Fertirrigation with cattle wastewater in Tifton 85 grass and black oat: effects on soil and plants / Fertirrigação de capim-Tifton 85 e aveia preta com águas residuárias de bovinocultura: efeitos no solo e nas plantas

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

This study was conducted to evaluate the effects from the application of cattle wastewater (ARB) upon both physical and chemical properties of an Eutrophic Red Argisol and on the physiologic, nutritional and yield characteristics of the 85-Tifton grass (Cynodon spp.) and the black oat plant (Avena strigosa Schreb). The experiment was carried out in 20 drainage lysimeters under greenhouse conditions, pertaining to the Universidade Federal de Viçosa, MG. The entirely randomized experimental design was used with 5 treatments and 4 replications. The treatments was performed with four ARB application rates (25; 50; 75 and 100 kg ha-1 K) for each cropping cycle, besides a treatment with clear water and mineral fertilization. The following soil characteristics were analyzed: electric conductivity of the extract of the soil saturated paste (CEes); water-dispersed clay (ADA); sodium saturation index (ISNa); pH; cation exchange capacity (CEC); saturation by bases; total organic carbon (COT); and contents of P, K, Ca, Mg and Na. In plants, were evaluated: photosynthetic rate; transpiration rate; stomatic conductance; leaf chlorophyll content; forage productivity; plant height; leaf/stem ratio; crude protein content (PB);content of nutrients in the dry matter (P, K, Ca, Mg, Na, Zn and Cu) and nutrient removal. The cuts were performed every 50 days on average, for the 85-Tifton Grass, totalizing 3 cuts, and 82 days, the one cut for black oat. The increasing ARB application rates provided increments in the pH, CEC, bases saturation as well as in the concentrations of P, K, Ca and Mg in the soil surface layers. They did not cause salinization in the soil profile, although the percent clay dispersed in water and the concentration of the exchangeable sodium and ISNA increased, therefore indicating that the steady-state ARB application may provide risks for reduction in the permeability of the soil. According to the plant results, the use of ARB caused no stress due to the osmotic effect neither direct toxicity by the chemical elements under analysis, besides providing nutrient absorption and forage yield at levels close to the recommended ones. Therefore, this ARB can partially substitute the mineral fertilization in cropping the Tifton 85 grass and black oat. Then, the cattle wastewater use in the fertirrigation of these forages is a promising alternative, besides contributing to the improvement of the management processes of the residues from dairy cattle and the reduction of this activity costs.

ASSUNTO(S)

engenharia de agua e solo wastewater disposal on soil argila dispersa em água water-dispersed clay physiological variables variáveis fisiológicas disposição de águas residuárias no solo

ACESSO AO ARTIGO

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