331. Common bean yield and the suppressive effect of winter cover crops on summer weeds.; Produtividade de feijao-guara e efeito supressivo de culturas de cobertura de inverno em espontaneas de verao.

• Authors:
  • Comin, J. J.
  • Lovato, P. E.
  • Bittencourt, H. von H.
  • Lana, M. A.
  • Altieri, M. A.
• Source: ACTA SCIENTIARUM-AGRONOMY
• Volume: 31
• Issue: 4
• Year: 2009
• Summary: The effect of the winter cover crops rye, oat, ryegrass, vetch and fodder radish (and their mixtures) in no-tillage systems was investigated on soil cover, cover crop biomass and summer weed biomass during the critical competition stage with common bean. Bean yield was also evaluated. The experimental design was randomized complete blocks and four repetitions. The highest soil cover during winter was observed in the treatments rye+vetch, rye+vetch+fodder radish and oat+vetch. The highest values of cover crops biomass production were observed in the treatments rye+vetch+fodder radish. Weed suppression was higher in the ryegrass monoculture and in the rye+vetch+fodder radish association, and there was no correlation between cover crop biomass and summer weed suppression; the best bean yields were achieved with the following treatments: ryegrass in monoculture, oat in monoculture and rye+vetch, producing 1,950, 1,730 e 1,790 kg ha -1 respectively. The monocultures of ryegrass and oat showed the lowest costs with seeds and the highest economic returns.

332. Host suitability of Avena spp. genotypes to Meloidogyne incognita race 4.; Reacao de genotipos de Avena spp. a Meloidogyne incognita raca 4.

• Authors:
  • Santos, V. P.
  • Antedomenico, S. R.
  • Borges, D. C.
  • Inomoto, M. M.
• Source: Tropical Plant Pathology
• Volume: 34
• Issue: 1
• Year: 2009
• Summary: The black oat ( Avena strigosa), the white oat ( A. sativa) and the Algerian oat ( A. byzantina) have been widely used as cover crops under succession with soybean, cotton, bean, potato and carrot, which are crops highly damaged by Meloidogyne incognita. The management of M. incognita may have as a component the use of oat genotypes that reduce the nematode population density. Three greenhouse experiments were carried out in order to evaluate the host suitability of five genotypes of black oat ('CPAO 0010', 'Common', 'Embrapa 29', 'Embrapa 140' and 'IPFA 99006'), one of white oat ('UFRGS 17') and one of Algerian oat ('Sao Carlos') to three isolates of M. incognita race 4 (BA, SP and MT). The black oats increased the population density of the nematode. The oats 'UFRGS 17' and 'Sao Carlos' reduced or caused a small increase in the population of M. incognita race 4, and neither differentiated from Crotalaria spectabilis. Therefore, the white oat 'UFRGS 17' and the Algerian oat 'Sao Carlos' should be used in preference to black oats as cover crops in areas infested with M. incognita race 4.

333. Seeding rate and planting arrangement effects on growth and weed suppression of a legume-oat cover crop for organic vegetable systems.

• Authors:
  • Smith, R. F.
  • Boyd, N. S.
  • Brennan, E. B.
  • Foster, P.
• Source: Agronomy Journal
• Volume: 101
• Issue: 4
• Year: 2009
• Summary: Winter cover crops can add soil organic matter, improve nutrient cycling, and suppress weeds in organic vegetable systems. A 2-yr study was conducted on organic farms in Salinas and Hollister, CA, to evaluate the effect of seeding rate (SR) and planting arrangement on cover crop density, ground cover, and cover crop and weed dry matter (DM) with a mixed cover crop. The mix contained legumes (35% Vicia faba L., bell bean; 15% Vicia dasycarpa Ten., woolypod vetch; 15% Vicia benghalensis L., purple vetch; and 25% Pisum sativum L., pea) and 10% oat ( Avena sativa L.) by seed weight. Three SRs (112, 224, and 336 kg ha -1) and two planting arrangements (one-way versus grid pattern) were evaluated. Planting arrangement had no effect on the variables measured. When weeds were abundant, weed DM declined linearly with increasing SR from approximately 300 kg ha -1 at the low SR to

334. 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.

335. Effects of cover crop quality and quantity on nematode-based soil food webs and nutrient cycling.

• Authors:
  • Ferris, H.
  • DuPont, S. T.
  • Horn, M. van
• Source: Applied Soil Ecology
• Volume: 41
• Issue: 2
• Year: 2009
• Summary: Soil food webs cycle nutrients and regulate parasites and pathogens, services essential for both agricultural productivity and ecosystem health. Nematodes provide useful indicators of soil food web dynamics. This study was conducted to determine if nematode soil food web indicators and crop yield can be enhanced by combinations of cover crops in a conservation tillage system. The effects of three cover crop treatments (vetch/pea, oat/wheat and oat/wheat/pea/vetch) with low, medium and high C:N and a bare fallow control were investigated in Davis, CA. Nematode fauna, soil properties and plant productivity were measured. Soil food web indices, including the Enrichment Index (EI), Structure Index (SI), Basal Index (BI), and Channel Index (CI), based on the composition of nematode assemblages, were calculated to infer soil food web condition. Cover cropped tomato/corn rotations had twice the number of enrichment opportunist bacterial feeding nematodes, active participants in nitrogen mineralization, than fallowed tomato/corn rotations (opportunist bacterial feeders=163 versus 98). In winter fallowed plots food webs were basal, common in disturbed, nutrient-poor conditions (BI=37). Total number of enrichment opportunist nematodes, soil NH 4-N levels, and inferred nitrogen mineralization, were higher in cover crop treatments with low to mid C:N ratios. Omnivore and predator nematodes were scarce, averaging less than 6 nematodes 100 g -1 in all treatments. In year one, plant productivity was highest after fallow. In contrast, in year two productivity was highest after cover crops with high nitrogen content and productivity significantly correlated with the structure of the soil fauna. Monitoring the abundance of enrichment opportunists may provide managers with a new tool to evaluate soil food web nitrogen mineralization and plant productivity.

336. Integrating winter annual forages into a no-till corn silage system.

• Authors:
  • Eastridge, M. L.
  • Dick, R. P.
  • Barker, D. J.
  • Sulc, R. M.
  • Fae, G. S.
  • Lorenz, N.
• Source: Agronomy Journal
• Volume: 101
• Issue: 5
• Year: 2009
• Summary: The benefits of cover crops within crop rotations are well documented, but information is limited on using cover crops for forage within midwestern United States cropping systems, especially under no-tillage management. Our objective was to evaluate plant, animal, and soil responses when integrating winter cover crop forages into no-till corn ( Zea mays L.) silage production. Three cover crop treatments were established no-till after corn silage in September 2006 and 2007 at Columbus, OH: annual ryegrass ( Lolium multiflorum L.), a mixture of winter rye ( Secale cereale L.) and oat ( Avena sativa L.), and no cover crop. Total forage yield over autumn and spring seasons was 38 to 73% greater ( P≤0.05) for oat+winter rye than for annual ryegrass. Soil penetration resistance (SPR) in May 2007 was 7 to 15% greater ( P≤0.10) in the grazed cover crops than in the nongrazed no cover crop treatment; however, subsequent silage corn yield did not differ among treatments, averaging 10.4 Mg ha -1 in August 2007. Compared with the no cover crop treatment, cover crops had three- to fivefold greater root yield, threefold greater soil microbial biomass (MB) in spring 2008, and 23% more particulate organic carbon (POC) concentrations in the 0- to 15-cm soil depth. Integration of forage cover crops into no-till corn silage production in Ohio can provide supplemental forage for animal feed without detrimental effects on subsequent corn silage productivity, with the added benefit of increasing labile soil C.

337. The effect of plant mulches on the nutritive value of red cabbage and onion.

• Authors:
  • Kosterna, E.
  • Zaniewicz-Bajkowska, A.
  • Jabonska-Ceglarek, R.
  • Franczuk, J.
  • Rosa, R.
• Source: Vegetable Crops Research Bulletin
• Volume: 70
• Year: 2009
• Summary: The effect of three methods of soil mulching: autumn or spring ploughing and leaving mulch as a cover crop on the soil surface without incorporation till the end of cabbage growth on the contents of selected nutrients in red cabbage and onion was investigated. The following plants were used as intercropped mulches: phacelia, vetch, Serradella and oat. Mulching effects were compared to a non-mulched control as well as a farmyard manure application at the rate of 40 t.ha -1. Nutrient content in both vegetable species depended on weather conditions and varied in study years. Accumulation of dry matter in cabbage was favoured by phacelia and oat mulches, irrespective of the date of ploughing. Non-incorporated oat and autumn-incorporated phacelia increased dry matter content in onion. An increase in the protein content in cabbage was observed when following Serradella and vetch mulches. The protein content in onion cultivated in the second year following mulching did not change significantly as a result of the influence of examined factors. Among an the mulches taken into study, Serradella and oat increased the content of vitamin C in cabbage. Similarly, autumn- or spring-incorporated oat mulch and non-incorporated Serradella mulch increased the content of vitamin C in onion.

338. 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.

339. Cover crop use in tomato production in plastic high tunnel.

• Authors:
  • Hirata, T.
  • Hoshino, Y.
  • Hane, S.
  • Hajime, A.
• Source: Horticulture Environment and Biotechnology
• Volume: 50
• Issue: 4
• Year: 2009
• Summary: More than 70% of fresh tomato is produced in plastic high tunnel or greenhouse and much fertilizer and agricultural chemicals have been applied for tomato production. Cover crop is one of the important tools for sustainable agro-production because of improving soil properties. Effect of cover cropping on soil properties and tomato production in plastic high tunnel was examined in Sapporo, Japan, snow cover region. Plastic high tunnel was set before snow-melting, late in March, 2007. Two cover crops, legume (hairy vetch; Vicia villosa R.) and non legume (wild oat; Avena sterigosa L.), were planted each alone or mix-planted in the plot (0.8 m in width and 3.5 m in length) early in April. Seeding density in mono-culture was 5 kg/10a in hairy vetch and 10 kg/10a in wild oat. For bi-culture, density was 3.5 kg/10a in hairy vetch and 5 kg/10a in wild oat. Above ground biomass (dry weight) was shown 445 kg/10a in hairy vetch and 982 kg/10a in wild oat late in May. However, in mix-culture, it was 190 kg/10a in hairy vetch and 602 kg/10a in wild oat. Cover crops were killed for residue mulch just before tomato planting. Seedlings of tomato 'Momotaro' were planted in the plots covered with cover crop residue and 12 kg/10a N fertilizer application (12 kg N/10a) and bare plot with 12 kg/10a or 24 kg/10a N fertilizer (24 kg N/10a) application. Nitrate concentration of the petiole sap in the leaf just below the first fruit cluster was higher in the tomatoes grown in bare plot with 24 kg N/10a and in hairy vetch mulch with 12 kg N/10a at 40 days after transplanting. Large yield was shown in bare plot with 24 kg N/10a (7.9 t/10a) and in hairy vetch plot with 12 kg N/10a (7.8 t/10a). The yield in bare plot with 12 kg N/10a and Mix plot with 12 kg N/10a was 6.9 t/10a. The yield in wild oat plot with 12 kg N/10a was the smallest (6.1 t/10a). Soil carbon in the plots with cover crop mulch became higher than that of bare plots after tomato production. It will be possible to obtain current yield and to increase soil carbon in cover cropping with reduction of N fertilizer. This technique will lead the organically grown system in plastic high tunnel production.

340. Weed suppression in organic pepper ( Capsicum annuum L.) with winter cover crops.

• Authors:
  • Ngouajio, M.
  • Kaya, E.
  • Isik, D.
  • Mennan, H.
• Source: Crop Protection
• Volume: 28
• Issue: 4
• Year: 2009
• Summary: Weed control is a major constraint for organic production around the world. Field studies were conducted in pepper ( Capsicum annuum L.) from 2004 to 2006 at the Black Sea Agricultural Research Institute experimental field in Turkey to determine the weed suppressive effects of winter cover crops. Treatments consisted of ryegrass ( Lolium multiflorum L.), oat ( Avena sativa L.), rye ( Secale cereale L.), wheat ( Triticum aestivum L.), gelemen clover ( Trifolium meneghinianum Clem.), Egyptian clover ( Trifolium alexsandrinum L.), common vetch ( Vicia sativa L.), hairy vetch ( Vicia villosa Roth.) and a bare fallow with no cover crop. Weed density and total weed dry biomass were assessed at 14, 28, and 56 days after incorporation to quantify effects of cover crops during a subsequent pepper crop. Cover crop establishment was similar in both growing seasons and individual species produced in the range of 1800-3500 kg/ha biomass. Ryegrass produced the greatest biomass compared with other species. Weed dry biomass production just before cover crop incorporation varied with year and cover crop species. Hairy vetch, ryegrass, oat and common vetch were the most competitive cover crops based on total weed dry biomass. Hairy vetch was the most promising cover crop and reduced weed density by 73% and 70% at 28 and 56 DAI, respectively. Pepper yields were higher following all cover crops except Egyptian clover. The highest yield was obtained from hairy vetch plots in both years. This research indicates that cover crops such as hairy vetch, ryegrass, oat and common vetch could be used in integrated weed management programs to reduce weed infestation in organic pepper.