bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Acidity and N Source on the Growth and Thatch Accumulation of Tifgreen Bermudagrass and on Soil Nutrient Retention1
Authors: Sartain J. B. 
Published: July 2010

AbstractTurfgrasses are commonly grown on a soil with a near neutral pH using synthetic organic slow‐release N sources which are more costly than soluble inorganic N materials. Acidic soil conditions slows nitrification and may decrease the long‐term leaching loss of inorganic NH+4 source fertilizers, thereby increasing the N efficiency of the fertilizer source. Specific studies evaluating the effects of soil acidity on N fertilizer efficiency and turfgrass growth and thatch accumulation have not been conducted; therefore this study was initiated with the following objectives: (a) to assess the influence of acidity and N source on the quality, growth rate, N uptake, and thatch accumulation of Tifgreen bermudagrass [Cynodon transvaalensis Burtt‐Davis ✕ C. dactylon (L.) Pers.] and (b) to evaluate the effects of acidity on the retention of selected nutrients by the soil. Treatments were applied in a randomized complete block design with four replications to a 5‐year‐old Tifgreen bermudagrass turf growing on a loamy fine sand (Typic Quartzipsamment). Three N sources (Ammonium sulfate [AS], Isobutylidene diurea [IBDU], and activated sewage sludge [SS]) were applied at two frequencies (5 g and 10 g N m−2) every 14 and 28 days, respectively. The bermudagrass was rated every 14 days, clippings were collected every 45 days for growth rate and N uptake estimates and cores for thatch accumulation estimates were collected after each of three growing seasons. Maximum growth rates occurred at pH less than 4.0. Overall turfgrass quality was not significantly influenced by N source or frequency of application. Acidity promoted thatch accumulation, except in the presence of applied Ca. Significantly lower levels of thatch accumulated on plots receiving IBDU. Application of 5 g N m−2 as AS every 14 days promoted the accumulation of more thatch than 10 g N m−2 applied every 28 days. Frequency of application had no effect on the thatch accumulation of plots receiving IBDU and SS. Mehlich I extractable nutrients (P, K, Ca, and Mg) in the top 5 cm of soil declined with increasing levels of acidity. Turfgrass growth rate was not reduced in the presence of a 100 to 1 soil extractable Ca to Mg ratio.
Effect of N, P, and S Fertilizers on Alfalfa Grown on Three Soil Types in Northeastern Saskatchewan. I. Yield and Soil Tests1
Authors: Nuttall W. F. 
Published: July 2010

AbstractExperiments were conducted on three soil types to determine the effect of N, P, and S fertilizers on herbage yield of alfalfa (Medicago media Pers.) and on nutrients in soils over extended periods of time. Rates of 10,45, and 67 kg N ha−1 were applied in combination with 0,22, and 45 kg S ha−1 in the spring of each year. Twenty kilograms of P ha−1 was applied with these treatments. A control with no fertilizer yielded an average of 2.15 Mg ha−1 per cut Waitville loam (Wv 1, Typic Cryoboralf). An additional treatment (22 N, 0 P, and 26 S kg ha−1) yielded 3.01 Mg ha−1 per cut (avg. 10 cuts) which was the most economical treatment on Wv 1. Response to S fertilizer was significant on Wv 1, but only significant in 1 year on Whitefox fine sandy loam (Wf fsl, Typic Cryoboralf) which was Initially slightly lower in 0.01 M CaCl2 soluble‐S [18.4 vs. 16.5 S mg (4 kg)−1 soil]. Contrary to expectation, yield responses to S as much as 0.76 Mg ha−1 of herbage were obtained in 2 years on Melfort silty clay (M sic, Typic Cryoboroll), a soil initially containing a very high amount of So4‐S [46 mg (4 kg)−1 soil]. Results indicated that soils need to be tested every 4 to 5 years to provide a basis for adjusting S fertilizer rates. Regression analyses revealed that N significantly increased yield per cut on Wv 1 and Wf fsl soils and that S increased yield on Wv 1, averaged over 5 years. Because an expected response to S was not obtained on one site, tissue analyses should be investigated further as a method for determining availability of S.
Soybean Yield Response Prediction from Soil Test and Tissue Manganese Levels1
Authors: Gettier S. W. , Martens D. C. , Donohue S. J. 
Published: July 2010

AbstractManganese deficiency continues to be a yield limiting factor in soybean [Glycine max (L.) Merr.] production on many Atlantic Coastal Plain soils. Field research was conducted in order to refine the double acid (also known as the Mehlich I) extractable Mn soil test and to determine critical Mn deficiency levels for whole plant, leaf and seed plant parts. Experiments on Mn deficiency in soybeans were conducted at 30 field locations with 13 soil types, spanning 7 years. A total of eight soybean cultivars were used in this field research. A yield prediction equation was developed (r = 0.68**, significant at the 0.01 level) with the inverse relationship of pH and double acid extractable Mn in the Ap horizon. Inclusion of organic matter and the same soil parameters in the B horizon did not improve the equation's predictive ability. Yield prediction equations were developed for whole plant (r = 0.44*, significant at the 0.05 level), leaf (r = 0.94**), and seed (r = 0.73**) Mn concentrations. Based on 90% of maximum yield as the definition of the critical deficiency level, the critical Mn levels for whole plant, leaf, and seed were 45, 17, and 20 mg/kg, respectively. The eight soybean cultivars evaluated in this study had similar responses to low levels of available Mn.
Chloride and Liming Effects on Soil Nitrogen Form and Take‐all of Wheat1
Authors: Christensen N. W. , Brett Marcia 
Published: July 2010

AbstractLittle is known about how chloride (Cl) functions in suppressing take‐all root rot of wheat (Triticum aestivum L.). A field experiment was conducted to determine the effects of liming and CI application on ammonium (NH+4 and nitrate (NO−3‐N) concentrations in soil as they correlate with development of the disease. ‘Hill 81’ soft white winter wheat was grown on a limed (pH 6.6) and unlimed (pH 5.5) Aquultic Argixeroll fertilized with a factorial combination of 30 kg N ha−1 as NH4NO3, (NH4)2SO4, or NH4Cl banded at planting and 140 kg N ha−1 as Ca(NO3)2, (NH4)2SO4, or NH4Cl topdressed in the spring. Soil was sampled to 10 and 20 cm depths and analyzed for NH+4‐N, NO−3‐N, Cl, and pH at weekly intervals for 10 weeks following spring application of N. Take‐all was assessed at 0, 6, and 11 weeks after spring fertilization. Take‐all severity, NH+4‐N and NO−3‐N concentrations, NH+4‐N:NO−3‐N ratios, and grain yield were all influenced by a highly significant interaction between liming and spring‐topdressed Cl. Liming hastened disappearance of NH+4‐N and increased appearance of NO−3‐N in soil. Chloride slowed disappearance of NH+4‐N and appearance of NO−3‐N in unlimed soil but not in limed soil. A “critical” NH+4‐N:NO−3‐N ratio for take‐all suppression of 3:1 was estimated from data in the literature. Takeall severity was negatively correlated (r2=0.84) with the length of time the NH+4‐N:NO−3‐N ratio remained above the estimated critical ratio. Chloride increased grain yield from 3.5 to 4.7 Mg ha−1 on the unlimed soil but had no effect on yield on the limed soil. Results suggest that Cl may reduce take‐all severity and increase grain yield on moderately acid soils in western Oregon by reducing nitrification and maintaining a favorable NH+4‐N:NO−3‐N ratio for disease suppression.
Responses of Soybean Canopy Photosynthesis and Transpiration to Whole‐Day Temperature Changes in Different CO2 Environments1
Authors: Jones Pierce , Allen L. H. , Jones J. W. 
Published: July 2010

AbstractResponse of plants to increased temperatures, as well as increased CO2, is one of the concerns about the global consequences of continued burning of fossil fuel. In this study, soybeans [Glycine max (L.) Merr. cv. Bragg] were grown in controlled‐environment chambers located outdoors and acclimated to two environmental CO2 levels, 330 and 800 µmol mol−1. Canopies were exposed to different day‐long dry bulb temperature treatments that were maintained for a few days. Comparisons of CER‐light response curves and daytime total CO2 exchange from both low and high CO2 treatments indicated that canopy CER was not significantly affected by dry bulb temperature in the range 28°C to 35°C (nighttime temperature was 23°C). Canopy water use increased significantly in both CO2 treatments as dry bulb temperature was increased and the dewpoint temperature was kept at 21°C. Calculated total canopy resistances were constant throughout the temperature treatments in each of the CO2 treatments. This indicated that between dry bulb treatments, changes in canopy water use resulted strictly from temperature‐driven changes in the vapor pressure gradients within the canopy. Characteristic ratios of internal to external canopy CO2 concentrations were calculated and found to be similar among all temperature treatments and in both CO2 treatments. Across all temperature treatments, cumulative daytime transpiration was nearly equal between the two CO2 treatments, however, water‐use efficiency (WUE) decreased in both CO2 treatments as dry bulb temperature increased. Since CER response in both CO2 treatments was unaffected by air temperature across the range of 28 to 35°C, the decrease in WUE with increasing temperature was due solely to increasing transpiration.
Tillage and Low‐Pressure Center‐Pivot Irrigation Effects on Corn Yield1
Authors: Wilhelm W. W. , Mielke L. N. , Gilley J. R. 
Published: July 2010

AbstractLow‐pressure sprinkler irrigation systems have the potential to save energy, but also may aggravate soil‐ and water‐management problems. The objective of this research was to determine the influence of center‐pivot sprinkler irrigation method in combination with various tillage practices on corn (Zea mays L.) yield and yield components. A center‐pivot irrigation machine was redesigned to apply water by high‐pressure‐impact (HPI), low‐pressure‐impact (LPI), and low‐pressure‐spray (LPS) nozzles. Nozzles were sized and spaced to apply three different amounts of water: 100% (full irrigation), 75 and 50%. Three tillage treatments were used—till‐plant (T), disk (D), and till‐plant with chisel after last cultivation (C)—for each method and amount of water applied. The field study was conducted over a 4‐year period (1978 to 1981) on a Sharpsburg silty clay loam (fine, montmorillonitic, mesic Typic Argiudolls). Yields were influenced by the seasonal distribution and amount of precipitation, irrigation water applied, tillage, and the combined management inputs. The method of water application (HPI, LPI, and LPS nozzles) did not significantly (P > 0.10) influence grain yield. In 1979, the chisel tillage treatment produced significantly less grain than other treatments because severe root pruning limited stored water uptake during an extremely stressful period immediately following the chisel operation. No inherent differences in productivity were associated with low‐pressure center‐pivot‐sprinkler irrigation, or with various conservation‐tillage practices used in combination with reduced‐pressure‐sprinkler irrigation. Therefore, use of these practices can reduce production costs without reducing yield.
Effect of N Fertilization on Earthworm and Microarthropod Populations in Kentucky Bluegrass Turf1
Authors: Potter Daniel A. , Bridges Barry L. , Gordon F. Carter 
Published: July 2010

AbstractEarthworms and microarthropods are abundant in turfgrass and may be important to thatch decomposition and nutrient recycling. There is little published information concerning the effects of cultural practices on the soil fauna in turf. The purpose of this study was to determine the influence of prolonged N fertilization on populations of earthworms, Collembola, and Acari involved h decomposition processes in Kentucky bluegrass, and to relate these effects to changes in soil pH and thatch accumulation. Six rates of ammonium nitrate fertilizer ranging from 0 to 25 g N m−2 were applied annually for 7 years to replicated plots of ‘Kenblue’ Kentucky bluegrass (Poa pratensis L.) growing on a Maury silt loam soil (fine‐silty, mixed, mesic Typic Paleudalf) near Lexington, KY. Populations of earthworms and soil microarthropods were enumerated in May and October 1983. Increasing the rate of N fertilization resulted in a significant decline in soil and thatch pH and in exchangeable Ca and K, and caused a significant increase in thatch. Regression analyses indicated a highly significant linear decrease in earthworm density and biomass as annual rates of N fertilization increased. Collembola were more abundant at an intermediate fertilizer rate, whereas Acaridae were unaffected by N fertilization. Cryptostigmata, predominantly Scheloribates sp., were the most abundant arthropod decomposers in the turf. Each of the seven oribatid mite species differed in its response to N fertilization. The study indicates that when N fertilizer is applied to Kentucky bluegrass at rates sufficient to cause soil acidification, populations of earthworms and certain other decomposers may be severely reduced. Thatch accumulation was negatively correlated With earthworm density and biomass, although other factors probably also contributed to thatch development.
Water Uptake and Release by Alfalfa Roots1
Authors: Dirksen C. , Raats P. A. C. 
Published: July 2010

AbstractWater release to dry upper soil by alfalfa roots amply supplied with water in the bottom of the rootzone could not be measured by gamma‐ray attenuation. Variations in the CO2and O2concentrations of the soil water had no measurable effect on water release. After having been nearly inactive with respect to water uptake in dry soil for more than 50 days, the upper roots took up water at a high rate immediately after rewetting. If metabolic influences of the plants are negligible, such polarity between water uptake and release must depend on the location and relative magnitudes of the main resistances in the two types of flow. Comparison of leaf water and soil water total potentials indicated little resistance in the xylem and major resistance in the radial pathway. Water uptake across large radial resistances causes low water potentials inside the xylem. For this water to be released to drier soil elsewhere, water potentials there must be even lower than in the xylem. Associated large soil‐root interface resistances are likely to prevent water release of any significance. Such resistances are suggested as an explanation for the generally observed polarity between water uptake and release.
Comparison of Urea and Urea‐Ammonium Polyphosphate with Ammonium Nitrate in Production of Tall Fescue1
Authors: Murdock L. W. , Frye W. W. 
Published: July 2010

AbstractThe yield response of tall fescue (Festuca arundinacea Schreb, cv. Kentucky 31) to urea (45% N) and urea‐ammonium polyphosphate (34% N; 7.5% P) was compared with that from ammonium nitrate (33% N). The fertilizers were surface‐applied to the fescue at a rate of 78 kg ha−1N several times during the growing season. Ammonium nitrate and urea were applied twice per month from early April through mid‐September of 1973, 1974, 1975, and 1977. Urea‐ammonium polyphosphate was applied monthly during the same period of 1974, 1975, and 1977. Yield response, defined as yield with N fertilizer minus yield without N fertilizer, was significantly lower (P < 0.05) with urea than with ammonium nitrate at all application dates except mid‐April and early May and September. The difference in September was significant at the 10% level. Yield response with urea‐ammonium polyphosphate was not significantly different (P > 0.10) than with urea at the same application dates. The lower yield response to urea compared with ammonium nitrate was thought to result from volatilization loss of NH3. Fitted polynomials of the relationship between yield response to urea relative to ammonium nitrate (RRn) and the number of days following urea application until cumulative rainfall of at least 2.5, 5, 10, and 20 mm gave 2values of 0.55, 0.54, 0.48, and 0.33, respectively; RR, values were usually higher when at least 2.5 mm of rain fell in < 3 days after application, and that amount of rainfall within that time appeared to be adequate to prevent large volatilization loss of NH3. The RRnvalues were usually lower when the first rainfall, regardless of amount, occurred > 3 days after application.
Shade‐Sensitive Interval of Kernel Number of Maize1
Authors: Kiniry J. R. , Ritchie J. T. 
Published: July 2010

AbstractThere have been many investigations into the time interval when maize (Zea maysL.) yield is most susceptible to stress. Knowledge of this interval is important for understanding yield potential, modeling, irrigation scheduling, and the study of the partitioning of assimilate into grain. The objective of this experiment was to determine the growth stage when shading stress affected number of kernels per ear. Three commercial maize hybrids were grown on a Houston black clay (fine montmorillonitic, thermic Udic Pellustert) under irrigation near Temple, TX in 1982 and 1983. Plants were stressed using horizontal shade panels that reduced the light by 79% for approximately 13‐day intervals. In order to define when number of kernels was affected, the panels were moved three times each week to provide an overlapping series of treatments. The number of kernels of each treated plant was measured and treatment means were compared with unshaded controls. The growth stage when shading decreased the final kernel number was closely associated with early kernel development, occurring near the end of the lag period of grain filling. Duration of the sensitive period varied from 6 to 23 days. It was speculated that a stress applied in the first 1 to 2 weeks after pollination caused a temporary shortage of assimilate for the ear, severely limiting endosperm cell number of some tip kernels. These kernels would not fill later, even if stress was relieved.
In Vitro Digestion, Chemical Composition, and Fermentation of Ammoniated Grass and Grass‐Legume Silage1
Authors: Moore K. J. , Lechtenberg V. L. , Lemenager R. P. , Patterson J. A. , Hendrix K. S. 
Published: July 2010

AbstractPost harvest treatment of low‐quality grass hays with anhydrous ammonia (NH3) has been demonstrated to improve energy availability and crude protein concentration. Two experiments were conducted to determine what effect NH3treatment would have on the composition, fermentation, and digestibility of grass and grass‐legume silage. In the first experiment mature first‐cutting orchardgrass (Dactylis glomerataL.) herbage was harvested, ammoniated at 0, 7.5, 15, and 30 g/kg dry weight (DW), and ensiled at a moisture concentration of 703 g/kg wet weight (WW) for 8 weeks. The ensiled herbages had pH values of 4.4, 4.8, 5.8, and 5.9, respectively. Ammoniation at 7.5, 15, and 30 g/kg DW increased the concentration of total N by 5, 11, and 24 g/kg DW, respectively. Ammoniation at 30 g/kg DW increased (P<0.05) in vitro digestibility of dry matter (DM), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose, and cellulose by 104, 132, 110, 132, and 128 g/kg, respectively. Ammoniation at 7.5 and 15 g/kg DW had no effect (P>0.05) on the digestibility of DM or any fiber constituent. In the second experiment, mature first‐cutting herbage composed of approximately 90% orchardgrass and 10% white clover (Trifolium repensL.) was ammoniated at 0,15, and 30 g/kg DW prior to ensiling for 10 weeks at a moisture concentration of 635 g/kg WW. The silages had pH values of 4.7,6.8, and 7.1, respectively. Ammoniation at 15 and 30 g/kg DW increased (P<0.05) the concentration of total N by 14 and 23 g/kg DW, respectively. Ammoniation at 15 and 30 g/kg DW increased (P<0.05) the extent for in vitro NDF digestion by 126 and 236 g/kg NDF. Rate constants for in vitro NDF digestion did not differ (P>0.05) among ammoniated silages but were greater (P<0.05) than those observed in the control. Rate constants averaged 0.061/h for the ammoniated silages and 0.051/h for the control.
Effect of Irrigation Interval on St. Augustinegrass Rooting1
Authors: Peacock Charles H. , Dudeck A. E. 
Published: July 2010

AbstractIrrigation is an integral part of a turfgrass management program. Turfgrass rooting characteristics within the soil profile determine how much soil moisture is available to support turfgrass growth. Determination of optimum irrigation intervals and the effects on turfgrass rooting will help provide better utilization of irrigation water resources. Rooting response to irrigation intervals was studied on ‘Floratam’ St. Augustinegrass [Stenotaphrum secundatum(Walt.) Kuntze] during the 1980 and 1981 growing seasons. Root mass and length on a dry‐weight basis were determined in 15‐cm profile increments to a depth of 75 cm from field plot samples at beginning and end of the study period. Treatments received the same irrigation volume but irrigation interval was every 2, 3, 4, or 6 days.Root mass and length density were unaffected by irrigation treatments during 1980. Total root mass density decreased 42% and root length density decreased 37% within the profile on a land‐area basis from beginning to end of the study period. Over 40% of the root mass occurred below 30 cm in the profile.Root mass density increased during 1981 from initial to final sampling for all profile depths except 60 to 75 cm but there was no treatment effect. In contrast to 1980, only 9% of the roots were distributed below 30 cm in the soil profile. Root length density increased for the 30‐ to 45‐cm and 45‐ to 60‐cm depths but was unchanged for the other depths. Total root mass density on a land‐area basis increased for all treatments but total root length density did not. This indicates that with the irrigation volume applied, St. Augustinegrass increased root size but not root length, regardless of irrigation interval. This would afford an advantage in survivability but not in drought avoidance.
Soil Compaction and Moisture Stress Preconditioning in Kentucky Bluegrass. I. Soil Aeration, Water Use, and Root Responses1
Authors: Agnew M. L. , Carrow R. N. 
Published: July 2010

AbstractSoil compaction and moisture stress are major problems on recreational turfgrass sites. In the greenhouse, we investigated root responses to soil compaction and moisture stress preconditioning, and their effects on water use of Kentucky bluegrass (Poa pratensisL. ‘Ram I’). The compaction treatments included: (i) NC = no compaction, (ii) LT = long‐term compaction (equivalent to 720 J energy) over a 99‐day period, and (iii) ST = short‐term compaction for 9 days. Irrigation regimes were initiated at the same time as LT compaction. They included: (i) well watered = irrigation at −0.045 MPa and (ii) water stressed = irrigation at −0.400 MPa. Ninety‐nine days after initiation of preconditioning treatments and after watering each treatment to saturation, a dry‐down cycle was started. Compaction treatments reduced ODR to below 0.20 µg cm−2min−1for 143 h compared with 26 h in the uncompacted turf. Long‐term compaction increased root weights in the upper 5 cm and decreased root weights in the lower 10 to 20 cm profile. Short‐term compaction decreased root weights only at 15 to 20 cm. Root porosity was increased by LT compaction, but the greatest increase was for the combination of LT compaction and water stress resulting in root porosities of 23%. Plants with higher root porosities also exhibited greater water uptake during low soil O2conditions. Soil compaction reduced total water use and moisture extraction in the deeper zones. Moisture stress preconditioning had no effect on root distribution but resulted in greater total water use, primarily from the 0‐ to 5‐ and 5‐ to 10‐cm soil zones.