe and minor elements. The slops were concentrated to 50-64" Brix by vacuum evaporation. The concentrated slops contained 35% OM, 6% K20, 1.5% MgO, 1.0% CaO and other minor elements, but lack N and P (Table 2). Solidifying concentrated slops. The farmers of Taiwan-used to applying solid fertilizer-were unfamiliar with liquid To prepare solid organic compound fertilizer, the concentrated slops had to be solidified. Bagasse is a raw material of bagasse pulp, particle board and fiber board; and large amounts of bagasse pith (20-30 %) are produced and discarded or used as raw materials for compost making because of easy decay. Bagasse pith was selected as a carrier for concentrated slops because of its high liquid absorption. Four parts of concentrated slops and one portion of bagasse pith were mixed and dried using routine drying processes such as shallow pan drying, drum drying or particle flow drying. Table 3 gives the components of the dehydrated slops powder, which contained 68 % OM, 8.18 % K20, 2.3 % MgO, 1.63 % CaO and 1.99 % total N and had a ph of 4.48. Its Fe ion (coming from the soil in the bagasse pith) was especially high (> 3000 ppm), but it was below the compost
Products: Sub-Products Table 2. Components of concentrated ethanol distillery slops. Table 1. Components of ethanol distillery slops. PH Alkalinity (mgll as CaCO,) 4.00 5.6 Conductivity X 103(mmhos/cmat 25) 17.8 COD (PPm) 94.40 BOD (Ppm) Suspension solids wpm) 33.5 1,495 Total N (%) ' 0.17 p~05 (%) 0.015 K2O (%) Soluble cation (meqll) ig Ca+' 1.06 59.0 Mg+2 94.9 K+' 197.4 Na+' 10.3 Total 362 Soluble anion (meqll) ig HCOO,-1 0 Cl-' 130.65 SOi2 82.49 Total Fe (Ppm) Mn (PP~) cu (PP~) zn (PP~) Cd (Ppm) Cr (Ppm) Pb (PP~) ph Brix Organic carbon (%) OM (%) Moisture (%) Total N (%) p205 (%I K20 (%I CaO (%) MgO (%) Na,O (%) Fe (Ppm) Mn (PP~) cu (PP~) Cd (Ppm) Cr (Ppm) Pb (PP~) Table 3. Components of slo@ powder. ph Moisture (%) OM (%) Total N (%) p2.5 (%) K20 (%) CaO (%) MgO (%I N%O (%I
Y.T. Liu, Y.C. Kuo, G.D. Wu&L.B. Li standard. The heavy metals were within limits of the ~ ~ 4, b~~~~l~ l ~ of solid organic compost standard so it could be used as the raw material for solid organic compound Composition of organic compound By Content Preparation combining the concentrated slops and chemical fertilizer, a complete fertilizer can be made according to the Composition (kg) soils and crop requirements. Any fertilizer can be used, slops powder 51.2 30.7 but preferably it should be low cost. Table 4 shows a calcium superphosphate 8.5 5.1 suitable composition for fruit trees (N-P@,-K20-MgO urea 22.2 13.3 = 4-5-8-3); and Table 5 its composition. Kc1 6.5 3.9 For a liquid form, the chemical fertilizer used should be MgS0,.7H20 11.6 7.0 highly soluble in nature to facilitate combining it with the concentrated slops. Table 6 gives an example of a liquid organic compound fertilizer; Table 7, its composition. It contained 21 % OM, 12 % N, 7.7 % P205, 8.3 % K,O and various minor elements in a neutral 80" Brix paste (N-P205-K20 = 12-8-8). Compositions of N-P205-K20 = 12-4-8, 4-8-10, 16-4-8, 8-8-8, 6-12-6 and 4-8-12 were formulated. In some cases the concentrated slops should be diluted a little to prevent recrystalization. Testing fertilizer effectiveness Short-term crops were planted to determine the effects of the liquid and solid organic compound fertilizers on crop growth, productivity and production costs. The fertilizers used were slops powder (A); liquid organic-compound fertilizer (N-P205-K20 = 12-8-8) (B); solid organic compound fertilizer (N-P205-K,O-MgO = 4-5-8-3) (C); and chemical complex fertilizer (Tai-Fe No. 1, N-P205-K20 = 20-5-10) (D). The soil was a poor sandy loam, ph 7.4, containing 1.4 % OM, 0.04 % total N, 14 ppm effective P (P20,) and 90 ppm effective K &O). Leafy vegetables. Lettuce was selected as the type crop for leafy vegetables. The treatments were set on the amount of total nitrogen Table 5. Example of components (TN) applied per hectare (50, 100, 150 and 200 kg) applied basally. of solid organic compound A split-block design with three experiments was used. The fertilizer was incorporated in a 1 m2 area with 12 cm soil (180 kg). Each area had 4 rows with 10 lettuce plants in each. Harvesting was done at 4 wk. Fruit-producing vegetables. Tomatoes were selected as the type PH 4.21 crop for cultivation. Treatments were established with 200 kg Nlha, OM (%) 11.26 applied basally. A randomized complete block design of double Total N (%) 4.45 experiments was used. The fertilizer was incorporated in a 1 m2 area p2 5 (%) 5.48 with 60 cm soil (900 kg) in conical form. Three tomato plants were K20 (%) 8.98 planted in each area on 21 Jan,and harvested from 97 days onward CaO (%) 9.65 to the end of the experiment (28 April to late May). Ma0 (%) 3.46 RESULTS AND DISCUSSION Leafy vegetables The consolidated results of the three lettuce experiments are shown in Table 8. The solid organic compound fertilizer (C) had greatest yields of lettuce, followed by the liquid organic compound fertilizer (B) Slops powder (A) had little effect because of low N content (1.99%) and a high CIN ratio (16). The N in the slops powder was barely enough for propagating soil microorganisms and could not supply plants but might be useful for long-term crops. The
Products: Sub-Products' Table 7. Example of the components of liquid organic compound Table 6. Example of liquid organic compound Content Preparation Composition (%I (kg) Concentrated slops 55 33 (NH,)zHPO, Urea 15 18 9 10.8 KC1 12 7.2 PH Brix 6.54 80.14 Viscosity (CPS) 1.098 Moisture (%) 35.29 OM (%) 20.56 Total N (%) 12.12 p2 5 (%) 7.68 K20 (%) 8.25 CaO (%) 0.59 MgO (%I 0.92 Na,O (%) 0.14 Fe (PP~) ' 289.2 Mn (PP~) 1.8 zn (PP~) 6.8 cu (PP~) 6.8 Cd O?P~) 1.8 0. (PP~) 7.4 Pb (PP~) 5.2 Table 8. Lettuce cultivation experiments. Treatments Lettuce productivity (g/m2) (kgm A B C D Total' Total' 419 a 2845 c 4186 d 639 b 8069 Same letter indicates no significant difference (F'=0.05). Fertilizer LSD: 216 for 5% and 328 for 1 %; Nitrogen LSD: 419 for 5% and 569 for 1 %. A = slops powder; B = liquid organic compound fertilizer (N-P205-&O = 12-8-8); C = solid organic compound fertilizer (N-P20, -&O-MgO = 4-5-8-3); and D = chemical compound fertilizer (N-P205-&O = 20-5-10).
Y.T. Liu, Y.C. Kuo, G.D. Wu & L.B. Li CIN ratios of solid and liquid or- Table 9. Tomato cultivation experiments. ganic compound fertilizers were 3.9 ---- and 1.67, respectively, so, they Tomato No. Total Tomato could provide N for both microor- Fertilizer height tomatoes production juice Qual~ty ganisms and plants in a short time. (TN 200 kglha) (cm) produced (glplant) Brix inspection1 The most suitable amount of N in ---- the organic compound fertilizer was A 170 23 2712 4.1 1.9 200 kgha and could be added to the B 190 32 5130 6.1 2.4 basal application. The chemical C 200 26 3965 5.4 1.6 compound fertilizer (Tai-Fe No. 1) D 180 25 3620 4.5 1.2 contained 20% N. The suitable --- amount for lettuce cultivation was 50 'Inspections were performed by 17 people: 3 points = good, 2 points = kglha, but lettuce production was average and 1 point = low quality. The average scores are presented. only one-sixth that with solid orgadic compound A negative effect was observed with increasing chemical compound fertilizer use: the more fertilizer, the less lettuce. It was evident that the slops powder or the chemical fertilizer alone could not stimulate maximum prqtion; but combining the two fertilizers to make organic compound fertilizer resulted in a synergistic effect, stimulatmg maximum production. F'ruit-producing vegetables The consolidated resdts of the two tomato experiments are shown in Table 9. As regards plant height, the solid organic compound fertilizer was the most effdve, while the slops powder had little effect. The number of fruits, total production and Brix of the tomato juice were higher for the plants cultivated with liquid organic compound fertilizer and lower for the plants with slops powder. Results were similar for fiuit taste. This indicated that neither the slops powder nor chemical fertilizer produced the maximum effect, but combining the two materials exerted a synergistic effect, greatly increasing growth, productivity and quality of the vegetables. CONCLUSIONS The ethanol distillery slops-which contain yeast metabolites, yeast cells, nucleic acids, proteins, vitamins and minerals-were mixed with chemical fertilizer to form different liquid organic compound fertilizers. As the slops and bagasse pith used to absort> them were waste products, they could be supplied at low cost. The effect of the composed organic compound fertilizer on crop production indicated that the slops powder or chemical fertilizer alone could not stimulate maximum production, but that combining the two materials had a synergistic effect, greatly increasing plant growth, productivity and quality of vegetables. ACKNOWLEDGMENTS The authors are grateful to Mr M.C. Tseng and Ms T. Liu for their assistance in preparing the organic compound fertilizers. REFERENCES Chao, M.C. & Liu, Y.T. (1980). Report on Korean and Japanese L-lysine fermentation industry. Taiwan Sugar Corp., Taipei, pp 22-23. Lu, K.H. & Wang, S.L. (1986). TSC develops the first commercial fermentation industry waste watertreatment plant in Taiwan. Taiwan Sugar 33(5):17-19. Paturou, J.M. (1982). By-products of the cane sugar industry, pp 241-244. Weng, T. (1990). Report on manufacturing technology of the enzyme and biosynthetic products in Japan. Taiwan Sugar Corp., Taipei, pp 49-51.