Search Results

You are looking at 71 - 80 of 2,935 items for :

  • cover crops x
  • All content x
Clear All
Free access

Wilfred Singogo, William J. Lamont Jr., and Charles W. Marr

Four cover crops {alfalfa (Medicago sativa L. `Kansas Common'), hairy vetch (Vicia villosa Roth), Austrian winter pea [Pisum sativum subsp. arvense (L.) Poir], and winter wheat (Triticum aestivum L. `Tam 107')}, alone and in combination with feedlot beef manure at 5 t·ha–1 were evaluated for 2 years to determine whether sufficient N could be supplied solely by winter cover cropping and manure application to produce high-quality muskmelons (Cucumis melo L. `Magnum 45') in an intensive production system using plastic mulch and drip irrigation. Among the legumes, hairy vetch produced the most biomass (8.9 t·ha–1) and accumulated the most N (247 kg·ha–1). Winter wheat produced more biomass (9.8 t·ha–1) than any of the legumes but accumulated the least N (87 kg·ha–1). Melon yields produced using legume cover crops alone were similar to those receiving synthetic N fertilizer at 70 or 100 kg·ha–1. Melons produced on plots with cover crops combined with beef manure did not differ significantly in yield from those produced on plots with only cover crops. Legume cover crops alone, used with plastic mulch and drip irrigation, provided sufficient N for the production of high-quality muskmelons.

Free access

Thierry Vrain, Robyn DeYoung, John Hall, and Stan Freyman

Cover crops used in red raspberry plantings (Rubus idaeus L.) are often good hosts of the root-lesion nematode (Pratylenchus penetrans Filipjev & Sch. Stekoven), a major soilborne pathogen of raspberry. The effects of two susceptible cover crops, white clover (Trifolium repens L.) and barley (Hordeum vulgare L.), planted in between rows, on nematode density and growth of raspberry plants were compared to those of three cover crops resistant to the nematode: redtop (Agrostis alba L.), creeping red fescue (Festuca rubra L.), and `Saia' oat (Avena sativa L.). Nematode multiplication in raspberry roots and in cover crop roots was assessed over 4 years. Growth and vigor of plants were estimated at the end of the experiment by counting primocanes and determining height and biomass. Nematode multiplication was suppressed in roots of `Saia' oat, fescue, and redtop compared to barley or white clover. Nematode density in roots and rhizosphere soil of raspberry was not affected by the choice of cover crops. Nematode suppression in the three resistant cover crops did not translate into increased vigor of raspberry plants.

Free access

N.K.D. Ranwala, K. Brock, C.L. Ray, K. Greene, and D.R. Decoteau

The effects of two winter cover crops, rye and crimson clover, on bell pepper yield were studied. Cover crops were planted in fall and incorporated into the soil prior to bell pepper planting. Both cover crops increased the marketable number and weight of bell peppers, and reduced the cull number of bell peppers compared to fallow (control) treatment. Delaying the harvest increased the marketable yield in both cover crops. Since there was no difference in bell pepper yield between two cover crops, both cover crops can be used effectively for bell pepper production. Use of cover crops may reduce the production costs and harmful effects on the environment by reducing chemical dependency, and increase the crop yield.

Full access

Orion P. Grimmer and John B. Masiunas

Winter-killed cover crops may protect the soil surface from erosion and reduce herbicide use in an early planted crop such as pea (Pisum sativum). Our objective was to determine the potential of winter-killed cover crops in a snap pea production system. White mustard (Brassica hirta) produced the most residue in the fall but retained only 37% of that residue into the spring. Barley (Hordeum vulgare) and oats (Avena sativa) produced less fall residue but had more residue and ground cover in the spring. Greater ground cover in the spring facilitated higher soil moisture, contributing to higher weed numbers and weight and lower pea yields for oat and barley compared with a bare ground treatment. White mustard had weed populations and pea yields similar to the bare ground treatment. Within the weed-free subplot, no differences in pea yields existed among cover crop treatments, indicating no direct interference with pea growth by the residues. In greenhouse experiments, field-grown oat and barley residue suppressed greater than 50% of the germination of common lambsquarters (Chenopodium album) and shepherd's-purse (Capsella bursapastoris), while in the field none of the cover crop provided better weed control than the fallow.

Full access

Lydia J. Stivers-Young and Frances A. Tucker

Surveys of vegetable growers in a six-county region in western New York were conducted in 1997 to determine which cover cropping practices were being used on commercial vegetable operations; to identify producers' needs for further research and information, and to assess the impact of cooperative extension programs in this area. In a broad survey, 118 responses were returned out of 315 surveys sent (37%). Respondents represented >37,000 acres (14974 ha) of vegetable production, or ≈53% of the vegetable acreage in the region. Vegetable acreage per operation ranged from 1 to 4000 acres (0.4 to 1619 ha). Sixty-nine percent responded that they grew cover crops on a total of 15,426 acres (6243 ha). Oats (Avena sativa L.), rye (Secale cereale), clover (Trifolium pratense), and wheat (Triticum vulgare) were the most commonly used cover crops. Seventy-six percent of the reported cover-cropped acres were planted to small grains, and 19% to legumes, almost entirely clovers. In open ended questions, the most important benefits of cover cropping identified by respondents were erosion control (46% of respondents) and organic matter additions (42%). The most important problems associated with cover crops were that they interfere with spring field work or fall harvest (26%), and that they are difficult to incorporate or plow under (24%). A targeted survey of nineteen onion (Allium cepa L.) producers in the same region measured the recent adoption of sudangrass (Sorghum sudanense Piper) and sorghum-sudan hybrid (Sorghum bicolor L. × S. sudanense) cover crops, the focus of the several years of extension research and educational programs. Nine of the onion producers had adopted the practice, and six of these had done so since the beginning of these extension programs. The implications of these results for research and extension are discussed.

Free access

Tom TenPas and John Luna

The effect on corn yield of interplanting two different cover crops, Trifolium repens, and Lolium perens into sweet corn, Zea mays, at 4 different times from corn planting was examined. Sweet corn was planted in 30 inch rows, and the cover crop was planted 0, 7, 14, and 21 days afterwards. The study was designed as a complete randomized block experiment with 4 replications. Weed management practices included pre-emergent herbicides and cultivation only treatments.

No significant yield differences in corn yields were detected (alpha=.05). Most of the plots had very little weed competition, including those with no herbicide treatment. Earlier planted cover crops were better established at time of corn harvest. Additional work is needed to examine this practice in conditions of greater weed competion.

Free access

Howard F. Harrison, Judy A. Thies, Richard L. Fery, and J. Powell Smith

A preliminary screening experiment was conducted to evaluate 47 cowpea [Vigna unguiculata (L.) Walp.] genotypes for use as a weed-suppressing cover crop. Of these, 11 were selected for further testing on the basis of vigorous growth and weed-suppressing ability. In a field experiment repeated over 4 years, the selected genotypes were not different from the leading cover crop cultivar `Iron Clay' in biomass production. Vigor ratings, vine growth ratings, and canopy widths of some genotypes exceeded those of `Iron Clay' Vigor ratings and canopy measurements were efficient selection criteria that could be useful for breeding cover crop cowpea cultivars. All except one selection were highly resistant to southern root knot nematode [Meloidogyne incognita (Kofoid and White) Chitwood], and the selections varied in seed size, photoperiod, and response to foliar diseases.

Free access

Nancy G. Creamer, Mark A. Bennett, Benjamin R. Stinner, John Cardina, and Emilie E. Regnier

Field and laboratory studies were conducted to investigate the mechanisms of weed suppression by cover crops. High-performance liquid chromatograph analysis and a seed germination bioassay demonstrated that rye (Secale cereale L.) can be leached of its allelochemicals, redried, and used as an inert control for separating physical suppression from other types of interference. In a field study, rye, crimson clover (Trifolium incarnatum L.), hairy vetch (Vicia villosa Roth.), barley (Hordeum vulgare L.), and a mixture of the four species suppressed the emergence of eastern black nightshade (Solanum ptycanthum Dun.). Crimson clover inhibited the emergence of eastern black nightshade beyond what could be attributed to physical suppression alone. The emergence of yellow foxtail [Setaria glauca (L.) Beauv.] was inhibited by rye and barley but not by the other cover crops or the cover crop mixture.

Free access

Harbans L. Bhardwaj

Winter legume cover crops have been successfully used to meet N needs of many summer crops, but they are not being used extensively in Virginia and the mid-Atlantic region, especially for specialty crops such as muskmelon and sweet corn. The objective of these studies was to determine the potential of winter legume cover crops in meeting N needs of muskmelon (Cucumis melo L.) and sweet corn (Zea mays L.). Comparisons of performances of muskmelon and sweet corn, grown after lupin (Lupinus albus L.), hairy vetch (Vicia villosa Roth.), Austrian winter pea ([AWP] Pisum arvense L.), and control fertilized with 112 kg N ha–1, and unfertilized control were made during 1999, 2000, and 2001. The interactions between cover crop treatments and years were, generally, significant. The muskmelon fruit yields were 53.6, 45.0, 23.1, 13.0, and 5.6 Mg·ha–1 during 1999; 27.8, 26.3, 8.6, 5.8, and 2.2 Mg·ha–1 during 2000; and 41.1, 39.9, 25.5, 21.4, and 2.1 Mg·ha–1 during 2001 respectively for lupin, hairy vetch, AWP, 112 kg N ha–1, and control. Similar results were obtained for number and size of muskmelon fruits. The sweet corn ear yields (Mg·ha–1) were 8.5, 5.6, 3.1, 1.5, and 0.7 during 1999; 5.2, 3.9, 4.0, 4.8, and 1.2 during 2000; and 2.6, 2.4, 1.9, 2.0, and 0.9 during 2001, respectively for lupin, hairy vetch, AWP, 112 kg N ha–1, and control. White lupin and hairy vetch, as winter cover crops, were superior than AWP and 112 kg N ha–1 for sweet corn ear number and size, and plant height. These results demonstrated that winter legume crops, especially lupin and hairy vetch, can be excellent winter cover crops for meeting N needs of muskmelon and sweet corn.

Free access

Teresa Olczyk, Yuncong Li, Waldemar Klassen, and Qingren Wang

Summer cover crops can improve soil fertility by adding organic matter, supplying nutrients through mineralization, reducing nutrient leaching, and improving soil water and nutrient holding capacity. Other benefits include weed suppression and reduction of soil parasitic nematodes. A series of field experiments have been conducted at the UF IFAS Tropical Research and Education Center in Homestead, Florida to evaluate several summer cover crops for use in vegetable production in South Florida followed by field demonstrations conducted in the growers' fields. Best performing cover crops were legumes: velvet bean (Macuna deeringiana) and sunn hemp (Crotalaria juncea L. `Tropic Sun') providing 13 and 11 Mt of dry matter/ha, respectively. Sunn hemp supplied 330 kg N/ha followed by velvet been with 310 kg N/ha. Traditional summer cover crop sorghum-Sudan produced 4 Mt of dry matter/ha and retained only 36 kg N/ha. In addition Sunn hemp significantly reduced soil parasitic nematodes for successive crops. Limitations in use of Sunn hemp by more vegetable growers in South Florida include cost and availability of seeds.