Evandro Spagnollo

Leguminosas estivais intercalares como fonte de nitrogênio para o milho, no sul do Brasil

The use of legume cover crops contributes to soil conservation and would be an economical N source to maize. Since only winter legumes were evaluated in southern Brazil, this study was carried out to assess the effect of four intercropped summer species (Canavalia ensiformis, Cajanus cajan, Stizolobium niveum and Glycine sp.) on N supply and maize yield increase, in comparison with a control treatment, without legume cover crops. Cropping system effects on maize crop were evaluated under three mineral N rates (0, 60 and 120 kg ha-1), in two individual long-term trials, under reduced tillage (RT) or conventional tillage (CT), from 1993 to 1998. Both experiments were conducted on a Hapludox in the northwest of Santa Catarina State. Averaged across years, dry matter yield of legume species varied from 1.26 to 5.48 Mg ha-1, and N in aboveground phytomass from 31 to 132 kg ha-1. In comparison with the control treatment, without cover crops and mineral N, the legumes increased maize yield in a magnitude that ranged from 17 to 93 % (423 to 2256 kg ha-1) on CT, and from 12 to 43 % (281 to 1031 kg ha-1) on RT, and these increments were equivalent to those promoted by amounts of mineral N varying from 12 to > 120 kg ha-1 under CT, and from 50 to 86 kg ha-1, under RT. Besides protecting the soil, cultivation of summer legumes in a maize-legume intercrop enhances N availability and maize yield in the following season. Thus, it is an alternative N source, especially for small farms where maize is manually harvested.

Incremento de carbono e nitrogênio num latossolo pelo uso de plantas estivais para cobertura do solo

Accumulation of organic matter in soils is an important strategy to improve both soil and environmental quality. We evaluated the medium-term effect (5-yr) of four maize cropping systems [maize: M; M+Canavalia ensiformes; M+Cajanus cajan; M+Stizolobium niveum; and M+Glicine sp] on the stocks of organic carbon (OC) and total nitrogen (TN) on a southern Brazilian Oxisol under reduced tillage. The previous soil cultivation during 23-yr under conventional tillage determined a decrease on soil organic matter stocks equivalent to 50-60% of the stocks in the adjacent native forest soil. In comparison with maize system, legume based maize cropping systems resulted in accumulation rates from 0.39 to 2.23Mg ha1yr1 of OC, and from 0.15 to 0.22Mg ha1yr1 of TN. In addition to environmental benefits of carbon sequestration in soils, the increase of soil organic matter contributed to increase of the cation exchange capacity, which represents an important improvement on the quality of this low activity clay soil.

Atributos químicos de um Latossolo Vermelho após nove anos de aplicação de dejeto líquido de suínos

The objective of this study was to evaluate the pig slurry application effects on chemical attributes of a Hapludox soil managed under no-tillage system. Treatments consisted of 50, 100 and 200 m3 ha-1 per year of pig slurry application, and a control with replacement of P and K exported through harvested grains. Attributes related to soil chemical reaction, exchange complex, and nutrient contents were determined in soil samples collected in the ninth year of experimentation from 0 - 0.025, 0.025 - 0.05, 0.05 - 0.10, 0.10 - 0.20, 0.20 - 0.40 and 0.40 - 0.60 m soil depths. The continuous application of high doses of pig slurry on the Oxisol surface under no-tillage acidifies the soil and increases Al, P, Cu, and Zn contents down to 0.2-m depth, and K levels down to 0.6-m depth.

Análise econômica do uso de leguminosas estivais intercalares à cultura do milho, na ausência e na presença de adubação nitrogenada, no oeste de Santa Catarina

Legumes cover-crops represent a good alternative to supply N as well as to improve yield of commercial crops. The acceptance of this technique by growers and extension agents, however, depends on its economical advantage in relation to traditional systems. In this study, the effect of four summer legumes cover-crops (Canavalia ensiformis, Cajanus cajan, Stizolobium niveum and Glycine sp), was evaluated in association with three N rates (0, 60 and 120 kg ha-1), on the net income of corn. Two medium-term (4- and 5-yr) experiments were carried out, respectively, under conventional tillage (CT) and reduced tillage (RT), in the Northwest of Santa Catarina State, Brazil. In absence of cover-crops and mineral N, corn production gave a net income of 25 and 40 U

Atributos de solo e produtividade de feijão após diferentes formas de uso do solo no inverno, no quinto ano de experimentação

ha-1 (1 U

Produtividade, incidência de podridões de colmo e qualidade de grãos de milho cultivados sob diferentes arranjos espaciais e densidades de plantas

= 1.80 R

EFEITO DE PÓ DE BASALTO NO SOLO E EM CULTURAS ANUAIS DURANTE QUATRO SAFRAS, EM SISTEMA DE PLANTIO DIRETO1

), respectively, on CT and on RT. The use of cover-crops raised the net income from 35 to 173 U

Sistema de cultivo e doses de nitrogênio na sanidade e no rendimento do milho

ha-1 (142 a 693%) under CT, and from 32 to 82 U

Potential of carbon accumulation in no-till soils with intensive use and cover crops in Southern Brazil.

ha-1 (79 a 204%) under RT, in absence of N. When N was applied, the economic benefits of such crops were smaller, but still advantageous. Thus, cultivation of summer legumes in the inter-rows of corn, as cover-crops, has economical advantages, probably enough to off-set the higher costs of family labor involved.

Indicadores de eficiência técnica e econômica do milho cultivado em sistema plantio direto no Estado de Santa Catarina, Brasil

The objective of this study was to evaluate in the fifth year of experimentation, the effect of winter soil uses on residual straw on the soil, physical and chemical soil attributes and grain yield of common bean cultivated in succession. An experiment was carried out in the North Plateau of Santa Catarina State, Brazil, from May 2006 to April 2011. Five winter soil uses were investigated: 1) multicropping with black oat + ryegrass + common vetch without grazing (multicropping cover); 2) the same multicropping, with grazing and 100kg ha-1 of nitrogen year-1, applied during the growing period (pasture with N); 3) the same multicropping, with grazing and without nitrogen fertilization (pasture without N); 4) oil seed radish, without grazing (oil seed radish); and 5) natural vegetation, without grazing (fallow). In the fifth year of experimentation, multicropping cover treatment inputted greater straw on the soil, but it was not observed expressive differences in soil attributes among the five winter soil uses. Cover crops, annual pasture and winter fallow did not affect the grain yield of common bean cultivated in succession.