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Engenharia Agrícola

Print version ISSN 0100-6916On-line version ISSN 1809-4430

Eng. Agríc. vol.35 no.1 Jaboticabal Jan./Feb. 2015

http://dx.doi.org/10.1590/1809-4430-Eng.Agric.v35n1p63-75/2015 

Scientific Papers

Technology for sugarcane agroindustry waste reuse as granulated organomineral fertilizer

Tecnologia para aproveitamento de resíduos da agroindústria sucroalcooleira como biofertilizante organomineral granulado1

MARCÍLIO N. DO A. GURGEL2 

SIMONE T. R. CORREA3 

DURVAL DOURADO NETO4 

DURVAL R. DE PAULA JÚNIOR5 

2Engº Agrônomo, Doutor, Engenharia de Desenvolvimento, Dedini S/A Indústrias de Base/Piracicaba-SP, Fone: (19) 98154 8730,marcilio.gurgel@terra.com.br

3Engª Agrônoma, Pós-Doutoranda, Programa de Sustentabilidade, Laboratório Nacional de Ciência e Tecnologia do Bioetanol (CTBE)/Campinas-SP,simone.correa@bioetanol.org.br

4Engº Agrônomo, Prof. Doutor, Departamento de Produção Vegetal, Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ)/Piracicaba-SP,d.dourado@gmail.com

5Engº Civíl, Prof. Livre Docente, Departamento de Água e Solo, Faculdade de Engenharia Agrícola, Universidade Estadual de Campinas, Campinas – SP.

ABSTRACT

Aiming to evaluate the use of sugarcane industry waste such as byproducts from vinasse concentration process, it was assessed the organomineral fertilizer BIOFOM (concentrated vinasse, filter cake, boiler ash, soot from chimneys and supplemented with mineral fertilizers). The study included characterization and agronomic potential analysis of a test plant (corn), by noting the differences between mineral fertilizers and BIOFOM fertilization until 45 days after sowing. The technology traditionally used to produce BIOFOM was based on vinasse evaporation with high heat transfer coefficients. It was observed that the technology, which can be formulated according to the needs of any crop, could be used in many cases as mineral fertilizer. Therefore, the use of this organomineral fertilizer reduces waste generation of sugarcane industry.

Key words: biofertilizer; vinasse; sugarcane agribusiness; organic waste; filter cake

RESUMO

Com o objetivo de avaliar o uso de resíduos da agroindústria sucroalcooleira como vantagens do processo de concentração da vinhaça, utilizou-se o BIOFOM (biofertilizante organomineral formulado com vinhaça concentrada, torta de filtro, cinzas de caldeira e fuligem das chaminés, e complementado com fertilizantes minerais). O presente estudo contemplou a caracterização e a análise do potencial agronômico envolvendo uma planta-teste (milho), observando as diferenças entre os tratamentos (adubação com fertilizante mineral versus adubação com BIOFOM), até 45 dias após a semeadura. A tecnologia (tradicionalmente usada para a produção do BIOFOM) utilizada para concentrar a vinhaça baseou-se na evaporação do resíduo com elevados coeficientes de troca térmica. Observou-se que o BIOFOM, que pode ser formulado de acordo com as necessidades de qualquer cultura, pode substituir, parcial ou totalmente, a utilização do fertilizante mineral. O produto reduz a geração de resíduos da agroindústria sucroalcooleira.

Palavras-Chave: biofertilizante; vinhaça; agroindústria canavieira; resíduos orgânicos; torta de filtro

INTRODUCTION

The National Alcohol Program (PROALCOOL), created in 1975 to stimulate the production of ethanol in order to meet the needs of the domestic and foreign markets and the automotive fuels policy (SILVA & FISCHETTI, 2008), first drove the remarkable expansion of sugarcane farming. From this date, a major expansion of sugarcane activity was promoted in Brazil, as well as its concentration in certain areas and agricultural regions, especially in areas of the state of São Paulo. The second major thrust in sugar cane industry was the introduction of vehicles powered by gasoline and ethanol (flex-fuel) in 2003, and the worldwide movement pro-use of renewable fuels, from the mid-2000s on (RAMOS et al., 2008).

The environmental issue, however, has not received the same concern as the increase in production. Essential factors for sustainable development of sugarcane production were never taken into account. With population growth, in the vast majority urban, and increased industrial development, water and solid wastes have been generated in large quantities (TASSO JÚNIOR et al., 2007). This fact resulted in intensification of major environmental problems such as degradation of ecosystems, atmospheric pollution caused by fires and pollution of watercourses and groundwater caused by excessive application of vinasse “in natura” (SZMRECSÁNYI, 1994).

Some successful experiences with waste management in power plants and distilleries show that the filter cake, solid organic material obtained from sugar production, has been used in the fertilization of sugarcane crops. The sugarcane bagasse, which was already being used to generate energy in industrial units, has also been used in recent years in energy cogeneration, allowing power plants and distilleries not to consume electricity from distribution networks.

Vinasse is a byproduct from alcohol manufacture, being composed mostly of water (CÓ JUNIOR et al., 2008) and is the main effluent of the distilleries by fermentation, which had previously released directly into rivers, causing severe environmental problems. Nowadays, it is largely used to irrigate and fertilize sugarcane fields. It must be mentioned that the use of wastes deserves attention for possible problems concerning soil and water degradation and contamination (SPADOTTO, 2008).

Since waste production from sugarcane processing is quite voluminous, for both ethanol and sugar, the search for appropriate technologies to promote the management, treatment and use, constitutes a determining factor for an environmentally sustainable development of the sugarcane agro-industrial complex.

In this context, this research aimed to evaluate a patented organic fertilizer and commercially known as BIOFOM produced with waste from sugar and alcohol industry (concentrated vinasse, filter cake, boiler ash and soot from chimneys), and supplemented with mineral fertilizers to obtain equivalent formulations to those used in conventional fertilization of sugar cane.

MATERIAL AND METHODS

The experiment with BIOFOM, using corn as "test plant", was carried out from October to December 2008 in a greenhouse at the Department of Soil Sciences from the "Luiz de Queiroz" College of Agriculture, University of São Paulo, in Piracicaba (SP), Brazil. The location is at 547 meters of altitude and 22º 43' 31" S latitude and 47º 38' 57" W longitude. The greenhouse has 200 m2, with East-West orientation and plastic cover, and a moistened air circulation through a Pad House system performed the environmental cooling.

The agronomic potential of BIOFOM was evaluated through fertilizer lots that were produced with vinasse, filter cake, ash and soot; and supplemented with chemical fertilizers and granulated.

As shown in the Table 1, the experimental design was in randomized blocks consisting of 25 treatments and four replications: (i) Control; (ii) Molasses vinasse BIOFOM + broth with 30% and 45% of total soluble solids (TSS) + 50%, 75% and 100% mineral fertilizer; (iii) Molasses vinasse BIOFOM with 30% and 45% of TSS + 50%, 75% and 100% of the mineral fertilizer dose; (iv) Broth vinasse BIOFOM with 30% and 45% TSS + 50%, 75% and 100% of the mineral fertilizer dose; (v) Mineral fertilizer equivalent to 100%, 75% and 50% of the dose; (vi) Molasses vinasse + concentrated broth at 30% of TSS + complement; (vii) Concentrated molasses vinasse at 30% of TSS + complement and; (viii) Concentrated broth vinasse at 30% of TSS + complement. The comparisons of the differences between treatments were performed by Tukey test (significance level of 5%). For statistical analysis it was used the software SAS 9.2 (Statistical Analysis System).

TABLE 1 Treatments (T) of the experiment to evaluate the Biofom with corn (test plant). 

T Composition Abreviation
1 Control: soil corrected with limestone Control
2 Molasses vinasse BIOFOM + broth with 30% of total soluble solids (TSS) + 50% mineral fertilizer (0.823g of urea, 1.626 g of triple superphosphate and 1.289 g of KCl) Mixed 30-50
3 Molasses vinasse BIOFOM + broth with 30% TSS + 75% mineral fertilizer dose (1.234 g urea, 2.439 g of triple superphosphate and 1.933 g of KCl) Mixed 30-75
4 Molasses vinasse BIOFOM + broth with 30% TSS + 100% mineral fertilizer dose (1.645 g urea, 3.252 g of triple superphosphate and 2.577 g of KCl) Mixed 30-100
5 Molasses vinasse BIOFOM + broth with 45% of ST + 50% mineral fertilizer dose Mixed 45-50
6 Molasses vinasse BIOFOM + broth with 45% of TSS + 75% mineral fertilizer dose Mixed 45-75
7 Molasses vinasse BIOFOM + broth with 45% of TSS + 100% of the mineral fertilizer dose Mixed 45-100
8 Molasses vinasse BIOFOM with 30% of TSS + 50% of the mineral fertilizer dose Molasses 30-50
9 Molasses vinasse BIOFOM with 30% of TSS + 75% of the mineral fertilizer dose Molasses 30-75
10 Molasses vinasse BIOFOM with 30% TSS + 100% of the mineral fertilizer dose Molasses 30-100
11 Molasses vinasse BIOFOM with 45% of TSS + 50% of the mineral fertilizer dose Molasses 45-50
12 Molasses vinasse BIOFOM with 45% of TSS + 75% of the mineral fertilizer dose Molasses 45-75
13 Molasses vinasse BIOFOM with 45% of TSS + 100% of the mineral fertilizer dose Molasses 45-100
14 Broth vinasse BIOFOM with 30% TSS + 50% of the mineral fertilizer dose Pure 30-50
15 Broth vinasse BIOFOM with 30% TSS + 75% of the mineral fertilizer dose Pure 30-75
16 Broth vinasse BIOFOM with 30% TSS + 100% of the mineral fertilizer dose Pure 30-100
17 Broth vinasse BIOFOM with 45% of TSS + 50% of the mineral fertilizer dose Pure 45-50
18 Broth vinasse BIOFOM with 45% of TSS + 75% of the mineral fertilizer dose Pure 45-75
19 Broth vinasse BIOFOM with 45% of TSS + 100% of the mineral fertilizer dose Pure 45-100
20 Mineral fertilizer equivalent to 100% of the dose (500 kg of 4-20-20 (N, P, K) + 30 kg of N in coverage) * Mineral 100
21 Mineral fertilizer equivalent to 75 % of the dose Mineral 75
22 Mineral fertilizer equivalent to 50% of the dose Mineral 50
23 Molasses vinasse + concentrated broth at 30% of TSS + complement Mixed
24 Concentrated molasses vinasse at 30% of TSS + complement Molasses
25 Concentrated broth vinasse at 30% of TSS + complement Pure

* Reference values - 100%: 50, 100 and 100kg.ha-1 of N, P2O5 and K2O, respectively, this formulation adopted for being the most representative and standard in planting sugar cane in Mills in the Center-South of Brazil. In treatments T23, T24 and T25, complementation was made in order to match the quantities of nitrogen, phosphorus and potassium applied in Treatment 20 (T20).

The concentrated vinasse is derived from water evaporation process by the TASTE technology (Thermally Accelerated Short Time Evaporation system) (GURGEL, 2012). Vinasse of treatments came from three origins: (i) Mixed - vinasse from sugar and ethanol plant; (ii) Molasses - vinasse from a sugar mill; (iii) Broth - vinasse from an ethanol plant. Treatments took as a basis for comparison the amounts of N, P and K from the mineral fertilizer 100, 75 and 50%. Treatments of concentrated vinasse with 30% total soluble solids (TSS 30 = 22 °Brix, vinasse concentrated ± 10 times) and 45% of total soluble solids (TSS 45 = 55 °Brix vinasse concentrated ± 15 times) had the same source of (i) (ii) and (iii), and were also supplemented with chemical nutrients, as well as the BIOFOM treatments with 30% and 45% of total soluble solids.

BIOFOM preparation followed the method proposed by GURGEL (2009a, b), according to the following proportions: 10.7 (filter cake): 9.8 (vinasse with 30 or 45% of TSS): 5.0 (additives): 3.0 (molasses): 2.4 (ash): 1.5 (soot): 1.7 (urea): 1.0 (KCl) (by weight). Fertilizer granulation was made in dispersing discs driven by a 3 hp engine and 1710-rpm rotation, in which a reducer was installed to decrease disc rotation to 35 rpm. First, the quantified mixture of dry filter cake + boiler ashes + chimney soot was placed on the disc, and then concentrated vinasse containing 30 or 45% soluble solids was sprinkled, depending on the treatment. Together with the byproducts, three additives were added (polymer resin and humectant), which were responsible for stability of the final granules. Granule hardness of around 2.0 kgf.cm-2 was expected for this method and final bead humidity near 8%, considering that the moisture removed in the dryer for storage ranged between 30 and 40%.

Once prepared with pure broth, molasses and mixed broth, the BIOFOM was characterized by physical-chemical analysis, performed at the Mineral Plant Nutrition Laboratory of the "Luiz de Queiroz" College of Agriculture, University of São Paulo.

The amounts of urea, total soluble solids and potassium chloride in the different treatments of BIOFOM and vinasse are described in Table 2.

TABLE 2 Amounts of urea, total soluble solids (ST) and potassium chloride (KCl) in the different treatments of BIOFOM and vinasse, in g plot-1. 

Treatments BIOFOM Vinasse

Source Urea TSS KCl Urea TSS KCl
1 Control Limestone - - - - - -
2 Mixed 30-50 Limestone+BIOFOM 0.981 0.538 0.780 - - -
3 Mixed 30-75 Limestone+BIOFOM 1.472 0.807 1.170 - - -
4 Mixed 30-100 Limestone+BIOFOM 1.963 1.077 1.560 - - -
5 Mixed 45-50 Limestone+BIOFOM 0.894 0.544 0.780 - - -
6 Mixed 45-75 Limestone+BIOFOM 1.340 0.816 1.170 - - -
7 Mixed 45-100 Limestone+BIOFOM 1.787 1.088 1.560 - - -
8 Molasses 30-50 Limestone+BIOFOM 0.432 0.439 0.780 - - -
9 Molasses 30-75 Limestone+BIOFOM 0.648 0.658 1.170 - - -
10 Molasses 30-100 Limestone+BIOFOM 0.864 0.878 1.560 - - -
11 Molasses 45-50 Limestone+BIOFOM 0.709 0.481 0.780 - - -
12 Molasses 45-75 Limestone+BIOFOM 1.064 0.722 1.170 - - -
13 Molasses 45-100 Limestone+BIOFOM 1.418 0.963 1.560 - - -
14 Pure 30-50 Limestone+BIOFOM 0.657 0.496 0.780 - - -
15 Pure 30-75 Limestone+BIOFOM 0.985 0.744 1.170 - - -
16 Pure 30-100 Limestone+BIOFOM 1.314 0.993 1.560 - - -
17 Pure 45-50 Limestone+BIOFOM 0.958 0.630 0.780 - - -
18 Pure 45-75 Limestone+BIOFOM 1.436 0.945 1.170 - - -
19 Pure 45-100 Limestone+BIOFOM 1.915 1.260 1.560 - - -
20 Mineral 100 Limestone+4-20-20 - - - 0.411 0.813 0.644
21 Mineral 75 Limestone+4-20-20 - - - 0.308 0.610 0.483
22 Mineral 50 Limestone+4-20-20 - - - 0.206 0.407 0.322
23 Mixed Limestone+MV1+MC2 - - - 0.411 0.813 0.644
24 Molasses Limestone+molasses+MC2 - - - 0.411 0.813 0.644
25 Pure Limestone+CP3+MC2 - - - 0.411 0.813 0.644

1 MV: Mixed vinasse.

2 MC: Mineral complement corresponding to dose 100 of the mineral fertilizer

3 Pure broth.

BIOFOM pots at dose 100 for the respective sources (mixed, molasses and broth) and concentrations (30% and 45% TSS) were, respectively, 19.498 g, 20.942 g, 15.180 g, 19.168 g, 21.040 and g 22.561 g of product per pot. The pots at doses 75 and 50 were given the above mentioned percentage quantities. The pots with mixed vinasse (T23), molasses (T24) and broth (T25) each received a total of 0.644 g KCl, and for the first two cases, 0.277g and for the third case, 0.290 g of KCl equivalent as vinasse. As for the triple superphosphate (TSP), these treatments received in total per pot 0.813 g, with 0.019 g, 0.024 g 0,051g the equivalent amounts of vinasse. The same was true for urea, whose total dose per pot, T23, T24 and T25, corresponded to 0.411 g, however, from this total, 0.048 g, 0.057 g and 0.087g corresponded to the equivalent amounts in vinasse.

Soil used in the experiment was removed from the first 25 cm surface Red-Yellow Ultisol medium texture (more than 25% clay in the B horizon), with the chemical characteristics given by soil analysis of the Soil Laboratory from the "Luiz de Queiroz" College of Agriculture, University of São Paulo. These analysis results were used to calculate the amount of dolomite limestone added to the soil to correct it.

Each pot contained 2.5 liter capacity, to which 2 kg of soil was added (with density of approximately 1.3 kg L-1) and limestone corresponding to 0.625 g of CaCO3 and 0.625g of MgO. BIOFOM granules and fertilizer for each treatment were homogenized with the soil from the bottom half of the pot and then supplemented with soil in the upper half. After liming and fertilizing, aiming at accelerating the effect of limestone, the pots were kept at water pot capacity (CASAROLI & VAN LIER, 2008) for seven days. Soil within pots was saturated with water in a recipient until saturation by capillary action was reached, what occurred after two days. Immediately after, they were covered with plastic film to prevent evaporation and placed to drain freely, weighing the mass after a period superior to 24 hours. From the gravimetric method (GARDNER, 1986), the values of water content in the soil were obtained. Then two corn seeds were sown per pot, using the Dow-2B-710 corn variety, whose emergence occurred uniformly in three days. After 8 days from sowing, thinning was performed leaving only one plant per pot.

Pot irrigation after the incubation period was carried out daily and irrigation quantification was performed with the gravimetric method mentioned above.

At 50 days after emergence, samples were taken and results evaluated with respect to the following variables leaf area (LA), by leaf area integrator LI-Cor® model LI 3100; shoot and root dry mass (SDM and RDM), by drying in an oven with air-ventilation at 65 °C for 48 hours. Macro and micronutrients were measured in plant shoot. Thus, the dry plant material was weighed and ground in Willey type mill and sampled to quantify macro and micronutrients, as described in MALAVOLTA et al., (1997).

Differences among treatments was performed by Tukey test (significance level at 5% probability). Statistical analysis was performed using SAS 9.2 software (Statistical Analysis System).

RESULTS AND DISCUSSION

In relation to chemical fertilizer, the BIOFOM formulated presents similar particle size, but its production cost is shared with other processes such as production of sugar, ethanol and electricity. Compared to natural vinasse, the BIOFOM has no odor, has facilitated application because it is solid and grainy, and does not suffer percolation into the ground.

Vinasse can be originated from fermenting of different wort types: from molasses, from broth and mixed (broth + molasses). Vinasse from molasses has higher concentrations than broth and mixed have of the following items: soluble mineral waste, P, K, Ca, Mg, Mn, Zn and Na (Table 3).

TABLE 3 Physical-chemical analysis of the organomineral fertilizers (BIOFOM) used. 

Determinations Pure broth Molasses Mixed broth

30% TSS1 45% TSS 30% TSS 45% TSS 30% TSS 45% TSS
pH in CaCl2 (0.01 M) 6.2 5.8 6.5 6.5 6.7 6.5
Density (g.cm-3) 0.52 0.58 0.50 0.52 0.54 0.57
Humidity lost at 60-65°C (%) 4.20 3.89 3.66 3.45 3.30 3.92
Humidity lost between 65 and 110 °C (%) 4.22 3.84 4.29 4.22 5.81 4.6
Total humidity (%) 8.42 7.73 7.95 7.76 9.01 8.52
Total organic matter (combustion) (%) 46.84 43.9 46.4 43.72 44.83 39.8
Compost organic matter (%) 45.44 41.45 41.55 41.6 41.73 36.25
Organic matter resistant to composting (%) 1.40 2.45 4.85 2.12 3.10 3.55
Total carbon (organic and mineral) (%) 26.02 24.39 25.78 24.29 24.91 22.11
Organic carbon (%) 25.24 23.03 23.08 21.11 23.19 20.14
Total mineral waste (%) 44.73 48.37 45.65 48.52 46.16 51.68
Insoluble mineral waste (%) 28.55 33.74 23.56 29.84 28.77 35.83
Soluble mineral waste (%) 16.18 14.63 22.09 18.68 17.39 15.85
Total nitrogen (%) 2.81 3.82 2.56 3.33 4.53 3.84
Phosphorous (P2O5) total (%) 2.17 2.57 2.66 2.31 2.54 2.39
Potassium (K2O) total (%) 4.30 4.01 5.96 4.72 4.64 4.32
Calcium (Ca) total (%) 2.17 2.50 2.81 2.56 2.45 2.42
Magnesium (Mg) total (%) 0.51 0.53 0.6 0.59 0.51 0.48
Sulfur (S) total (%) 0.28 0.28 0.40 0.58 0.31 0.27
Ratio C/N (total C and total N) 9/1 16/1 10/1 7/1 5/1 6/1
Ratio C/N (organic C and total N) 9/1 15/1 9/1 7/1 5/1 5/1
Total copper (Cu) (mg.kg-1) 36 41 38 39 51 36
Total manganese (Mn) (mg.kg-1) 1013 1226 1322 1122 1154 1139
Total Zinc (Zn) (mg.kg-1) 167 213 224 183 208 197
Total iron (Fe) (mg.kg-1) 11665 13865 12022 11845 11738 12898
Total boron (B) (mg.kg-1) 2 2 2 2 2 2
Total sodium (Na) (mg.kg-1) 1769 1343 2693 2408 1681 1486
Hardness (kgf.cm-2) 1.28 1.19 0.96 1.43 1.54 1.44

1 TSS: total soluble solids.

For the variables in Table 4, the leaf area (LA) values had coefficient of variation of 12.47% and significant minimum deviation of 879.2 cm2 plant-1. In the dry weight of plant shoot (SDM), the results showed coefficient of variation of 7.97% and significant minimum deviation of 5.81 g plant-1, and regarding the dry weight of roots (RDM), the coefficient of variation was of 7.87% and the significant minimum deviation of 1.92 g plant-1.

TABLE 4 Leaf area (LA, cm2 plant-1), dry material mass of the corn plants aerial part (SDM, g plant-1), mass of dry material from the roots of corn plants (RDM, g plant-1). 

Treatment LA SDM RDM
1 Control 546.1 F 3.27 H 8.25 C
2 Mixed - 30-50 2781.6 CDE 14.52 BCDEF 8.72 BC
3 Mixed - 30-75 2498.8 CDE 9.92 FG 8.86 ABC
4 Mixed - 30-100 2113.6 DE 5.76 GH 8.10 C
5 Mixed - 45-50 2759.0 CDE 13.31 DEF 8.98 ABC
6 Mixed - 45-75 2752.5 CDE 12.12 EF 8.67 ABC
7 Mixed - 45-100 2361.1 DE 9.55 FG 8.50 ABC
8 Molasses - 30-50 1961.9 E 15.35 ABCDEF 10.42 A
9 Molasses - 30-75 2293.0 DE 15.83 ABCDE 9.31 ABC
10 Molasses - 30-100 2653.7 CDE 15.92 ABCDE 10.22 AB
11 Molasses - 45-50 2767.3 CDE 13.89 CDEF 9.14 ABC
12 Molasses - 45-75 2675.2 CDE 13.77 CDEF 8.39 BC
13 Molasses - 45-100 2902.5 BCD 13.26 DEF 8.33 BC
14 Pure - 30-50 2098.8 DE 14.36 BCDEF 8.91 ABC
15 Pure - 30-75 2490.3 CDE 15.30 ABCDEF 9.92 ABC
16 Pure - 30-100 2848.8 CD 15.15 ABCDEF 9.19 ABC
17 Pure - 45-50 2450.7 DE 15.32 ABCDEF 9.79 ABC
18 Pure - 45-75 2701.8 CDE 16.10 ABCDE 8.55 ABC
19 Pure - 45-100 2870.1 CD 14.94 ABCDEF 9.07 ABC
20 Mineral - 100 3771.0 AB 20.42 A 9.14 ABC
21 Mineral - 75 3891.3 A 19.51 ABC 9.64 ABC
22 Mineral - 50 3361.5 ABC 17.68 ABCDE 9.38 ABC
23 Mixed 2812.4 CDE 19.79 AB 8.66 ABC
24 Molasses 2527.8 CDE 18.72 ABCD 9.27 ABC
25 Pure 2616.3 CDE 18.36 ABCD 9.81 ABC

* Same letters indicate that the means do not differ significantly to the 5% level of significance by the Tukey test.

As for the leaf area, the three doses of mineral fertilizer (T20, T21 and T22) showed no significant differences among them, and treatments 20 and 22 showed no significant differences of molasses vinasse BIOFOM 45 at dose 100 (T13). Dose 50 of the mineral fertilizer (T22) showed no significant differences from doses 50 and 75 of mixed vinasse BIOFOM 30 and 45 (T2, T3, T5 and T6), from dose 100 of molasses BIOFOM 30 (T10) and from dose 3 of molasses BIOFOM 45 (T11, T12 and T13), from doses 75 and 100 of broth vinasse BIOFOM 30 and 45 (T15, T16, T18 and T19) and from the three concentrated vinasse at 30% total solids, with the mineral supplementation corresponding to dose 100 of the mineral fertilizer (T23, T24 and T25). For this parameter, the Control differed significantly from all other treatments.

BIOFOM performance, of molasses vinasse concentrated at 30% total solids at any dose, can be understood as satisfactory when compared to the treatment of mineral fertilizers 100 (S20). In the same way, it can be noted for BIOFOM from pure broth vinasse concentrated 30% or 45% TSS, except for T14, concentrated at 30% TSS, which has a dose of 50% of the dose of the mineral fertilizer.

For plant shoot dry material, the three doses of mineral fertilizer (T20, T21 and T22) showed no significant differences among them or from the three doses of broth vinasse BIOFOM 30 and 45 (T14 to T19), from the three doses of molasses vinasse BIOFOM 30 (T8, T9 and T10) and from the three vinasse concentrated at 30% total solids, with mineral complementation corresponding to dose 100 of the mineral fertilizer (T23, T24 and T25).

The fact that the treatments with the application of mineral fertilizer have promoted larger leaf area and dry matter mass of plant shoot shows that part of the nutrients in BIOFOM was not available until 45 days after application. This is an advantage when working in an open system, where leaching of mobile nutrients may occur. In this experiment, once it is a closed system (vessels), this loss did not occur; leading treatments in which fertilization with mineral fertilizers was made to have higher efficiency, which will certainly not occur in the field.

For root dry mass, dose 50 of molasses vinasse BIOFOM 30 (T8) only showed significant difference from molasses vinasse BIOFOM 45 at doses 75 and 100 (T12 and T13), from the mixed vinasse BIOFOM 30 at doses 50 and 100 (T2 and T4) and from the control. For this parameter, the witness only differed from treatments of mixed vinasse BIOFOM 30, at doses 100 and 50 (T8 and T10).

Table 5 presents the average values of four replicates of the main macronutrients accumulation in the shoots of maize plants.

TABLE 5 Accumulation of macronutrients (mg plant-1) in aerial part of corn plants. 

Treatments N P K Ca Mg S
1 Control 35.44 D 2.82 I 33.56 D 12.61 E 25.57 E 2.96 D
2 Mixed 30-50 195.68 C 20.54DEFGH 357.83 BC 44.55 BCD 65.15 AB 15.71 BC
3 Mixed 30-75 226.12 C 24.79 CDEFGH 369.62 BC 35.98 CDE 38.18 BCDE 14.30 BC
4 Mixed 30-100 161.47 CD 11.91 HI 236.12 CD 22.19 DE 28.34 DE 11.17 CD
5 Mixed 45-50 214.73 C 18.63 EFGHI 365.16 BC 45.00 BCD 57.03 ABC 14.94 BC
6 Mixed 45-75 236.80 C 23.98 CDEFGH 424.17 ABC 36.25 CDE 46.58 ABCDE 15.75 BC
7 Mixed 45-100 222.01 C 23.37 CDEFGH 362.87 BC 31.22 CDE 31.87 CDE 14.84 BC
8 Molasses 30-50 158.96 CD 18.00 EFGHI 348.11 BC 42.15 BCD 45.28 ABCDE 10.30 CD
9 Molasses 30-75 190.44 C 24.82 CDEFGH 540.78 AB 55.06 ABC 51.17 ABCDE 12.52 BCD
10 Molasses 30-100 213.21 C 25.98 CDEFGH 608.35 AB 55.03 ABC 51.27 ABCDE 16.95 ABC
11 Molasses 45-50 190.52 C 18.21 EFGHI 366.50 BC 47.34 BC 46.50 ABCDE 12.13 CD
12 Molasses 45-75 197.61 C 23.02 CDEFGH 531.62 ABC 49.72 ABC 49.77 ABCDE 15.14 BC
13 Molasses 45-100 231.01C 27.18 CDEFGH 418.67 ABC 51.42 ABC 42.74 ABCDE 16.91 ABC
14 Pure 30-50 131.86 CD 15.02 GHI 314.73 BCD 38.61 BCD 49.04 ABCDE 9.23 CD
15 Pure 30-75 167.44 CD 19.69 DEFGH 432.04 ABC 39.68 BCD 51.90 ABCDE 12.39 BCD
16 Pure 30-100 223.77 C 24.12 CDEFGH 378.33 BC 43.18 BCD 43.58 ABCDE 15.49 BC
17 Pure 45-50 193.29 C 17.01 FGHI 350.47 BC 36.09 CDE 55.28 ABCD 12.62 BCD
18 Pure 45-75 231.84 C 23.67 CDEFGH 448.34 ABC 38.10 BCD 58.36 ABC 13.80 BC
19 Pure 45-100 255.18 BC 29.24 CDEFG 468.91 ABC 41.07 BCD 51.69 ABCDE 17.24 ABC
20 Mineral 100 490.73 A 71.43 A 702.79 A 73.20 A 60.66 AB 26.06 A
21 Mineral 75 369.68 AB 51.91 B 613.54 AB 60.44 AB 61.77 AB 22.38 AB
22 Mineral 50 245.05 BC 35.17 CD 396.95 BC 47.13 BC 70.22 A 14.38 BC
23 Mixed 226.06 C 38.20 BC 503.61 ABC 46.50 BC 55.54 ABCD 17.69 ABC
24 Molasses 184.84 C 33.23 CDE 457.79 ABC 38.91 BCD 55.12 ABCD 13.87 BC
25 Pure 185.88 C 31.33 CDEF 442.25 ABC 48.73 BC 59.94 ABC 14.26 BC

* Same letters indicate that the means do not differ significantly at the 5% level of significance by the Tukey test.

Nitrogen (N): The results showed a coefficient of variation of 22.82% and significant minimum deviation of 132.08 mg plant-1. Dose of 100 of the mineral fertilizer (T20) was not significantly different from dose 75 (T21), nor the latter from dose 50 (T22) and from dose 100 of the broth vinasse BIOFOM 45 (T19). All other treatments of BIOFOM and concentrated and complemented vinasse did not differ significantly from T22. Mass productivity of the aerial part of the Control treatment was significantly lower than all other treatments due to the low supply of nutrients.

Phosphorus (P): The results for this nutrient showed a coefficient of variation of 22.58%, and a significant minimum deviation of 15.87 mg plant-1. Dose 100 of the mineral fertilizer (T20) showed significant difference from dose 75 (T21) and this, in turn, did not differ significantly from vinasse molasses + broth, supplemented with mineral fertilizer (T23). All BIOFOM treatments and other complemented vinasse did not differ significantly from dose 50 of the mineral fertilizer (T22), except for the treatments of broth vinasse and molasses vinasse BIOFOM 30 and 45 at dose 50 (T8, T11, T14 and T17), the molasses vinasse + broth 30 at dose 100 (T4) and the molasses vinasse + broth 45 at dose 50 (T5) which did not differ significantly from the Control. The fact that the treatments with doses 100 and 75 of the mineral fertilizer (T20 and T21) promoted greater phosphorus accumulation in plant shoot shows that part of the phosphorus present in the BIOFOM was not available until 45 days after application.

Potassium (K): The results showed a coefficient of variation of 26.82%, and a minimum significant deviation of 302.22 mg plant-1. Dose 100 of the mineral fertilizer (T20) was not significantly different from dose 75 (T21), from the three concentrated and supplemented vinasse (T23, T24 and T25) and from broth vinasse BIOFOM 45, at doses 75 and 100 (T18 and T19), from broth vinasse BIOFOM 30 at dose 75 (T15), from molasses vinasse BIOFOM 30 and 45, at doses 75 and 100 (T9, T10, T12 and T13), and from mixed vinasse BIOFOM 45, at dose 75 (T6). The control, without fertilizer application, resulted in the lowest values of K accumulation in the aerial part, not differing only from treatments Mixed 30-100 (T4) and Pure 30-50 (T14), but differing from the others.

Calcium (Ca): The results showed coefficient of variation of 22.75%, and a minimum significant deviation of 24.12 mg plant-1. Dose 100 of the mineral fertilizer (T20) was not significantly different from dose 75 (T21) and from molasses vinasse BIOFOM 30 and 45 at doses 75 and 100 (T9, T10, T12 and T13). Dose 75 of the mineral fertilizer (T21) showed a significant difference from broth vinasse BIOFOM 30 at dose 50 (T14), from mixed vinasse BIOFOM 30 and 45 at doses 75 and 100 (T3, T4, T6 and T7) and broth vinasse BIOFOM 45 at dose 50 (T17). Control did not differ only from treatments T3, T4, T6, T7 and T17. The fact that the treatments with the application of mineral fertilizer at doses 100 and 75 promoted higher calcium accumulation in plant shoot is due to the greater availability of N, P and K to the plant in the first 45 days, which did not occur in the same magnitude with plants receiving complemented vinasse and BIOFOM.

Magnesium (Mg): For Mg, the results showed a coefficient of variation of 20.86%, and a minimum significant deviation of 28.12 mg plant-1. All three doses of mineral fertilizer (T20, T21 and T22) showed no significant difference among them and against BIOFOM treatments, except the mixed vinasse 30 at dose 100 (T4), and the mixed vinasse 45 at dose 100 (T7). The control differed significantly from the three complemented vinasse (T23 to T25), from the three doses of mineral fertilizer, from broth vinasse BIOFOM 45 at doses 50 and 75 (T17 and T18) and from mixed vinasse BIOFOM 30 and 45 at dose 50 (T2 and T5).

Sulfur (S): For this parameter, the results showed a coefficient of variation of 25.64%, and a minimum significant deviation of 10.02 mg plant-1. Doses 100 and 75 of the mineral fertilizer (T20 and T21) showed no significant difference between them and the complemented mixed vinasse (T23), the broth vinasse BIOFOM 45 at dose 100 (T19) and the molasses vinasse BIOFOM 45 and 30 at dose 100 (T10 and T13). Dose 75 of the mineral fertilizer (T21) showed a significant difference from the Control and from broth vinasse BIOFOM 30 at dose 50 (T14), from molasses vinasse 45 and 30 at dose 50 (T8 and T11) and from mixed vinasse 30 at dose 100 (T4). The Control differed significantly from the three complemented vinasse (T23 to T25), from the three doses of mineral fertilizer (T20 to T22), from the broth vinasse and molasses vinasse BIOFOM 45 at doses 100 and 75 (T12, T13, T18 and T19), from the molasses and broth vinasse BIOFOM 30 at dose 100 (T10 and T16), from the mixed vinasse BIOFOM 45 at the three doses (T5 to T7) and from molasses vinasse BIOFOM + broth 30 at doses 75 and 50 (T2 and T3).

In general, it was noted that treatments T20 and T21, with the application of doses 100 and 75 of the mineral fertilizer, promoted greater accumulation of N, P and K in plant shoot, showing that part of these nutrients in the BIOFOM was not available within 45 days after application - which is an advantage when working in an open system where there is leaching of mobile nutrients in the soil. In the experiment, because it is a closed system (pots), this loss did not occur, leading treatments where the fertilization with mineral fertilizers was performed to present a slightly higher efficiency, which should not occur in the field.

For sugar cane, whose cycle is from 12 to 18 months, long enough for the rest of the N, P, K of the BIOFOM to be made available in an open system, BIOFOM behavior can be expected to be similar, or even better than those with mineral fertilizer.

Table 6 shows the experimental results regarding the accumulation of the main micronutrients within corn plant shoot.

TABLE 6 Accumulation of micronutrients (μg plant-1) in aerial part of corn plants. 

Treatment B Cu Fe Mn Zn
1 Control 77.15 B 18.87 D 402.14 E 937.57 F 11118.48 E
2 Mixed 30-50 306.94 AB 100.14 ABC 1373.92 ABCDE 9824.32 CDE 539.36 ABCD
3 Mixed 30-75 275.90 AB 87.51 BCD 1151.89 BCDE 8199.16 CDEF 408.88 CD
4 Mixed 30-100 166.46 AB 47.25 CD 787.82 DE 5455.51 EF 247.99 DE
5 Mixed 45-50 350.54 AB 83.22 BCD 1408.22 ABCD 9135.06 CDE 524.21 ABCD
6 Mixed 45-75 377.47 AB 94.32 ABC 1353.43 ABCDE 8104.59 CDEF 447.78 BCD
7 Mixed 45-100 332.81 AB 78.21 CD 940.30 CDE 6879.79 EF 349.25 CDE
8 Molasses 30-50 156.84 AB 75.81 CD 1670.96 ABCD 9345.58 CDE 480.45 ABCD
9 Molasses 30-75 353.74 AB 87.22 BCD 1645.13 ABCD 6532.62 EF 447.14 BCD
10 Molasses 30-100 404.43 AB 112.30 ABC 1719.73 ABCD 7410.00 DEF 453.77 BCD
11 Molasses 45-50 266.01 AB 73.95 CD 1419.51 ABCD 5427.56 EF 525.57 ABCD
12 Molasses 45-75 375.91 AB 89.78 ABCD 1705.98 ABCD 7681.92 DEF 520.17 ABCD
13 Molasses 45-100 222.42 AB 95.02 ABC 1463.14 ABCD 9070.85 CDE 542.96 ABCD
14 Pure 30-50 481.48 AB 71.66 CD 1567.92 ABCD 6635.32 EF 381.28 CDE
15 Pure 30-75 305.24 AB 77.13 CD 1427.05 ABCD 7774.58 DEF 450.96 BCD
16 Pure 30-100 383.57 AB 110.75 ABC 1579.58 ABCD 9525.57 CDE 455.36 BCD
17 Pure 45-50 214.13 AB 80.89 BCD 1459.13 ABCD 8904.68 CDE 422.29 BCD
18 Pure 45-75 467.17 AB 82.80 BCD 1383.64 ABCDE 10259.91 CDE 453.20 BCD
19 Pure 45-100 223.48 AB 109.58 ABC 1240.20 ABCDE 9442.37 CDE 498.91 ABCD
20 Mineral 100 511.12 AB 159.47 A 2230.22 A 17813.58 AB 775.77 A
21 Mineral 75 379.33 AB 151.14 AB 2104.15 AB 20910.64 A 710.36 AB
22 Mineral 50 473.87 AB 106.31 ABC 1846.04 ABC 15425.94 ABC 579.78 ABC
23 Compl. Mixed 447.70 AB 112.22 ABC 1905.89 ABC 14689.61 ABCD 558.89 ABC
24 Compl. Molasses 456.87 AB 91.57 ABC 1615.97 ABCD 12105.27 CDE 505.65 ABCD
25 Compl. Pure 539.51 A 112.23 ABC 1509.33 ABCD 9363.25 CDE 506.33 ABCD

* Averages in each row, followed by the same letters, do not differ significantly at the 5% level of significance by the Tukey test.

* Médias, em cada coluna, seguidas de letras iguais não diferem significativamente a 5% de probabilidade pelo teste de Tukey.

Boron (B): For this micronutrient, the results showed a coefficient of variation of 48.10%, accumulating variations of concentrations of B and dry material, and a minimum significant deviation of 442.54 μg plant-1. Control significantly differed only from the complemented broth vinasse (T25), and no other treatments differed from each other due to the high coefficient of variation of B concentrations within corn plant shoot and to the high value of the minimum significant deviation.

Copper (Cu): The results showed a coefficient of variation of 28.82%, and a minimum significant deviation of 71.61 μg plant-1. All three doses of mineral fertilizer (T20 to T22) showed no significant difference among them or against the three supplemented vinasse (T23 to T25), broth vinasse BIOFOM 30 and 45 at dose 100 (T16 and T19), of molasses vinasse 45 at doses 75 and 100 (T12 and T13), of molasses vinasse 30 at dose 100 (T10), of mixed vinasse 45 at dose 75 (T6) and of mixed vinasse 30 at dose 50 (T2). Control differed significantly from the three complemented vinasse (T23 to T25), from the three doses of mineral fertilizer, from the broth vinasse BIOFOM 30 and 45 at dose 100 (T16 and T19), from the molasses vinasse BIOFOM 30 and 45 at dose 100 (T10 and T13), from the mixed vinasse BIOFOM 45 at dose 75 (T6) and from mixed vinasse 30 at a dose 50 (T2).

Iron (Fe): For this nutrient, the results showed coefficient of variation of 25.04%, and a minimum significant deviation of 994.44 μg plant-1. All three doses of mineral fertilizer showed no significant differences among them (T20 to T22). Treatment T21 differed only from the treatment of molasses vinasse BIOFOM + broth 30 at dose 100 (T4), from the molasses vinasse BIOFOM treatment + broth 45 at dose 100 (T7) and Control. Control did not differ from treatments 2, 3, 4, 6, 7, 18 and 19.

Manganese (Mn): In the case of Mn, the results showed coefficient of variation of 29.31%, and a minimum significant deviation of 7470 μg plant-1. All three doses of mineral fertilizer showed no significant difference among them and the complemented mixed vinasse (T23). Dose 50 of the mineral fertilizer (T22) showed a significant difference from the broth vinasse BIOFOM 30 at doses 50 and 75 (T14 and T15), from molasses vinasse BIOFOM 45 at doses 50 e75 (T11 and T12) and from molasses 30 at doses 75 and 100 (T9 and T10), from mixed vinasse 30 and 45 at dose 100 (T4 and T7) and from the Control. This, in turn, did not differ significantly, in addition to those which differed from dose 50 of mineral fertilizer, from the mixed vinasse BIOFOM 30 and 45 at dose 75 (T3 and T6).

Zinc (Zn): For this parameter, the results showed coefficient of variation of 23.07%, and a minimum significant deviation of 295.34 μg plant-1. All three doses of mineral fertilizer (T20 to T22) showed no significant difference among them or from the three supplemented vinasse (T23 to T25), from broth vinasse BIOFOM 45 at dose 100 (T19), from molasses vinasse BIOFOM 45 in three doses (T11 to T13), from molasses vinasse BIOFOM 30 at dose 50 (T8), from mixed vinasse 30 and 45 at dose 50 (T2 and T5). Control did not differ significantly from the broth vinasse BIOFOM 30 at dose 50 (T14), from mixed vinasse 30 and 45 at dose 100 (T4 and T7).

Organic matter applied via BIOFOM promotes the improvement of soil physicochemical properties, cation exchange capacity and porosity, which favors the nutrient absorption and reduce losses caused by leaching (GURGEL, 2012).

After 60 days from corn planting, it was observed that the BIOFOM was attached to the roots due to its fertilizer condition, wherein the organic matter provides the gradual release of nutrients.

FIGURE 1 BIOFOM granules adhered to roots of corn plant. 

The BIOFOM reduces the generation of waste from the sugar and ethanol industry, using the residues rationally to produce organomineral fertilizers.

Thus, BIOFOM is a sustainable solution, and complies with applicable environmental laws. Ordinances, MINTER nº 323 of 1978, prohibit the release of vinasse in surface watercourses. Resolutions from CONAMA (National Environment Council), 0002 of 1984 and 0001 of 1986, determine, respectively, the study and development of standards to control effluent from ethanol distilleries and the obligation of performing EIA (Environmental Impact Studies) and RIMA (Report on Environmental Impact) for new plants or expansions of existing ones. Law nº 6134/ 1988 (art. 5) of the State of São Paulo determines that waste from activities (industrial and others) must not pollute groundwater. In this sense, waste use benefits the environment because all residue produced within sugarcane processing can be transformed into BIOFOM, minimizing the risk of groundwater and soil contamination by washing wastes.

CONCLUSIONS

Considering soil type and crop to be grown, we can conclude that BIOFOM can replace the use of mineral fertilizers, and the pure broth vinasse BIOFOM with 30% and 45% of total solids and the ones from molasses vinasse with 30% total solids achieved the same performance of the mineral fertilizers and of the three supplemented vinasse (mineral supplementation corresponding to dose 100 of the mineral fertilizer). Organomineral fertilizers (BIOFOM) from mixed vinasse with 30% and 45% total solids and the ones from molasses vinasse with 45% total solids, with adjustments in the amounts of the mineral fertilizer added, depending on the cropped plant, may have same performance as the mineral fertilizer and the three supplemented vinasse.

The use of BIOFOM, in the context of sugarcane industry, can reduce production costs, especially for the lower cost of mineral fertilizer, transportation, operations and infrastructure, given the elimination of individual application of vinasse, filter cake and ash.

The addition of mineral fertilizer enables the use of wastes from sugar and alcohol industry as a granulate organomineral fertilizer involving the concentration of vinasse, in addition to the aforementioned benefits, also provides the opportunity for reuse of evaporated water in the processes of recirculation and closing of circuits, allowing the minimization of water uptake by sugarcane agribusiness.

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1The present paper is part of the first author’s dissertation presented to the FEAGRI-UNICAMP, being a major accomplishment to obtain PhD degree in Agricultural Engineering.

Recibido: 02 de Octubre de 2012; Aprobado: 02 de Septiembre de 2014

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