311. Crop successions seeded in no-till and conventional systems in tilled plain areas.; Sucessao de culturas em solos de varzea implantadas nos sistemas plantio direto e convencional.

• Authors:
  • Gomes, A. da S.
  • Vernetti Junior, F. de J.
  • Schuch, L. O. B.
• Source: Revista Brasileira de Agrociencia
• Volume: 15
• Issue: 1/4
• Year: 2009
• Summary: In the state of Rio Grande do Sul, Brazil, there are 5,5 million ha of tilled plain soils that have been partly cropped with irrigated rice ( Oryza sativa L.), the remainder area lodging extensive beef cattle raising. This research was undertaken aiming chiefly to identify one or more technical solutions to the agribusiness associated with the agro-ecosystem of the "Temperate Climate region". The work was carried out at experimental area of Lowland Agricultural Research Station of Embrapa Temperate Climate (31degrees 52′S; 52degrees 21′24W), Brazil. The experiment was planned in a split-plot randomized blocks design with three replications and performed along ten years. The treatments were successive winter and spring-summer crops growing during five years, followed by two years of no-cropping and then three years of irrigated rice crop growing. The spring-summer crops were corn and soybean, besides rice; the winter crops were poaceae (Ps), fabaceae (Fs), species mixtures (Ms), turnip (T) and native grass species (NG). Seeding was performed either by no-ploughing (PD) or conventional (SC). Grain and dry-matter yields were estimated and evaluated. The evaluations were performed by analysis of variance (F and Duncan tests). The results allowed the following conclusions: (1) Ps and Fs had the highest yields; (2) corn yields were higher when its crop followed Fs species and/or Ms; (3) corn crop in tiled plains shows better performance when planted in no-plow; (4) soybean crop following Ps performed better than following Fs; (5) no-plough favors the soybean crop in tilled plains; (6) irrigated rice yields are higher succeeding the corn crop.

312. Physical properties of a Haplic Cambissol subjected to integrated crop-livestock system.; Propriedades fisicas em Cambissolo Haplico manejado sob o sistema integracao lavoura-pecuaria.

• Authors:
  • Veiga, M.
  • Pelissari, A.
  • Moraes, A.
  • Balbinot Junior, A.
  • Dieckow, J.
  • Nesi, C.
• Source: Revista de Ciencias Agroveterinarias
• Volume: 8
• Issue: 1
• Year: 2009
• Summary: Animal trampling is one of the major causes of soil compaction in areas subjected to integrated crop-livestock system. The objective of this work was to evaluate the effect of winter annual pasture grazing, in crop-livestock system, and other winter soil uses on soil compaction. The experiment was carried out from May 2006 to February 2007 at three sites of the North Plateau of Santa Catarina State, Brazil. Five winter treatments were investigated on each site: (1) intercropping with black oat+ryegrass+vetch+arrow leaf clover without grazing and nitrogen fertilization (multicropping cover); (2) the same intercropping, with grazing and 100 kg ha -1 of nitrogen, (grazing with N); (3) the same intercropping, with grazing and without nitrogen fertilization (grazing without N); (4) oil seed radish, without grazing and nitrogen fertilization (oil seed radish); and (5) natural vegetation, without grazing and nitrogen fertilization (fallow). Undisturbed cores were collected from the layers 2 to 7 cm and 10 to 15 cm, at three times: experiments implantation (May 2006), at maize sowing in succession of winter soil use (November 2006) and close to maize physiological maturity (February 2007). Soil total porosity, bulk density and soil resistance to penetration were evaluated in these samples. According to the environmental and management conditions, as well as the time of experimentation, the livestock presence in winter pastures, winter cover crops and fallow did not affect the variables related to soil compaction.

313. Performance of common bean cultivated after different soil use during the winter.; Desempenho da cultura do feijao apos diferentes formas de uso do solo no inverno.

• Authors:
  • Dieckow, J.
  • Pelissari, A.
  • Veiga, M.
  • Moraes, A.
  • Balbinot Junior, A.
  • Carvalho, P.
• Source: Ciencia Rural
• Volume: 39
• Issue: 8
• Year: 2009
• Summary: Soil use and management during the winter can affect soil physical properties, reminiscent straw and performance of the crop cultivated in succession. The effect of winter soil use on these variables, cultivating black bean ( Phaseolus vulgaris) under no tillage system in summer, was investigated. Three experiments were carried out in the North Plateau of Santa Catarina State, Brazil, during 2007/08 crop season, with five strategies of soil use during the winter: (1) multicropping with black oat+ryegrass+commom vetch+arrow leaf clover ( Trifolium vesiculosum) without grazing and N application (multicropping cover); (2) the same multicropping, with grazing and 100 kg N ha -1 application (pasture with N); (3) the same multicropping, with grazing and without N application (pasture without N); (4) oil seed radish, without grazing and N application (oil seed radish); and (5) natural vegetation, without grazing and N application (fallow). The highest straw dry mass was verified in multicropping cover, but the strategies of winter soil use did not affect significantly the soil bulk density and macroporosity. The soil use with winter annual pasture in crop-livestock system, cover crops and fallow did not affect the black bean performance in succession, under no tillage system.

314. Soluble nitrogen content in runoff water from three forms of oat and vetch sowing.; Teor de nitrogenio soluvel na agua de erosao hidrica em cultura de aveia e ervilhaca em tres formas de semeadura.

• Authors:
  • Gonzalez, A.
  • Luciano, R.
  • Bertol, I.
  • Barbosa, F.
  • Vazquez, E.
• Source: REVISTA BRASILEIRA DE CIENCIA DO SOLO
• Volume: 33
• Issue: 2
• Year: 2009
• Summary: Where nutrients are lost by water erosion, the eroded soil is impoverished and crop productivity is reduced, apart from the water contamination. Soluble N in the runoff is biologically available and contributes to eutrophication of the water and, depending on the form and content in the water, may be toxic to aquatic organisms. In order to evaluate the N content in the form of ammonium and nitrate in the runoff water, an experiment was conducted with simulated rainfall from April to November 2006, on an Inceptisol under conventional tillage. A combination of three factors was studied: crop type, sowing form and simulated rainfall test. The crops black oat ( Avena strigosa) [ Avena nuda] and common vetch ( Vicia sativa) were studied, as well as the sowing forms: mechanical, along rows in slope direction; broadcast by hand; and mechanized along contour lines; and five simulated rainfall tests, at a constant and planned intensity of 64 mm/h and rainfall duration of 1 h. The first four rainfall tests were applied during the crop cycles and the fifth on the crop residues maintained on the soil surface. Nitrogen application to oat as urea cover dressing, immediately before rainfall test 1, resulted in a higher N-NH 4+ content in the runoff water from oat than from vetch, exceeding the acceptable level for the aquatic community. The residues decomposition on the soil surface under rainfall, the content of soluble N-NO 3- in the runoff water was higher in the crops of contour sowing than of slope sowing. The contents of soluble N-NH 4+ and N-NO 3- in the runoff water decreased from the beginning to the end of the crop cycles, but increased in the rainfall test on vetch mulch, to higher values than in the treatment with oat residue.

315. Corn response in different physical conditions of soil and amount soil cover residues with or without irrigation.; Rendimento do milho em diferentes condicoes fisicas de solo e quantidade de residuo na ausencia ou na presenca de irrigacao.

• Authors:
  • Mazurana, M.
  • Debiasi, H.
  • Trein, C.
  • Levien, R.
  • Conte, O.
• Source: Ciencia Rural
• Volume: 39
• Issue: 4
• Year: 2009
• Summary: This study evaluates the effect of machine traffic, soil mobilization, soil cover by crop residues and water supply on corn under no tillage on a Paleudult. Machine traffic intensity, working depth of driller shank furrow opener for fertilizer deposition and amount of residues covering the soil surface, with and without irrigation, were evaluated. The experimental design used was split plot, with 36 plots being 18 with irrigation and 18 without irrigation. The treatments were quantities (0, 2, 4, 5, 6 and 8 Mg ha -1) of black oats ( Avena strigosa) and vetch ( Vicia sativa) residues, two driller shank depths for fertilizer deposition (6 and 12 cm) and traffic machine conditions (tractor and combine) in a triple factorial design with three replicates. Corn was sowed in 12/10/2005, using 62.000 seeds per hectare. A basal dressing of NPK 5-20-20 was applied at a rate of 400 kg ha -1. Two top dressing nitrogen applications were performed, totalizing 180 kg ha -1 of N. Corn grain yield, plant population and root dry matter were evaluated. Corn yield and plant population were influenced by presence or absence of irrigation. None of the above parameters were modified by working depth of driller shank furrow opener for fertilizer deposition. Wheel traffic conditions affected corn yield and plant population.

316. Black oat management methods to avoid its resurgence as weed plant in wheat.; Metodos de manejo de aveia preta para evitar sua ressurgencia como planta daninha em trigo.

• Authors:
  • Sattler, A.
  • Faganello, A.
  • Fontaneli, R. S.
  • Vargas, L.
• Source: Ciencia Rural
• Volume: 39
• Issue: 7
• Year: 2009
• Summary: Black oat ( Avena strigosa [ Avena nuda]), an important winter cover crop in south Brazil, is a weed problem in cool season grain crops as well as ryegrass. Two trials in a randomized complete block design were conducted in Passo Fundo, Rio Grande do Sul, Brazil, to study different oat management methods applied on black oat at anthesis and milk stages to avoid it from becoming a weed plant in wheat cropped after soyabean. The plot area was 60 m 2. Nine treatments were tested in both trials: spray herbicide; roll plus herbicide; hay harvest; silage harvest; mowing; grinding, silage; rolling; disking; and grain harvesting. The average total biomass at anthesis was 5016 kg DM/ha and at milk stage was 6050 kg DM/ha. Soyabean cropped in the summer season yield 2080 kg/ha and it was not affected by black oat treatments. During the second year, the wheat plots sprayed herbicide before planting yielded 2472 kg/ha and spike density of 355/m 2, however, plots without herbicide yielded 836 kg/ha and had 225 spikes/m 2. On black oat milk stage managements, the yield average was 1733 kg/ha and 334 spikes/m 2, on sprayed herbicide plots before planting. In opposite, the plots without herbicide, wheat plants were completely dominated by resurgent black oat plants, due to managements applied during the previous winter. Mechanical management methods applied only in black oat development stages allowed seed germination during winter crops cycle. This problem is avoided by spraying herbicide before oat anthesis, because after that any management method tested was unsuccessful to control oat after the following winter crops, so it is necessary to spray herbicide before seeding winter cash crops.

317. Modifications in the edaphic fauna during the decomposition of black oat and ray straw in a no-tillage system.; Modificacoes na fauna edafica durante a decomposicao da palhada de centeio e aveia preta, em sistema plantio direto.

• Authors:
  • Denardin, R. B. N.
  • Wildner, L. do P.
  • Coimbra, J. L. M.
  • Gatiboni, L. C.
• Source: Biotemas
• Volume: 22
• Issue: 2
• Year: 2009
• Summary: The present study was carried out with the aim of monitoring the edaphic fauna modifications during the decomposition of cover crops straw. The experiment was carried out in the 2005/2006 spring-summer season in Chapeco/SC, Brazil. The treatments were: (1) Straw of black oat ( Avena strigosa Scrheb.); (2) Straw of black oat cultivated with addition of 50 kg ha -1 of nitrogen; (3) Straw of rye ( Secale cereale L.); (4) Straw of rye cultivated with addition of 50 kg ha -1 of nitrogen; (5) Uncovered soil. The cover crops were cultivated until flowering, when they were handled with a roll-knife. Ten evaluations of the edaphic fauna were made during the straw decomposition process (from 23/09/2005 to 03/02/2006) using pitfall traps. The first sampling was taken six days before the handling of cover crops, and the others were taken at 4, 18, 32, 46, 67, 83, 98, 112 and 127 days after handling. The results showed that the evaluated edaphic fauna groups were sensitive to the remaining amount of straw covering the soil under no tillage, and that the straw decomposition induced a decrease in fauna diversity because of the relative increase of the Collembola group.

318. Physical properties of an Oxisol and crops yield under succession and rotation.; Atributos fisicos de um Latossolo Vermelho e produtividade de culturas cultivadas em sucessao e rotacao.

• Authors:
  • Albuquerque, J. A.
  • Reichert, J. M.
  • Reinert, D. J.
  • Genro Junior, S. A.
• Source: CIENCIA RURAL
• Volume: 39
• Issue: 1
• Year: 2009
• Summary: A study was conducted to evaluate the effects of crop succession and rotation on the crop yields and physical properties of an oxisol (clayey Haplortox) under no-tillage system, in Rio Grande do Sul State, Brazil. The treatments included four cropping sequences, used from 1998 to 2001: (1) succession wheat/soyabean; (2) rotation corn/oat/corn + Cajanus cajan/wheat/soyabean/wheat; (3) rotation Cajanus cajan/wheat/soyabean/wheat/soybean/oat; and (4) rotation Crotalaria juncea/wheat/soyabean/oat/corn/wheat. In October 2000 and 2001, soil samples were collected to determine the physical properties, and in all years, crop yields were measured. The oxisol under no-tillage had a high degree of compaction with the greater soil bulk density and lower macroporosity than the critical limit for clay texture. The largest limitations were observed below the layer of 0-0.03 m, because in the uppermost layer, soil mobilization by successive operations of fertilizer application and sowing increased soil porosity and reduced soil density. Thus, greater volume of pores was observed between soil saturation and field capacity, responsible for soil aeration, and between field capacity and wilting point, responsible for storage of plant available water. The use of cover crops once every three years was not efficient to reduce soil compaction. The yield of the subsequent crops was positively influenced in the rotation with Crotalaria juncea, while the other cropping systems did not differ from crop succession.

319. Parameters of soil-machine in function of the amount of cover residues and different fertilizer deposition depths in direct drilling.; Parametros solo-maquina em funcao de doses de residuos vegetais e profundidades de deposicao de adubo em semeadura direta.

• Authors:
  • Debiasi, H.
  • Trein, C.
  • Levien, R.
  • Kamimura, K.
  • Conte, O.
• Source: ENGENHARIA AGRICOLA
• Volume: 29
• Issue: 3
• Year: 2009
• Summary: The continuous and inadequate machine traffic on soils under direct drilling has been changing the soil physical and mechanical properties, influencing therefore crop productivity. The experiment was carried out at the Agricultural Research Station of the Universidade Federal do Rio Grande do Sul (Eldorado do Sul, RS, Brazil) on Typic Paleudlt. The main aim of the work was to measure coulter draft requirements and physical attributes under black oats ( Avena strigosa Schieb) and common vetch (CV) ( Vicia sativa L.) partially decomposed. The experimental design was carried out in randomized blocks, with split-split-plots and three repetitions. The main treatments were plots with different amount of residues of the winter crop (0, 1,3; 2,6; 3,2; 3,8 and 5,1 Mg ha -1), sub-plots were two working depth of the driller chisel-type furrow opener, and two traffic conditions (combine and tractor wheel traffic). The physical characteristics of the soil were influenced by the traffic tracks. The whole tractor-drill was influenced by the depths of fertilizer shanks and traffic of traffic tracks and combine.

320. Winter cover crops in no-tillage system whitout herbicides: effects on weed biomass and tomato yield.; Plantas de cobertura de inverno em sistema de plantio direto de hortalicas sem herbicidas: efeitos sobre plantas espontaneas e na producao de tomate.

• Authors:
  • Lovato, P.
  • Lana, M.
  • Fayad, J.
  • Comin, J.
  • Kieling, A.
• Source: Ciencia Rural
• Volume: 39
• Issue: 7
• Year: 2009
• Summary: To eliminate herbicide use in no-tillage tomato production, an experiment was carried out to evaluate the best combination of winter cover crops for weed control and tomato production at the Ituporanga Experimental Station in Santa Catarina, Brazil. Oat ( Avena strigosa [ Avena nuda]), vetch ( Vicia villosa) and fodder radish ( Raphanus sativus) were grown in monoculture and in mixes. The tomato cv. Marcia-EPAGRI was stake-trained and grown under fertigation. The highest values in above-ground dry biomass were obtained by oat+vetch and oat monoculture, followed by vetch+radish, oat+radish, and oat+vetch+radish. Treatments with oats had the best performances in controlling resident vegetation, while vetch was associated with the worst performances. There were no significant differences between the treatments for total yield and marketable fruit production.