• Authors:
    • Singer, J.
  • Source: Agronomy Journal
  • Volume: 100
  • Issue: 6
  • Year: 2008
  • Summary: Surveying end-users about their use of technologies and preferences provides information for researchers and educators to develop relevant research and educational programs. A mail survey was sent to Corn Belt farmers during 2006 to quantify cover crop management and preferences. Results indicated that the dominant cereal cover crops in Indiana and Illinois are winter wheat ( Triticum aestivum L.) and cereal rye ( Secale cereale L.), cereal rye and oat ( Avena sativa L.) in Iowa, and oat in Minnesota. Legumes were used more frequently in Indiana and Illinois, and red clover ( Trifolium pratense L.) was the dominant choice across the region. Farmers relied solely on herbicides 54% of the time to kill cover crops. Ninety-three percent of respondents indicated that they received no cost sharing for using cover crops and 14% indicated that they would plant cover crops on rented land. Corn Belt farmers prefer cover crops that overwinter (68%) and fix N (64%). The information provided in this survey supplements existing knowledge that can be used to develop relevant research and educational programs to address agronomic production systems that include cover crops.
  • Authors:
    • Moorman, T.
    • Cambardella, C.
    • Singer, J.
  • Source: Agronomy Journal
  • Volume: 100
  • Issue: 6
  • Year: 2008
  • Summary: Coupling winter small grain cover crops (CC) with liquid manure injection may increase manure nutrient capture. The objectives of this research were to quantify manure injection effects using target swine ( Sus scrofa) manure N rates of 112, 224, and 336 kg N ha -1 on CC plant density, fall and spring shoot biomass, N, P, and K uptake and subsequent corn ( Zea mays L.) yield. A winter rye ( Secale cereale L.)-oat ( Avena sativa L.) CC was established before fall manure injection. Manure injection lowered mean CC plant density 25% because of CC mortality in the injection zone. Fall CC dry matter (DM) was 26% lower in the manure treatments than the no manure CC control, although no difference was detected for N (9.4 kg ha -1) or P (1.4 kg ha -1) uptake. No difference was detected for spring DM between CC no manure and manure treatments. Shoot DM, N, P, and K uptake increased 29, 41, 31, and 25% from the CC manure 112 to CC manure 224 with no increase above CC manure 224. Cover crop N uptake was higher in CC manure vs. no manure (60.1 vs. 35.6 kg ha -1). Cover crop P and K uptake were also higher in CC manure vs. no manure (9.2 vs. 6.6 kg P ha -1 and 41.3 vs. 30.0 kg K ha -1). Corn grain yield was unaffected by CC and responded positively to manure application (11,022 with manure vs. 9,845 kg ha -1 without manure). Coupling manure injection and cover crops can increase nutrient capture without lowering corn yield.
  • Authors:
    • Endale, D. M.
    • Schomberg, H. H.
    • Fisher, D. S.
    • Jenkins, M. B.
    • Sharpe, R. R.
    • Cabrera, M. L.
  • Source: Agronomy Journal
  • Volume: 100
  • Issue: 5
  • Year: 2008
  • Summary: Corn (Zea mays L.) producers in the southeastern United States must overcome soil and water limitations to take advantage of the expanding corn market. In this 2001 to 2005 study on a Cecil sandy loam (fine, kaolinitic, thermic Typic Kanhapludult) near Watkinsville, GA, we compared dry land corn biomass and yield under conventional tillage (CT) vs. no-tillage (NT) with ammonium nitrate or sulfate (based on availability) as conventional fertilizer (CF) vs. poultry litter (PL). In a randomized complete block split plot design with three replications, main plots were under tillage and subplots under fertilizer treatments. The cover crop was rye (Secale cereale L.). Over 5 yr, NT and PL increased grain yield by 11 and 18%, respectively, compared with CT and CF. Combined, NT and PL increased grain yield by 31% compared with conventionally tilled and fertilized corn. Similarly, soil water was 18% greater in NT than CT in the 0- to 10-cm depth. In 2 yr of measurements, dry matter of stalks and leaves and leaf area index under PL were an average of 39 and 22% greater, respectively, than under CF during reproduction. Values were 21 and 6% greater, respectively, under NT than CT but during tasseling. Analysis of 70 yr of daily rainfall records showed that supplemental irrigation is needed to meet optimal water requirement. Our results indicate that corn growers can use rainfall more efficiently, reduce yield losses to drought, and expect increased corn yields with a combination of no-tillage management and long-term use of poultry litter.
  • Authors:
    • Kang, J.
    • Osmond, D. L.
  • Year: 2008
  • Authors:
    • Stevens, W. B.
    • Jabro, J. D.
    • Sainju, U. M.
  • Source: Journal of Environmental Quality
  • Volume: 37
  • Issue: 1
  • Year: 2008
  • Summary: Management practices can influence soil CO2 emission and C content in cropland, which can effect global warming. We examined the effects of combinations of irrigation, tillage, cropping systems, and N fertilization on soil CO2 flux, temperature, water, and C content at the 0- to 20-cm depth from May to November 2005 at two sites in the northern Great Plains. Treatments were two irrigation systems (irrigated vs. non-irrigated) and six management practices that contained tilled and no-tilled malt barley (Hordeum vulgaris L.) with 0 to 134 kg N ha-1, no-tilled pea (Pisum sativum L.), and a conservation reserve program (CRP) planting applied in Lihen sandy loam (sandy, mixed, frigid, Entic Haplustolls) in western North Dakota. In eastern Montana, treatments were no-tilled malt barley with 78 kg N ha-1, no-tilled rye (Secale cereale L.), no-tilled Austrian winter pea, no-tilled fallow, and tilled fallow applied in dryland Williams loam (fine-loamy, mixed Typic Argiborolls). Irrigation increased CO2 flux by 13% compared with non-irrigation by increasing soil water content in North Dakota. Tillage increased CO2 flux by 62 to 118% compared with no-tillage at both places. The flux was 1.5- to 2.5-fold greater with tilled than with non-tilled treatments following heavy rain or irrigation in North Dakota and 1.5- to 2.0-fold greater with crops than with fallow following substantial rain in Montana. Nitrogen fertilization increased CO2 flux by 14% compared with no N fertilization in North Dakota and cropping increased the flux by 79% compared with fallow in no-till and 0 kg N ha-1 in Montana. The CO2 flux in undisturbed CRP was similar to that in no-tilled crops. Although soil C content was not altered, management practices influenced CO2 flux within a short period due to changes in soil temperature, water, and nutrient contents. Regardless of irrigation, CO2 flux can be reduced from croplands to a level similar to that in CRP planting using no-tilled crops with or without N fertilization compared with other management practices.
  • Authors:
    • Reddy, K. C.
    • Tazisong, I. A.
    • Nyakatawa, E. Z.
    • Senwo, Z. N.
    • Sainju, U. M.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 127
  • Issue: 3-4
  • Year: 2008
  • Summary: Disposal of poultry litter, a widely available organic manure in the southeastern USA because of a large-scale poultry industry, is a major concern because of its contamination in surface- and groundwater through N leaching and P runoff. Application of poultry litter in no-tilled intensive cropping system could increase soil C and N sequestration compared with the conventional-tilled system with inorganic N fertilization and reduce environmental contamination. We evaluated the 10-year effects of tillage, cropping systems, and N fertilizer sources on crop residue (stems + leaves) production and soil bulk density, organic C (SOC), and total N (STN) at the 0-20 cm depth in Decatur silt loam (clayey, kaolinitic, thermic, and Typic Paleudults) in northern AL, USA. Treatments were incomplete factorial combinations of three tillage practices [no-till (NT), mulch till (MT), and conventional till (CT)], two cropping systems [cotton (Gossypium hirsutum L.)-cotton-corn (Zea mays Q and rye (Secale cereale L.)/cotton-rye/cotton-corn], and two N fertilization sources and rates (0 and 100 kg N ha(-1) from NH4NO3, and 100 and 200 kg N ha(-1) from poultry litter) in randomized complete block with three replications. Rye was grown as winter cover crop and corn as residual crop without tillage and fertilization. Mean crop residue returned to the soil from 1997 to 2005 was greater in rye/cotton-rye/cotton-corn than in cotton-cotton-corn and greater with NH4NO3 than with poultry litter at 100 kg N ha(-1). While SOC and STN concentrations at 10-20 cm after 10 years were not influenced by treatments, SOC and STN contents at 0-20 cm were greater with poultry litter than with NH4NO3 in NT and CT. These resulted in a C sequestration rate of 510 kg C ha(-1) year(-1) and N sequestration rates of 41-49 kg N ha(-1) year(-1) with poultry litter compared with -120 to 147 kg C ha(-1) year(-1) and -23 to -3 kg N ha(-1) year(-1), respectively, with NH4NO3. Cropping and fertilization sequestered C at 730 kg C ha(-1) year(-1) and N at 67 kg N ha(-1) year(-1) compared with fallow and no-fertilization in NT. Tillage and cropping system did not influence SOC and STN. Long-term poultry litter application or continuous cropping can sequester C and N in the soil compared with inorganic N fertilization or fallow, thereby increasing soil quality and productivity and reducing the potentials for N leaching and greenhouse gas emission. Published by Elsevier B.V.
  • Authors:
    • Plowden, Y.
    • Benham, E. C.
    • Franks, E. C.
    • Salon, P. R.
    • Dell, C. J.
  • Source: Journal of Soil and Water Conservation
  • Volume: 63
  • Issue: 3
  • Year: 2008
  • Summary: No-till (NT) crop production is expected to sequester soil C, but little data is available for dairy forage systems. Our objective was to quantify impacts of NT and rye (Secale cereale L.) cover crops on soil C and N pools and associated soil properties on Pennsylvania dairies. Samples were collected from seven fields following corn harvest. The NT fields had approximately 50% more C and N in particulate and mineral-associated pools in the upper 5 cm (2 in) compared to conventional tillage, but C and N accumulations below 5 cm were similar. This suggests a C sequestration rate of ~0.5 Mg ha-1 y-1 (~0.2 tn ac-1 yr-1) in the 8 to 13 years NT has been used. Soil aggregate stability and cation exchange capacity were proportional to C pool sizes. Rye cover crops had no clear impact. Findings show that expected increases in C sequestration and soil quality with NT can be achieved in dairy forage systems.
  • Authors:
    • Ngouajio, M.
    • Wang, G.
  • Source: Hortscience
  • Volume: 43
  • Issue: 6
  • Year: 2008
  • Summary: The effects of two cover crops [cereal rye ( Secale cereale L.) and oat ( Avena sativa L.)], four tillage systems [no tillage (NT), strip tillage (ST), conventional tillage with cover crops incorporated (CTC), and conventional tillage without cover crop (CTN)], and three pre-emergence herbicide rates (full rate, half rate, and no herbicide) on pickling cucumber ( Cucumis sativus L.) growth and production, weed populations, and the incidence of pythium fruit rot were studied. Weed infestations, cucumber establishment, and cucumber leaf chlorophyll content were similar between the rye and oat treatments. However, the oat treatment had higher cucumber fruit number and weight and a lower percentage of cucumber fruit infected with Pythium spp. compared with the rye treatment. The NT and CTC systems reduced cucumber stand and leaf chlorophyll content, but had equivalent cucumber fruit number and weight compared with CTN. The NT and ST had lower weed biomass and weed density than CTN and CTC. The NT also reduced the percentage of cucumber fruit affected with pythium compared with CTN and CTC. Reducing the pre-emergence herbicide rate by half did not affect weed control or cucumber fruit yield compared with the full rate. However, weeds escaping herbicide application were larger in the half-rate treatment. The experiments indicate that with the integration of cover crops and conservation tillage, it is possible to maintain cucumber yield while reducing both herbicide inputs (by 50%) and the incidence of fruit rot caused by Pythium spp. (by 32% to 60%).
  • Authors:
    • Leser, J. F.
    • Wheeler, T. A.
    • Keeling, J. W.
    • Mullinix, B.
  • Source: JOURNAL OF NEMATOLOGY
  • Volume: 40
  • Issue: 2
  • Year: 2008
  • Summary: Terminated small grain cover crops are valuable in light textured soils to reduce wind and rain erosion and for protection of young cotton seedlings. A three-year study was conducted to determine the impact of terminated small grain winter cover crops, which are hosts for Meloidogyne incognita, on cotton yield, root galling and nematode midseason population density. The small plot test consisted of the cover treatment as the main plots (winter fallow, oats, rye and wheat) and rate of aldicarb applied in-furrow at-plant (0, 0.59 and 0.84 kg a.i./ha) as subplots in a split-plot design with eight replications, arranged in a randomized complete block design. Roots of 10 cotton plants per plot were examined at approximately 35 days after planting. Root galling was affected by aldicarb rate (9.1, 3.8 and 3.4 galls/root system for 0, 0.59 and 0.84 kg aldicarb/ha), but not by cover crop. Soil samples were collected in mid-July and assayed for nematodes. The winter fallow plots had a lower density of M. incognita second-stage juveniles (J2) (transformed to Log 10 (J2+1)/500 cm 3 soil) than any of the cover crops (0.88, 1.58, 1.67 and 1.75 Log 10(J2+1)/500 cm 3 soil for winter fallow, oats, rye and wheat, respectively). There were also fewer M. incognita eggs at midseason in the winter fallow (3,512, 7,953, 8,262 and 11,392 eggs/500 cm 3 soil for winter fallow, oats, rye and wheat, respectively). Yield (kg lint per ha) was increased by application of aldicarb (1,544, 1,710 and 1,697 for 0, 0.59 and 0.84 kg aldicarb/ha), but not by any cover crop treatments. These results were consistent over three years. The soil temperature at 15 cm depth, from when soils reached 18°C to termination of the grass cover crop, averaged 9,588, 7,274 and 1,639 centigrade hours (with a minimum threshold of 10°C), in 2005, 2006 and 2007, respectively. Under these conditions, potential reproduction of M. incognita on the cover crop did not result in a yield penalty.
  • Authors:
    • Zieminska-Smyk,M.
  • Source: Annales Universitatis Mariae Curie-Skodowska. Sectio E, Agricultura
  • Volume: 63
  • Issue: 3
  • Year: 2008
  • Summary: The characteristics of weeding in cereals were based on 68 phytosociological releves taken from ploughlands of traditional management. The main crops there were: rye, winter wheat, spring wheat, mixture of oat and barley, oat and triticale. Most of the records were taken from winter wheat (30). Cereal was the main crop of the area in Skierbieszowki Landscape Park. 26 samples were taken from spring cereals and 42 samples from winter cereal. Segetal weeds communities of the winter cereals were richer than spring cereals when the number of species is considered, which is shown with an average number of weed species in one single sample: 20.3 species in winter cereals and 17.7 species in spring cereals. Weed coverage varied from 20% to 70% but only occasionally reached 70%. Cereals fields were not very weeded because of good fertilization and crop protection chemicals. Most of the weeds in spring and winter cereals were short-lived rather than perennial, which can be a result of progress rhythm in arable crops. Spring cereals were less weeded than winter cereals. It can be noticed by covering coefficient which were 7.500 in spring cereals and 9.600 in winter cereals.