ABSTRACT
The objective of this study was to evaluate the availability of phosphorus (P) in a soil under no-tillage system after successive applications of liquid swine manure (LSM) doses in soil samples collected at different depths and to select the most appropriate chemical extractors. It was used soil with LSM applications for 19 years, using doses of 0, 25, 50, 75 and 100 m3 ha-1 and mineral fertilization (350 kg ha-1 in formulation 02-20-18), evaluated at the following depths: 0-10, 10-20 and 20-40 cm. The extractors used were Mehlich-1, Mehlich-3, Prem, Olsen, Bray-1 and Resin. Successive fertilizations with LSM, especially with 100 m3 ha-1, increase the availability of P, especially in the 0-10 cm layer, as well adding P in the deeper layers evaluated (20-40 cm). The organic P content in relation to the total P ranged from 16 to 19 %. Bray-1, Olsen and Resin extractors are more efficient in extracting P in soil under no-tillage cultivation after successive fertilizations with liquid swine manure.
ABSTRACT
Slaughterhouses generate large amounts of rumen content and its use as a fertilizer may offer an environmentally friendly strategy for its management. The effect of an organic fertilizer produced from slaughterhouse waste on the fertility of sandy and clayey soils as well as soybean yield (Glycine max L.) and corn (Zea mays L.) crops was evaluated. Field experiments were set up and five rates up to 16 t ha1 of organic fertilizer (293 kg ha1 N, 334 kg ha1 P and 27 kg ha1 K) were applied annually, before sowing in spring/summer, as well as a mineral fertilization of 300 kg ha1 in the formulation 2-20-20 for soybean and 300 kg ha1 of 12-15-15 for corn. The organic fertilizer changed soil fertility in the field experiments by increasing pH, Ca, Mg, K, P-Mehlich and P-resin. Such effects were more evident in the sandy than in the clayey soil, and the most superficial layer was affected more. The organic fertilizer rate needed to achieve maximum yield decreased for corn in both soils and for soybean in the sandy soil, although the amounts required may still be regarded as high.
Subject(s)
Composting , Organic Chemicals , Waste Management , Abattoirs , Glycine max , Zea maysABSTRACT
Slaughterhouses generate large amounts of rumen content and its use as a fertilizer may offer an environmentally friendly strategy for its management. The effect of an organic fertilizer produced from slaughterhouse waste on the fertility of sandy and clayey soils as well as soybean yield (Glycine max L.) and corn (Zea mays L.) crops was evaluated. Field experiments were set up and five rates up to 16 t ha1 of organic fertilizer (293 kg ha1 N, 334 kg ha1 P and 27 kg ha1 K) were applied annually, before sowing in spring/summer, as well as a mineral fertilization of 300 kg ha1 in the formulation 2-20-20 for soybean and 300 kg ha1 of 12-15-15 for corn. The organic fertilizer changed soil fertility in the field experiments by increasing pH, Ca, Mg, K, P-Mehlich and P-resin. Such effects were more evident in the sandy than in the clayey soil, and the most superficial layer was affected more. The organic fertilizer rate needed to achieve maximum yield decreased for corn in both soils and for soybean in the sandy soil, although the amounts required may still be regarded as high.(AU)