bluuebunny/crossref_metadata_2025_split huggingface dataset:
Non‐Uniform Infiltration Under Potato Canopies Caused by Interception, Stemflow, and Hilling1
Authors: Saffigna P. G. , Tanner C. B. , Keeney D. R. 
Published: July 2010

AbstractIt is generally assumed that infiltration of sprinkler irrigation and rainfall under potato is uniform. However we observed non‐uniform infiltration beneath the hills of sprinkler‐irrigated potatoes (Solanum tuberosum L, var. Russet Burbank) grown on Plainfield loamy sand (Typic Udipsamment; sandy, mixed, mesic). The objective of this field study was to determine the effects of foliage interception and hilling on non‐uniform infiltration, since concentrating water in local zones would increase deep drainage and nitrogen leaching. To do this we traced the rainfall and irrigation infiltration pattern with Rhodamine WT dye and collected the stemflow in stem collars. Throughfall of rainfall, the soil water content, and soil water tension also were measured.From 20 to 46% of the irrigation and from 4 to 23% of the rainfall on the canopy flowed down the stems. Stemflow increased the soil water content around the stems and moved Rhodamine dye deep beneath the soil surface. Deep movement of dye beneath the furrows was caused by runoff from the hills and by leaf drip from the outer foliage.The results obtained suggest that irrigation and fertilizer management could be improved by taking this non‐uniform infiltration pattern into account. Smaller irrigations should improve water use efficiency and minimize nitrate leaching. Further, evaluation of solute movement by soil sampling should consider the spatial variation introduced by the non‐uniform infiltration. Finally, predictive leaching models should account for non‐uniform infiltration.
Comparison of Modified Montmorillonite to Salts and Chelates as Carrier for Micronutrients for Plants: II. Supply of Iron1
Authors: Navrot Jerzy , Banin Amos 
Published: July 2010

AbstractSymptoms of iron deficiency appear very frequently in the calcareous soils which represent a major part of the agricultural soils of Israel; therefore a search for novel carriers of iron is constantly conducted. Previous studies showed that Cu, Zn, and Mn, attached to modified montmorillonite, can effectively replace salts and chelates as carriers for micronutrient elements for plants.In this research, the effect of iron attached to montmorillonite clay on element uptake and yield of plants was compared to that of commonly used iron sulphate or EDTA and EDDHA chelates. In the greenhouse, beans (Phaseolus vulgaris L.) were grown in two calcareous, (Rendzina), iron deficient soils and were treated with either FeSO4, Fe+3‐EDTA, Fe+3‐EDDHA, or Fe+2 bound to montmorillonite clay. The rates of iron added varied from 15 to 60 mg Fe/kg soil for the salt and 3 to 12 mg Fe/kg soil for the chelates and the clay forms. It was found that Fe+3‐clay and Fe+3 in chelates, added at equivalent rates, supplied iron in comparable amounts; FeSO4, added at the conventional rates which are five to ten times higher than that added as clay‐ and chelate‐bound iron, caused similar or lower uptake and yields. Moreover, the slow release of iron from Fe‐clay, even when supplied in high rates, prevented excessive iron uptake which otherwise, as in the case of the chelate FeEDDHA, interfered with plant development. It is suggested that iron attached to mortmorillonite clay can be used as an efficient source of iron for plants grown in calcareous soils.
Relationships among Agronomic Characteristics of Corn and Sorghum Cultivars and Silage Quality1
Authors: Schmid A. R. , Goodrich R. D. , Jordan R. M. , Marten G. C. , Meiske J. C. 
Published: July 2010

AbstractIf agronomic characteristics could be used as criteria for judging quality of corn and sorghum cultivars for silage, the selection of genotypes best suited for silage would be facilitated. The objective of this study was to determine if agronomic characteristics of corn (Zea mays L.) and sorghum [Sorghum bicolor (L.) Moench, S. sudanense (Piper) Stapf, and their hybrid] cultivars are related to their silage quality. Over a period of 3 years, 49 silages, involving 11 corn cultivars and 14 sorghum cultivars, were produced and fed to sheep in conventional feeding trials. Eleven of the 14 sorghum cultivars were the sweet‐stem silage type. We measured fodder yield, height, %dry matter, and % plant parts [stems, ears or heads (EH), and leaves]. The quality measurements were acid detergent fiber (ADF); in vivo measurements, with sheep, of digestible dry matter (DDM); average daily gain (ADG); and dry matter intake/animal/day (DMI).The highest correlations were obtained between % stems or % EH and quality for both corn and sorghum silages. Percent leaves and plant height were in some cases highly correlated with quality measurements, but these relationships could be explained by high correlations of % leaves and plant height to % EH and stems.ADF concentration was lower in corn silage (29.0%) than in sorghum silage (34.9%). The low ADG of sheep fed sorghum silage (18.1 g compared to 64.5 g for corn silage) was primarily due to low DMI (649 g) and low DDM (55.6%) of the sorghum silage compared to the high DMI (777 g) and high DDM (63.8%) of corn silage. A regression analysis showed that nearly equal amounts of DDM intake above maintenance were needed for a unit of ADG from corn silage and from sorghum silage.
Anion Leaching in Two Kentucky Soils under Conventional Tillage and a Killed‐sod Mulch1
Authors: McMahon M. A. , Thomas G. W. 
Published: July 2010

AbstractThis study was established to determine the reasons for the larger losses of nitrogen under corn grown in killed sod as compared to conventionally tilled corn. No crop was grown. Two soils, Maury silt loam, a well‐drained soil with rapid permeability and Lowell silty clay loam, a well‐drained soil with slow permeability, were used. Chloride was used as a tracer for nitrate since it is little affected biologically. Soils were sampled by hand using a soil tube periodically to a depth of 90 cm in 15 cm increments so that both nitrate and chloride could be determined. Differences between distributions of nitrate and chloride were ascribed to mineralization and/or denitrification.On the Maury silt loam (Typic Paleudalfs, fine, mixed, mesic), no evidence of denitrification was found. Mineralization of nitrate was high and no leaching of chloride or nitrate occurred under conventional tillage during the growing season. Under the killed sod, mineralization was lower and leaching was appreciable during the growing season. During the following winter, leaching was similar on both tillage treatments, but because of the differences in leaching during the growing season, essentially all of the chloride and nitrate were removed from the 90 cm profile under the killed sod and only about half from conventionally tilled soil by the following April.On Lowell silty clay loam (Typic Hapudalfs, fine, mixed, mesic) there was similar behavior during the growing season except that some leaching occurred even on the conventionally tilled soil and denitrification apparently occurred under both tillage treatments at the depth where organic matter was highest.The results suggest that, during the growing season, nitrate losses by leaching and a lower rate of mineralization are responsible for the lower yields of corn observed with low nitrogen rates under a killed‐sod mulch. Rates of nitrate and chloride movement during the winter were about the same under both conventional tillage and killedsod mulch.
Nitrogen Flux into Corn Roots as Influenced by Shoot Requirement1
Authors: Edwards J. H. , Barber S. A. 
Published: July 2010

AbstractKnowledge of the N flux characteristics of corn (Zea mays L.) roots is important in determining the N fertilizer practices needed for efficient N fertilizer use. Fertilizing a portion of the root system with N increases the N uptake required per unit of root fertilized over that in which all roots are fertilized with N. The effect that fertilizing a portion of the roots with N has on the N influx characteristics of corn roots has not been evaluated. Hence the objective of this research was to determine if shoot N requirement influenced N influx/m of corn root. Trimmed‐ and split‐root procedures were used in solution culture experiments in the growth chamber to vary the amount of N‐absorbing roots/unit of shoot and determine its effect on N influx. Both NH+4 and NO−3 forms of N were used.Trimming corn roots 2 days before measuring influx resulted in only small increases in N influx/m of root so that N uptake/plant was greatly reduced by trimming. Splitting the roots between N‐containing and N‐free solutions from seedling stage until 16 or 18 days, when influx was measured, resulted in larger increases in net N influx than when the roots were trimmed 2 days before influx measurement. Nitrogen level within the root was not related to N uptake rate/m of root in either experiment.It appears that increasing shoot demand for N does not immediately affect N influx into the root but that the capability for higher N influx is developed when plants are grown under N stress.
Corn Plant Water Stress as Influenced by Chiseling, Irrigation, and Water Table Depth1
Authors: Reicosky D. C. , Campbell R. B. , Doty C. W. 
Published: July 2010

AbstractImproved plant water status through improved soil and water management practices can result in efficient crop production and water utilization in the compact layered soils that restrict rooting in the Southeast. The effect of chiseling and irrigation on plant water status was evaluated through leaf water potential, stem diameter, and stomatal resistance measurements. Corn (Zea mays L.) was grown on a Varina sandy loam (Typic Paleudult) chiseled to 38 cm and compared with that grown on conventionally tilled plots. In 1972 chiseling had no measurable effect on the daily minimum leaf water potential under the same radiant energy level. At tasseling in 1973, with a water table 80 cm from the surface, chiseling resulted in deeper‐rooted corn that enabled utilization of water in the capillary fringe above the water table, and resulted in slightly higher (less negative) daily minimum leaf water potential, lower stomatal resistance, and smaller stem diameter fluctuations. In 1973, plant‐water status on chiseled plots was comparable with that on furrow‐irrigated plots. The cumulative effects of the small improvement in midday plant water status from chiseling resulted in a 8‐metric ton/ha increase in corn ear yields. These findings suggest chiseling of soils with root restricting layers can result in increased corn production, particularly when the water table is approximately 80 cm from the soil surface at tasseling.
Genotype Variation in Nutrient Uptake Efficiency in Corn1
Authors: Bruetsch T. F. , Estes G. O. 
Published: July 2010

AbstractInformation is lacking on the efficiency of nutrient use by corn (Zea mays L.) genotypes of varying maturity. The objective of this study was to characterize the nutrient accumulation of 12 corn genotypes of commercial importance and of varying maturity under field conditions. Relative maturity of the genotypes was established based on percent dry matter (% DM) of the plant tops after 115 days of growth. Significant variability occurred among the genotypes with respect to dry matter yield and accumulation of P, K, Ca, Mg, Fe, and Zn. Significant positive correlations existed between % DM and foliage P (concentration and content) indicating that higher P levels occurred in the earlier maturing genotypes. Genotypes also differed in dry weight production per gram of N, P, K, Ca and Mg absorbed; the relationship between P concentration and relative maturity of the genotypes was the most consistent. The efficiency of dry matter production per unit of P absorbed was greatest for the later maturing hybrids.
Chemical Desiccation of Grain Sorghum1
Authors: Gigax D. R. , Burnside O. C. 
Published: July 2010

AbstractDesiccation of grain sorghum [Sorghum bicolor (L.) Moench] could benefit seed producers and farmers by permitting earlier combining, maintaining seed viability, and controlling perennial weeds. The rate of sorghum seed drying, seed viability, and plant lodging following desiccation was determined. ‘RS 626’, a widely grown hybrid grain sorghum, was desiccated with glyphosate [N‐(phosphonomethyl)glycine], paraquat (1,1′‐dimethyl‐ 4,4′‐bipyridinium ion), and a 28% N solution at 30 and 25% seed moisture in 1973 and 35% seed moisture in 1974. Six grain sorghum inbred lines desiccated in 1973 gave differential responses. Glyphosate at 2.24 kg/ha and paraquat at 1.12 kg/ha would permit combining (20% seed moisture) 5 to 7 days earlier when desiccated at 30% seed moisture in 1973 and 35% in 1974. However, when desiccated at 25% seed moisture in 1973, only 2 days were gained. Combine yields were reduced due to sorghum lodging following desiccation with glyphosate at 1.12 and 2.24 kg/ha and paraquat at 1.12 kg/ha at 30% seed moisture in 1973. Similar combine losses were experienced on plots receiving glyphosate at 1.12 and 2.24 kg/ha applied at 35% seed moisture in 1974. Data for 1974 showed that germination and emergence percentages of seed from desiccated plots were higher than that from unsprayed plots because an early killing frost reduced seed viability of higher moisture seed from untreated checks. Common milkweed (Asclepias syriaca L.) stands in the succeeding growing season were reduced in one of two experiments with fall applications of glyphosate at 1.12 and 2.24 kg/ha.
Use of Acrylic Plastic as Rhizotron Windows1
Authors: Taylor H. M. , Böhm W. 
Published: July 2010

AbstractReliable cotton (Gossypium hirsutum L.) rooting densities (cm roots/cm3 soil) for bulk soil have been estimated previously from the number of visible roots in sandy soil immediately behind glass rhizotron windows. The present study determined whether soybean [Glycine max (L.) Merr. ‘Corsoy’] rooting densities could be estimated reliably in Ida silt loam (fine‐silty, mixed, mesic, Typic Udorthent) from the number of visible roots at the soil‐acrylic plastic windows of the Ames, Iowa rhizotron.Rooting density was evaluated as a function of soil depth and distance from the plastic‐soil interface in one compartment at the rhizotron. Fifty volumetric soil samples were collected at ten depths and at five distances from the interface. Roots were washed from the Ida silt loam soil. Root length contained in the sample was estimated using a laser modification of the Rowse‐Phillips root‐length instrument.Rooting density was substantially greater in the 2‐mm thick layers near the plastic‐soil interface than in bulk soil behind it. Acrylic plastic windows apparently are satisfactory for use in root growth boxes or rhizotron compartments for phenological or for comparative experiments, but glass rhizotron windows should be used in rooting density studies.
Evaluation of Resistance and Mass Transport Evapotranspiration Models Requiring Canopy Temperature Data1
Authors: Blad Blaine L. , Rosenberg Norman J. 
Published: July 2010

AbstractThe increasing use of thermal scanners on aircraft and satellites makes it likely that data on surface temperature for large areas will become routinely available. If reliable evapotranspiration methods which incorporate surface temperature data can be developed an important tool for research and application in hydrology, in irrigation scheduling, and in other water management procedures will result.A ‘resistance model’ which stems from the work of Brown and Rosenberg and a mass transport (Daltonian) model for estimating evapotranspiration (ET) were tested on large fields of naturally subirrigated alfalfa (Medicago sativa L.). Both models make use of crop canopy temperature data. Temperature data were obtained with an IR thermometer and with leaf thermocouples. A Bowen ratio‐energy balance (BREB) model, adjusted to account for underestimation of ET during periods of strong sensible heat advection, was used as the standard against which the resistance and mass transport models were compared.Daily estimates by the resistance model were within 1C% of estimates made by the BREB model. Daily estimates by the mass transport model did not agree quite as well. Performance was good on clear and cloudy days and also during periods of nonadvection and strong advection of sensible heat.The performance of the mass transport and resistance models was less satisfactory for estimation of fluxes of latent heat for short term (15 min) periods. Both models tended to overestimate at low LE fluxes.
Resistance‐energy Balance Method for Predicting Evapotranspiration: Determination of Boundary Layer Resistance and Evaluation of Error Effects1
Authors: Verma S. B. , Rosenberg N. J. , Blad B. L. , Baradas M. W. 
Published: July 2010

AbstractAccurate estimates of evapotranspiration (ET) over large areas are needed for hydrologic studies, irrigation planning and scheduling, and other practices related to efficient utilization of water resources. One approach is the use of a resistance‐energy balance model of ET, the data for which can be supplied, in part, by remote sensing and in part from easily accessible records of National Weather Service observations. This model requires measurement of boundary layer resistance, crop and air temperature, net radiation, and soil heat flux. The objectives of this paper are i) to test the utility of the proposed model, ii) to determine boundary layer resistance at varying stages of crop growth, and iii) to evaluate the relative influence of errors in measurement of the meteorological and crop input parameters used.Measurements were made in fields of sorghum [Sorghum bicolor (L.) Moench] and millet (Panicum meliaceum L.) grown at Mead and Mitchell, Neb. Boundary layer resistance was estimated from friction velocity measurements used in a stability‐corrected aerodynamic method. Friction velocity was computed by means of the Deacon‐Swinbank approach. Evapotranspiration rates estimated by the resistance model compared well with results of lysimetric and energy balance measurements, on both a short‐period and a daily basis.The error analysis, in conjunction with field measurement, indicates that the resistance model evapotranspiration estimates are quite sensitive to errors in crop temperature measurement, especially in nonadvective conditions, but are less strongly affected by errors in the estimation of boundary layer resistance.
System for Growing Plants under Controlled Redox Potential‐PH Conditions1
Authors: Reddy C. N. , Jugsujinda Aroon , Patrick W. H. 
Published: July 2010

AbstractRedox potential and pH are two soil conditions that exert major influence on the solubility and availability of plant nutrients. In order to study the effects of these conditions on the transformation of plant nutrients in the soil and their uptake by plants, it is necessary to control pH and redox potential over a wide range of values. A relatively simple system has been developed by which soils can be incubated under conditions of controlled redox potential and pH. Rice plants were grown in the soil suspensions incubated at six different redox potentials (—200, —100, 0, +100, +200, and +400 mV) and four pH values (5, 6, 7, and 8).
Extended Field Use of Screen‐Covered Thermocouple Psychrometers1
Authors: Brown Ray W. , Johnston Robert S. 
Published: July 2010

AbstractThe use of screen‐covered thermocouple psychrometers for in situ measurements of soil water potential has been criticized because of possible soil and micro‐organism contamination through the screen covering. Double‐junction Peltier psychrometers with a screen covering were installed in the soil under field conditions for periods ranging from 2 to 40 months of continuous exposure, and were then removed and examined for evidence of loss of calibration sensitivity and contamination by soil particles and micro‐organisms. The uncleaned psychrometers were recalibrated in the laboratory and then disassembled and examined under a microscope (250 ✕) for contamination. Although slightly more than half of the units lost some sensitivity after field exposure, the average decrease was less than 5%. The psychrometer cavities were all nearly free of soil particles, the thermocouple junctions were shiny, and no evidence of microbial attack was evident. It appears that long‐term field exposure of screen‐covered psychrometers is no more detrimental to their performance than that of ceramic or other psychrometers.
The Bur Enclosure of the Caryopses of Buffalograss as a Factor Affecting Germination1
Authors: Ahring Robert M. , Todd Glenn W. 
Published: July 2010

AbstractThe seed‐bur of buffalograss, Buchloe dactyloides (Nutt.) Engelm., consists of a tightly held rigid cluster of four to five spikelets enclosed in thickened glumes. Germination of the bur is often difficult, requiring lengthy prechill treatments to attain maximum percentages. Caryopses contained in the bur germinate readily when extracted by hand, generally without additional pregermination treatment. The objective of this study was to evaluate the effect of the oil present in the bur enclosures on germination.Fresh seed burs were hammermilled to separate caryopses from their enclosures. Hulls or empty burs (100 g samples) were further pulverized and then refluxed in 1,000 ml of distilled water overnight. The oil(s) present in the aqueous solution was evaporated in diethylether, and its properties characterized with infrared spectrophotometry and gas chromatography. A series of tests on the effect of the oil on germination and seedling growth was conducted. Treatments to counteract the effect of the bur enclosure on germination were also studied.The results showed that: 1) Empty burs contain 2.8% oil(s) by weight; 2) Caryopses extracted by hand germinate readily, the outer glumes, by restricting water movement, may account for low laboratory germination of the seedburs; 3) Dipping the caryopses in the oil extract reduced germination by 47.2%; and 4) Dipping the root tips of healthy seedlings in the oil extract resulted in stunting plant growth. Prechilling at 5 to 10 C for 6 to 8 weeks or presoaking seed‐burs in 5.25% sodium hypochlorite for 72 hours was sufficient to overcome the bur effect on germination. The length of both treatments needed to promote germination varied between seed lots studied. Subjecting the seed‐burs to heat (drying) up to 70 C for 12 hours improved germination. Treatments beyond 70 C for more than 12 hours reduced seed viability.
Production of Corn and Sorghum Grain in Double‐Cropping Systems1
Authors: Nelson L. R. , Gallaher R. N. , Bruce R. R. , Holmes M. R. 
Published: July 2010

AbstractDouble‐cropping systems involving no‐till planting are becoming popular in the southeastern USA, but adequate management practices have not been developed. Therefore, this study was conducted to determine the effects of the following tillage systems. Corn [Zea mays (L.)] and grain sorghum [Sorghum bicolor (L.)] were planted without tillage following winter wheat [Triticum aestirum (L.)] or barley [Hordeum vulgate (L.)] and with conventional tillage following previous summer crop at two locations in Georgia for 4 years with and without irrigation. Corn and grain sorghum yields did not differ significantly for conventional tillage and no‐till plantings made on the same date. No‐till corn and grain sorghum produced higher yields when early planted (after small grain for forage) than when late planted (after small grain for grain). Irrigation increased conventionally tilled corn yields by 31% (at Experiment) and grain sorghum yields by more than 20%. The smaller increases observed for irrigated early‐planted no‐till corn and grain sorghum were attributed to a higher soil water content on nonirrigated no‐till. Irrigation did not increase yields of late planted no‐till corn and grain sorghum due to interfering biological factors.