No-till Corn Research Articles

Effects of Tillage and Prior Crop on the Incidence of Five Key Pests on Ohio Corn

Pest management records representing a decade of field scouting observations of field corn in two Ohio counties were analyzed to determine the relative incidence of black cutworm, Agrotis ipsilon (Hufnagel), stalk borer, Papaipema nebris (Guenee), armyworm, Pseudaletia unipuncta (Haworth), slugs, and European corn borer, Ostrinia nubilalis (Hubner) in relation to tillage practices and prior crop. The incidence of black cutworm, stalk borer, armyworm, and slug infestations exceeding a potential action threshold increased as tillage was reduced, especially in no-tillage corn. The incidence of first-brood European corn borer infestations was less in no-tillage compared with that of either conventional or reduced tillage corn. Prior crop history did not significantly influence the relative incidence of black cutworm, stalk borer, or slugs on corn, including that planted no-till. Armyworm infestations exceeding the potential action threshold were primarily limited to corn sites planted no-tillage into a grassy prior crop. The incidence of European corn borer was greater in continuous corn than in corn following other crops.

Winter Cover Crop Suppression Practices and Natural Enemies of Armyworm (Lepidoptera: Noctuidae) in No-Till Corn

Rye, Secale cereale L., used as a winter cover crop was killed by the herbicide paraquat or by mowing with a rotary mower. In subsequent no-till corn, Glyptapanteles militaris (Walsh) (Hymenoptera: Braconidae) and Periscepsia laevigata (Wulp) (Diptera: Tachinidae) were the most abundant of twelve species of parasitoids that emerged from field-collected larvae of the armyworm, Pseudaletia unipuncta (Haworth). No effects of cover crop suppression practices were detected for parasitism rates for any individual species or for total armyworm parasitism. Seasonal parasitism rates ranged from 32 to 45%. Higher numbers of Pterostichus spp. and Scarites spp. (Coleoptera: Carabidae), and wolf spiders (Araneae: Lycosidae) occurred early in the corn season in the mowed cover crop treatment compared with the herbicide killed cover crop treatment. Subsequent reduction of larval densities of amryworm in mowed plots following higher predator densities suggests the role of these generalist predators in biological control of armyworm.

Feasibility of No-Tillage and Ridge Tillage Systems in the Northeastern USA

Rolling, potential erodible cropland predominates the Northeast dairy region so corn (Zea mays L.) acreage under no-tillage (NT) or ridge tillage (RT) may increase. Farmer-operated studies were conducted on well-drained, moderately well-drained, some-what poorly drained, and poorly drained sites in 1986, 1987, and 1988 to evaluate the competitiveness of NT and RT corn systems relative to conventional or moldboard plow (MP) corn systems. Compared with MP, NT had lower plant populations in seven and lower grain yields in five of the 12 site-year comparisons (...)

Seed Quality Effect on Corn Performance under Conventional and No-Tillage Systems

In northern regions, no-tillage corn (Zea mays L.) planting often results in reduced and/or delayed seedling emergence and growth. The objective of this research was to evaluate the effects of seed quality on the performance of three commercially available corn hybrids grown with conventional-tillage (CT), no-tillage (NT), and no-tillage with in-row residue removed (NT-R). Field studies were conducted under the three tillage systems with seed lots having high (95–99%), medium (89–98%), and low (84–95%) warm and cold germination test values. Hybrids used were FR20A × FR31, LH74 × LH51, and A632 × LH39. The studies were conducted from 1986 to 1988 on Piano silt loam (fine, mixed, mesic Typic Arguidoll) soils near Arlington and Janesville, WI. There were also early (mid- to late April) and late (mid- to late May) planting dates at Arlington. Increased residue cover with NT and NT-R systems resulted in 2 to 4 °F cooler soil temperatures at planting compared to CT, which reduced average percentage corn emergence by 3%, delayed emergence by 2 to 5 d, reduced vegetative dry weight at 45 d after planting by 30 to 60%, delayed silking 5 to 7 d, and increased harvest grain moisture 1 to 5%. Average grain yields were also reduced by 9% under NT compared to CT. Compared to high quality seed, medium and/or low seed quality caused 4 to 6% lower emergence, delayed emergence less than 1 d, reduced vegetative dry weight by 10 to 15%, extended days to silking by 1 to 2 d, increased grain moisture about 1%, and decreased average grain yield by 4% (despite thinning to constant final stands). Seed quality effects were usually smaller than tillage system effects, and tillage system by seed quality interactions were infrequent. Special concern about seed quality under NT is unwarranted, but to optimize probability for high yields growers should plant high quality seed regardless of the tillage system used.

Diurnal Abundance and Spatial Distribution of Armyworm, (Lepidoptera: Noctuidae) in No-till Corn

Armyworm, Pseudaletia unipuncta (Haworth), spatial and diurnal abundance in no-till corn was sampled at six-h intervals (at 0200,0800, 1400, and 2000) during three 24 h periods. During the early growth stages of corn, armyworm density on corn plants was higher during nighttime, and differed significantly between 0200 and 1400 hours. The number of armyworm feeding on leaf edges of the early growth stages of corn was significantly higher at 0200 than during any other time, and the proportion of total larvae on corn plants that were on leaf edges was significantly higher at 0200 than during the daytime. Daytime foliage sampling will underestimate the true populations of armyworm feeding on foliage by 1.8 to 31 fold, depending on the time and thoroughness of the sampling program.

Influence of Winter Cover Crop Suppression Practices on Seasonal Abundance of Armyworm (Lepidoptera: Noctuidae), Cover Crop Regrowth, and Yield in No-Till Corn

Rye ( Secale cereale L.), used as a winter cover crop, was killed by paraquat or by mowing with a bushog. In the early stages of subsequent no-till corn, abundance of armyworm, Pseudaletia unipuncta (Haworth), was lower in the mowed treatment compared with the sprayed treatment in three of five fields and did not differ in another field. Over the duration of the first armyworm generation, cumulative armyworm-days in the sprayed treatment were greater than in the mowed treatment in three of five fields and did not differ in another field. Mowing the cover crop was 40% less expensive than spraying. Competition from rye regrowth in the mowed treatment did not diminish yields. Corn silage yields were increased by mowing ( P = 0.07), and the average increase in net benefit from mowing the cover crop compared with spraying was 91–113/ha. Cover crop mowing may be an economical and effective means of managing armyworm populations in no-till corn.

No-Till Corn Response to Nitrogen Rate and Timing in the Middle Atlantic Coastal Plain

Improved N use efficiency for no-till corn (Zea mays L.) production on sandy soils may be enhanced with split applications of N fertilizer immediately prior to periods of highest N uptake. A field study was conducted in 1988 and 1989 at the Eastern Shore Agricultural Experiment Station in Painter, VA, on a Bojac loamy sand (coarse-loamy, mixed, thermic Typic Hapludult) to investigate split N applications near silking. Nitrogen treatments (as 30% N-urea ammonium nitrate solution) of 0, 36, 72, 108, and 144 lb N/acre at the 5-leaf growth stage (ENR) were factorially arranged with 0, 25, 50, 75, and 100 lb N/acre applied at the 16-leaf stage (LNR) in a randomized complete block design with three replications. Corn cultivar Pioneer Brand 3320 was planted no-till into a killed winter rye (Secale cereale L.) cover crop onto the same site each spring. At the 14-leaf stage, samples of the leaf immediately below the whorl were collected from each plot and analyzed for N, P, K, Ca and Mg. Yield response was attributed less to timing of N applications than to the total N rate; however, at least 36 lb N/acre were required at the 5-leaf stage to prevent N deprivation and reduction of yield potential. While LNR treatments increased yield at all ENR treatments, the greatest yield response to late N application was obtained between 36 and 72 lb N/acre applied early. At equal N rates, N use efficiency was not significantly affected when fertilizer N applications were split between the 5-leaf and 16-leaf growth stages. Under the high rainfall conditions which increased yield and nitrate leaching potentials, recommended 16-leaf stage N rates for 14-leaf N concentrations of 1.7 to 2.0% ranged from 85 to 92 lb/acre. Calibration of 16-leaf stage fertilizer N requirements with 14-leaf stage critical N values were not successfully developed for leaf N concentrations greater than 2% because yields were not maximized despite total N applications considerably higher than routinely recommended. Diagnosis and Recommendation Integrated System (DRIS) norms developed in Georgia did not accurately diagnose corn N status in Virginia; hence, local calibration of DRIS norms is necessary.

Chemical Attributes of Soils Subjected to No-Till Cropping with Rye Cover Crops

Rye (Secale cereale L.) cover crops are often promoted to supply additional residue in no-till production situations; however, the effect of inclusion of rye on soil chemical properties is largely unknown. Soils were sampled, 20 cm deep, from four 4-yr studies in which no-till corn (Zea mays L.) and soybean (Glycine max L. Merr.) were grown continuously or in rotation on a Canfield silt loam (fine-loamy, mixed, mesic Aquic Fragiudalf) or in rotation only on a Hoytville silty clay (fine, illitic, mesic Mollic Ochraqualf), with and without a winter rye cover crop. Corn had been fertilized each spring with 224 kg N ha−1 as either injected anhydrous ammonia or surface-broadcast urea-ammonium nitrate (UAN) solution. All plots sampled showed greater concentrations of organic C, exchangeable K, and Bray-1 extractable P in the surface 5-cm increment of soil than deeper in the sampled profile. Exchangeable Ca and Mg concentrations were often less at this depth than deeper in the profile, particularly when N was applied as surface-broadcast UAN solution. Soil pH was generally lowest in the zone of N application. Addition of the rye cover crop had little effect on the distribution of chemical attributes, other than increasing concentrations of exchangeable K near the soil surface in several comparisons.

No-till Sweet Corn in Three-legumes' Cover-crops for Improved Productivity

No-till Sweet Corn in Three-legumes' Cover-crops for Improved Productivity

A Method for Observing Below-ground Pest-Predator Interactions in Corn Agroecosystems

A method was developed and evaluated in no-tillage corn fields to investigate the possibility of direct observations of below-ground pest-predator interactions. Rectangular-shaped plexiglass plates were buried parallel to each plant so that roots and a stage of southern corn rootworm (SCR), Diabrotica undecimpunctata howardi Barber, .could be observed. These direct observations through plexiglass demonstrated that five predators were able to remove large numbers of SCR stages; however, only one arthropod (Lasius spp., Formicidae) was an important predator of all SCR stages. Most arthropods successfully attacked only one or two SCR stages. This method enabled detailed observations of below-ground pest-predator interactions and indicated which soil arthropods were important SCR predators. This method elucidated many aspects of SCR-predator activity that had not been possible to observe in previous experiments.

SOIL MICROARTHROPODS IN LONG-TERM NO-TILLAGE AND CONVENTIONAL TILLAGE CORN PRODUCTION

Cultivation is known to reduce the number and diversity of microarthropod (Acarina and Collembola) populations from levels observed under natural forest or grassland vegetation. Under no-tillage crop production, the soil remains relatively undisturbed and plant litter decomposes at the soil surface, much like in natural soil ecosystems. The objective of this study was to investigate whether microarthropod populations under long-term (19 yr) continuous corn (Zea mays L.) production were increased by no-tillage (NT) vs. conventional tillage (CT; moldboard plow and harrowing) management. Numbers of microarthropods were also obtained from a soil managed as the CT treatment for 15 yr until seeding to bromegrass (Bromus inermus L.) hay for the last 4 yr. During the growing seasons over 2 yr, soil cores were taken every 2–3 wk and extracted for microarthropods using a high gradient extractor. The surface 5 cm of soil was sampled during the first year. All three treatments were different (P < 0.05), with bromegrass, NT and CT soils containing respectively, 15.9, 12.4, and 5.8 microarthropods × 1000 m−2 of which 84, 69, and 70% were Acarina. In the second year, the surface 15 cm was sampled and the number of microarthropods in the corn soils was similar (P < 0.05), containing 33.6 microarthropods × 1000 m−2, 92–98% of which were Acarina. However, microarthropods and soil organic-C were more concentrated in the surface 5 cm of soil in NT than CT. The soil under bromegrass contained 1.3 times more microarthropods (99% were Acarina) than under continuous NT and CT corn. Thus, when examined to a depth of 15 cm, 19 yr of NT corn did not increase the size of the microarthropod populations compared to CT, whereas production of bromegrass hay for 3–4 yr following long-term continuous CT corn did increased microarthropod numbers. Key words: Microarthropods, Collembola, Acarina, Zea mays, Bromus inermus, no-tillage, conservation tillage, soil carbon

Reducing energy inputs to a simulated dairy farm

Mixed-integer linear programming was used to simulate the energy requirements of a 50-ha and 50 cow dairy farm. The farm could be configured for 24 combinations of: diesel fuel or on-farm ethanol fuel production; surface applied or injected manure management alternatives; continuous corn, corn-soybeans or corn-alfalfa crop sequences; or conventional tillage or no-tillage corn production. The model analyzed the flow of total energy (the sum of direct and indirect) produced and/or consumed inside the farm boundaries and the energy crossing the farm boundaries as inputs or outputs. Substituting on-farm produced fuel ethanol for diesel fuel reduced the external fossil energy inputs to the farm for all configurations by 15–19%. In contrast, the total energy consumption of these configurations was 12–38% greater than the diesel-based configurations. Manure injection and surface application alternatives affected total energy utilization by <10% for all farm configurations. Energy inputs in fertilizer nitrogen were 62 and 79% less for soybean and alfalfa-based crop sequences, respectively, than the continuous-corn sequence. No-till corn production generally had less effect on external energy inputs than the selection of manure management alternatives. External energy per product ratio ranged from 3.88 GJ Mg −1 milk for diesel fuel/conventional tillage/surface manure application to 1.78 GJ Mg −1 milk for on-farm fuel/conventional tillage/injected manure application. Total energy per product ratio ranged from 4.38 GJ Mg −1 milk for on-farm fuel/conventional tillage/surface manure application to 2.08 GJ Mg −1 milk for diesel fuel/no-till/injected manure application. Since external energy input and total energy consumption are not always directly linked, the energy use goals for a farm must be clearly specified and the implications understood when farm management selections are made. Otherwise, the intended energy use goals may not be reached.

Weed Management to Minimize Black Cutworm (Lepidoptera: Noctuidae) Damage in No-Till Corn

Field studies were conducted in 1984 and 1985 to evaluate the interaction between black cutworm, Agrotis ipsilon (Hufnagel), damage and weed competition on notill corn (Zea mays L.) growth and yields. Corn seedling damage by A. ipsiLon introduced as third instars 5 d before planting was most severe when weeds were removed at the coleoptile stage and larvae were predicted to be fifth to sixth instars. Delaying weed removal until plants had attained the two-leaf stage significantly decreased the percentage of corn plants damaged by A. ipsiLon larvae. A. ipsiLon larvae introduced as second instars or a combination of neonate, second, and third instars 5 d before planting damaged more corn plants when weed removal was performed at two-leaf stage corn and larvae were predicted to be fifth to sixth instars. A significant relationship between the number of corn seedlings cut and weed population occurred for these introduced smaller instars when weed removal occurred at two-leaf stage corn. Delaying weed removal until four-leaf stage corn resulted in significant grain yield reductions from both weed competition and A. ipsiLon damage in 1984 and only from weed competition in 1985.

Control of Legume Cover Crops in No-Till Corn (Zea mays) and Cotton (Gossypium hirsutum)

Eight herbicide treatments per crop were evaluated for hairy vetch and crimson clover cover-crop control in no-till corn and cotton at two locations in North Carolina. Paraquat alone or combined with dicamba, 2,4-D, or cyanazine, and cyanazine alone, controlled clover the best in both crops. All herbicide treatments, except glyphosate alone, controlled at least 89% of hairy vetch in corn. However, only 2,4-D and cyanazine alone or combined with glyphosate controlled greater than 89% of hairy vetch in cotton. Except for poor control of hairy vetch and crimson clover by glyphosate alone, reduced legume control did not consistently decrease corn or cotton yield. Weed control was reduced in crimson clover treated with glyphosate alone, but control was similar among the remaining herbicide treatments. Effectiveness of legume control did not influence the N concentration of corn or cotton. Corn stand, height, and yield were greater in hairy vetch than in crimson clover. Seed cotton yield did not differ between vetch and clover.

Effect of Lumbricus terrestris L. burrows on hydrology of continuous no-till corn fields

This paper reviews research performed at the USDA-Agricultural Research Service, North Appalachian Experimental Watershed, Coshocton, Ohio into the importance of earthworm burrows, primarily those made by Lumbricus terrestris L., on the hydrology of no-till corn fields. Long-term runoff records showed that infiltration and therefore, potential ground water recharge, could increase by more than 100 mm yr −1 in watersheds farmed with no-till practices as compared to similar fields that were conventionally tilled. The difference in hydrologic response appeared to be due to differences in soil physical properties, possibly those attributable to earthworm activity. When crop residues were left on the surface under continuous no-till corn management, earthworms thrived and their large, nearly vertical burrows persisted. Field studies showed that dye and chemical tracers applied in simulated rainfall moved in the earthworm burrows. The number and sizes of burrows and other macropores were determined and water and nitrate movement in > mm diameter burrows were measured. Flow in these earthworm burrows during 12 growing season storms accounted for an average of 4% of rainfall, (range 1–10%) or 13 times more than would be predicted based solely on their cross-sectional area. Total movement of nitrate in the burrows during these 12 storms was estimated to be <1 kg ha −1.

DISTRIBUTION OF THE STALK BORER PAPAIPEMA NEBRIS (LEPIDOPTERA: NOCTUIDAE) IN NO-TILL CORN

Significantly higher numbers of stalk borer (SB) Papaipema nebris (Guenée) larvae infested no-till corn seedlings were found adjacent to (ie. ca 4 m) field margins, compared to numbers found 30 meters from field margins. Plant species abundant in the areas surrounding SB infested no-till corn fields in southwestern Virginia included tall fescue, Fescuta arundinacea Schreb., and orchardgrass, Dactylus glomerata L. Contour and transect maps of infested fields from 1983 to 1985 suggested SB distribution to be clumped. This distribution was confirmed by high variance to mean ratios of 7.3, 5.8, 12.4, and 9.4 for 1983, 1984, 1985a and 1985b fields, respectively. Green's coefficient of dispersion and Morisita's coefficient of dispersion showed clumping of the SB independent of the mean, variance, and sample size. This is the first documentation that the SB infests fields predominantly on field borders, and the first quantification of the distribution of the SB in no-till corn.

Characterization of Triazine-Resistant Giant Foxtail (Setaria faberi) and its Control in No-tillage Corn (Zea mays)

Triazine-resistant giant foxtail was identified in 1984 near Delta, PA. In field studies conducted from 1985 to 1987, preemergence applications of atrazine with cyanazine or simazine provided poor (≤60%) season-long control of this annual grass in no-tillage corn. Best season-long preemergence control was obtained with metolachlor or microencapsulated formulations of alachlor or EPTC. Postemergence applications of cyanazine or tridiphane + atrazine + crop oil provided poor giant foxtail control. Postdirected applications of paraquat resulted in fair (≥70%) control of giant foxtail through midseason. In greenhouse studies, triazineresistant (R) giant foxtail tolerated preemergence applications of atrazine or simazine at dosages to 9.0 kg ai/ha. Triazine-sensitive (S) giant foxtail was injured by 2.2 kg/ha and higher rates of atrazine and simazine. In laboratory studies, the I50for inhibition by atrazine of photoinduced electron transport in thylakoids isolated from S and R biotypes was determined to be 0.24 and 205 μM, respectively. The differential sensitivity was paralleled by simazine. However, the limited solubility of simazine prevented determination of an I50value with thylakoids from the R biotype.

Profits and risks of using crimson clover and hairy vetch cover crops in no-till corn production

AbstractWinter legume cover crops are receiving increasing attention from agronomists and farmers as a source of nitrogen for summer crops. While agronomists are continually providing new technical information on using legumes as a nitrogen source, little is known on the economics of their use. Previous economic research on legume cover crops has focused mainly on budgeting analysis. In the present work, a twofactorial experiment was designed to test the use of legumes as a nitrogen source for corn(Zea mays L.)in north Georgia. The first factor was winter cover crop with treatments being crimson clover(Trifolium incarnatumL.),hairy vetch(Vicia villosaRoth),wheat(Triticum aestivumL.), and no cover crop or winter fallow. The second factor was nitrogen (N) fertilizer applied at five different rates: 0, 25, 50, 100, or 200 pounds per acre. For each combination of the two factors, mean yield and yield variance were determined. Results indicated that legume cover crops increased both average corn yield and yield variance. The greater yield variance from the use of legume cover crops increases economic risk. Risk-averse farmers must be compensated for increased profit variance by higher average profits. A safety first method was used to evaluate the tradeoff between average profit and profit variance for the risk-averse individual The results showed that hairy vetch with 50 pounds of N per acre was the best combination of cover crop and fertilizer rate for risk-neutral farmers. For risk-averse farmers, hairy vetch without any nitrogen fertilizer is preferred.

Effects of conventional and No-till corn grown in rotation on three soils in Eastern Ontario, Canada

Conventional tillage and no-till were compared on 3 soil types (gently to moderately sloping, well drained fine sandy loam; level to very gently sloping, imperfectly drained very fine sandy (v.f.s.) loam; and level, poorly drained loam) for corn ( Zea mays L.) grown in rotation with cereal grains and hay in eastern Ontario. Averaged over 3 years, there were no significant differences in yields between treatments. Soil temperatures at 0.10-m depth were 0–3°C lower in the no-till throughout the growing season. There were no significant differences in soil water content. Saturated porosity and drainable porosity were reduced in the first year of no-till ( P<0.01). Saturated hydraulic conductivity was greater ( P<0.025) under no-till in the 0–0.30-m depths of the loam and v.f.s. loam sites in the first year of the study. Cone penetrometer resistance was greater in the upper 0.20 m of the no-till plots at the two sandy loam sites, but interactions with depth ( P<0.01) resulted in greater penetrometer resistance in the conventional-till than in the no-till sites below 0.25-m depth. At the loam and v.f.s. loam sites, wheel pressure during planting resulted in a greater increase in penetrometer resistance in the tilled plots than in the no-till ( P<0.01). Bulk density data suggested the formation of a tillage pan below the plowed layer under conventional till at the v.f.s. loam site. Erosion measurements at a sloping site showed that soil loss on the spring-plowed tilled plots average 2.6 times greater than on the no-till.

No-Till Corn Production in a Living Mulch System

Combinations of grass and legume mulches were planted in growing corn during the fall in 1985 and 1986, and the following spring no-till corn was planted into these living mulches. Mulch treatments consisted of a single species or grass plus legume mixtures. Fluazifop-P, 2,4-D, and atrazine were broadcast applied in late April to suppress the mulches and reduce their competition with corn. Chewings fescue and ladino clover competed least with dryland corn. Weed growth associated with chewings fescue and the ladino clover mulches was similar to that in the conventional disk-plant treatment, but corn yields were lower. Hairy vetch mulch was killed by 2,4-D. The winter rye mulch competed with corn and reduced yield.