Produção de matéria seca e composição bromatológica de milho e soja hidropônicos em diferentes substratos inertes e doses de N em cobertura
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Data
2020-12-14
Autores
Holanda, Juliana Maria Freitas de Assis
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Universidade Estadual Paulista (Unesp)
Resumo
Dentre as atividades pecuárias desenvolvidas em Rondônia, destaca-se a criação de ruminantes. Um dos maiores limitantes ao crescimento da pecuária é a degradação das pastagens, principalmente em solos de baixa fertilidade. Sendo a pastagem o principal constituinte alimentar destes animais, a baixa oferta de alimento em época de estiagem, restringe a sua produção e desenvolvimento. Desta forma, o desenvolvimento de tecnologias que permitam produzir alimentos em sistemas intensivos, com menor ocupação do solo e uso de insumos, torna-se importante. Com essa finalidade, destaca-se o cultivo hidropônico de forragem verde em substratos orgânicos. Assim, o objetivo do presente estudo foi avaliar a produção de matéria verde, produção de matéria seca e composição bromatológica de milho e soja hidropônicos, em substratos inertes e doses de N em cobertura. Foram conduzidos dois experimentos, em períodos diferentes, no Instituto Federal de Educação Ciência e Tecnologia de Rondônia, Campus Cacoal, em condições de casa de vegetação tipo estufa. O experimento 1 foi conduzido em delineamento inteiramente casualizado, em esquema fatorial 2 x 2 x 2, constituindo-se de 8 tratamentos com 4 repetições, ou seja, 2 cultivos (100 % milho e 75% milho + 25% soja), 2 substratos (casca de café e casca de arroz) e presença ou não de adubação nitrogenada em cobertura. No experimento 2, utilizou-se apenas o substrato casca de arroz e 6 tratamentos, constituídos de 3 cultivos (100% milho, 75% milho + 25% soja e 50% milho + 50% soja), na presença ou não de adubação nitrogenada em cobertura. As parcelas possuíram área útil de 1,0m x 1,0m x 0,04 m de profundidade. Para o experimento 1, foram avaliados os parâmetros teor relativo de clorofila, matéria verde e matéria seca do material (substrato + plântulas) realizadas no 15º dia após a semeadura, adicionalmente ao que foi mensurado no experimento 1, no experimento 2 avaliou-se, também, a composição bromatológica do material (substrato + plântulas). Os dados foram submetidos à análise de variância, pelo teste F e as médias comparadas entre si pelo teste de Tukey (=0,05), quando observada significância, utilizando-se o software computacional SISVAR. No experimento 1, os resultados obtidos demonstraram que, o teor relativo de clorofila nas folhas não altera em função dos substratos e uso de nitrogênio em cobertura em milho hidropônico aos 15 dias pós a semeadura. Para o experimento 2. Os teores de proteína, cinzas e extrato etéreo, aumentaram com a inclusão de 25% e 50% de soja em consórcio com o milho. O substrato casca de arroz é o mais indicado para produção de milho hidropônico e o consórcio entre milho e soja não alterou a produção de matéria verde e seca em sistema de hidroponia com substraro casca de arroz.
Among the livestock activities developed in Rondônia, the creation of ruminants stands out. One of the biggest limitations to the growth of livestock is the degradation of pastures, especially in soils with low fertility. As a pasture is the main food constituent of these animals, a low supply of food in times of drought, restricts their production and development. Thus, the development of technologies that produce food in intensive systems, with less land use and use of inputs, becomes important. This highlights the hydroponic cultivation of green forage on organic substrates. Thus, the aim of the present study was to evaluate the production of green matter, dry matter production and chemical composition of hydroponic corn and soybeans, in inert substrates and doses of N under cover. Two experiments were conducted, at different times, at the Federal Institute of Science and Technology Education of Rondônia, Campus Cacoal, under greenhouse conditions. Experiment 1 was conducted in a completely randomized design, in a 2 x 2 x 2 factorial scheme, consisting of 8 treatments with 4 replications, that is, 2 crops (100% corn and 75% corn + 25% soybean), 2 substrates (coffee husk and rice husk) and the presence or not of nitrogen fertilization in under cover. In experiment 2, only the rice husk substrate was used and 6 treatments, consisting of 3 crops (100% corn, 75% corn + 25% soybean and 50% corn + 50% soybean), with or without nitrogen fertilization in under cover. The plots had a useful area of 1.0m x 1.0m x 0.04m in depth. For experiment 1, the parameters related to chlorophyll content, green matter and dry matter of the material (substrate + seedlings) were evaluated on the 15th day after sowing, in addition to what was measured in experiment 1, in experiment 2 it was evaluated, also, the chemical composition of the material (substrate + seedlings). The data were submitted to analysis of variance, by the F test and the means compared to each other by the Tukey test ( = 0.05), when significance was observed, using the computer software SISVAR. In experiment 1, the results obtained demonstrated that the relative chlorophyll content in the leaves did not change due to the substrates and nitrogen use in under cover in hydroponic corn at 15 days after sowing. For experiment 2. The levels of protein, ash and ether extract increased with the inclusion of 25% and 50% of soybean in a consortium with corn. The levels of Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF) were not influenced by the type of intercropping and nitrogen fertilization. The substrate rice husk is the most suitable for the production of hydroponic corn and the intercropping between corn and soybean didn´t alter the production of green and dry matter in a hydroponics system rice husk substrate.
Among the livestock activities developed in Rondônia, the creation of ruminants stands out. One of the biggest limitations to the growth of livestock is the degradation of pastures, especially in soils with low fertility. As a pasture is the main food constituent of these animals, a low supply of food in times of drought, restricts their production and development. Thus, the development of technologies that produce food in intensive systems, with less land use and use of inputs, becomes important. This highlights the hydroponic cultivation of green forage on organic substrates. Thus, the aim of the present study was to evaluate the production of green matter, dry matter production and chemical composition of hydroponic corn and soybeans, in inert substrates and doses of N under cover. Two experiments were conducted, at different times, at the Federal Institute of Science and Technology Education of Rondônia, Campus Cacoal, under greenhouse conditions. Experiment 1 was conducted in a completely randomized design, in a 2 x 2 x 2 factorial scheme, consisting of 8 treatments with 4 replications, that is, 2 crops (100% corn and 75% corn + 25% soybean), 2 substrates (coffee husk and rice husk) and the presence or not of nitrogen fertilization in under cover. In experiment 2, only the rice husk substrate was used and 6 treatments, consisting of 3 crops (100% corn, 75% corn + 25% soybean and 50% corn + 50% soybean), with or without nitrogen fertilization in under cover. The plots had a useful area of 1.0m x 1.0m x 0.04m in depth. For experiment 1, the parameters related to chlorophyll content, green matter and dry matter of the material (substrate + seedlings) were evaluated on the 15th day after sowing, in addition to what was measured in experiment 1, in experiment 2 it was evaluated, also, the chemical composition of the material (substrate + seedlings). The data were submitted to analysis of variance, by the F test and the means compared to each other by the Tukey test ( = 0.05), when significance was observed, using the computer software SISVAR. In experiment 1, the results obtained demonstrated that the relative chlorophyll content in the leaves did not change due to the substrates and nitrogen use in under cover in hydroponic corn at 15 days after sowing. For experiment 2. The levels of protein, ash and ether extract increased with the inclusion of 25% and 50% of soybean in a consortium with corn. The levels of Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF) were not influenced by the type of intercropping and nitrogen fertilization. The substrate rice husk is the most suitable for the production of hydroponic corn and the intercropping between corn and soybean didn´t alter the production of green and dry matter in a hydroponics system rice husk substrate.
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Palavras-chave
Adubação nitrogenada, Casca de arroz, Proteína, Hidroponia, Rondônia, Nitrogen fertilization, Rice husk, Protein, Hydroponics