19862015
  • Authors:
    • Conte, O.
    • Levien, R.
    • Trein, C.
    • Cepik, C.
  • Source: REVISTA BRASILEIRA DE ENGENHARIA AGRICOLA E AMBIENTAL
  • Volume: 14
  • Issue: 5
  • Year: 2010
  • Summary: No tillage implies keeping the soil surface covered with crops or crop residues, which might influence planter performance. Using fixed shanks as furrow openers to place fertiliser is an alternative to minimize compaction, as it mobilizes the soil in the sowing line. The aim of this research was to evaluate the effect of different amounts of winter cover crop residues evenly distributed on the soil, the effect of the shanks working depth and quantity of planter lines on power demand, cross sectional furrow area and total volume of soil mobilized in the lines and corresponding wheel slippage in distrophic red Argisol. During winter, black oats and black oats plus turnip were used as cover crops before maize and beans, respectively. Increasing the working depth showed an increase in power demand, as measured directly at the shanks (three lines for maize and five for beans). There was also an effect of residue, increasing power demand on the shanks, but only measurable with the planter operating with three lines in maize sowing. Soil mobilization in the sowing lines was influenced by the amount of residues, the working depths of shank and the quantity of planter lines. Wheel slippage was higher with larger amounts of soil cover residues and when power demand was higher.
  • Authors:
    • Vieira, F. C. B.
    • Flores, J. P. C.
    • Anghinoni, I.
    • Souza, E. D.
    • Costa, S. E. V. G. A.
    • Martins, A. P.
    • Ferreira, E. V. O.
  • Source: Soil & Tillage Research
  • Volume: 109
  • Issue: 1
  • Year: 2010
  • Summary: The distribution of phosphorus in the soil profile as a function of soil tillage, fertilizer management system and cultivation time is strongly related to root distribution. As the dynamics of this process are not well understood, long-term experiments are useful to clarify the cumulative effect through time. The study evaluated an 18-year-old experiment carried out on Rhodic Paleudult soil, located in Rio Grande do Sul state - Brazil, with cover crops (black oat and vetch) in the winter and corn in the summer. In the 0- to 20-cm layer, the amounts of clay, silt and sand were 22, 14, and 64 g kg -1, respectively. This layer had a mean slope of 3%. The mean local annual rainfall is 1440 mm. The climate is subtropical with a warm humid summer (Cfa), according to the Koeppen classification. The treatments consisted of three soil managements (conventional tillage, no tillage and strip tillage) and three application modes (broadcast, row and strip) for triple superphosphate and potassium chloride fertilizers. Data for phosphorus and root distribution in the soil from the 1989/90, 1999/00 and 2006/07 growing seasons were used. Phosphorus stratification occurred through time, irrespective of soil and fertilizer management, mainly in the 0- to 5-cm layer. The tillage and fertilization systems promoted significant differences in the Pi and Pt fractions up to a depth of 20 cm. For the Po fraction, significant differences were found only in the 0- to 5- and 15- to 20-cm layers. Inorganic phosphorus accumulated in the fertilized zone (0-10 cm), with higher intensity in the no-tillage system under row fertilization with values around 150 mg dm -3. Root distribution presented a strong positive relationship with phosphorus distribution, exhibiting redistribution in the soil profile through time. This redistribution was accompanied by increases in organic phosphorus and total organic carbon content. Corn grain yield was not affected by long-term tillage systems.
  • Authors:
    • Vuckovic, S.
    • Eric, P.
    • Mikic, A.
    • Krstic, D.
    • Cupina, B.
    • Pejic, B.
  • Source: TURKISH JOURNAL OF AGRICULTURE AND FORESTRY
  • Volume: 34
  • Issue: 4
  • Year: 2010
  • Summary: Field pea ( Pisum sativum L.) has the potential to be a suitable companion crop for the establishment of red clover ( Trifolium pratense L.), as it is fast growing and is harvested early, and thus reduces the duration of competition and allows light to be transmitted through its canopy to an undersown species more so than other companion crops such as small grains. The aim of this study was to determine the suitability of field pea as a companion crop for red clover, and in particular to determine the effect of pea cultivar and plant population density. The field experiment comprised 2 sowing years, (2004 and 2005), and the first cut in the first full harvest year in 2005 and 2006. The factorial component of the experiment involved 2 pea varieties (Jezero: semi-leafless; Javor: normal leaves with reduced leaflet size) and 3 densities (30, 60, and 90 plants m -2). Two control treatments were also included in the experiment, i.e. red clover grown as pure stand (control I) and red clover with oat as a cover crop (control II). When the field pea had reached the harvestable stage all plots were cut, followed by 2 additional cuts in the sowing year. Yields at the first cut in the following year were also recorded. Forage and protein yields, as well as the weed proportion were measured. On average, control II produced the highest forage yield, followed by pea as the cover crop; the lowest yield was obtained in the pure stand of red clover. Field pea cultivar yields did not differ significantly. The highest average yield was obtained with 90 plants m -2. The first cut comprised the highest proportion of annual yield (50%-69% when field pea was included). Red clover establishment was not adversely affected by competition from peas. As crude protein content did not vary much, crude protein yield followed the same trend as forage yield (r=0.83).
  • Authors:
    • Hoffmann, A. A.
    • Penfold, C. M.
    • Sharley, D. J.
    • Thomson, L. J.
    • Danne, A.
  • Source: Environmental Entomology
  • Volume: 39
  • Issue: 3
  • Year: 2010
  • Summary: Indigenous cover crops have the potential to promote an increase in natural enemies providing fortuitous control of pest species and other ecosystem services. We test this idea in a vineyard in south eastern Australia, where reduced water availability because of drought coupled with increased temperatures has generated interest in sustainable alternatives to the exotic perennial cover crops commonly planted. Three endemic perennial cover crops, comprising the grasses Austrodanthonia richardsonii and Chloris truncata and a mix of two saltbushes ( Atriplex semibaccata and Atriplex suberecta) were established as cover crops and compared with introduced oats ( Avena sativa). Abundance of a range of predators and parasitoids was higher in vines with native cover crops compared with the oat control. In addition, predation levels of sentinel eggs of a common vineyard pest, light brown apple moth ( Epiphyas postvittana), were increased in the native cover crops. However, the native cover crops also increased the abundance of some potential pest species. Native plants therefore have potential to increase abundance of beneficial invertebrates that assist in pest control, but need to be used carefully to ensure that they do not increase local pest problems.
  • Authors:
    • Karmakar, R.
    • Das, S. K.
    • Das, I.
  • Source: SATSA Mukhaptra Annual Technical Issue
  • Volume: 14
  • Year: 2010
  • Summary: In India, rice-wheat cropping system (RWCS) has contributed and will continue to contribute largely towards food security. Well-planned steps are necessary to make it sustainable and more productive without any adverse effects on the natural resources and the environment. Past studies indicate that sustainability of RWCS in the Indo-Gangetic Plains is at risk mainly due to decline in groundwater levels, soil organic matter content and nutrient availability, increased soil salinization and pest incidence. Practices for sustainable management diversified crop rotations that enhance soil cover and fertility, and accelarated adoption of resource conserving technologies like zero-tillage, bed planting, laser leveling, surface seeding, intercropping of high value crops, furrow irrigated raised bed planting technique, etc., all of which have been briefed in the present paper.
  • Authors:
    • Conte, O.
    • Trein, C. R.
    • Levien, R.
    • Debiasi, H.
    • Kamimura, K. M.
  • Source: PESQUISA AGROPECUARIA BRASILEIRA
  • Volume: 45
  • Issue: 6
  • Year: 2010
  • Summary: The objective of this work was to evaluate the effect of soil winter covers and soil mechanical loosening on soybean and corn yield, in no-tillage system. Two experiments were carried out in Rio Grande do Sul state, Brazil, in a compacted Argissolo Vermelho (Haplic Acrisol), in the 2005/2006 and 2006/2007 crop seasons. The first experiment was carried out in a complete block design, with a split plot arrangement. The treatments were two theoretical working depths of a driller chisel-type furrow opener (0.06 and 0.12 m, split plot), and three soil winter covers (main plot): fallow, black oat ( Avena strigosa), and black oat+common vetch ( Vicia sativa). In 2006, the soil cover black oat+common vetch was replaced by oilseed radish ( Raphanus sativus). In the second experiment, in a complete block design, the soil was chiseled and treatments consisted of black oat or oilseed radish as winter cover crops. Cover crops reduced soil superficial (0-0,06 m) compaction compared to fallow and, in the 2005/2006-crop season, under low water availability, provided higher soybean and corn yields. In the 2006/2007-crop season, when water availability was higher, the same did not happen. Increasing working depths of the chisel-type furrow opener did not affect soybean or corn yields. Soil chiseling reduced soybean and corn yields in comparison to the continuous no-tillage system.
  • Authors:
    • Rosa, R.
    • Kosterna, E.
    • Zaniewicz-Bajkowska, A.
    • Franczuk, J.
    • Pniewska, I.
    • Olszewski, W.
  • Source: ACTA SCIENTIARUM POLONORUM-HORTORUM CULTUS
  • Volume: 9
  • Issue: 2
  • Year: 2010
  • Summary: Very important element of proecological vegetables cultivation it is cover plants applied. They have favourable influence on the soil environment, indicated the possibility of limiting mineral fertilizer use and also reduce an application of herbicides, allow to keep soil fertility and in this same achieve high and good quality of yield. An experiment was carried out in 2002-2005 at the Experimental Farm in Zawady belonging to University of Podlasie. The objective of the study was the effect of cover plants (phacelia, spring vetch, serradella and oat) ploughed down in the autumn, spring or retained on the soil surface as a cover crop on the yield of red and savoy cabbage, and dry matter and vitamin C contents in white and savoy cabbage was investigated. The effects of covers were compared to the uncovered control. White cabbage cv. 'Masada F 1', red cabbage cv. 'Koda' and savoy cabbage cv. 'Wirosa F 1' were cultivated. Irrespective of the date of ploughing down of cover plants, serradella was the best plant cover preceding red cabbage, and phacelia was most beneficial when preceded savoy cabbage. Oat cover ploughed down in the autumn favoured dry matter accumulation, when spring-incorporated, stimulated vitamin C in white cabbage. The autumn-incorporated phacelia cover resulted in the greatest dry matter and vitamin C contents in savoy cabbage.
  • Authors:
    • Przybylowicz, W.
    • Mesjasz-Przybylowicz, J.
    • Cramer, M.
    • Hawkins, H.
    • Louw, E.
    • O'Brien, C.
  • Source: Acta Horticulturae
  • Issue: 869
  • Year: 2010
  • Summary: Utilisation of previously cultivated land for Proteaceae crops is a viable alternative to using pristine land. However, cultivated lands have usually been fertilized and typically have soil [P] unsuitably high for Proteaceae, resulting in P toxicity. After establishing that the main effects of P toxicity on the shoot were increased leaf P and Mn, but reduced leaf Fe and Zn, it was hypothesized that binding soil P and providing additional Fe and Zn to leaves would ameliorate P toxicity. Various soil and leaf amendments were tested for their efficacy in reducing soil P in unplanted lands, or ameliorating or preventing P toxicity in lands or pots planted with Protea 'Sylvia'. In an unplanted field, deep ploughing to 50 cm reduced available P from 16213 to 8.82.6 mg P kg -1 soil, i.e. by 95%. Sowing two seasons of the cover crops oat and lupin also greatly reduced available P (80%) whilst Al 2(SO 4) 3 application (278 g m -2) reduced available soil P by 80-65% depending on initial soil [P]. Ploughing was associated with disadvantages such as reduced cations and possible disruption of microbial populations. Thus use of cover crops or, for more immediate reduction in available soil P, aluminium application may be preferable. Application of Al 2(SO 4) 3 was also shown to be effective in prevention and amelioration of P toxicity symptoms in Protea 'Sylvia' in the field, while a Fe-containing compound 'OX' and a Fe/Zn containing foliar spray were only effective in preventing P toxicity in a pot experiment. Calcium sulphate was not effective as a P-binder in the field. Different agents may be used for different requirements but Al 2(SO 4) 3 application was effective in both prevention and amelioration of P toxicity.
  • Authors:
    • Muchaonyerwa, P.
    • Chiduza, C.
    • Murungu, F. S.
  • Source: African Journal of Agricultural Research
  • Volume: 5
  • Issue: 13
  • Year: 2010
  • Summary: Production of large biomass yields and weed suppression from cover crops have been major constraints affecting success and uptake of conservation agriculture technologies by smallholder irrigation farmers. A field study was undertaken to evaluate biomass accumulation and N uptake by oats ( Avena sativa), grazing vetch ( Vicia dasycarpa), faba bean ( Vicia faba), forage peas ( Pisum sativum) and Lupin ( Lupinus angustifolius) and their winter weed suppression efficacy in the 2007 and 2008 winter seasons. Cover crops were grown at two fertiliser levels: no fertiliser and fertilized. Control plots were included where no cover crop was grown. At the end of each winter season, glyphosate was applied to kill the cover crops and maize planted. Oats, grazing vetch and forage pea's cover crops produced mean dry weights of 13873, 8945.5 and 11073 kg ha -1 respectively while lupin had the lowest dry weight of 1226 kg ha -1. Oats responded to fertilisation while, there was little or no response from the other cover crops. Oats and grazing vetch also reduced weed density by 90 and 80% respectively while lupin only reduced weed density by 23% compared with the control plots. Grazing vetch fixed a mean of 112 kg N ha -1. The results suggest that legumes such as grazing vetch and forage peas may be grown to maximise biomass yields with minimal fertilizer inputs. Amount of biomass produced was a major factor in controlling winter weeds, while there was a progressive decline in the winter weed burden from the first to the second season. The low C:N ratio of grazing vetch (
  • Authors:
    • Sakai, R. H.
    • Ambrosano, E. J.
    • Melo, P. C. T. de
    • Negrini, A. C. A.
    • Schammass, E. A.
    • Rossi, F.
  • Source: HORTICULTURA BRASILEIRA
  • Volume: 28
  • Issue: 1
  • Year: 2010
  • Summary: The performance of lettuce in sole and intercropped with green manures was assessed under different establishment times. The lettuce fresh and dry weight, number of leaves per plant, diameter and length of head, and fresh and dry weight of green manure were evaluated. The intercropping design was additive and both cash and cover crops were planted in rows. The experimental design was of randomized complete blocks in split plot scheme, with six replicates. The plots represented the green manure sowing days (0, 20, 40 and 60 before transplanting of lettuce), and the sub-plots were assigned by cropping systems (lettuce in sole crop and intercropped with black oat, cowpea or white lupin). Simultaneous planting in the intercropping did not affect the lettuce performance. However, when the green manures were sown before lettuce, they influenced it in a negative way. Among the green manures, cowpea increased biomass and had a higher negative effect on lettuce performance compared to white lupin, which appeared to produce less competition. The sole crop and the intercropping with simultaneous planting of the green manures resulted in a better lettuce performance.