For premium quality transplant production, it is critical to provide balanced and complete nutrition before and after seed germination. In organic production systems, nutrient management is complex and variable, unlike in inorganic production systems that allow for precise and readily nutrient availability (Russo, 2005). Organic transplant production typically involves incorporating an organic fertilizer or amendment into the substrate. The effects of the organic fertilizers on vegetable seed germination and subsequent transplant growth are not well understood (Díaz-Pérez et al., 2008; Dufault, 1998; Hartz and Johnstone, 2006; Nair et al., 2011).
There are few studies on the use of BM and FM fertilizers for both transplant and field productions (Hadas and Kautsky, 1994; Jenkins, 2009). Tomato transplants and other vegetables have been successfully produced in peat-based substrate mixed with BM and FM at 2.2 g·kg−1 N (Gagnon and Berrouard, 1994) and with FM at 2.7 g·kg−1 N (Koller et al., 2004). Blood meal (12% to 14% N) and FM (7% to 13% N) have higher levels of N than other organic fertilizers (Hartz and Johnstone, 2006). This high N concentration makes the use of BM and FM an attractive option for organic transplant production as less fertilizer material is needed compared with other organic fertilizers.
Nitrogen mineralization is the process by which soil microorganisms transform organic N in organic fertilizers into NH4+-N. Nitrogen mineralization increases with temperature (Agehara and Warncke, 2005; Zak et al., 1999). Commonly, pH >7.5, high temperature, accumulation of phenolic-based allelopathic compounds, and poor oxygen supply (e.g., poor substrate draining due to container tray geometry) inhibit nitrifying microorganisms, resulting in higher rates of net ammonification than net nitrification (Britto and Kronzucker, 2002). Seed germination and seedling establishment can be inhibited by ammonia (Cook, 1962). Symptoms of ammonia toxicity appear when external ammonia concentration is above 0.1 to 0.5 mmol (1.7 to 8.5 ppm) (Britto and Kronzucker, 2002).
Nitrogen mineralization in BM and FM is fast (Hartz and Johnstone, 2006; Mondini et al., 2008), with the highest ammonia production occurring in the first (Agehara and Warncke, 2005; Hartz and Johnstone, 2006) and second weeks (Koller et al., 2004). Khalil et al. (2005) observed a rapid increase in ammonia production in the first 2 weeks for crop residues and chicken manure. The potential of BM as an effective organic fertilizer was supported by the large increase in available N and the enhancement of the size and activity of soil microorganisms. Blood meal and FM, however, may be detrimental to seed germination and transplant growth. Rosemary transplants had reduced root development when grown with FM (Pitchay and Díaz-Pérez, 2008; Valenzuela et al., 2001). The objective of this study was to determine the effects of application rates of BM and FM on tomato seed germination.
Agehara, S. & Warncke, D.D. 2005 Soil moisture and temperature effects on nitrogen release from organic nitrogen sources Soil Sci. Soc. Amer. J. 69 1844 1855
Allred, S.E. & Ohlrogge, A.H. 1964 Principles of nutrient uptake from fertilizer bands. VI. Germination and emergence of corn as affected by ammonia and ammonium phosphate Agron. J. 56 303 313
Bremner, J.M. & Krogmeier, M.J. 1988 Elimination of the adverse effects of urea fertilizer on seed germination, seedling growth, and early plant growth in soil Proc. Natl. Acad. Sci. USA 85 4601 4604
Díaz-Pérez, J.C., Silvoy, J., Phatak, S.C., Pitchay, D.S. & Morse, R. 2008 Organic tomato transplant production in compost-amended substrate Acta Hort. 782 241 243
Eklind, Y., Ramert, B. & Wivstad, M. 2001 Evaluation of growing media containing farmyard manure compost, household waste compost or chicken manure for the propagation of lettuce (Lactuca sativa L.) transplants Biol. Agr. Hort. 19 157 181
Ells, J.E., McSay, A.E. & Workman, S.M. 1991 Toxic effects of manure, alfalfa, and ammonia on emergence and growth of cucumber seedlings HortScience 26 380 383
Gagnon, B. & Berrouard, S. 1994 Effects of several organic fertilizers on growth of greenhouse tomato transplants Can. J. Plant Sci. 74 167 168
Hashemimajd, K., Kalbasi, M., Goichin, A. & Shariatmadari, H. 2004 Comparison of vermicompost and composts as potting media for growth of tomatoes J. Plant Nutr. 27 1107 1123
Jenkins, K. 2009 Evaluation of bat guano, blood meal, chicken manure, and feather meal as nitrogen sources for production of organic vegetable transplants. Univ. Georgia, Athens, GA, M.S. Thesis
Khalil, M.I., Houssain, M.B. & Schmidhalter, U. 2005 Carbon and nitrogen mineralization in different upland soils of the subtropics treated with organic materials Soil Biol. Biochem. 37 1507 1518
Koller, M., Alfödi, T., Siegrist, M. & Weibel, F. 2004 A comparison of plant and animal based fertiliser for the production of organic vegetable transplants Acta Hort. 631 209 215
Megie, C.A., Pearson, R.W. & Hiltbold, A.E. 1967 Toxicity of decomposing crop residues to cotton germination and seedling growth Agron. J. 59 197 199
Mondini, C., Cayuela, M.L., Sinicco, T., Sanchez-Monedero, M.A., Bertolone, E. & Bardi, L. 2008 Soil application of meat and bone meal. Short-term effects on mineralization dynamics and soil biochemical and microbiological properties Soil Biol. Biochem. 40 462 474
Nair, A., Ngouajio, M. & Biernbaum, J. 2011 Alfalfa-based organic amendment in peat-compost growing medium for organic tomato transplant production HortScience 46 253 259
Pitchay, D.S. & Díaz-Pérez, J.C. 2008 Is it possible to produce healthy organic herbal plug seedlings through different proportions of organic materials? Acta Hort. 782 215 222
Valenzuela, H.R., Goo, T. & Radovich, T. 2001 The effect of bone meal on the yield of jicama, Pachyrhizus erosus, in Oahu, Hawaii Proc. Annu. Meet. Fla. State Hort. Soc. 113 222 226
Wong, M.H., Cheung, Y.H. & Cheung, C.L. 1983 The effects of ammonia and ethylene oxide in animal manure and sewage sludge on the seed germination and root elongation of Brassica parachinensis Environ. Pollut. 30 109 123
Yang, J.A. & Lu, C.Y. 2010 Possible mechanism associated with herbicidal activity of soybean meal hydrolysate (SMH) Agr. Sci. China 9 854 860
Zak, D.R., Holmes, W.E., MacDonald, N.W. & Pregitzer, K.S. 1999 Soil temperature, matric potential, and the kinetics of microbial, respiration and nitrogen mineralization Soil Sci. Amer. J. 63 575 584