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Quality of hydroponic forage corn cultivated on different by-product substrates

Abstract

Hydroponic corn cultivation is an efficient, fast, and feasible alternative for periods of food scarcity; however, there is still little information on the qualitative and quantitative parameters of the produced biomass, especially with regard to substrates. This study aimed to evaluate the productive and qualitative aspects of hydroponic feed corn grown on different substrates with a cultivation period of 15 days. Four substrates were evaluated: 1) fermented whole açaí seeds, 2) crushed açaí seeds, 3) sugarcane bagasse, and 4) ground Tifton hay, with five replications under a randomized block design. Substrate temperature was monitored during the production period. After harvesting on day 15, roots length (RL), shoot length (SL), biomass dry matter content (BDM), dry biomass yield, forage dry mass productivity, crude protein (CP), and ash content were assessed. There was no correlation of growth period and substrate temperature. RL was not affected by substrates, BDM was lower in treatment 3, CP was not influenced, and ash content was higher in treatment 1. In general, the best development was observed in treatment 1 because of the absence of distinction regarding qualitative parameters (CP and ash) and higher granulometry of whole açaí seeds which affects mass density and substrate aeration, thus allowing higher dry biomass yield.

Keywords:
açaí seed; agroindustry by-products; animal nutrition; forage production

Resumo

O cultivo hidropônico de milho é uma alternativa eficiente, rápida e viável para períodos de escassez de alimentos; entretanto, ainda são poucas as informações sobre os parâmetros qualitativos e quantitativos da biomassa produzida, principalmente no que diz respeito aos substratos. Este trabalho teve como objetivo avaliar os aspectos produtivos e qualitativos do milho hidropônico para ração cultivado em diferentes substratos com um período de cultivo de 15 dias. Quatro substratos foram avaliados: 1) sementes de açaí inteiras fermentadas, 2) sementes de açaí trituradas, 3) bagaço de canade-açúcar e 4) feno de Tifton moído, com cinco repetições em delineamento de blocos ao acaso. A temperatura do substrato foi monitorada durante o período de produção. Após a colheita, no dia 15, foram avaliados o comprimento das raízes (RL), o comprimento da parte aérea, o teor de matéria seca da biomassa (BDM), o rendimento da biomassa seca, a produtividade da massa seca da forragem, a proteína bruta (PB) e o teor de cinzas. Não houve correlação entre período de crescimento e temperatura do substrato. O RL não foi afetado pelos substratos, o BDM foi menor no tratamento 3, o PB não foi influenciado e o teor de cinzas foi maior no tratamento 1. Em geral, o melhor desenvolvimento foi observado no tratamento 1 devido à ausência de distinção quanto aos parâmetros qualitativos (PB e cinzas) e maior granulometria das sementes inteiras de açaí que afetam a densidade de massa e aeração do substrato, permitindo maior rendimento de biomassa seca.

Palavras-chave:
caroço de açaí; coproduto da agroindústria; nutrição animal; produção de forragem

Introduction

Livestock plays an important role in global food security; however, climate change has complicated the production of primary feed for livestock. Thus, new production alternatives are essential for this sector to remain competitive, profitable, and sustainable(11 Moorby JM, Fraser MD. Review: New feeds and new feeding systems in intensive and semi-intensiveforage-fed ruminant livestock systems. Animal. 2021 Jul 24;100297.).

Hydroponic forage production refers to growing plants using a nutrient solution in a natural substrate, or even without substrate, during the initial growth period of forage plants(22 Gutiérrez SF, Camacho EC. Aplicación de abono orgánico líquido aeróbico en la producción de forrajeverde hidropónico, en dos variedades de cebada (Hordeum vulgare L.) en el Centro Experimental de Cota Cota. Apthapi. 2019;5(1):1430-40.,33 Maucieri C, Nicoletto C, Os E van, Anseeuw D, Havermaet R Van, Junge R. Hydroponic Technologies.Aquaponics Food Prod Syst [Internet]. 2019;77-110. Available from: https://link.springer.com/chapter/10.1007/978-3-030-15943-6_4
https://link.springer.com/chapter/10.100...
), and this approach may be used when forage cannot be grown conventionally due to adverse conditions(44 Naik P. Effect of seed rate on yield and proximate constituents of different parts of hydroponics maizefodder. Indian J Anim Sci. 2017 Jan 1;87:109-12.).

Hydroponic forage is a denomination given to a method of growing plants using a nutritive solution under natural substrates, or even no substrate, to the initial growth of the forage plants(55 Sambo P, Nicoletto C, Giro A, Pii Y, Valentinuzzi F, Mimmo T, et al. Hydroponic Solutions for SoillessProduction Systems: Issues and Opportunities in a Smart Agriculture Perspective. Front Plant Sci. 2019 Jul 24;0:923.). Piccolo et al.(66 Píccolo MA, Coelho FC, Gravina G do A, Marciano CR, Rangel OJP. Produção de forragem verdehidropônica de milho, utilizando substratos orgânicos e água residuária de bovinos. Rev Ceres. 2013 Aug;60(4):544-51.) observed that accumulation of nutrients from the solution along with seeds in the absence of a substrate, inducing plant death at the beginning of their development.

Using corn forage, Ndaru et al.(77 Ndaru PH, Huda AN, Marjuki, Prasetyo RD, Shofiatun U, Nuningtyas YF, et al. Providing High QualityForages with Hydroponic Fodder System. IOP Conf Ser Earth Environ Sci. 2020 Apr 1;478(1):012054.) reported forage production of 12 kg m-22 Gutiérrez SF, Camacho EC. Aplicación de abono orgánico líquido aeróbico en la producción de forrajeverde hidropónico, en dos variedades de cebada (Hordeum vulgare L.) en el Centro Experimental de Cota Cota. Apthapi. 2019;5(1):1430-40., with moderate fiber content of 10% neutral detergent fiber (NFD) and 15% crude protein (CP) after 20 days of cultivation.

Numerous by-products of agriculture or agroindustry such as bagasse and whole or crushed seeds can be used as substrates in hydroponic cultivation to improve the sustainability of production systems, reduce environmental impacts, and increase use efficiency of natural resources. However, substrates for forage hydroponic production are typically included in the final biomass of animal feed, thus, apart from providing support and nutrients to plants, they must be consumable by animals.

The use of substrates in hydroponic forage production contributes to increasing the plants’ dry mass content, thus, it may affect the nutritional value of the final product. Araújo et al.(88 Araújo J dos S, de Oliveira GF, Lima HC, da Silva JS, Santos L dos, de Souza MN, et al. Organic substrates for production of corn hydroponic forage for animal feed. Acad J Agric Res. 2018;6(2):38-41.) observed higher productivity of hydroponic feed corn on substrates with smaller particles, and Campêlo et al.(99 Campêlo JEG, Oliveira JCG de, Rocha A da S, Carvalho JF de, Moura GC, Oliveira ME de, et al. Forragemde milho hidropônico produzida com diferentes substratos. Rev Bras Zootec. 2007;36:276-81.) observed lower CP content and higher dry mass productivity using rice hull, followed by higher NDF, ADF, and ash, compared to Pennisetum grass as a substrate.

The choice of substrate depends on its ability to support and supply nutrients to plants, as well as its effect as an ingredient in animal food. Thus, the aim of this study was to evaluate the productive and qualitative aspects of hydroponic feed corn production using different substrates.

Material and methods

The study was carried out in the experimental area of the Universidade Federal Rural da Amazônia (UFRA) on the Campus of Paragominas, Pará, Brazil. The experiment was conducted for 15 days in the dry season from June to December 2019, during which forage is typically produced. The local climate is classified as Aw (the predominant climate in this region is hot and humid tropical), according to Köppen, with an average temperature of 26.6 ºC and 1.805 mm annual rainfall, and the rainy season is from December to May.

The experimental design was carried out in a randomized block design using four substrates for hydroponic corn cultivation, with five replicates. The following substrates were used: 1) fermented whole açaí seeds, 2) crushed açaí seeds, 3) sugarcane bagasse, and 4) ground Tifton hay. Seed grains were collected from a 2018/19 crop.

The grains were considered industrial-use quality, with 99.98% purity. Impurities comprised burnt, broken, and/or damaged grains and dirt. The conventional industrial management of grains and their exposure to high temperatures in the drying process requires verification of germination ability. Thus, evaluation of seed physiological quality was assessed using four replicates of 50 seeds distributed on two sheets of germitest paper which was humidified with distilled water (three times the weight of dehydrated paper); a third paper sheet was used to cover the seeds which were then placed in a transparent bag.

Seeds were placed in a B.O.D. germinator with a constant temperature of 25 ºC for four days (10), which resulted in a germination rate of 88.5%. Considering purity (P) and germination (G) rates, the cultural value (CV) was 88.5%, using the equation CV=(%P×%G)/100.

Fermentation of açaí seeds is necessary because of their high germination ability. For this, humid seeds were placed in bags and were exposed to natural irradiation for approximately 30 days, after which they were spread on the soil surface in a protected environment to dry.

Milling of açaí seeds and Tifton hay was performed using an electrical mill without a sieve. Sugarcane bagasse was obtained as an industrial by-product.

The experimental unit comprised a plot in a plane area of 1.0 × 0.5 m covered with plastic canvas. Substrates were applied in two 2-cm layers, i.e., one layer underneath and one above the seeds. Seed density was 2.5 kg m-22 Gutiérrez SF, Camacho EC. Aplicación de abono orgánico líquido aeróbico en la producción de forrajeverde hidropónico, en dos variedades de cebada (Hordeum vulgare L.) en el Centro Experimental de Cota Cota. Apthapi. 2019;5(1):1430-40. of viable pure seeds applied to experimental units over the first substrate layer which was humidified.

Fertilization was applied twice, i.e., once before seeding and once three days before harvesting, using the commercial formulas 4-14-8 and 20-0-20 diluted in water and applied at 35 g m-2.

Absorption capacity of each substrate was determined and adjusted according to Souza(1111 Souza CC de, Oliveira FA de, Silva I de F da, Amorim Neto M da S. Avaliação de métodos dedeterminação de água disponível e manejo da irrigação em terra roxa sob cultivo de algodoeiro herbáceo. Rev Bras Eng Agrícola e Ambient. 2000 Dec :4(3):338-42.), which was based on initially applying water to 60% of the retention capacity of each substrate to 5, 4, 8, and 8 L m-22 Gutiérrez SF, Camacho EC. Aplicación de abono orgánico líquido aeróbico en la producción de forrajeverde hidropónico, en dos variedades de cebada (Hordeum vulgare L.) en el Centro Experimental de Cota Cota. Apthapi. 2019;5(1):1430-40. to sugarcane bagasse, ground Tifton hay, crushed açaí seeds, and fermented whole açaí seeds. After shoot emergence, the moisture level was maintained through daily irrigation in the mornings and afternoons, according to the observed humidity conditions.

From the 3rd to 14th day of cultivation, the temperature of the cultivation substrate was evaluated using a mercury thermometer at three points of each substrate per plot at 1.00 p.m. as at this time, the highest incidence of solar radiation was observed, and the substrates were assumed to show increased temperature and high heat generation due to fermentation.

Fifteen days after seeding, the complete plants (roots and shoots) and substrate were collected for evaluation. Biomass yield and dry matter content were measured in samples collected with a sampler of 0.25 × 0.25 m in the center of each plot. The development of corn plants was evaluated using 10 units sampled at the center of each plot to measure shoot and root lengths.

Fresh biomass samples were weighed and placed in an oven with forced air circulation heated to 65 ºC for 72 h to record partial dry matter content (DM; #930.15). Dried biomass samples were ground in a mill (to 1 mm) for analysis of CP (CP; # 2001.11), according to AOAC (12), and ash content ass assessed using a muffle heated to 600 °C.

All variables were tested for normality using the Shapiro-Wilk test before further analysis at a significance level of p < 0.05, and any variable that deviated from normal distribution was transformed through the RANK procedure of SAS (SAS Inst. Inc., Cary, NC, USA). The PROC RANK statement with the NORMAL option was used to produce normalized transformed data. All data were analyzed using the MIXED procedure in SAS (SAS Inst. Inc.).

Results and discussion

The temperature of the cultivation substrates was adjusted to a negative quadratic curve, independent of the treatments (Figure 1).

Figura 1
Cultivation substrate temperatures during the experimental period.

The peak temperature of the cultivation substrates occurred on the 8th day after seeding (Figure 1). The temperature increase may be a consequence of fermentation of non-germinated seeds or of the substrate once the substrate moisture produced anaerobic microenvironments. According to Biaggioni et al.(1313 Biaggioni MAM, Lopes AB de C, Jasper SP, Berto DA, Gonçalves EV. Qualidade da silagem de grãoúmido em função da temperatura ambiente e pressão interna de armazenagem. Acta Sci Agron. 2009;31(3):377-82. A), anaerobic respiration through degradation of carbohydrate molecules leads to the release of carbonic gas and production of heat. In addition, the data did not follow the pattern of ambient temperatures, particularly during the peak phase from the 6th to the 10th day, thus suggesting substrate or grain fermentation. Although there was no interaction effect between treatments and time on cultivation substrate temperature, average temperatures differed between treatments (Table 1).

Lower substrate temperatures were observed in fermented whole açaí seeds (Table 1), with the average being 0.89 ºC lower than that of other treatments. The physical form of whole açaí seeds with large particles and rough surface possibly allowed higher air circulation and gas exchange, resulting in lower temperatures.

Treatments had no effect on root length (Table 2); the lack of an effect may be explained by the growth phase, as root development depends less on external factors during the first days of development due to nutrient reserves contained in the seeds(1414 Tonetto CJ, Pires CC, Müller L, Rocha MG da, Silva JHS da, Frescura RBM, et al. Rendimentos de cortesda carcaça, características da carne e componentes do peso vivo em cordeiros terminados em três sistemas de alimentação. Rev Bras Zootec. 2004 ;33(1):234-41.).

Table 1
Average temperatures of cultivation substrates
Table 2
Root length (RL) and shoot length (SL) of hydroponic corn plants grown on different substrates for 15 days

Shoot length of plants grown on fermented whole açaí seeds was 45.52% longer compared to plants grown on sugarcane bagasse, which was not significantly different (p = 0.0329) from plants grown on ground Tifton hay and crushed açaí seeds (Table 2). This treatment represented the largest particle size, which possibly led to higher air circulation in the root environment, facilitating increased plant growth, whereas all other substrates showed a stronger tendency to logging. According to Santos(1515 Santos MM dos, Costa RB da, Cunha PP, Seleguini A. Tecnologias para produção de mudas de rosa dodeserto (Adenium obesum). Sci J. 2015;1(3).), substrates with high porosity facilitate seedling emergence.

Sugarcane bagasse has been studied as a substrate for hydroponic forage cultivation with adequate results(1616 Chaves J da S, Leal ML de A, Alves RN, Rodrigues TG, Souza FG de, Miranda AFM, et al. Avaliação daprodutividade de milho hidropônico sobre substrato de bagaço de cana-de-açúcar. Brazilian Appl Sci Rev. 2020;4(4):2236-47.); however, it showed lower individual plant development, compared to ground Tifton hay and açaí seed treatments, although it had no effect on total forage dry matter productivity (Table 3).

Table 3
Biomass (forage + substrate) dry matter content (BDM), yield of dry biomass (YDB) and forage dry mass productivity (FDMP) of hydroponic corn grown on different substrates

Biomass dry matter content and yield can be influenced by the physicochemical characteristics of the substrates, such as density and water retention capacity, in addition to decomposition speed. Pilau et al.(1717 Pilau FG, Bonnecarrère AC, Schmidt D, Manfron PA, Santos OS, Medeiros SLP, et al. Produção hidropônica de forragem em túnel plástico. Rev Norte, Rolim Moura. 2004;7:11-119.) attributed higher dry mass of hydroponic forage cultivated on rice hull to larger amounts of the substrate used to provide the same layer thickness and lower decomposition speed as corn straw.

Total dry biomass differed between substrates; however, no effect on forage dry matter was observed (Table 3). Among several substrates evaluated to produce hydroponic corn forage(1010 Rocha RJS, Salviano AAC, Alves AA, Neiva JNM, Lopes JB, Silva LRF. Produtividade e composiçãoquímica da forragem hidropônica de milho em diferentes densidades de semeadura no substrato casca de arroz. Rev Científica produção Anim. 2014;16:25-31.), the dry matter of 85.8% from rice hull influenced the dry matter production of the produced biomass.

Considering the absence of treatment effects on forage productivity, the substrate choice must be based on dry biomass yield (Table 3), chemical and nutritional value for animal food, and production costs. However, CP content was similar among treatments (Table 4).

During early developmental stages, plants such as hydroponic corn, contain high levels of protein, thus increasing their nutritional value(1818 Assefa G, Urge M, Animut G, Assefa G. Effect of variety and seed rate on hydroponic maize fodderbiomass yield, chemical composition, and water use efficiency. Biotechnol Anim Husb. 2020;36(1):87-100.). The observed CP values (Table 4) corroborated previously reported values of hydroponic feed corn(1919 Almeida JCS, Valentim JK, Faria DJG, Noronha CMS, Velarde JMDS, Mendes JP, et al. Bromatological composition and dry matter production of corn hydroponic fodder. Acta Sci Anim Sci. 2020 Aug 19;43:e48800.), and satisfied the requirements of adult cattle(2020 Lazzarini Í, Detmann E, Paulino MF, Valadares Filho S de C, Valadares RFD, Oliveira FA, et al. Nutritional performance of cattle grazing on low-quality tropical forage supplemented with nitrogenous compounds and/or starch. Rev Bras Zootec. 2013 Sep;42(9):664-74.). Corn forage is thus superior to typical tropical forages used during the dry season.

Ash content differed between treatments (Table 4). Biomass produced with whole açaí seeds was superior to sugarcane bagasse, whereas no difference was observed between the other treatments. The higher ash content may indicate a favorable nutrient level in plants, probably explaining the increased shoot length (Table 2). Holanda(2121 Holanda JMF de A, Lazarini E, Sanches IR. Produção de matéria seca e composição bromatológica demilho e soja hidropônicos em palha de arroz e N em cobertura. Res Soc Dev. 2021;10(6):e26310615765.) found higher ash content in plants with increasing physiological maturity, which resulted in increased root growth and thus facilitated increased uptake of minerals.

Table 4
Crude protein (CP) and ash content of hydroponic corn biomass grown on different substrates

All substrates examined here supported hydroponic forage production, and apart from ground Tifton hay, all substrates were agro-industrial by-products, which is important considering sustainability. Although its quantitative performance was lower, sugarcane bagasse may also be a feasible alternative for this cultivation technique, particularly for farmers located near sugarcane production facilities.

The use of a substrate depends on the costs of logistics and handling. Treatments with açaí seeds showed higher dry biomass yield (Table 3), which thus represents an attractive alternative, mainly in Amazon areas where large açaí extraction facilities are located. This substrate has already been used for vegetable and fruit cultivation, mainly by familiar agriculture(2222 Correa BA, Parreira MC, Martins JS, Ribeiro RC, Silva EM. Reaproveitamento de resíduos orgânicosregionais agroindustriais da Amazônia Tocantina como substratos alternativos na produção de mudas de alface. Rev Bras Agropecuária Sustentável. 2019;9(1):97-104.), but it remains an otherwise unmarketable by-product with low handling and logistic effort.

Further evaluations of nutritional aspects, such as dry matter digestibility and gases emitted by ruminants (including greenhouse gases) are necessary for accurate decisions. In addition, it should be examined whether the larger particle size of açaí whole seeds may result in lower forage digestibility due to its lower specific surface area.

Biomass, which comprises forage and substrates of hydroponic corn production, was quantitatively influenced by the substrate, even though productivity and quality of forage plants were little affected. This suggests that hydroponic forage production is useful for utilization of by-products as an alternative to animal feed production. Thus, more research is required on substrate production management, use in animal feed, and economic viability to ensure a desirable cost/benefit ratio, as such methods can be applied throughout the year, regardless of climatic conditions.

Conclusion

Agroindustrial co-products as substrates showed potential for use in hydroponic feed corn production. Açaí seeds stood out among the tested substrates as it produced higher yield with regard to aerial biomass production.

Acknowledgments

The authors thank the members of the Forage Studies Team (GEF) for their assistance with the field test setup and the Cooperativa Agroindustrial Paragominense - Coopernorte.

References

  • 1
    Moorby JM, Fraser MD. Review: New feeds and new feeding systems in intensive and semi-intensiveforage-fed ruminant livestock systems. Animal. 2021 Jul 24;100297.
  • 2
    Gutiérrez SF, Camacho EC. Aplicación de abono orgánico líquido aeróbico en la producción de forrajeverde hidropónico, en dos variedades de cebada (Hordeum vulgare L.) en el Centro Experimental de Cota Cota. Apthapi. 2019;5(1):1430-40.
  • 3
    Maucieri C, Nicoletto C, Os E van, Anseeuw D, Havermaet R Van, Junge R. Hydroponic Technologies.Aquaponics Food Prod Syst [Internet]. 2019;77-110. Available from: https://link.springer.com/chapter/10.1007/978-3-030-15943-6_4
    » https://link.springer.com/chapter/10.1007/978-3-030-15943-6_4
  • 4
    Naik P. Effect of seed rate on yield and proximate constituents of different parts of hydroponics maizefodder. Indian J Anim Sci. 2017 Jan 1;87:109-12.
  • 5
    Sambo P, Nicoletto C, Giro A, Pii Y, Valentinuzzi F, Mimmo T, et al. Hydroponic Solutions for SoillessProduction Systems: Issues and Opportunities in a Smart Agriculture Perspective. Front Plant Sci. 2019 Jul 24;0:923.
  • 6
    Píccolo MA, Coelho FC, Gravina G do A, Marciano CR, Rangel OJP. Produção de forragem verdehidropônica de milho, utilizando substratos orgânicos e água residuária de bovinos. Rev Ceres. 2013 Aug;60(4):544-51.
  • 7
    Ndaru PH, Huda AN, Marjuki, Prasetyo RD, Shofiatun U, Nuningtyas YF, et al. Providing High QualityForages with Hydroponic Fodder System. IOP Conf Ser Earth Environ Sci. 2020 Apr 1;478(1):012054.
  • 8
    Araújo J dos S, de Oliveira GF, Lima HC, da Silva JS, Santos L dos, de Souza MN, et al. Organic substrates for production of corn hydroponic forage for animal feed. Acad J Agric Res. 2018;6(2):38-41.
  • 9
    Campêlo JEG, Oliveira JCG de, Rocha A da S, Carvalho JF de, Moura GC, Oliveira ME de, et al. Forragemde milho hidropônico produzida com diferentes substratos. Rev Bras Zootec. 2007;36:276-81.
  • 10
    Rocha RJS, Salviano AAC, Alves AA, Neiva JNM, Lopes JB, Silva LRF. Produtividade e composiçãoquímica da forragem hidropônica de milho em diferentes densidades de semeadura no substrato casca de arroz. Rev Científica produção Anim. 2014;16:25-31.
  • 11
    Souza CC de, Oliveira FA de, Silva I de F da, Amorim Neto M da S. Avaliação de métodos dedeterminação de água disponível e manejo da irrigação em terra roxa sob cultivo de algodoeiro herbáceo. Rev Bras Eng Agrícola e Ambient. 2000 Dec :4(3):338-42.
  • 12
    AOAC - Association of Official Analytical Chemists. Official methods of analysis of AOAC International.18th ed. William Horwitz, George W. Latimer J, editors. Vol. 4. Gaithersburg; 2011.
  • 13
    Biaggioni MAM, Lopes AB de C, Jasper SP, Berto DA, Gonçalves EV. Qualidade da silagem de grãoúmido em função da temperatura ambiente e pressão interna de armazenagem. Acta Sci Agron. 2009;31(3):377-82. A
  • 14
    Tonetto CJ, Pires CC, Müller L, Rocha MG da, Silva JHS da, Frescura RBM, et al. Rendimentos de cortesda carcaça, características da carne e componentes do peso vivo em cordeiros terminados em três sistemas de alimentação. Rev Bras Zootec. 2004 ;33(1):234-41.
  • 15
    Santos MM dos, Costa RB da, Cunha PP, Seleguini A. Tecnologias para produção de mudas de rosa dodeserto (Adenium obesum). Sci J. 2015;1(3).
  • 16
    Chaves J da S, Leal ML de A, Alves RN, Rodrigues TG, Souza FG de, Miranda AFM, et al. Avaliação daprodutividade de milho hidropônico sobre substrato de bagaço de cana-de-açúcar. Brazilian Appl Sci Rev. 2020;4(4):2236-47.
  • 17
    Pilau FG, Bonnecarrère AC, Schmidt D, Manfron PA, Santos OS, Medeiros SLP, et al. Produção hidropônica de forragem em túnel plástico. Rev Norte, Rolim Moura. 2004;7:11-119.
  • 18
    Assefa G, Urge M, Animut G, Assefa G. Effect of variety and seed rate on hydroponic maize fodderbiomass yield, chemical composition, and water use efficiency. Biotechnol Anim Husb. 2020;36(1):87-100.
  • 19
    Almeida JCS, Valentim JK, Faria DJG, Noronha CMS, Velarde JMDS, Mendes JP, et al. Bromatological composition and dry matter production of corn hydroponic fodder. Acta Sci Anim Sci. 2020 Aug 19;43:e48800.
  • 20
    Lazzarini Í, Detmann E, Paulino MF, Valadares Filho S de C, Valadares RFD, Oliveira FA, et al. Nutritional performance of cattle grazing on low-quality tropical forage supplemented with nitrogenous compounds and/or starch. Rev Bras Zootec. 2013 Sep;42(9):664-74.
  • 21
    Holanda JMF de A, Lazarini E, Sanches IR. Produção de matéria seca e composição bromatológica demilho e soja hidropônicos em palha de arroz e N em cobertura. Res Soc Dev. 2021;10(6):e26310615765.
  • 22
    Correa BA, Parreira MC, Martins JS, Ribeiro RC, Silva EM. Reaproveitamento de resíduos orgânicosregionais agroindustriais da Amazônia Tocantina como substratos alternativos na produção de mudas de alface. Rev Bras Agropecuária Sustentável. 2019;9(1):97-104.

Publication Dates

  • Publication in this collection
    14 Jan 2022
  • Date of issue
    2021

History

  • Received
    31 July 2021
  • Accepted
    03 Nov 2021
  • Published
    06 Jan 2021
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