A comparison of a pasture ley with a maize monoculture on the soil fertility and nutrient release in the succeeding crop |
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| Authors: | Margarida Arrobas Peltier Aguiar M Ângelo Rodrigues |
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| Institution: | 1. Mountain Research Centre, Polytechnic Institute of Bragan?a, Bragan?a, Portugalmarrobas@ipb.pt;3. Instituto Superior Politécnico do Kuanza Sul, Sumbe, Angola;4. Mountain Research Centre, Polytechnic Institute of Bragan?a, Bragan?a, Portugal |
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| Abstract: | Specialization within agriculture has been a key factor in increasing farm income. The production systems have become increasingly simple, since farmers only grow a small number of crops which have a favourable market price. However, monocultural systems require increasing use of agrochemicals leading to unsustainable environmental costs. In this work, the soil fertility of two plots in a crop rotation previously grown for 5 years as pasture or maize monoculture was evaluated. In the pasture, the upper 0–20 cm soil layer sequestered 17.4 Mg organic C ha?1 and accumulated 403 kg N ha?1 more than under maize monoculture. Analytical data from pot experiments showed that soil samples from the pasture plot released significantly more mineral N than soil samples from the maize monoculture. Maize dry matter (DM) yields in 2012 and 2013 were 15.3 and 10.0 Mg ha?1 in the pasture plot and 8.8 and 8.4 Mg ha?1 in the maize monoculture plot. Nitrogen recoveries by maize were 175.4 and 68.0 kg ha?1 in the pasture and 78.3 and 50.3 kg ha?1 in the maize monoculture plot. The pool of organic matter accumulated during the pasture phase immobilized important nutrients which benefited the succeeding crop as the organic substrate was mineralized. |
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| Keywords: | Crop rotation ley-farming monoculture Zea mays soil fertility |
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