Inter-row Management Research Articles

Influência do manejo da entrelinha do pomar na produtividade da laranjeira-'Pera'

O manejo das entrelinhas dos pomares de citros tem sofrido grandes alterações nos últimos anos. Dessa forma, este trabalho teve por objetivo avaliar influência da adubação verde de inverno e o uso de roçadoras laterais, na produção da laranjeira-'Pera'[Citrus sinensis (L.) Osbeck]. O ensaio foi conduzido em duas safras (2007/2008 e 2008/2009), em esquema de parcela subdividida, onde, nas parcelas, semearam-se três espécies de inverno (aveia-preta, tremoço e nabo forrageiro) e nas subparcelas utilizaram-se dois tipos de roçadoras laterais (convencional e "ecológica"). Vegetação espontânea e herbicida (glyphosate) em área total foram tratamentos de referência. No mês de julho (2007 e 2008), quantificaram-se a massa verde e a seca das vegetações intercalares e da projeção da copa, após roçagem. Para o cálculo da produção da laranjeira-'Pera', colheram-se os frutos das diferentes parcelas, efetuando-se as pesagens e, posteriormente, obtendo-se a eficiência de produção. Os tratamentos com adubo verde proporcionaram maior produção de massa verde e seca, e a utilização da roçadora "ecológica" lançou quantidade de material vegetal significativamente superior sob a copa das plantas de laranjeira-'Pera'. Nas duas safras, maior produção e eficiência de produção de frutos foi observada nas parcelas com uso da roçadora "ecológica". Quanto aos adubos verdes de inverno, apenas o tremoço incrementou a eficiência de produção em 2009. Conclui-se que o uso de roçadora "ecológica" incrementa a produção de laranjeira-'Pera'.

Establishment of Wild Roses for Commercial Rose Hip Production in Atlantic Canada

ABSTRACT Rose species of the genus Rosa are found growing wild throughout the Atlantic Provinces of Canada in a multitude of different habitats. Rose hips, the marketable product from these rose species, are a rich natural source of bioactive compounds useful in the pharmaceutical industry. In 2004, a wild rose field experiment was established using planting stock propagated from numerous wild rose (Rosa virginiana ×carolina) isolate accessions collected from populations throughout Prince Edward Island. The objective of this study was to investigate the effects of several field management practices on the establishment of a commercial rose hip plantation in Atlantic Canada. Treatments were applied at planting and included three in-row mulch (none, bark, and straw) treatments, three in-row fertility (none, compost, and fertilizer) treatments, and two interrow management (tilled and sod) treatments. Mulching increased nutrient uptake of N and P and increased plant growth. Fertilizer increased plant growth and yield of rose hips compared to no fertilizer or compost treatments. Tilled interrow treatment increased in shoot lengths, diameters, and plant spreads compared to interrow sod. This study indicates that during the early establishment years of a rose hip plantation, wild roses grow best with the use of mulch, fertilizer, and tillage between the rows.

Produção de laranja 'Pêra' em sistemas de preparo de solo e manejo nas entrelinhas

O preparo convencional do solo utilizado na implantação de pomares cítricos com base na remoção da cobertura vegetal e no revolvimento do solo em área total, assim como o manejo de pomares com eliminação da cobertura vegetal das entrelinhas, têm causado erosão e redução da fertilidade dos solos, com reflexos negativos sobre as plantas cítricas e o ambiente. O objetivo deste estudo foi avaliar sistemas de manejo que contribuam para controle da erosão e melhoria da fertilidade de Argissolos originados do arenito Caiuá, cultivados com citros no noroeste do Paraná. Foram avaliados dois sistemas de preparo do solo: convencional (PC), em área total, e preparo em faixas (PF), de 2 m de largura, com diferentes formas de manejo nas entrelinhas. O estudo foi realizado em um pomar de laranja 'Pêra' (Citrus sinensis) enxertada em limoeiro 'Cravo' (Citrus limonia), em um Argissolo Vermelho distrófico latossólico. O experimento foi implantado em área ocupada por pastagem (Brachiaria humidicola), em agosto de 1993, no espaçamento de 7 x 4 m, em delineamento de blocos ao acaso, com três repetições e seis tratamentos, sendo: (1) PC e cultivo intercalar com abacaxi, sucedido por controle da vegetação espontânea com herbicida pós-emergente; (2) PC e cobertura vegetal com a leguminosa Calopogonium mucronoides; (3) PC e cobertura vegetal com a leguminosa perene amendoim forrageiro Arachis pintoi; (4) PC e cobertura vegetal com gramínea mato-grosso ou batatais Paspalum notatum; (5) PC e cobertura com vegetação espontânea da gramínea Brachiaria humidicola; e (6) PF e manutenção da gramínea (pastagem) remanescente (Brachiaria humidicola). De 1996 a 2005, foram avaliadas a composição química do solo e das folhas e a produção de frutos. No solo, foram observados incrementos significativos no teor de C orgânico (CO) nos tratamentos 4 e 6, em relação aos tratamentos 1 e 3. Não houve diferenças significativas entre os tratamentos para produção acumulada de frutos nas safras de 1996 a 2005. O preparo de solo em faixas, com manutenção de gramínea remanescente nas entrelinhas, mostrou-se apropriado para implantação dos pomares. As plantas de cobertura permanente utilizadas nas entrelinhas do pomar não comprometeram a produção de laranja, sendo importantes para melhoria da fertilidade do solo. As gramíneas foram mais indicadas que as leguminosas como cobertura vegetal nas entrelinhas do pomar.

Field Measurement of Soil Surface Chemical Transport Properties for Comparison of Management Zones

Management of chemicals in soil is important, yet the complexity of field soils limits prediction of management effects on transport. To date, few methods have been available for field measurement of chemical transport properties, but a recently developed dripper–time domain reflectometry technique allows rapid collection of data for determining these properties. The objective of this work was to apply this technique for comparison of chemical transport properties for different soil management zones. Experiments were conducted comparing four interrow management zones: no‐till nontrafficked, no‐till trafficked, chisel plow nontrafficked, and chisel plow trafficked. Drip emitters were positioned at 12 locations in each zone and used to apply water followed by a step input of CaCl2 tracer solution. Breakthrough curves were measured via electrical conductivity with time domain reflectometry probes. The mobile–immobile model was fit to the breakthrough curves to determine chemical transport properties. Mean chemical transport properties were 0.34, 0.11 h−1, 10 cm h−1, 164 cm2 h−1, and 5 cm, for the immobile water fraction, mass exchange coefficient, average pore‐water velocity, mobile dispersion coefficient, and dispersivity, respectively. All five properties showed significant differences between management zones. Differences in mass exchange and mobile dispersion coefficients coincided with differences in tillage, while differences in mean pore water velocities coincided with differences in traffic. The immobile water fraction was largest for the no‐till nontrafficked zone. These results represent one of very few reports for field measurement of chemical transport properties and the first application of this approach for comparison of chemical transport properties across management zones.

Weed community structure of mandarin orchards under conventional and integrated management in northern Spain

Abstract Mandarin orchards under conventional and integrated production (IP) practices were surveyed in the area around the delta of the Ebro River (Spain). The floristic and functional structures were evaluated to compare weed communities and to determine the relationship between community structure, mandarin orchard characteristics and type of management. The alpha diversity observed was 12.3 (S.D. 5.84) and 18.0 (S.D. 5.50) for conventional and IP orchards, respectively, and gamma diversity was 77 for conventional and 96 for IP agricultural practices. Differences were found in overall inter-row vegetation cover (11.3% conventional, 90.4% IP). Analyses of variance and mean comparison tests revealed no differences in any of the functional traits considered between the two types of management. All the multivariate methods of analysis employed revealed that the weed community composition was related to the inter-row management system. Mowing orchard inter-rows led to a successional trajectory from typically agrestal weed communities to ruderal vegetation, giving rise to high richness and also high cover.

An evaluation of estimating and indexing methods to simplify the determination of management treatment effects on raspberry yields

The effectiveness of using several proposals to estimate or index yield and size of raspberries as an alternative to picking berries as they ripen was examined in two field plot trials over two seasons at two locations in south coast British Columbia. The evaluation included examination of general correlations of the proposed estimate and index values with fresh picked yield, comparison of the significant nutrient and inter-row management treatment effects on proposed method values with effects on fresh picked yield values, influence of individual cane variability to distinguish significant treatment effects, and the effect of N on plant components used to derive the estimate and index method. Correlation coefficients for all yield estimate and index method values with fresh picked yields were generally good. Crop management treatment effects determined by the estimate and index values, however, were not the same as determined by harvesting the berries as they ripened. This showed that the estimate and index method values were biased relative to picked yield. Cane-to-cane variability within individual treatment plots was sufficiently large that differences between treatments had to be greater than 10 to 15% to be significant at P < 0.05 when five canes were randomly sampled for index component measurements to represent the plants in the plot. The five canes sampled for each plot were 5 to 10% of all the floricanes in the plots of this study. The concentration and biomass N measurements that were possible on the floricane components that were sampled for the index methods showed that management treatments of the two trials of the study could have influenced berry development, and hence contributed to the bias of the estimate and index method values relative to fresh picked yield. Although the estimate and index methods were generally quite well correlated with fresh picked yield, caution is advised when they are used directly as alternatives to fresh picking to evaluate crop management treatment effects on berry yield. Further knowledge about the physiological changes that occur during berry ripening may provide opportunities to improve the estimate and index measurements. Key words: Raspberry, Rubus idaeus L., yield estimate, yield index, nutrient effects, nitrogen effects

Vegetation management in farm forestry: a comparison of alternative methods of inter-row management

Forestry Commission and ADAS experiments on the inter-row management of vegetation within wide spaced (3 m between rows) new farm woodlands are described. Strip weeding with mowing proved to be a cost effective method of establishing new woods on fertile lowland former agricultural sites. Sowing kale was also effective, and provided game cover early in a woodland's life. Sowing of a grass-wild flower mix inter-row enhanced diversity, but can be expensive, and seeded species need to be chosen carefully. Maintaining completely weed-free conditions maximized tree growth, but was costly and impractical. However, maintaining around 90 per cent weed-free conditions can be achieved relatively cheaply, although the potential for leaching and soil erosion may be increased. Carrying out no vegetation management significantly reduced tree growth and survival, and is not recommended. Planting trees at closer spacings (2 x 2 m or less) may be a quicker and more reliable means of establishing a woodland environment, within which other objectives can be achieved, if necessary through carrying out an early thinning or respacing regime.

Effect of ground covers and tillage between raspberry rows on selected soil physical and chemical parameters and crop response

The use of inter-row ground covers has been suggested to reduce soil degradation in raspberry (Rubus idaeus L.) production. The effect after 6 yr of consistent inter-row management of ground covers or roto-tillage in raspberry on soil wet aggregate stability (WAS), bulk density, organic C and total N, and mineralizable nitrogen in the Fraser Valley of British Columbia was studied. Management treatments included no cover crop or cover crops of barley (Hordeum vulgare L.), sheep's fescue (Festuca ovina L.), perennial ryegrass (Lolium perenne L.), and white clover (Trifolium repens L.). A general pattern of perennial grasses > legume and barley > control was observed for soil WAS. Some quantitative and qualitative differences in the organic component of the soil profile to 30 cm were detected among management treatments. The differences were not statistically strong because the changes were small relative to the large pool present, but were relatively consistent overall. The white clover treatment tended to have more organic carbon, particularly in the subsurface, than the other treatments. The four treatments that included inter-row vegetation tended to have a greater amount of total and mineralizable N than the clean-tilled control. Crop vigour, as indicated by cane diameter, was reduced by the perennial grasses, but the inter-row management had only limited effects on berry yield. White clover appears to provide the best compromise between improving soil quality and minimizing competition with the berry crop. Key words: Wet aggregate stability, barley, sheep's fescue, perennial ryegrass, white clover

Root Development and Growth Response of Corn Following Mulching, Cultivation, or Interrow Compaction1

AbstractField studies were conducted to determine the effect of interrow management on root growth and rooting pattern in corn (Zea mays L.) and to relate these with changes in soil environment. Four cultural treatments, 1) control 2) 5‐cm deep postplanting cultivation, 3) 2‐cm thick straw mulch, and 4) interrow compaction, were established on sandy loam and loamy sand soils during 1970 and 1971. Straw mulch and cultivation enhanced root growth in the upper 15 cm of soil and increased the lateral spread of roots both years. The mulch treatment had less roots than the control below 15 cm. The cultivated plants had more symmetric root distribution. Interrow compaction inhibited lateral spread of roots in the surface layers and caused downward growth of roots. At the 5‐cm depth straw mulch reduced the maximum soil temperature by 2.6 C in 1970 and 2.3 to 6.3 C in 1971. Greater lateral spread and enhanced root growth in the surface layers of mulched plots were associated with reduction of soil temperature and reduction of moisture losses and resulted in better plant growth and higher yield.