Compost and phosphorus amendments for stimulating microorganisms and growth of ryegrass in a Ferralsol and a Luvisol |
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Authors: | Khalid Saifullah Khan Rainer Georg Joergensen |
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Institution: | 1. Department of Soil Biology and Plant Nutrition, University of Kassel, Nordbahnhofstra?e 1a, 37213 Witzenhausen, Germany;2. Permanent address: Department of Soil Science, PMAS‐Arid Agriculture University, Murree Road, 46300 Rawalpindi, Pakistan |
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Abstract: | A greenhouse pot experiment was carried out to investigate the effects of different P‐fertilizer application forms (triple superphosphate TSP], compost + TSP, TSP‐enriched compost) on the growth of ryegrass and the soil microbial biomass. The fertilizers were applied at equivalent doses for all nutrients to a neutral Luvisol in comparison with an acidic Ferralsol. Fertilizer application led to significantly increased contents of microbial biomass C, N, and P. Furthermore, yields of shoot C and root C, and concentrations of P, Ca, Mg, K, Fe, and Mn in shoots and roots were significantly increased. These increases always followed the order TSP < compost + TSP < TSP‐enriched compost. Sole TSP application led only to maximum concentrations of N and S. In the Ferralsol, TSP had only minimal positive effect on the P concentration of the grass shoots. The positive effect of TSP‐enriched compost, i.e., incubating TSP together with compost for 24 h, did not differ between the neutral Luvisol and the acidic Ferralsol, i.e., the effect is independent of the soil type. Consequently, soluble inorganic P fertilizer should generally be mixed into an organic fertilizer before application to soil. |
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Keywords: | P fertilization triple superphosphate compost microbial biomass grass biomass |
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