Uso fertilizante do subproduto da agroindústria processadora de goiabas II: estado nutricional e produção de goiabas

Abstract

RESUMO -O conhecimento sobre a dinâmica dos nutrientes provenientes da aplicação de resíduos orgânicos faz-se necessário, principalmente visando sua a reciclagem, considerando que a quantidade desses materiais tem aumentado rapidamente com o tempo. Assim, objetivou-se avaliar o estado nutricional e a produção de frutos de um pomar de goiabeiras, em função da aplicação do subproduto da indústria processadora de goiabas. O delineamento empregado foi o de blocos casualizados, com cinco tratamentos e quatro repetições, sendo as doses do subproduto (moído) iguais a zero; 9;18; 27 e 36 t ha -1 (peso do material seco). Foram feitas cinco aplicações do subproduto em 2006, 2007, 2008, 2009 e 2010. Avaliou-se o estado nutricional das goiabeiras, via diagnose foliar (macro e micronutrientes), bem como a produção de frutos por seis safras consecutivas. A aplicação do subproduto da indústria processadora de goiabas promoveu alterações no estado nutricional e na produção de frutos. As doses do subproduto incrementaram os teores foliares de N, Mg e Mn da goiabeira. A produção de goiabas cresceu de forma linear em função das doses do subproduto. Os efeitos da aplicação do subproduto foram verificados primeiramente no solo, posteriormente nos teores foliares e, finalmente, na produção de frutos, ao longo das safras. Termos para indexação: Psidium guajava; Resíduo; Diagnose foliar. AGRONOMIC USE OF BY-PRODUCT OF GUAVA PROCESSING INDUSTRY -II -NUTRITIONAL STATUS AND PRODUCTIONABSTRACT -The knowledge about the dynamics of nutrients from the application of organic waste is needed, especially in order to recycle, since the quantity of these materials has increased rapidly over time. Thus, this study aimed to assess the nutritional status and yield of guava, depending on application of by-product from the guava processing industry. The experimental was a randomized block design with five treatments and four replications, the doses of by-product were equal zero, 9, 18, 27 and 36 t ha -1 (dry weight of the material). There were five applications of waste in 2006, 2007, 2008, 2009 and 2010. It was evaluated the nutritional status of guava (macronutrients and micronutrients), as well as fruit production for six consecutive years. The application of by-product in guavas processing industry promoted changes in the nutritional status and fruit production. Doses of by-product increased foliar content of N, Mg and Mn. Fruit yield increased linearly as a function of residue doses. The effects of the by-product were observed primarily in the soil, then in the leaf contents and finally in the production of fruits along the seasons.

Guava Waste to Sustain Guava (Psidium guajava) Agroecosystem: Nutrient “Balance” Concepts

“…Despite small annual variations in compositions between batches of guava waste, the differences between nutrient inputs and outputs remained linear (Figure 1 ). At maximum fruit yield of 60–61 Mg fruit ha −1 (de Souza et al, 2014b ), all nutrients but K were found to be in excess of removal through harvest, indicating potential soil accumulation of all nutrients but K. While guava waste has been classified as a slow-released N fertilizer (de Souza et al, 2011 ), indicating potential residual effects of guava waste on the following crop as was the case for manure and compost (Eghball et al, 2004 ), there was no N shortage even at low dosage. Although guava yield response was found to be linearly related to added guava waste (de Souza et al, 2014b ), a closer examination of the data showed that yield response apparently plateaued at 9 Mg ha −1 where added N was 101–118 kg N ha −1 .…”

“…Considering that waste production is 80 kg waste Mg −1 of fresh fruits, the state of São Paulo generates 5.5 × 10 9 kg of guava waste per year, most often discarded in landfills because their fertilizer value is little documented (de Souza et al, 2014a,b). In an agroecosystem approach, guava waste should be recycled to sustain plant nutrition over several guava production cycles.…”

“…Guava processing into juice and jelly generates large amounts of waste with great potential for recycling as slow-release nitrogen fertilizers (Mantovani et al, 2004 ; de Souza et al, 2011 ). Considering that waste production is 80 kg waste Mg −1 of fresh fruits, the state of São Paulo generates 5.5 × 10 9 kg of guava waste per year, most often discarded in landfills because their fertilizer value is little documented (de Souza et al, 2014a , b ). In an agroecosystem approach, guava waste should be recycled to sustain plant nutrition over several guava production cycles.…”