ABSTRACT Application of organic fertilizers of animal origin can increase organic carbon in the soil and increase its content in macroaggregates. This study aimed to evaluate carbon contents and fractions in two classes of soil aggregates in response to the application of organic and mineral fertilizers in an integrated crop-livestock system. The experiment was established in Concórdia, Santa Catarina State, in a Nitossolo Vermelho Eutroférrico típico, (Rhodic Kandiudox according to the WRB system) (0.00-0.05, 0.05-0.10, and 0.10-0.20 m), in an integrated crop-livestock, with corn and soybean in the summer, black oat and rye in the winter, shepherded by sheep. The design used was randomized blocks, with treatments in factorial design (5 × 3 + 1), with four replications, five sources of fertilizers, three rates and the control with no fertilization. Three organic fertilizers were applied: poultry litter, pig manure and compost; and two minerals fertilizers: M1 (formulated according to the composition of the pig slurry) and M2 (adjusted according to the composition of the poultry litter), combined with three applications rates, corresponding to 75, 100 and 150 % of the recommendation for the crop of interest, based on the element with greater demand. Total organic carbon (TOC), particulate (POC) and mineral-associated organic carbon (MAC) contents were determined in two classes of soil aggregates C1 (8.00 to 4.76 mm) and C2 (4.76 to 2.00 mm), in samples collected in the 2018/2020 crop season. Crop yields were determined in every season. The results were analyzed using analysis of variance to compare sources and polynomial regression analysis for fertilizer rates. The soil has high aggregate stability, even so, the use of organic and mineral fertilizers increased aggregation. The poultry litter organic fertilizer increases aggregation, forming largely aggregates with a size of 8.00-4.76 mm, and increases the contents of total fractions of soil organic carbon, providing the system with a more stabilized carbon. In the 0.00-0.05 m layer, organic fertilizers increased the content of total organic carbon. The stabilized fraction (MAC) showed a higher proportion of total soil organic carbon than particulate organic carbon (POC).

ABSTRACT The use of organic fertilizers from pig slurry and poultry litter can increase soil organic carbon and crop productivity. This study aimed to evaluate soil organic carbon fractions and corn yield after applying organic and mineral fertilizers. The experiment was conducted in the western region of Santa Catarina State, southern Brazil on a Nitossolo Vermelho Eutroférrico típico (Rhodic Kandiudox). The production system was an integrated crop-livestock using corn and soybean in the summer and black oat and rye with grazing by sheep in the winter. The experimental design was randomized blocks, with treatments in factorial 5 × 3 + 1, with four replications, five sources of fertilizers, three rates and the control with no fertilization. The treatments were three organic fertilizers: poultry litter, pig slurry and compost from pig slurry and two minerals fertilizer (M1 and M2). Mineral fertilizers were formulated from pig slurry (M1) and poultry litter (M2), with the application of three rates, which represent 75, 100 and 150 % of the recommendation for the crop, based on the element that is most demanding by the plant (K for soybeans and N for corn). Soil samples were collected at the layers of 0.00-0.05, 0.05-0.10 and 0.10-0.20 m in which fractions of total soil organic carbon (TOC), namely particulate (POC) and mineral-associated organic carbon (MAC) were determined. Corn yield was evaluated in the 2018/2019 and 2019/2020 seasons. The results were analyzed through analysis of variance to compare sources and polynomial regression analysis for fertilizer rates. The MAC fraction has a higher proportion of TOC and its contents were higher with increasing rates of organic and mineral fertilizers, mainly in the surface layer. Poultry litter and compost fertilizers increased TOC’s particulate fraction (POC), showing the highest levels at the highest fertilization recommendation rate. Organic and mineral fertilizers positively increase corn yield, and animal-derived fertilizers show that they can be an alternative for high crop yields.

ABSTRACT Use of organic fertilizers in integrated crop-livestock (iCL) systems may affect soil phosphorus fractions. This study aimed to determine phosphorus fractions in the soil under the iCL system after six years of application of organic or mineral fertilizers. The experiment was conducted on a Rhodic Kandiudox (Nitossolo Vermelho Distroférrico) in a randomized block design, using a 5 × 3 + 1 factorial scheme, with four replicates. The treatments consisted of three organic fertilizers (poultry litter, pig slurry, and compost) and two mineral fertilizers (M1, equivalent to pig slurry; and M2, equivalent to poultry litter) in interaction with three application rates, corresponding to 75, 100, and 150 % of the fertilizer recommendation for the crop of interest and a control (with no fertilizer). Soil sampling was performed in the 0.00-0.05, 0.05-0.10, and 0.10-0.20 m layers for determination of the phosphorus fractions. Successive use of organic or mineral fertilizers for six years in the iCL system considerably raises the labile and moderately labile P fractions up to the 0.20 m depth and, with less intensity, raises the non-labile fractions up to the 0.10 m depth. The soil P increase associated with fertilizer input raises soybean and corn yields, and it does not exceed the critical P limit according to local environmental legislation.

Resumo: O objetivo deste trabalho foi avaliar os efeitos de fertilizantes organominerais e minerais, em suas formas sólidas e fluidas, em solos de carga variável com elevada fertilidade construída sobre os conteúdos de nitrogênio, fósforo e potássio no solo e nas plantas, bem como nas produtividades de milho (Zea mays) e aveia-preta (Avena strigosa). Os tratamentos foram constituídos de um controle e de quatro fertilizantes - dois organominerais e dois minerais -, nas formas sólida (SO e SM) e fluida (FO e FM), aplicados em Cambissolo e Nitossolo, sob plantio direto. O uso de fertilizantes organominerais e minerais nas formas sólidas e fluidas contribui para elevar o teor de N total no solo e manter o teor de K trocável em ambos os solos e pode elevar o teor de P disponível até a profundidade de 0,6 m em Cambissolo. Esses fatores permitiram aumentar significativamente a produtividade de milho, independentemente do fertilizante, e estabelecer maior efeito residual para a forma fluida do organomineral na produção de aveia-preta no inverno, mesmo em solos sob elevada fertilidade.

Abstract: The objective of this work was to evaluate the effects of organomineral and mineral fertilizers, in their solid and fluid forms, on soils with variable charges with high fertility built up from nitrogen, phosphorus, and potassium contents in the soil and plant, as well as on corn (Zea mays) and black oat (Avena strigosa) yield. The treatments consisted of one control and four fertilizers - two organomineral and two mineral - in solid (SO, solid organomineral; and SM, solid mineral) and fluid (FO, fluid organomineral; and FM, fluid mineral) forms applied in Rhodic Kandiudox and Distrochrept soils with no-tillage. The use of organomineral or mineral fertilizers in fluid and solid forms increases total N content in the soil, maintains exchangeable K content in both soils, and may enhance available P content to the depth of 0.6 m in Distrochrept. These factors allowed significantly increasing corn yield, regardless of the fertilizer, and establishing greater residual effect for fluid organomineral fertilizer in the winter black oat yield, even in soils with high fertility.

ABSTRACT Organic fertilizers derived from poultry litter and pig slurry are alternatives to mineral fertilizers in increasing soil nutrient availability. The aim of this study was to evaluate soil response, through characterization of organic C and available N, P, and K contents, and corn yield response to increasing amounts of poultry litter, pig slurry, and mineral fertilizers in an integrated crop-livestock production system (ICL) from 2011 to 2013. The experimental design consisted of randomized blocks in a 4 × 3 + 1 factorial arrangement with four replicates. The treatments consisted of four types of fertilizer, two organic (poultry litter and pig slurry) and two mineral, balanced with the same amounts of N, P and K as the organic fertilizers, one of which corresponded to the levels in the pig slurry (M1) and the other to the levels in the poultry litter (M2) in combination with three .increasing application rates of N (100, 200, and 300 kg ha-1 N) and control without fertilizer. For two years after implementing the ICL system, the application of the different rates of N using organic (pig slurry and poultry litter) or mineral (M1 and M2) fertilizers increased corn yields and K and P availability in the soil; these results were accompanied by small changes in organic C and total N content. There are similar efficiencies between the treatments pairs (pig slurry/M1 and poultry litter/M2).

Este trabalho foi conduzido com o objetivo de verificar o efeito da fertilização com dois tipos de camas sobrepostas de suínos (CSS), à base de casca de arroz (CA) e maravalha (MA), sobre a produção de uma pastagem natural, com predomínio de Axonopus sp. e Paspalum sp., sobressemeada com leguminosas (cornichão e trevo-branco). As camas sobrepostas foram aplicadas em quantidades equivalentes a 180, 360, 540 e 720 kg/ha de P2O5, constituindo quatro níveis de cama de casca de arroz (30, 60, 90 ou 120 t/ha) e quatro níveis de cama de maravalha (20,6; 41,2; 62,2 ou 82,8 t/ha). Foram incluídos dois tratamentos-testemunha: 180 kg/ha de superfosfato triplo (SFT) e ausência de adubação (AA). A sobressemeadura das leguminosas foi realizada em maio de 2004 e, a partir de agosto de 2004, foram realizados nove cortes da pastagem, a cada seis semanas. As maiores produções de matéria seca (MS) anuais (setembro/2004 a agosto/2005) com as aplicações de cama de casca de arroz foram obtidas nos níveis 30 e 60 t/ha e, com cama de maravalha, nos níveis 62,2 e 82,8 t/ha, que resultaram em produções de MS de 8.083 e 8.276 kg/ha, superiores às obtidas com superfosfato triplo (4.091 kg MS/ha) e sem adubação (3.071 MS kg/ha). A produção de MS de trevo-branco aumentou linearmente no outono e no inverno, de acordo com os níveis de adubação com cama de maravalha, mas não variaram com a adubação com cama de casca de arroz. O efeito fertilizante varia entre os tipos de cama sobreposta, que podem influenciar a composição botânica de pastagens mistas de leguminosas-gramíneas.

This work aimed to evaluate the effect of two swine deep beddings (SDB): rice husk (CA) and sawdust coarse (MA) on the production of natural pasture. The predominant species in this pasture were Axonopus sp. and Paspalum sp. that was sod-seeded with the forage legumes birdsfoot trefoil and white clover. The SDBs were applied in amounts equivalent to 180, 360, 540, and 720 kg/ha of P2O5. In order to achieve the target P application, different levels of CA (30, 60, 90, and 120 t/ha) and MA (20.6; 41.2; 62.2; and 82.8 t/ha) were applied. Two control treatments were used: mineral fertilization (180 kg/ha of triple superphosphate, TSP) and no fertilization (AA). The legumes were sod-seeded in May/2004. After August/2004, the plants were cut every six weeks and nine cuts were performed. The highest annual (September/2004 to August/2005) dry matter (DM) production was obtained with 30 and 60 t/ha of CA or 62.2 and 82.8 t/ha of MA, with DM productivity ranging from 8,083 to 8,276 kg DM/ha. This productivity was greater than the one obtained with both TSP (4,091 kg DM/ha) and AA (3,071 kg DM/ha). The white-clover DM production increased linearly in the fall and in the winter seasons, as a function of MA and did not change with the CA rates. The results indicated that the CSS type (CA or MA) affects the fertilizing effect of these manures, influencing the production and the botanical composition of the pastures, specially the proportion of grasses and legumes.