bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface‐Banded and Broadcast Dairy Manure Effects on Tall Fescue Yield and Nitrogen Uptake
Authors: Bittman Shabtai , Kowalenko C. Grant , Hunt Derek E. , Schmidt Orlando
Published: July 2010

Efficient use of slurry manure nutrients for feeding forage crops on dairy farms is important. The main objective of this study was to compare the response of tall fescue (Festuca arundinacea Schreb.) to N in dairy (Bos taurus) slurry manure applied with a splash plate (broadcasting) or a drag‐shoe (surface banding) applicator, and broadcast mineral fertilizer, in spring, summer, and autumn. The effects of delayed application and band spacing were also examined. The study was conducted from 1994 to 1996 in southwestern British Columbia on a Monroe series soil described as a Eutrochrept (eluviated eutric Brunisol) of moderate to good drainage. Dairy slurry was applied at two rates (50 and 100 kg ha−1 of NH3–N) with splash plate or drag‐shoe applicators at the beginning of growth (early) or 7 to 10 d later (late). Ammonium nitrate fertilizer was broadcast at 0 to 125 kg N ha−1 in 25‐kg increments (only 50 and 100 kg ha−1 rates on the late date). Yield response to manure banded with the drag‐shoe applicator was similar to fertilizer applied at equivalent rates of mineral N. Yield response to splash‐plate‐applied manure was generally 0.5 to 1.0 Mg ha−1 lower than to fertilizer in summer and spring, but similar in autumn. Total N uptake was 15 to 20 kg ha−1 greater from drag‐shoe than from splash‐plate applied manure at high N application rate in spring and summer; differences in autumn were smaller. Treatment differences in total N concentration were small (at equivalent rates of applied mineral N). Apparent recovery of mineral N from manure was 20 to 30% greater with drag‐shoe than with splash plate application in summer and 18% greater for the early application in spring. Delaying manure application had little effect on yield, but increased tissue N concentrations in some treatments in summer and autumn. Nitrate concentrations were always similar or lower for manure than for fertilizer treatments. This study showed that manure applied with the drag‐shoe applicator produced consistent crop response similar to N fertilizer at equivalent rates of mineral N.
Spectral Detection of Micronutrient Deficiency in ‘Bragg’ Soybean
Authors: Adams Matthew L. , Norvell Wendell A. , Philpot William D. , Peverly John H.
Published: July 2010

Iron and Mn deficiency are the most common micronutrient deficiencies in soybean [Glycine max (L.) Merr.] in the United States, although deficiencies in Zn and Cu have also been observed in the field. This study was conducted to assess the utility of leaf fluorescence and reflectance as a rapid means of detecting Mn, Zn, Fe, and Cu deficiency, and to determine whether spectral methods could be used to derive critical concentration levels for Mn, Fe, Zn, and Cu. ‘Bragg’ soybean plants were raised as seedlings in aerated, chelator‐buffered nutrient solutions in a growth chamber. Manganese, Zn, Cu, and Fe were supplied over a wide range of concentrations to induce a range of deficiency symptoms. Chlorophyll concentrations and reflectance and fluorescence characteristics of the youngest fully mature leaf were measured periodically. Reflectance characteristics responded to decreases in leaf total chlorophyll concentration, while fluorescence characteristics responded to changes in electron transport associated with Mn, Zn, Cu, or Fe deficiency. Critical concentration ranges estimated from spectral measures were 9 to 10 mg kg−1 for Mn, 12 to 18 mg kg−1 for Zn, 45 to 50 mg kg−1 for Fe, and 1.0 to 1.5 mg kg−1 for Cu. The spectral measures used in this study were useful in detecting Mn, Zn, Fe, and Cu deficiencies and may provide a rapid, nondestructive method for the detection of these deficiencies in the growth chamber, greenhouse, or field. The spectral measures were also useful for establishing critical levels for Mn, Zn, Fe, and Cu under controlled conditions.
Furrow and Flood Irrigation of Early‐Planted, Early‐Maturing Soybean Rotated with Rice
Authors: Heatherly Larry G. , Spurlock Stan R.
Published: July 2010

The ESPS (Early Soybean Production System) is being adopted in the midsouthern USA to avoid some of the effects of normal late‐season drought. Field studies with soybean [Glycine max (L.) Merr.] grown following rice (Oryza sativa L.) were conducted in 1994, 1995, and 1996 at Stoneville, MS, on Sharkey clay (very‐fine, smectitic, thermic Chromic Epiaquert) to compare yield of Maturity Group (MG) IV and V cultivars grown under furrow vs. flood irrigation, and yield and economic performance of nonirrigated (NI) and furrow‐ and flood‐irrigated MG IV and V cultivars. Three‐year average yields from irrigated MG IV and V cultivars were significantly greater than average NI yield. Within each year, yields from MG V cultivars equaled or exceeded those from MG IV cultivars in all environments. Furrow‐irrigated MG IV cultivars yielded significantly more than NI cultivars in all 3 yr, while flood‐irrigated MG IV cultivars yielded more than NI cultivars in 2 of the 3 yr. Both furrow‐ and flood‐irrigated MG V cultivars yielded significantly more than NI cultivars in 2 of the 3 yr. Three‐year average net returns from furrow‐ and flood‐irrigated environments were similar, and both were greater than those from the NI. Within each year, average net return from MG V cultivars in all environments was equal to or greater than that from MG IV cultivars. These results indicate that the ESPS can be used to effectively grow soybean in a rice–soybean rotation on clay soil, and that irrigation will usually result in greater profit from soybean.
Residual Effects of Fall Deep Tillage on Soybean Yields and Net Returns on Tunica Clay Soil
Authors: Wesley Richard A. , Smith Lowrey A. , Spurlock Stan R.
Published: July 2010

Seed yield of monocrop soybean [Glycine max (L.) Merr.] grown on nonirrigated clay soils in the Mississippi River alluvial flood plain has been consistently low and marginally profitable. Deep tillage (subsoiling) of certain clayey soils in the fall when the soil profile is dry significantly increases yields and net returns from this production system. Yields and net returns were evaluated for seven deep‐till treatments and a conventional‐till treatment that was disked annually (C). The deep‐till treatments included subsoiling annually and once every second, third, fourth, and fifth year (DT1, DT2, DT3, DT4, and DT5, respectively), Paratill annually (PT1), and profile modification every fifth year (MP). Over the 5‐yr study, DT1 produced the greatest yield (3452 kg ha−1), which was 1016 kg ha−1 (42%) above the average yield from C (2436 kg ha−1). Yields from DT2, DT3, and PT1 were virtually identical and averaged only 198 kg ha−1 (5–6%) less than the average yield from DT1, whereas yields from DT4 and DT5 averaged 291 kg ha−1 (9%) and 613 kg ha−1 (18%) less. Net returns from DT1 ($436 ha−1) averaged the highest, whereas returns from C ($220 ha−1) were the lowest. Net returns from DT2 and DT3 were within 5% of the net returns from DT1, whereas net returns from the DT4, DT5, PT1, and MP treatments respectively averaged 9, 26, 9, and 31% less than returns from DT1. Thus, fall deep tillage should be performed at least once every 3 yr to maximize and sustain higher yields and net returns from soybean grown on nonirrigated Tunica clay (clayey over loamy, smectitic, nonacid, thermic Vertic Haplaquept).
Design and Testing of a Global Positioning System‐Based Radiometer for Precision Mapping of Pearl Millet Total Dry Matter in the Sahel
Authors: Lawrence Peter R. , Gérard Bruno , Moreau Caroline , Lhériteau Fabrice , Buerkert Andreas
Published: July 2010

The nondestructive determination of plant total dry matter (TDM) in the field is greatly preferable to the harvest of entire plots in areas such as the Sahel where small differences in soil properties may cause large differences in crop growth within short distances. Existing equipment to nondestructively determine TDM is either expensive or unreliable. Therefore, two radiometers for measuring reflected red and near‐infrared light were designed, mounted on a single wheeled hand cart and attached to a differential Global Positioning System (GPS) to measure georeferenced variations in normalized difference vegetation index (NDVI) in pearl millet fields [Pennisetum glaucum (L.) R. Br.]. The NDVI measurements were then used to determine the distribution of crop TDM. The two versions of the radiometer could (i) send single NDVI measurements to the GPS data logger at distance intervals of 0.03 to 8.53 m set by the user, and (ii) collect NDVI values averaged across 0.5, 1, or 2 m. The average correlation between TDM of pearl millet plants in planting hills and their NDVI values was high but varied slightly depending on solar irradiance when the instrument was calibrated. There also was a good correlation between NDVI, fractional vegetation cover derived from aerial photographs and millet TDM at harvest. Both versions of the rugged instrument appear to provide a rapid and reliable way of mapping plant growth at the field scale with a high spatial resolution and should therefore be widely tested with different crops and soil types.
Evaluation of Irrigated Tall Fescue–Legume Communities in the Steppe of the Southern Rocky Mountains
Authors: Guldan Steven J. , Lauriault Leonard M. , Martin Charles A.
Published: July 2010

Producers in the irrigated steppe of the southern Rocky Mountains are seeking ways to improve the summer productivity of their established cool‐season grass pastures, commonly tall fescue (Festuca arundinacea Schreb.). From 1994 to 1997, a study was conducted under irrigation at the New Mexico State University Alcalde Sustainable Agriculture Science Center, in which dry matter yield of monoculture tall fescue was compared with that of swards containing tall fescue in mixtures with alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus corniculatus L.), cicer milkvetch (Astragalus cicer L.), and kura clover (Trifolium ambiguum M.B.) in a randomized complete block design with three blocks. Percent tall fescue in the sward and the yield of tall fescue in mixtures declined from 1994 to 1996 and then increased in all mixtures except tall fescue–kura clover in 1997. Dry matter yields of alfalfa and cicer milkvetch increased until 1996 then declined, while birdsfoot trefoil equilibrated in 1996 and 1997 and kura clover continued to increase. Combined dry matter yields followed a trend similar to that of the legume yields except that, in 1996 and 1997, yields of the tall fescue–cicer milkvetch mixture were comparable to those of monoculture tall fescue, which were 5.76 and 6.72 Mg ha−1 for 1996 and 1997, respectively. Over the life of the study, tall fescue–cicer milkvetch yielded less than one‐half that of tall fescue–alfalfa while mixtures of tall fescue with birdsfoot trefoil or kura clover were equal to each other and intermediate to the others.
Maize Yield as Affected by Organic Inputs and Urea in the West African Moist Savanna
Authors: Vanlauwe B. , Aihou K. , Aman S. , Iwuafor E. N. O. , Tossah B. K. , Diels J. , Sanginga N. , Lyasse O. , Merckx R. , Deckers J.
Published: July 2010

Nutrient depletion is a major constraint to crop production for moist savanna soils, and inputs of nutrients are required to overcome this constraint. The impact of sole and combined applications of organic inputs (OIs) [fresh tree prunings, Pueraria phaseoloides (Roxb.) Benth. residues, and manure] and urea [(NH2)2CO] on maize (Zea mays L.) performance was investigated at four sites in West Africa. Interactions between OIs and urea resulting in added benefits from their mixed rather than sole application were quantified, and likely causes were evaluated. Maize in the mixed treatments, receiving 45 kg ha−1 urea N and 45 kg ha−1 N as OIs, produced 1.6 and 3.7 Mg ha−1 grain in Sékou and Glidji, respectively. Based on the yields from sole application of either OIs or urea, added benefits from the mixture were 0.49 Mg ha−1 grain (P < 0.001) in Sékou and 0.58 Mg ha−1 (P < 0.15) in Glidji. These benefits were generated during grain filling, which was characterized by drought, and they were likely caused by improved soil water conditions with mixed applications compared with sole applications. Nitrogen recovery from urea was higher in the combined treatments (44% in Sékou and 32% in Glidji) relative to the sole urea treatments (22% in Sékou and 15% in Glidji). Positive interactions between OIs and urea occurred at two of four sites and were likely caused by improved soil water conditions after applying OIs. Organic inputs can alleviate constraints to crop growth other than N depletion and, as such, improve the use efficiency of N fertilizer.
Nutritive Value Responses of Rhizoma Peanut to Nitrogen and Harvest Frequency
Authors: Redfearn Daren D. , Venuto Brad C. , Pitman W.D.
Published: July 2010

Management strategies to enhance or preserve nutritive value of rhizoma peanut (Arachis glabrata Benth.) would be beneficial because high plant growth rates and adverse weather at harvest often result in low nutritive value for both pastures and hay along the coastal plain of the lower Gulf Coast. The objective of this study was to determine if a 30‐ or 60‐d harvest frequency or 0, 110, or 220 kg N ha−1 fertilization could be managed to enhance crude protein (CP) yield and nutritive value of rhizoma peanut at three locations in Louisiana. Crude protein, neutral‐detergent fiber (NDF), in vitro true digestibility (IVTD), and digestible NDF (DNDF) were measured on ‘Florigraze’ rhizoma peanut grown at three Louisiana locations in 1997 and 1998. Nitrogen fertilization increased CP yield approximately 80 kg ha−1 for the 110 and 220 kg N ha−1 treatments at two locations in 1 of 2 yr. Nitrogen fertilization affected nutritive value at two harvests at two locations in 1998 only. However, nutritive value was consistently lower for 60‐d harvests than for 30‐d harvests and was more consistent. Rhizoma peanut harvested in 1997 at 30‐d intervals had 50 g kg−1 greater CP, 72 g kg−1 greater IVTD, and 40 g kg−1 greater DNDF coupled with 80 g kg−1 lower NDF than rhizoma peanut harvested at 60‐d intervals. Likewise, there were seasonal influences on nutritive value. Responses in CP yield and nutritive value observed in this study were influenced more by environment (primarily rainfall) than by N fertilization and harvest management.
Economic and Agronomic Assessment of Deep Tillage in Soybean Production on Mississippi River Valley Soils
Authors: Popp Michael P. , Keisling Terry C. , Dillon Carl R. , Manning Patrick M.
Published: July 2010

Using deep tillage to alleviate the adverse effects of deleterious soil physical properties has been tried many times. Consistent economic returns have been reported for in‐the‐row subsoiling of loamy sand and coarser soils and for deep loamy soils where the subsoil slit bisects the water flow channel during rainfall events where there is runoff. Recent reports of yield responses on clayey soils and silt loams led to a reassessment of subsoiling of these soils in Arkansas. A randomized complete block design was conducted at four locations with tillage treatments of conventional shallow, deep chisel, subsoil dry, subsoil wet, subsoil at 45° to planting direction, and paratill. Plots were harvested for grain. Economic analysis was performed using the Mississippi State Budget Generator (MSBG). The machinery complement was commensurate with that found on farms in the region. Net returns above total specified costs (NRAT) rather than above direct costs were calculated to reflect the decision framework of a producer. A profitable yield response was obtained from subsoiling in dry soil on deep alluvial clayey and silt loam soils but not on the thin loessial silt loams. Net returns to subsoiling wet were not significantly higher than those to conventional shallow tillage. Tillage with a chisel plow as deep as it could be operated (approximately 15 cm) was not a substitute for subsoiling because yield responses from deeper tillage were not comparable. The 45° subsoiling in dry soil tended to be superior to all other tillage treatments.
Residue Decomposition and Soil Nitrogen are Affected by Mowing and Fertilization of Marigold
Authors: Ball‐Coelho Bonnie R. , Reynolds L.Bruce , Back Allison J. , Potter John W.
Published: July 2010

To suppress root‐lesion nematodes (Pratylenchus penetransCobb), marigold (Tagetessp.) is grown as a rotation crop; however, little is known about its decomposition. The timing of N release to soil affects both the nutrition of the subsequent crop and also the environment, which could possibly be altered by biocides produced by marigold. Decomposition was quantified in the field by monitoring residues of marigold and cereal rye (Secale cerealeL.), a common rotation crop, over time in litter bags subjected to different conditions. Marigold decomposition proceeded normally and without toxic effects on decomposers. In the fall of rotation years, topsoil NO3concentration was usually higher under marigold (1.1 mg kg−1) than under rye rotation (0.3 mg kg−1), but this depended on the method of marigold management. In marigold plots, fall NO3levels were greatest where plants were mowed early (August) or fertilized with 90 kg N ha−1and lowest where plants were left standing over winter. In plots where marigold was mowed in September or left standing, fall NO3levels were sometimes no higher than in rye plots. Overwinter N release from bags of marigold shoots (stems and leaves) on the soil surface (39 kg ha−1) was less than that from buried bags (119 kg ha−1). Together, these results suggest that a marigold rotation may be a viable alternative to rye, but to minimize N loss, marigold crops should be left standing over winter and preplant fertilized with 45 kg N ha−1
Barnyardgrass Growth Inhibition with Rice Using High‐Performance Liquid Chromatography to Identify Rice Accession Activity
Authors: Mattice John D. , Dilday Robert H. , Gbur Edward E. , Skulman Briggs W.
Published: July 2010

Some accessions of rice (Oryza sativa L.) have been shown to inhibit the growth of barnyardgrass (Echinochloa crus‐galli (L.) Beauv.). Our objective was to determine if high‐performance liquid chromatography (HPLC) chromatograms from leaf extracts of different accessions of rice correlated with weed control activity. Chromatograms of extracts consisting of 10 mg of fresh leaf tissue per milliliter of methanol (CH3OH) were obtained from 40 accessions of rice. Cluster analysis was performed using 20 peaks from the chromatograms. Three clusters were found, with one cluster being distinctly separated from the other two. Although weed control data are not available for all the accessions, the isolated cluster contains all of the accessions that have been shown to inhibit growth of barnyardgrass and none that do not. This indicates that the assay could be used year‐round to screen accessions of rice for weed control potential to determine which accessions should be further tested in the field. This could be done in a relatively short time using a small amount of space in the greenhouse. Because the assay requires only 10 mg of tissue per milliliter of methanol, it may potentially be used to test individual plants within an accession for weed control potential in a nondestructive manner.
Inclusion of the Fractal Dimension of Leafless Plant Structure in the Beer‐Lambert Law
Authors: Foroutan‐pour Kayhan , Dutilleul Pierre , Smith Donald L.
Published: July 2010

The Beer‐Lambert law is commonly used to describe the relationship between the proportion of light penetrating a plant canopy and the leaf area index (LAI). Although the geometric distribution of leaf area has a potential effect on the ability of a plant to intercept light, the equation contains no term to account for it. In this study, the geometric distribution of leaf area was quantified by the fractal dimension of leafless plant structure (FD). The objective was to evaluate the contribution of plant structure complexity to the Beer‐Lambert law, by including FD in the equation. The crop was soybean [Glycine max. (L.) Merr.]. Data were collected according to a block design with four blocks and five weekly repeated measures. The analyzed variables were LAI and light penetration (% per plant), and FD, estimated using leafless plants photographed from the side that allowed the maximum appearance of branches and petioles. Statistical analyses were performed week by week, on weekly means and on block means. When LAI and FD were significantly correlated (i.e., at the end of canopy development and on weekly means), inclusion of either variable as regressor in the equation provided similar goodness‐of‐fit. In other instances, inclusion of FD as a multiplicative factor of LAI increased the r2 value up to 0.31. In all instances, the correlation between light penetration and FD was stronger than between light penetration and LAI. In summary, the application of the Beer‐Lambert law for light penetration into the canopy is improved by inclusion of FD.
Production and Quality of Irrigated Timothy Hay in Saskatchewan for Export Hay Markets
Authors: Jefferson Paul G. , Coulman Bruce E. , Kielly G. Andrew
Published: July 2010

A market for timothy (Phleum pratense L.) hay exists in Asia and is adapted under irrigation in southern Saskatchewan, but variation among cultivars for the required quality characteristics was unknown. We evaluated forage yield and quality for export and traditional hay markets of timothy cultivars on two irrigated sites in southern Saskatchewan. Eleven cultivars were grown at two N fertilizer rates (100 and 150 kg N ha−1) at Swift Current and Outlook for 3 yr. Seed head length, stem length, leaf/stem ratio, forage dry matter yield, neutral detergent fiber, acid detergent fiber, and crude protein concentrations were determined. Seed head length and stem length, which are quality characteristics for export to Japan, were subject to site × cultivar × year interaction due to instability of some cultivars. ‘Drummond’ had the longest seed heads in five of six site‐years while ‘Toro’ had the shortest in four site‐years. ‘Timfor’ and Toro ranked first to fourth for stem length while Drummond and ‘Bottnia II’ had the shortest stems. Thus, the requirement for long heads and long stems was not met by one cultivar. Principal component analysis separated cultivars based on maturity compared with yield. Richmond, the earliest‐maturing cultivar, was distinct from Drummond, the latest cultivar. The second principal component separated Timfor, a high‐yield and low‐quality cultivar from Bottnia II, a low‐yield and high‐quality cultivar. Drummond is the best cultivar for export markets while Richmond is better suited for traditional markets.
A Relational Database for Agronomic and Genealogical Sugarcane Data
Authors: Stafne Eric T. , Brown James S. , Shine James M.
Published: July 2010

A comprehensive relational database has been created at the USDA‐ARS Canal Point Sugarcane Field Station to facilitate the entry and retrieval of data for the breeding program using Microsoft Access 2000. This software is readily available and easily adaptable to a wide variety of breeding programs. A relational database provides an efficient and powerful way to store, retrieve, manipulate, query, and report data in a multiuser environment. Data entry is performed through a series of self‐explanatory forms. Once entered, data can be accessed and queried through a local area network (LAN). Data from the seedling stage (true seed planting), Stage I and Stage II (the first two clonally propagated selection stages at Canal Point), and Stage IV (the final selection stage before cultivar release) of the breeding program have currently been included in the database. The database also includes the Canal Point clonal collection inventory, crossing information, seed (fuzz) inventory, and pedigree tracking. Future plans include incorporation of data from Stage III (the next to last clonally propagated selection stage), pathology data, and access through the Canal Point Internet web site (www.canalpoint.sugarcane.usda.gov).
Effects of Early Season Nitrogen on Grass–Clover Swards in the Northeastern USA
Authors: Stout William L. , Weaver Stefan R. , Elwinger Gerald F.
Published: July 2010

Grass–legume pastures that rely on biologically fixed N are often N deficient in the spring. Early season N applications to grass–clover pastures can help overcome this deficiency. Our objective was to test the effects of early season N application and harvest height on total dry matter (DM) yield and clover fraction of a grass–clover sward in the northeast USA. The study was conducted for 3 yr (1996–1998) at the Russell Larson Agricultural Research Center in Rock Spring, PA (40°48′N, 77°52′W; 330 m above sea level). The soil on the site is a Hagerstown silt loam (Typic Hapludalf, fine, mixed, mesic). The effect of early season N fertilization (0, 22.4, 44.8, and 89.6 kg ha−1) was measured on an orchardgrass (Dactyls glomerata L. cv. Pennlate)–white clover (Trifolium repens L. cv. Will) sward harvested at three sward heights (15, 22.5, and 30 cm). Increasing N fertilization and target sward harvest height (TSHH) generally increased the early season total DM yield and reduced the clover fraction in the sward. However, by the end of the growing season, the clover fraction from the fertilized treatments was identical to that of the unfertilized treatments. Total early season DM yields on mixed grass–clover swards were increased by 20% with an application of 45 kg N ha−1. Also, maintaining a 15‐cm TSHH along with 45 kg N ha−1 would maximize the clover fraction in the sward.
Peanut Response to Tillage and Fertilization
Authors: Jordan David L. , Barnes J. Steve , Bogle Clyde R. , Naderman George C. , Roberson Gary T. , Johnson P. Dewayne
Published: July 2010

Peanut (Arachis hypogaea L.) in the USA is generally seeded after several primary tillage operations that may include disking, chisel plowing, moldboard plowing, and bedding (conventional tillage systems). Concerns over erosion and production costs have increased interest in reduced tillage systems. Production in reduced tillage systems minimizes ability to incorporate fertilizers below the pegging zone, and residue on soil surface could impact movement of calcium sulfate (CaSO4) into the soil, reducing Ca availability to pegs. Research was conducted from 1997 through 1999 to compare peanut yield and gross economic value of virginia market type peanut planted in conventional and strip tillage systems. Preplant fertilizer did not affect response to tillage. Response did not differ among conventional tillage systems consisting of disk, disk and chisel, or disk and moldboard plow or among reduced tillage systems. Pod yield of peanut grown in the most effective conventional tillage system exceeded yield when peanut was strip‐tilled into stubble of the previous crop, strip‐tilled into a wheat (Triticum aestivum L.) cover crop, or strip‐tilled into beds prepared the previous fall without a cover crop. Tillage system and CaSO4 rate affected pod yield and gross value independently. Gross value increased when CaSO4 was applied regardless of tillage system. These data suggest that preplant fertilizer at relatively low, remedial rates does not affect peanut response to tillage systems. These data also suggest that tillage system does not have a major impact on peanut response to CaSO4. Collectively, these data indicate that the highest peanut yields occur in conventional tillage systems.
Dairy Compost, Variety, and Stand Age Effects on Kenaf Forage Yield, Nitrogen and Phosphorus Concentration, and Uptake
Authors: Muir James P.
Published: July 2010

The dairy and beef industries are looking for alternative forages with high yields that are capable of efficient manure‐P recycling when soil moisture is limiting. Three varieties of kenaf (Hibiscus cannabinus L.) were grown under dryland conditions and harvested at 60, 90, and 120 days after planting (DAP) with yearly applications of 0, 10 (56 kg P), and 20 (112 kg P) Mg DM ha−1 of dairy manure compost. Kenaf variety ‘India’ was less productive but had as high or higher N and P concentrations than either ‘Guatemala 4’ or ‘Everglades 41’ during the second year of the trial. Yields tended to increase and N or P concentrations decrease with DAP, but were affected by rainfall patterns. In 1998, when rainfall was concentrated during the first 60 DAP and the last 30 DAP, the 120 DAP harvest averaged 5.28 Mg DM ha−1 yr−1, 2.2 times the 90 DAP average. In 1999, when rainfall fell exclusively during the first 90 DAP, the 90 DAP harvest averaged 5.06 Mg DM ha−1 yr−1, 1.6 times the 120 DAP average. Plant P concentration tended to increase and N concentration to decrease with compost application the second year. The cumulative effect of compost application increased forage DM yields as well as P and N uptake during the second year. Average P removal by kenaf in the 10 and 20 Mg compost DM ha−1 plots was 10.4 and 6.8%, respectively, of the P equivalent added by the compost. This indicates that the average forage P concentration of 2.11 g kg−1 from the plots that received compost would result in insufficient forage P uptake to avoid excessive soil P buildup with sustained yearly compost application.
Detection of Phosphorus and Nitrogen Deficiencies in Corn Using Spectral Radiance Measurements
Authors: Osborne S. L. , Schepers J. S. , Francis D. D. , Schlemmer M. R.
Published: July 2010

Applications of remote sensing in crop production are becoming increasingly popular due in part to an increased concern with pollution of surface and ground waters due to over‐fertilization of agricultural lands and the need to compensate for spatial variability in a field. Past research in this area has focused primarily on N stress in crops. Other stresses and the interactions have not been fully evaluated. A field experiment was conducted to determine wavelengths and/or combinations of wavelengths that are indicative of P and N deficiency and also the interaction between these in corn (Zea mays L.). The field experiment was a randomized complete block design with four replications using a factorial arrangement of treatments in an irrigated continuous corn system. The treatment included four N rates (0, 67, 134, and 269 kg N ha−1) and four P rates (0, 22, 45, and 67 kg P ha−1). Spectral radiance measurements were taken at various growth stages in increments from 350 to 1000 nm and correlated with plant N and P concentration, plant biomass, grain N and P concentration, and grain yield. Reflectance in the near‐infrared (NIR) and blue regions was found to predict early season P stress between growth stages V6 and V8. Late season detection of P stress was not achieved. Plant N concentration was best predicted using reflectance in the red and green regions of the spectrum, while grain yield was estimated using reflectance in the NIR region, with the particular wavelengths of importance changing with growth stage.
Red Clover–Potato Cultivar Combinations for Improved Potato Yield
Authors: Sturz A. V. , Arsenault W. , Christie B. R.
Published: July 2010

One of the challenges to potato (Solanum tuberosum L.) production systems is to reduce N applications without incurring any marketable yield penalty. From previous studies, it was established that red clover (Trifolium pratense L.) can encourage the development of beneficial rhizobacterial communities that promote potato growth and development, in essence making agricultural soils as or more productive for specific quality attributes. In the present 2‐yr study, we examined the influence of the red clover cultivars AC Charlie, AC Endure, AC Kingston, Atlas, Marino, and Prosper on the potato cultivars Kennebec, Russet Burbank, and Shepody, grown in the following season. We found that the preceding clover cultivar had no influence on either Kennebec or Russet Burbank. However, Shepody potato following AC Kingston showed a significant yield advantage (P = 0.05), in tonnes per hectare, over other clover cultivars (except Atlas) in the Size 2 category of tubers (tubers >51 mm in diam. and <280 g), the grade for which growers are characteristically paid the most. We encourage breeding programs to examine the ability of any given line to manipulate its root zone microflora with respect to its own needs and to those of subsequent crops. While the complexities of plant–soil–microbial interactions are great, the beneficial biological interactions that stimulate crop yields and improve plant health can be evaluated relatively simply, and general management strategies can be devised accordingly for any given set of crop combinations and growing environments.
Irrigated Tall Fescue–Legume Communities in the Southern Rocky Mountains
Authors: Lauriault Leonard M. , Guldan Steven J. , Martin Charles A.
Published: July 2010

Short‐term testing of perennial forages may not determine their long‐term persistence and productivity. A study initiated in 1994 at New Mexico State University's Sustainable Agriculture Science Center at Alcalde was continued from 1998 to 2001, comparing irrigated monoculture tall fescue (Festuca arundinacea Schreb.) and tall fescue in binary mixtures with each of alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus corniculatus L.), cicer milkvetch (Astragalus cicer L.), or kura clover (Trifolium ambiguum M.B.) in three randomized complete blocks. Percentage of harvested grass in mixtures declined in midseason, but grass dry matter (DM) yield increased across the season. Grass DM yield averaged 7.78 and 4.79 Mg ha−1 yr−1 for the monoculture and mixtures, respectively. Seasonal distribution of kura clover and combined (kura + fescue) DM yield differed from other treatments causing year × harvest × treatment interactions. Cicer milkvetch–tall fescue performed poorly compared with the other treatments (mean annual yield 5.2 Mg ha−1). Mean annual yield (12.7 Mg ha−1) of the alfalfa–tall fescue mixtures was enough to enhance its usefulness over monoculture grass through reduced fertilizer inputs. The birdsfoot trefoil–tall fescue mixture also provided the benefit of reduced fertilizer requirements, but mean annual yield (8.2 Mg ha−1) equaled fertilized monoculture tall fescue. Kura clover–tall fescue average annual yields (14.1 Mg ha−1) equaled alfalfa–tall fescue. Stand longevity, reduced fertilizer inputs, and high yield and quality enhance the usefulness of kura clover in the southern Rocky Mountains. But, irregular seasonal distribution of kura clover between years may make forage budgeting difficult.
Economics of Annual Cropping versus Crop–Fallow in The Northern Great Plains as Influenced by Tillage and Nitrogen
Authors: DeVuyst Eric A. , Halvorson Ardell D.
Published: July 2010

Annualized yields with more intensive cropping (IC) systems tend to be greater than those of spring wheat–fallow (SW–F); however, little economic comparison information is available. The long‐term (12 yr) effects of tillage system and N fertilization on the economic returns from two dryland cropping systems in North Dakota were evaluated. An IC rotation [spring wheat (Triticum aestivum L.)–winter wheat (T. aestivum L.)–sunflower (Helianthus annuus L.)] and a SW–F rotation were studied. Tillage systems included conventional till (CT), minimum till (MT), and no‐till (NT). Nitrogen rates were 34, 67, and 101 kg N ha−1 for the IC system and 0, 22, and 45 kg N ha−1 for the SW–F system. Annual precipitation ranged from 206 to 655 mm, averaging 422 mm over 12 yr. The IC system generated higher profits than the SW–F system, but the IC profits were more variable. Within the IC system, MT generated higher profits than corresponding N treatments under CT and NT, but MT profits were more variable. Of the N rates evaluated, the largest N rates generated the largest profits. The dryland IC system with MT and NT was more profitable than the best SW–F system using CT for this location. Stochastic dominance analyses revealed that the SW–F system and IC system CT treatments were economically inefficient when compared with the IC system with MT and NT.
Management of Angular Leaf Spot in Common Bean (Phaseolus vulgaris L.) with Molybdenum and Fungicide
Authors: de Jesus Waldir Cintra , Vale Francisco Xavier Ribeiro , Coelho Reginaldo Resende , Hau Bernhard , Zambolim Laércio , Berger Richard D.
Published: July 2010

The yield of common bean (Phaseolus vulgaris L.) is affected by several factors, including diseases such as angular leaf spot (Phaeoisariopsis griseola) and N deficiency caused by lack of nodulation. In Minas Gerais State, Brazil, farmers have been using both fungicide and molybdenum (Mo) applications to improve crop yield. The objective of this research was to investigate the effect of Mo application in conjunction with variably applied fungicide on common bean in the management of angular leaf spot (ALS). Field experiments were conducted in two seasons, wet and dry, with eight fungicide treatment schedules, with and without Mo. Angular leaf spot severity, plant growth, photosynthesis, and yield were measured. A single application of Mo 25 d after sowing (DAS) decreased the area under the disease progress curve by 38% and increased the area under the leaf area progress curve by 20%, leaf photosynthesis by 26%, and yield by 51%. When combined with the Mo applications, fungicide spray applied once (at an early growth stage) or twice in the bean flowering period (25–45 DAS) should provide substantial control of ALS.
Performance of Bt Corn Hybrids, their Near Isolines, and Leading Corn Hybrids in Pennsylvania and Maryland
Authors: Dillehay Bryan L. , Roth Gregory W. , Calvin Dennis D. , Kratochvil Robert J. , Kuldau Gretchen A. , Hyde Jeffrey A.
Published: July 2010

The European corn borer [Ostrinia nubilalis (Hübner)] is an important pest of field corn (Zea mays L.) in the northeastern USA. One option for reducing yield loss from European corn borer (ECB) is the use of transgenic corn hybrids containing a modified Bacillus thuringensis (Bt) gene. This study evaluated Bt hybrids, their near isolines, and leading non‐Bt hybrids for grain yield, moisture, and test weight under natural infestations of ECB in 2000, 2001, and 2002 at four to six locations across Pennsylvania and Maryland each year. Averaged over all locations and years, Bt, isoline, and lead hybrids yielded 9.1, 8.6, and 8.5 Mg ha−1, respectively. Grain moisture content at harvest was 224, 216, and 214 g kg−1 and test weight was 705, 713, and 713 kg m−3 for Bt, isoline, and lead hybrids, respectively. Overall, Bt hybrids produced higher yields, but also had higher grain moisture content at harvest and lower test weight than isoline and lead hybrids. Yield and moisture content differences were correlated with ECB infestations, but test weight was not. Isoline and lead hybrid yields were reduced by 2.37 and 2.60% respectively, for each ECB tunnel. Precipitation had no consistent effect on Bt and non‐Bt hybrid differences for yield, moisture, or test weight. Delayed planting dates were associated with higher ECB infestations. This may be beneficial in predicting sites that could benefit from Bt hybrids. In some environments in Pennsylvania and Maryland, Bt hybrids can result in significant yield advantages.
A Statistical Method for Summarizing Results of Cultivar Performance Trials
Authors: Feyerherm A. M. , Paulsen G. M. , Fritz A. K.
Published: July 2010

Cultivars in yield trials are normally compared by means and ranks, but extrapolating results to the future is difficult because good estimates of variances are lacking. The purpose of this research was to construct and apply a statistical method capable of producing probabilistic inferences about future yielding ability from a sample of cultivar performance trials (CPTs). Our database was CPTs of fall‐ and spring‐planted wheat (Triticum aestivum L.) in the U.S. Great Plains. The mean yield of selected check cultivars that were common to a set of trials established the standard level of performance for each trial in that set. Differences in yields between other cultivars and the trial standard provided the differential yielding ability (DYA) values for those cultivars in that trial. Cultivars were judged by their performance in relation to check cultivars in a sample composed of trials from multiple locations over multiple seasons within an ecogeographic region. We assumed that environmental effects were random from trial to trial and DYA values were normally and independently distributed. This led to use of Student's t distribution for probabilistic inference about population mean DYA values. We applied our method to elite trials in several regions in our database. For each cultivar, we showed its mean DYA, standard error, and p value when testing the null hypothesis. The method can be applied to advancing generations of experimental lines in breeding trials as well as recommending late generations for release as new cultivars.
Disease Management in Overhead Sprinkler and Subsurface Drip Irrigation Systems for Peanut
Authors: Lanier James E. , Jordan David L. , Barnes J. Stephen , Matthews J. , Grabow Gary L. , Griffin William J. , Bailey Jack E. , Johnson P. Dewayne , Spears Janet F. , Wells Randy
Published: July 2010

Experiments were conducted during 2001 and 2002 at one location in North Carolina to compare development of early leaf spot (Cercospora arachidicola Hori), pod yield, and market grade characteristics when peanut (Arachis hypogea L.) was grown under overhead sprinkler irrigation (OSI) and subsurface drip irrigation (SDI) and fungicides were not applied or applied biweekly or based on weather advisories. Incidence of early leaf spot was lower when peanut was grown under SDI compared with OSI when fungicides were not applied. Fewer fungicide applications were needed when applications were based on weather advisories rather than when applied biweekly. There was no difference in early leaf spot control or leaf defoliation resulting from disease when fungicides were applied regardless of irrigation system or fungicide application approach. Pod yield was higher in 2001 under SDI compared with OSI when fungicides were not applied; yield was similar in 2002. Disease severity was much higher in 2001 than in 2002 and most likely explains differences in pod yield between years. No difference in yield was noted when fungicides were applied, regardless of irrigation system. The percentage of extra large kernels (%ELK) was lower in 1 of 2 yr under SDI compared with OSI. There were no differences in percentages of fancy pods (%FP), sound splits (%SS), and other kernels (%OK) among irrigation systems and fungicide programs. In a separate experiment where fungicides were applied biweekly, pod yield, %FP, and %ELK were similar under SDI and OSI but greater than nonirrigated peanut. The %OK was lower when peanut was irrigated.
Nitrogen Fertilization and Rotation Effects on No‐Till Dryland Wheat Production
Authors: Halvorson Ardell D. , Nielsen David C. , Reule Curtis A.
Published: July 2010

No‐till (NT) production systems, especially winter wheat (Triticum aestivum L.)‐summer crop‐fallow, have increased in the central Great Plains, but few N fertility studies have been conducted with these systems. Therefore, winter wheat (W) response to N fertilization in two NT dryland crop rotations, wheat‐corn (Zea mays L.)‐fallow (WCF) and wheat‐sorghum (Sorghum bicolor L.)‐fallow (WSF), on a Platner loam (fine, smectitic, mesic Aridic Paleustoll) was evaluated for 9 yr. Five N rates, 0, 28, 56, 84, and 112 kg N ha−1, were applied to each rotation crop. Wheat biomass and grain yield response to N fertilization varied with year but not with crop rotation, increasing with N application each year, with maximum yields being obtained with 84 kg N ha−1 over all years. Based on grain N removal, N fertilizer use efficiency (NFUE) varied with N rate and year, averaging 86, 69, 56, and 46% for the 28, 56, 84, and 112 kg ha−1 N rates, respectively. Grain protein increased with increasing N rate. Precipitation use efficiency (PUE) increased with N addition, leveling off above 56 kg N ha−1. A soil plus fertilizer N level of 124 to 156 kg N ha−1 was sufficient to optimize winter wheat yields in most years in both rotations. Application of more than 84 kg N ha−1 on this Platner loam soil, with a gravel layer below 120 cm soil depth, would more than likely increase the amount of NO3‐N available for leaching and ground water contamination. Wheat growers in the central Great Plains need to apply N to optimize dryland wheat yields and improve grain quality, but need to avoid over‐fertilization with N to minimize NO3‐N leaching potential.
Long‐Term Tillage, Cover Crop, and Nitrogen Rate Effects on Cotton: Plant Growth and Yield Components
Authors: Boquet Donald J. , Hutchinson Robert L. , Breitenbeck Gary A.
Published: July 2010

Cotton (Gossypium hirsutum L.) yield is influenced by tillage, cover crop, and N fertility, but the plant growth and yield component responses related to these yield responses have not been well defined. A field study was conducted from 1991 through 2001 on Gigger silt loam (fine‐silty, mixed, thermic Typic Fragidaulf) to determine the long‐term effects of tillage practices, cover crops, and N fertilization rates on cotton growth and yield components. Cotton was grown continuously without tillage (no‐till) or with surface tillage (surface till) following annual winter cover crops of wheat (Triticum aestivum L.), hairy vetch (Vicia villosa Roth), and volunteer winter vegetation in plots receiving fertilizer N rates of 0, 39, 78, 118, or 159 kg ha−1. Tillage practice, cover crop, and N rate significantly affected cotton plant height, main‐stem node number, number of nodes above white flower (NAWF), main‐stem internode length, lint fraction, percentage first harvest, individual boll weight, and boll number per square meter. Increases in lint yields were associated with increases in plant height (r = 0.73 to 0.95), node number (r = 0.71 to 0.83), internode length (r = 0.44 to 0.91), NAWF (r = 0.65 to 0.90), boll weight (r = 0.12 to 0.86), and boll number per square meter (r = 0.91 to 0.93). Lint fraction showed no association or, in some years, a negative association with lint yield (r = −0.12 to −0.70). No‐till management and optimal N rate improved the environment for plant growth, which enhanced several growth parameters and yield components that were associated with increases in yield.
Estimating Losses of Dry Matter from Simulated Rainfall on Bermudagrass and Orchardgrass Forages Using Cell Wall Components as Markers
Authors: Scarbrough D. A. , Coblentz W. K. , Humphry J. B. , Coffey K. P. , Sauer T. J. , Jennings J. A. , Daniel T. C. , Turner J. E. , Kellogg D. W.
Published: July 2010

Previous methodologies to measure losses of dry matter (DM) in wilting hays subjected to natural or simulated rainfall have relied generally on gravimetric techniques, resulting in variable and questionable estimates of DM loss. The objective of this study was to evaluate the use of fiber components and acid detergent insoluble ash (ADIA) as internal plant markers for accurately predicting losses of DM in bermudagrass [Cynodon dactylon (L.) Pers.] and orchardgrass (Dactylis glomerata L.) forages that were damaged by simulated rainfall. For both forages, concentrations of neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HEMI), cellulose (CELL), lignin, and ADIA generally increased with the amount of simulated rainfall in primarily linear patterns. Recoveries of all internal markers were high (≥952 g kg−1) and were not affected by simulated rainfall for either forage (P ≥ 0.06). Predicted losses of DM increased in primarily linear patterns with simulated rainfall for both forages when concentrations of NDF, ADF, HEMI, CELL, and ADIA were used as internal markers. Linear regressions of predicted losses of DM on values determined gravimetrically were good (r2 ≥ 0.73; P ≤ 0.03) when concentrations of any fiber constituent or ADIA were used to calculate losses of DM; however, NDF was an especially effective internal marker (Y = 1.12X − 5; r2 = 0.97; P < 0.01).