bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recovery of Nitrogen and Phosphorus after 17 Years from Various Fertilizer Materials Applied to Crested Wheatgrass1
Authors: Power J. F. 
Published: July 2010

AbstractInformation is limited regarding duration of residual effects from different N fertilizer sources upon herbage production and N and P recovery. A field experiment was conducted for 17 years on a Temvik silt loam (fine‐silty, mixed Typic Haploborolls) at Mandan, N.D., to study the effects of 5 years of N and P fertilization upon the production of crested wheatgrass [Agropyron desertorum (Fisch. ex Link), Schult.) and upon N and P recovery during and after fertilization. Fertilizer rates were 0, 90, and 180 kg N/ha from ammonium nitrate, ammonium sulfate, calcium nitrate, or urea, and 19 or 39 kg P/ha. Dry matter production and fertilizer N recovery in aboveground herbage production were least for urea, especially at 180 kg N/ha with P, but there was little difference between the other N sources. Cumulative 17‐year dry matter production was increased about 15 Mg/ha with 90 kg N/ha, and 20 to 25 Mg/ha with 180 kg N/ha. Residual effects from calcium nitrate persisted a few years longer than from other N sources and averaged 58 % recovery of N compared to 48 % for urea. Fertilizer P recovery varied from 26.8 % when P was applied with calcium nitrate to 18.2 % with ammonium sulfate. Cumulative dry matter production was increased 4 to 5 Mg/ha in 17 years by P fertilization. Fertilization with N doubled recovery of fertilizer P. Soil pH in the surface 150 mm of soil, 5 years after fertilization ceased, varied from 6.5 with calcium nitrate to 5.5 with ammonium sulfate. Fertilizer N recovered after fertilization ceased could largely be accounted for by depletion of inorganic soil N pools that had accumulated during the fertilization period. While ammonium sulfate was being applied, inorganic N accumulated primarily as exchangeable ammonium in the surface 0.3 m. Little inorganic soil N accumulated from urea application, suggesting that much N was lost by volatilization. From all sources, 70 to 160 kg fertilizer N/ha was still immobilized in the root biomass, 5 years after fertilization ceased.
Field Evaluation of a Water Relations Model for Soybean. 11. Diurnal Fluctuations1
Authors: Jones J. W. , Zur B. , Boote K. J. 
Published: July 2010

AbstractA field study was conducted on soybeans (Glycine max L. Merr. cv. Williams) growing in Arredondo fine sand, a member of the hypothermic, coated family of Typic Quartzipsamments to determine the effects of drying cycles on plant water relations for comparison with results predicted by a dynamic model. Two different drying cycle treatments were imposed on different plots during late vegetative development and mid‐to‐late pod fill stages and well irrigated plots were maintained for comparison. Every other day during each drying cycle, hourly measurements of leaf water potential, canopy carbon exchange rate (CER), and canopy transpiration were measured on dry and wet plots. During the initial phases of the drying cycles leaf water potential, transpiration, and CER followed diurnal cycles closely related to radiation flux. This response lasted for 9 and 5 days during the first and second drying cycles, respectively, when crop water deficits reached critical levels causing leaf water potentials of − 1.4 and − 1.7 MPa. After these critical time periods, midday leaf water potentials became relatively stable with time whereas transpiration and CER decreased such that diurnal fluctuations disappeared. The model was successful in simulating diurnal patterns of these variables for the crop exposed to the two drying cycles.
Alfalfa Establishment and Production with Continuous Alfalfa and Following Soybeans1
Authors: Kehr W. R. , Watkins J. E. , Ogden R. L. 
Published: July 2010

AbstractAlfalfa (Medicago sativa L.) is commonly grown in rotation with other crops but land can be continuously cropped with alfalfa. The purpose of this study was to determine the stand establishment and production of alfalfa cultivars that differed in disease resistance in a continuous alfalfa cropping situation, with limited supplemental irrigation. Two alfalfa cultivar experiments were spring‐seeded in 1970 at the Nebraska Agric. Exp. Stn. Mead Field Lab. on a Sharpsburg silty clay loam (fine, montmorillonitic, mesic Typic Argiudoll) soil with no known prior alfalfa cropping. The area was plowed in late May 1975 after the first cutting and fallowed. Soybeans (Glycine max L. Merr.) were seeded in 1976 on subareas reserved for seeding alfalfa in 1977 and 1978, and in 1977 on the subarea reserved for seeding alfalfa in 1978. Two alfalfa experiments were spring‐seeded per year in 1976, 1977, and 1978, a foliar fungicide and a fungicide seed treatment experiment. Forage yields did not differ among foliar fungicide treatments or between ‘Arc’ and ‘Ranger’ in the year of seeding or in subsequent years. Anthracnose (caused by Colletotrichum trifolii Bain) and foliar diseases were at subeconomic levels. Stands in the year of seeding did not differ among fungicide seed treatments or between ‘Agate’ and ‘Dawson’. Anthracnose and phytophthora root rot (caused by Phytophthora megasperma Drechs) were factors in stand decline and yield reduction of susceptible cultivars after the year of seeding. Stands in the year of seeding were excellent on the same land area where alfalfa was seeded in 1970 with no known previous alfalfa cropping, after plowing the 5‐year‐old stand of alfalfa in 1975 and seeding in 1976, and after 1 or 2 years of soybeans and seeding alfalfa in 1977 and 1978, respectively. Average forage yields of the experiments seeded in 1970 were 26% higher in the year of seeding, and 40 and 35% higher in the 1st and 2nd year after seeding, respectively, than in the experiments seeded in 1976 to 1978.
Alfalfa Responses to Irrigation Treatment and Environment1
Authors: Donovan T. J. , Meek B. D. 
Published: July 2010

AbstractWater management is critical for maximum production of alfalfa (Medicago sativa L.) with under irrigation resulting in loss of production and over irrigation resulting in a loss of stand. The purpose of this study was to determine the optimum irrigation rates under high evaporative demand. Growth of alfalfa was evaluated on replicated plots (6 × 6 m) established on a fine textured soil (Typic Torrifluvent, clayey over loamy, montmorillonitic, calcareous hyperthermic family) and differentially irrigated from July 1975 to January 1978. The irrigation treatments were applied at 56, 66, 75 (best estimate of Ep and 84% of pan evaporation (Ep) and described as dry, semidry, optimum and wet, respectively. Alfalfa yields increased with increase in water applied. Irrigation at 84% Ep for leaching did not enhance yield over the optimum water treatment possibly because of reduced stand from waterlogging. The protein concentration of alfalfa was higher in dry than in wet treatments in March and November. During the summer, plant temperatures in the dry treatment were up to 7 C higher than in the wet treatment.
Genetic and Hormonal Control of Shoot and Root Growth of Sorghum1
Authors: Wright S. A. , Jordan W. R. , Morgan P. W. , Miller F. R. 
Published: July 2010

AbstractSorghum [Sorghum bicolor (L.) Moench] exhibits a large degree of genetic diversity far shoot development, but diversity in root development has heen virtually unexplored. Tall and short lines of ‘kafir’ and ‘milo’ sorghum that were near‐isogenic for height were examined to determine if genes which control height also exert a similar inlluence on root growth. Lines were compared both in hydroponics and in soil‐filled (fine sandy loam, Udic Paleustalf) root chambers in the field. Since dwarfing genes in sorghum appear to mediate their response through regulation of endogenous gibberellin (GA) levels, effects of exogenous GA3 applied to the shoot were also evaluated. In the field, differences in height of approximately 1 m developed between isolines of both kafir and milo, but the taller lines also developed 25 to 39% greater leaf areas. More roots were observed in the upper 60 cm of the soil profile in chambers containing the tall isolines, but when total root numbers were normalized with leaf area there were no differences between isolines. The GA3 application to tall and 3‐dwarf milo plants in hydroponic culture stimulated internode length of both cultivars, but reduced leaf area, root length, and root volume. Shoot dry weights of the tall and short isolines were increased by 19.6 and 9.9%, respectively, by GA3 treatment, while corresponding root dry weights decreased by 20.7 and 20.4 5%. These results are inconsistent with the hypothesis that gibberellins promote both shoot and root growth in sorghum, and further suggest that the genetic control of shoot growth in sorghum is largely independent from control of root growth.
Circular Sprinkler Logger1
Authors: Regier Cecil 
Published: July 2010

AbstractCenter pivot sprinkler systems have come into common use throughout much of the United States, where irrigation is necessary to maintain or enhance crop yields. A device is described to locate at any time the center pivot sprinkler line with regard to fixed point and to calculate the speed that the center pivot system is traveling. The device is built from a liquid level recorder and the bottom of a 208 L (55 gallon) barrel with 36 notches cut into it. The barrel bottom is attached to the pivoting vertical water supply pipe of the center pivot. A lever rides on the notches and records each 10‐degree advance of the center pivot on the liquid level recorder.
Grain Production of Winter Wheat after Spring Freeze Injury1
Authors: Paulsen Gary M. , Heyne Elmer G. 
Published: July 2010

AbstractThe most extensive spring freeze reported on winter wheat (Trificum aestivum L.) in the Great Plains occurred in Kansas and adjoining states in 1981. We related magnitude of injury to prevailing temperatures and compared consequences of freeze injury in 1981 and previous years. The injury threshold nearly paralleled the 0°C isotherm during the freeze. Production losses ranged up to 85% in individual counties and averaged 62% in the affected area and 31% statewide in Kansas. Low grain production in 1981 contrasted with record production in states reporting freeze injury to winter wheat during previous years. Modeling showed record winter wheat production after spring freezes other years was associated with generally favorable conditions throughout the growing season, early development of wheat during the spring, and extraordinarily favorable conditions after the freeze. Spring freeze injury might affect winter wheat production locally, but production over large areas was frequently favored by conditions associated with localized freeze injury.
Cultivar Variation in Kentucky Bluegrass: P and K Nutritional Factors1
Authors: Mehall B. J. , Hull R. J. , Skogley C. R. 
Published: July 2010

AbstractWhile many Kentucky bluegrass (Poa pratensis L.) cultivars have been evaluated for their capacity to produce quality turf, little is known about the contribution of nutritional factors to the variability observed between cultivars. Recognizing these nutritional characters could speed the development of turfgrasses adapted to low fertility soils. In 1978 and 1979, 15 Kentucky bluegrass cultivars of differing quality, growth pattern, and place of origin were compared for clipping production rate, leaf blade P and K content, and the resulting P and K efficiency ratio (mg dry wt./mg nutrient). Correlation coefficients between these factors and turf quality scores were determined in 1978. Field plots on an Enfield silt loam (coarse‐silty over sandy skeletal, mixed, mesic, Typic Dystrochrept) were fertilized with 4.8 g N/m2/year and mowed twice weekly at 3.8 cm. On four dates each year, clippings were weighed and analyzed for P and K. Significant differences between cultivars were obtained for all factors tested. Despite substantial variability within and between seasons some cultivars exhibited reasonable consistency in their ranking for growth and nutrient content of clippings. Turf quality scores were correlated with leaf blade P content but not with clipping growth rate. The P and K efficiency ratios, based on the nutrient content of clippings, offered some promise as an indicator of cultivar nutrient use efficiency. The value of this factor for identifying cultivars adapted to low fertility soils remains to be demonstrated.
A Reliable Method for Processing Soybean Seed for Laboratory Analysis1
Authors: Schild J. A. , Olson R.A. 
Published: July 2010

AbstractEstablished procedures for milling soybean [Glycine max (L.) Merr.] seed entail use of solvents which can be dangerous to the user of the mill and which may cause uncertain dilutions and undesirable changes in the seed. A method for dry milling soybean seed was developed in this study to process seed material for assay, including 15N isotope ratio analysis. The method involved the use of a sealed grinding device and dry ice. The seed and ice are ground together for 2 min. The resulting meal is similar in texture and recoverability to that obtainable by grinding in a solvent, and the problem of cross contamination is minimal.
Sprinkler‐Applied and Side‐Dressed Nitrogen for Irrigated Corn Grown on Sand1
Authors: Gascho G. J. , Hook J. E. , Mitchell G. A. 
Published: July 2010

abstractMaintaining efficient N nutrition for irrigated corn (Zea mays L.) grown on deep sands is difficult due to low N supplying capabilities and leaching losses of applied N. Scheduled applications of N by the use of center‐pivot irrigation equipped with modern solution injection equipment should reduce leaching and increase N‐use efficiency. The objective of this study was to compare the efficiency of scheduled applications of N through sprinkler irrigation with the more conventional side‐dress method for maintaining N nutrition and obtaining high yields. Field experiments were conducted for 5 years on a Bonifay sand (loamy, siliceous, thermic, grossarenic, Plinthic Paleudult) using solid‐set irrigation systems. Treatments included side‐dressing, sprinkler application for 10 to 11 weeks after planting according to anticipated N needs, and combinations of the two methods, as well as, differential N rates ranging from 168 to 350 kg ha‐1. Maximum yields were obtained with approximately 280 kg N ha‐1. Scheduled sprinkler application of N did not provide better N nutrition than conventional side‐dressing. In 4 of the 5 years of the study, corn was planted in soil which had near average rainfall during the winter and some leaching rain in the early growing season. In those years, side‐dressing was equal or superior to sprinkler application; while a combination of side‐dressing young corn followed by later sprinkler applications produced the highest yields. These responses may be the result of the timing of N applications or of an improved N uptake from the banded method (side‐dressing) in comparison to a broadcast method (sprinkler application).
Peanut Growth Responses to Different Levels of Leafspot1
Authors: Teare I. D. , Shokes F. M. , Gorbet D. W. , Littrell R. H. 
Published: July 2010

abstractPeanut leafspot, a disease caused by Cercospora arachidicolaHori (early leafspot), and Cercosporidium personatum(Berk. and Curt.) Deighton (late leafspot) are the most destructive foliar pathogens of peanut (Arachis hypogaea L.) and occur each year in Florida in epidemic proportions. This research establishes a data base relating growth of 'Florunner' peanut to leafspot disease severity and can be used as an aid in evaluating other resistant lines. Five leafspot disease severity levels were applied to Florunner peanut during the 1982 growing season by spraying with five levels of chlorothalonil (tetrachloroisopthalonitrile) foliar sprays beginning 40 days after planting, and continuing on a 14 day schedule until harvest. The research was conducted at the Marianna Agricultural Research Center, on a Lucy fine sand (loamy, siliceous, thermic Arenic Paleudult). Disease severity levels were compared to peanut growth measurements of leaf area index (LAI), shoot weight (leaf and stem), root weight (lateral and tap root), sample pod weight, and total biomass during the pod fill period. Although ratings were made for early and late leafspot, late leafspot was the predominant foliar disease. The LAI, leaf weight, and lateral root weight were negatively influenced by invasion of late leafspot pathogens. A comparison of field pod yield to sample pod yield indicated that lower dosages of chlorothalonil were not effective in maintaining healthy pegs, and may have allowed early pod maturity and resulted in some shedding of pods.
A Differential Fluid Manometer for Hydraulic Lysimeters1
Authors: McLaughlin N. B. , Davidson H. R. 
Published: July 2010

AbstractA manometer that uses two fluids of different densities is described. The manometer is similar to the conventional manometer except that it has an enlarged reservoir at the top of the tube. The lower density fluid floats on the higher density fluid so that the interface between the two fluids is in the manometer tube and the free surface of the lower density fluid is in the reservoir. The manometer is read at the interface. The differential manometer has a greater sensitivity than the conventional manometer and is useful for measuring mass changes in a hydraulic lysimeter.
Irrigated Corn Yield Response to Nitrogen and Water1
Authors: Eck Harold V. 
Published: July 2010

AbstractIrrigated corn (Zea maysL.) is a relatively new crop on the Southern High Plains where the groundwater supply for irrigation is declining. Field studies were conducted to determine the plant nutrient needs for corn on a predominant soil of the area, the effects of timing and duration of drought stress periods, and the interacting effects of N levels and drought stress on N nutrition and production of corn. Fertilizer N rates ranged from 0 to 350 kg/ha. Irrigations were applied or deleted to allow the crop to be unstressed (I‐1), stressed 2 weeks during late vegetative growth (I‐2), stressed 2 weeks during early vegetative growth (1‐2a), stressed 4 weeks during vegetative growth (I‐3), stressed about 4 weeks during grain filling (I‐4), and stressed about 2 weeks during grain filling (1‐5). The soil was Pullman clay loam (fine, mixed, thermic Torrertic Paleustolls). Fouryear average data (three with graded furrow irrigation, one in level borders) showed that 140 kg N/ha were sufficient for maximum yields. However, simultaneous experiments conducted on graded furrows and level borders showed that while 140 kg N/ha gave maximum yields on graded furrows, 210 kg N/ha were required in level borders. This comparison illustrates the possible fallacy in conducting fertilizer trials under one method of irrigation and extrapolating results to another. Two and 4 weeks of plant water stress during vegetative growth reduced yields of adequately fertilized (210 kg N/ha) corn 23 and 46%, respectively. Two‐week stress periods during late (1‐2) and early (I‐2a) vegetative growth had similar effects on grain yields. Relationships between lengths of stress periods during grain filling and yield showed that yields were reduced 1.2% for each day stress was imposed during grain filling; however, as indicated by the r2(0.31), there was considerable variation in the data. A N × water stress interaction occurred on grain yields. Adequate N slightly increased corn grain yield under stress and greatly increased yield with full irrigation. Excessive N did not reduce yield even with severe water stress, thus, there would be no reason to reduce N rates to reduce water stress. As grain yields increased, the ratio of grain yield to N yield decreased until maximum yields were attained and then remained constant, indicating little luxury consumption of N. At maximum yield, typical grain yield/N yield ratios were about 52:l. At harvest soil NO−3‐N levels showed that plants had removed most of the N applied at rates up to 140 kg/ha, but increasing amounts remained when N application rates were above 140 kg/ha.
Effect of Soil Acidity Factors on Nodulation and Growth of Vigna unguiculata in Solution Culture1
Authors: Hohenberg J. S. , Munns D. N. 
Published: July 2010

AbstractEffects of low pH, low Ca, and high Al were tested on nodulation of Vigna unguiculatacultivars by the tolerant Rhizobiumstrain CB 756 in solution culture. Both pH (4.5) and Al (100 µM) caused delays in nodulation, particularly at low Ca (0.3 mM). At high Ca (3.0 mM) cultivar and treatment differences diminished with time. Cultivars differed in nodulation delay. In cultivar TVu 990 nodulation was most tolerant of acidity alone; in California Blackeye‐5 it was tolerant to Al; and in TVu 1190 it was sensitive to both stresses. Nodulation in three other cultivars was sensitive to Al. “Starter N” improved nodulation and plant growth. Cultivars whose growth was Al tolerant (in +N media) recovered more rapidly from effects of nodulation delay. Three types of symbiotic failure were observed. In TVu 1190, nodulation failure at high (100 µM) Al caused N deficiency. In TVu 990, host plant sensitivity to Al decreased N2fixation despite adequate nodule numbers. In Blackeye 5, nodulation was tolerant to Al and plant N was maintained, so that relative yields of +N and symbiotic plants were similarly decreased by Al.
Establishment, Dry Matter Yield, and Crude Protein of Fertilized Smooth Bromegrass on a Cleared Alaskan Soil1
Authors: Michaelson G. J. , Loynachan T. E. , Woodling F. J. 
Published: July 2010

AbstractA study was established to evaluate the fertilizer responses of smooth bromegrass (Bromus inermis Leyss. cv. Polar) during the first 3 years of growth on a newly cleared soil (Typic Cryochrept) in interior Alaska. The fertilization rates in the N4 by P4 by K4 complete factorial experiment were N at 0, 45, 90, and 135 kg/ha, and P and K each at 0, 34, 68, and 102 kg/ha. Yield responses to N were minimal without application of the first 34 kg/ha increment of P, and a significant N by P interaction occurred each of the 3 years of the study. During establishment (1979), the first increment of N (45 kg/ha) increased growth over sixfold above the level of the nonfertilized control. Growth was improved throughout the 0 to 102 kg/ha range of P, with over an eightfold increase in total production. Potassium (0 to 102 kg/ha) also improved growth but to a lesser extent than N or P, giving just over a 150% increase in production. In 1980 and 1981, total dry matter yields from the two cuttings increased with added N from 0.26 and 0.21 Mg/ha at the 0 N rate to 2.6 and 2.0 Mg/ha with 45 kg/ha N, respectively. Comparable yields at 90 and 135 kg/ha N were 3.8 and 4.3 Mg/ha in 1980 and 3.4 and 4.7 Mg/ha in 1981. Multiple regression equations were developed to predict bromegrass yield and N uptake for the 1980 and 1981 seasons. Relatively high coefficients of determination were obtained for dry matter yield (R2 = 0.845 for 1980 and 0.857 for 1981) and for N uptake (R2 = 0.861 for 1980 and 0.872 for 1981). Linear responses to N suggest that rates above 135 kg/ha N may provide even higher yields and protein contents.