731. 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.

732. The balances application technique for balance high yield in the dry land with middle and lower yield.

• Authors:
  • Huang, W.
  • Xiao, L.
  • Wang, H.
  • Pan, G.
  • Zheng, Y.
• Source: Guizhou Agricultural Sciences
• Issue: 1
• Year: 2009
• Summary: The intercropping and interplanting between maize and potato were studied in Guizhou, China, to investigate the application rates and cultivation measures for balance high yield in the dry land with middle and lower yield. The maximum profit of the dry land with middle and lower yield in Nayong county with middle and high elevation was 1336.55 yuan/667 m 2 under the application ratio of 1:0.53:0.83 of N:P 2O:K 2O, and the comprehensive utilization rate of N, P 2O and K 2O was 33.52, 17.51 and 44.71%. The maximum profit of the dry land with middle and lower yield in Weining county with high elevation was 1349.09 yuan/667 m 2 under the application ratio of 1:0.69:1.10 of N:P 2O:K 2O, and the comprehensive utilization rate of N, P 2O and K 2O was 29.68, 10.58 and 26.80%, respectively.

733. Effects of water management patterns in spring maize cultivation on the dryland soil temperature dynamics in the Loess Plateau.

• Authors:
  • Li, S.
  • Chen, X.
  • Xu, H.
  • Liu, Y.
  • Zhu, L.
• Source: Scientia Agricultura Sinica
• Volume: 42
• Issue: 12
• Year: 2009
• Summary: Objective: According to the investigations on soil temperature dynamics in the spring maize growing season, a field experiment was conducted to examine the effects of different maize culturing practices on soil temperature dynamics and soil accumulated temperature (>10degreesC) in Loess Plateau. Hence it has a certain reference value for understanding the influence of different culturing practices on spring maize growth. Method: Shendan10 was used as the test crop. Three field water management practices, including supplementary irrigation (SI), rain-fed (RF) and plastic film mulching (FM), were adopted in spring maize fields in 2007. Maize straw mulching (SM) was added in 2008. The experiment was arranged in a randomized complete block design. Result: The results showed that the plastic film had a significant warming effect while the maize straw mulching had a cooling effect. During the course of crop growing season, soil accumulated temperature (>10degreesC) had the peak at vegetative growth stages (VE-R1), followed by growth stages (R1-R6), and reached the lowest value at seedling stage (PT-VE). Moreover, soil accumulated temperature was different in different culturing practices during the course of crop growing stages. Soil accumulated temperature was lower in the PT-VE period in plastic film mulching treatment, VE-R1 period in supplementary irrigation treatment and R1-R6 period in rain-fed treatment. The response of plastic film mulching soil temperature was most sensitive to air temperature, and the response of straw mulching soil temperature was most insensitive to the air temperature. The crop grain yield was significantly improved under both the supplementary irrigation and the film mulching treatments compared to the rain-fed treatment, with the increases of 30.0% and 18.1% in 2007, and 25.7% and 29.7% in 2008, respectively. Conclusion: It is concluded that different maize culturing practices in the Loess Plateau not only affect the soil temperature dynamic changes, but also affect the maize growth and the utilization of the soil heat resources.

734. 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.

735. 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.

736. 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.

737. Nitrate and Escherichia coli NAR analysis in tile drain effluent from a mixed tree intercrop and monocrop system.

• Authors:
  • Gordon, A. M.
  • Thevathasan, N. V.
  • Dougherty, M. C.
  • Lee, H.
  • Kort, J.
• Source: Agriculture, Ecosystems & Environment
• Volume: 131
• Issue: 1/2
• Year: 2009
• Summary: Contamination of groundwater in agricultural areas by nitrate and Escherichia coli can potentially lead to several harmful health effects for those who consume or are exposed to it. The objective of this study was to determine if trees can reduce loadings of these contaminants to the groundwater. Tile drain effluent from two adjacent agricultural systems (a mixed tree intercrop and a monocrop) was collected from April to November during 2005 and 2006 from a mini watershed area of 17,200 m 2. An area of 1100 m 2 (6.4%) in each system was subject to application of a mixture of water and a biotracer E. coli NAR, a naturally occurring strain that is resistant to naladixic acid and has been shown to be safe for introduction into the environment. The effluent was analyzed for concentrations of the biotracer and NO 3--N. The premise of this study is to determine if the safety-net hypothesis is valid in a temperate intercropping system. This hypothesis states that the incorporation of trees into agricultural systems will allow for a more efficient use of resources, since the rooting system of the trees capture nutrients that are not captured by the crop component of the system. The quantities of NO 3--N in the leachate were similar in 2005: 57.37 and 54.74 kg ha -1 leached from the monocrop and intercrop sites, respectively. However, in 2006, NO 3--N levels were significantly higher ( p

738. 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.

739. 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.

740. 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.