Effects of Swine Lagoon Effluent Relative to Commercial Fertilizer Applications on Warm‐Season Forage Nutritive Value

Abstract

Sollenberger et al., 1989;Rusland et al., 1988). Inconsistent results have been reported on the effects of animal Two field experiments were conducted to evaluate the effects of waste on forage nutritive value, including CP, fiber concomparable rates of swine lagoon effluent and commercial fertilizer at different harvest dates on dry matter yield and nutritive value of tents, and digestibility. For example, Min et al. (2002) bermudagrass (Cynodon dactylon L.) grown on an acid Vaiden silty reported that application of dairy slurry to forage clay (very fine, montmorillonitic, thermic, Vertic Hapludalf) and johngrasses at rates of 410, 690, 830, and 970 kg N ha Ϫ1 songrass (Sorghum halepense L.) grown on an alkaline Okolona silty increased CP concentration compared with the control clay (fine, montmorillonitic, therimic, Typic Chromudert). At each treatment, but ADF and NDF were not affected. In site, a randomized complete block design with a factorial arrangement another study, Harvey et al. (1996) reported that CP of treatments replicated four times was used. Treatments were multiconcentration of bermudagrass increased only slightly ple effluent irrigations resulting in four N rates from 0 to 665 kg N when N rate from swine effluent application was inha Ϫ1 yr Ϫ1 . In each block, commercial fertilizer (N, P, and K) treatments creased from 456 to 873 kg ha Ϫ1 . Johnson et al. (2001) were applied to additional plots at rates equivalent to swine effluent reported that NDF and ADF concentration of bermurates. Total dry matter yield and crude protein (CP) for bermudagrass and johnsongrass reached a plateau with application of approximately dagrass increased quadratically with increasing N fertil-450 kg N ha Ϫ1 from either swine effluent or commercial fertilizer. ization, but an inverse relationship was observed for Neutral detergent fiber (NDF) and acid detergent fiber (ADF) peaked grass digestibility. Other researchers reported that inat the low fertilization rate and then declined with increasing effluent creased N fertilization had little to no effect on NDF and commercial fertilizer rates. An inverse relationship was obtained concentrations in timothygrass [Setaria sphacelata (Schufor in vitro true digestibility (IVTD) in response to fertilization rate mach.) Stapf & C.E. Hubb.] and bermudagrass, respecfor both grasses. Forage dry matter, CP, NDF, and ADF levels peakedtively (Anderson et al., 1993; Rogers et al., 1996). in the July harvest and then declined, but forage IVTD level declined Nitrogen is the primary element on which waste appliin July harvest. Only in July 1996, forage NO 3 -N concentration was cation rates have been based. Concentrations of NO 3 -N lower for swine effluent than commercial fertilizer. Swine effluent in forages may accumulate and reach toxic levels if aniand commercial fertilizer had similar effects on forage dry matter yield and nutritive value.

Resposta de pastagens perenes à adubação com chorume suíno: cultivar Tifton 85

“…no outono em resposta à diminuição do fotoperíodo e da intensidade luminosa. Do mesmo modo, Adeli et al (2005) não obtiveram resposta da grama-bermuda à adubação com chorume suíno no final da estação de crescimento e enfatizaram o maior risco de Figura 5 -Produção total de massa seca (MS) de capim-tifton 85 adubado com quatro doses de chorume suíno.…”

“…Sem a aplicação de chorume suíno, os teores de PB não variaram ao longo da estação de crescimento, com amplitude de um ponto percentual, ao passo que, sob efeito do chorume suíno, a amplitude foi de 2,5 pontos percentuais. Adeli et al (2005) obtiveram entre 14,8 e 18,3% de PB em grama-bermuda adubada com chorume suíno em doses equivalentes a 115 e 665 kg de N/ha/ano, respectivamente. Ressalta-se que, nesse caso, o intervalo de cortes foi de quatro semanas, enquanto neste trabalho, foi de seis semanas, o que seguramente induziu à redução no teor de PB.…”

“…Os resultados foram similares aos estimados por Adeli et al (2005) e Alvim et al (1998). O teor de FDN, no entanto, não foi afetado pela adubação e variou com a data de corte (Tabela 2).…”

“…Rogers et al (1996) também não verificaram efeito do chorume suíno no teor de FDN de grama-bermuda. Adeli et al (2005), no entanto, estimaram redução de 56,8 e 53% nesse componente sob aplicação de 115 e 665 kg N/ha/ano na forma de chorume suíno.…”

“…Em grama-bermuda fertilizada com efluentes de dejetos de suínos, Rogers et al (1996) observaram que a concentração de proteína bruta aumentou com a aplicação de chorume suíno em dose de nitrogênio equivalente a 846 kg/ha. Adeli et al (2005) Os cortes foram realizados com roçadeira costal a 10 cm da superfície do solo. Antes de cada corte, mediu-se a altura da pastagem e, em seguida, demarcou-se uma área de 1 m 2 (0,5 × 2 m) no centro da parcela, para coleta, pesagem da massa verde e retirada de subamostras de aproximadamente 500 g. As parcelas foram, então, roçadas e o restante do material foi retirado com auxílio de ancinhos.…”