bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serial Measures of Dry Matter Accumulation and Forage Quality of Leaves, Stalks, and Ears of Three Corn Hybrids1
Authors: Perry L. J. , Compton W. A. 
Published: July 2010

AbstractDry matter yields and forage quality of plant components (leaf, stalk, and ear) through maturity could vary among corn (Zea mays L.) hybrids. These potential differences could affect total forage quality yield and the hybrid choice for corn silage use. To compare plant composition, total plant dry matter, and forage quality among corn hybrids from flowering to physiological maturity, we studied leaf, stalk, and ear dry matter production and forage quality of three corn hybrids with maturity. Three corn hybrids, ‘Nebr. 611’, ‘Nebr. 612’, and ‘Nebr. 712’, were grown under field conditions with optimum agronomic conditions on a Sharpsburg silty clay loam (Typic Argiudolls) soil and harvested at six kernel development stages within 9 weeks following flowering during 1973 and 1974. All forage was separated for leaf, stalk, and ear dry matter production, and analyzed for crude protein, and in vitro dry matter disappearance (IVDMD). Total plant dry matter production increased at most harvests both years for all hybrids. Hybrid 712 yielded significantly more forage than 611 and 612 for most harvests. Stalk dry matter production declined over the harvests both years while leaf production increased during 1973. Leaf production remained the same over the harvests in 1974 for hybrids 611 and 612. Ear dry matter production increased at each harvest for all hybrids both years. Leaf crude protein was twice as large as stalk crude protein and declined over all harvests for the leaf component. Percent crude protein of ears declined through the first three harvests only. No hybrid differences were detected in percent crude protein of the three yield components. Leaf IVDMD was higher than that of stalk IVDMD. Rate of IVDMD decline was greater in stalks than leaves. Leaf IVDMD was consistently higher in 712 than 611 or 612. Little change occurred in ear IVDMD over the six harvests, however, the values were significantly greater in 1974 than 1973. The greatest plant protein and IVDMD yield occurred at the last harvest, physiological maturity, both years for all hybrids. Variation was detected among hybrids for total plant dry matter and plant component yields but less variation was detected among hybrids in forage quality for each plant component.
Transpiration Effects on Leaching Fractions1
Authors: Meiri A. , Kamburov Josephine , Shalhevet J. 
Published: July 2010

AbstractWater uptake by plants during the processes of infiltration and redistribution may introduce considerable errors in actual leaching when calculations are based on pre‐irrigation soil water deficit. The objective of the study reported here was to measure and demonstrate the importance of this water uptake in causing a reduction in the actual leaching.Experiments were conducted with sunflower plants (Helianthus annus L.) using containers with screen bottoms which drained into dry soil. The soil below the container was changed before each irrigation. Both saline (32 meq/liter NaCl + 16 meq/liter CaCl2) and non‐saline water were used at six leaching fractions (0.1 to 0.4). Drainage was doubled when plants were covered with plastic bags to suppress transpiration. Water uptake during leaching reduced the intended leaching fraction by 51 and 42% in the non‐saline and saline treatments, respectively (mean for all treatments).Measured chloride content in the containers was similar to that calculated from salt balance. The chloride concentration in the highly leached top soil indicated a 20% water uptake during flow.The results indicate that calculations of water application depth for leaching should not be based on soil moisture deficit but on the actual evapotranspiration of the crop. This is particularly true, for high frequency irrigations and for high transpiration rates.
Field Response of Four Tropical Legumes to Lime and Superphosphate1
Authors: Snyder G. H. , Kretschmer A. E. , Sartain J. B. 
Published: July 2010

AbstractThe generalization is often made that tropical legumes show little or no response to lime, even in acid soils low in Ca. Phosphorus responses, however, are generally observed. The effect of lime in an acid, virgin spodosol (Oldsmar fs) in southern Florida plots was investigated. Significant yield responses to lime and P were observed. Maximum total annual dry matter production of centro (Centrosema pubescens Benth.), desmodium (Desmodium heterocarpon DC.), stylo (Stylosanthes guyanensis Swartz), and ‘Siratro’ (Macroptilium atropurpureum Urb.) required lime applications of about 2,200 kg/ha. Regression analyses suggested that centro and Siratro might respond to higher lime rates if combined with P rates higher than those used in the study. Calculated optimum P rates ranged from 45 to 78 kg/ha, with desmodium requiring the least. Liming beyond the optimum rate appeared to seriously reduce production of desmodium and stylo.
Evaluation of Nitrapyrin as a Means of Improving N Efficiency in Irrigated Sands1
Authors: Hendrickson L. L. , Keeney D. R. , Walsh L. M. , Liegel E. A. 
Published: July 2010

AbstractThe efficiency of fertilizer N is usually low when potatoes (Solanum tuberosum L.) are grown on irrigated sands, because of rapid leaching of NO3. The objective of this research was to determine if optimum levels of N might be maintained throughout the growing season by delaying nitrification with a nitrification inhibitor, Nitrapyrin [2‐chloro‐6‐(trichloromethyl)pyridine] (NI). This method would increase fertilizer N efficiency and also reduce the potential for groundwater contamination. Several field experiments were conducted on a Plainfield loamy sand (Typic Udipsamment; sandy, mixed, mesic) involving various N sources, rates, and times of application with and without NI. Potato tuber yield and the forms and distribution of N in and below the fertilizer bands were determined. Nitrapyrin extended the persistence of applied NH4 in all experiments, but inhibition of nitrification was of relatively short duration. Nitrapyrin persistence was likely reduced by the more rapid volatilization and hydrolysis in sandy soils. Further, the effectiveness of NI was likely limited by rapid leaching of NH4 out of the NI‐treated zone. Application of NI reduced both total tuber yield and the proportion of marketable tubers. The greatest reductions were found on treatments receiving NI both at planting and at sidedress. The soil sampling data showed that NI maintained a much higher NH4‐N/NO3‐N ratio than comparable non‐NI treatments. It appears that the predominance of NH4‐N interfered with plant metabolism so that both yield and normal development of tubers were impaired.
Effect of Foliar Fertilization on Photosynthesis, Leaf Nutrition, and Yield of Soybeans1
Authors: Boote K. J. , Gallaher R. N. , Robertson W. K. , Hinson K. , Hammond L. C. 
Published: July 2010

AbstractFoliar fertilization (FF) was reported to increase seed yields of soybean [Glycine max (L.) Merr.] in field experiments in Iowa, but yield increases were not consistent. The researchers hypothesized that FF should minimize nutrient depletion from leaves during seed development, and thereby delay the resulting decrease in leaf photosynthesis. To test this hypothesis, we conducted a field experiment in 1976 to determine the effect of FF on leaf element concentrations, gross leaf photosynthesis (Pg), and soybean seed yield. Five weekly foliar sprays were applied during the seed‐filling period of ‘Bragg’ soybean grown at Gainesville, Florida on Kendrick loamy sand (loamy, siliceous, hyperthermic grossarenic paleudult). At weekly intervals, we sampled upper leaves and total canopy leaves and analyzed them for N, P, and K, and measured Pg of upper leaves in mid‐day sun with a 14CO2 gas flow technique. Foliar applications of N, P, K, and S increased the N, P, and K concentration of total canopy leaves from 3.28, 0.24, and 0.92% to 3.48, 0.29, and 1.32%, respectively. FF significantly increased upper leaf Pg only at two late sample dates when seed growth was nearly complete and most leaves had already senesced and dropped. Even though nutrient concentrations were increased, FF did not significantly affect yields nor did it extend Pg duration or delay maturity. Treated soybeans yielded 3617 kg/ha compared to 3825 kg/ha for control soybeans. Leaf Pg and concentrations of N and P in leaves progressively decreased during seed‐filling until maturity but K did not decline. Leaf Pg was positively correlated with N (r = 0.87) and approached zero at approximately 1.75% N, a concentration similar to that of senesced, recently abscised leaves. Maximum Pg was predicted at 4.6 to 6.0% leaf N. Leaf Pg and percent P were also positively correlated. The relationship of Pg to leaf N during N removal from leaves can potentially be used to model photosynthetic decline during seed‐filling.
Flowering, Abortion, and Yield of Early‐Maturing Soybeans at Three Densities1
Authors: Dominguez Carlos , Hume D. J. 
Published: July 2010

AbstractAttempts to extend the northern limits of soybean [Glycine max (L.) Merr.] production in North America are hampered by low yields. The earliest‐maturing genotypes are small, short‐statured plants. Their size suggests that yields could be increased by raising the plant population. In these trials, the early‐maturing genotypes, ‘Fiskeby V’, ‘052–903’, ‘Altona,’ and ‘Vansoy’, were grown in 30‐cm row widths at 40, 80 and 120 plants/m2 in 1975 and 1976 in a silty clay loam (Aquic Hapludalfs). The objective was to determine the influence of seeding rates on flower and pod production, abortion, yield components, and seed yield. Total flowers produced and initial and final numbers of pods per plant were decreased at high densities. The percentage of reproductive structures aborted also increased. More abortion occurred during the flowering period than post‐flowering period. The number of pods per plant was the yield component most affected by increasing density. The planting to flowering period, duration of flower production, number of seeds per pod, and seed size were cultivar characteristics not affected by density treatments. Final seed yields averaged 2,740 kg/ha over the 2 years. Seed yield increased by about 190 kg/ha when density was increased from 40 to 80 plants/m2 and by another 100 kg/ha when density was increased from 80 to 120 plants/m2. These responses represented only about twice the extra seed planted. The middle one‐third of the plants on a plant height basis produced an average of 44% of the seed yield. Increasing density decreased the percentage contribution of the bottom portion of the plant to final yield. Fewer bottom pods would be beneficial in reducing harvest losses with small, early‐maturing soybeans.
Recovery of Corn Leaf Water Potential After Severe Water Stress
Authors: Nulsen R. A. , Thurtell G. W. 
Published: July 2010

AbstractThe re‐establishment of vegetative growth after a period of water stress depends on the recovery of leaf water potential after rewatering. If the time to achieve recovery can be reduced, then overall plant production can be increased. This investigation examined the rates and patterns of leaf water potential recovery in corn plants (Zea mays L.) after alleviation of differing degrees of water stress. The experiments were done in a controlled environment chamber on corn plants grown in 5‐liter pots of 1:3 mixture of silica sand:calcined clay. Leaf water potential was measured in situ with a thermocouple dewpoint hygrometer. Plants were stressed by withholding water and, immediately upon rewatering, the growth chamber lights were turned off and the recovery pattern in the dark was monitored. Leaf water potential of corn plants stressed to −10 to −11 bars recovered in the dark 40 to 50 min after rewatering. When the plants were stressed to water potential values less than −11 bars they took between 95 and 300 min to recover. The recovery pattern always showed a distinct plateau phase during which time leaf water potential was relatively stable. The plateau occurred beween −9 and −7 bars and lasted 30 to 45 min. No plateau phase was observed in the rate of change of stalk diameter, but when stalks of severely stressed plants were severed under water to initiate recovery, we did not observe a plateau phase. Severing stalks under water, while leaf water potential was on a plateau, resuited in an immediate increase in potential. Applying pressure to the roots during the plateau phase caused af water potential to shift off the plateau. When pressure was released, however, the potential returned to the plateau and the plant continued a normal plateautype recovery. The results indicate that the main factors responsible for the plateau phase were in the roots, but that the stem and the leaves exerted some minor effects.
Value of Manure and Sewage Sludge as N Fertilizer1
Authors: Pomares‐Garcia F. , Pratt P. F. 
Published: July 2010

AbstractA greenhouse pot experiment in a Hanford soil (Typic Xerorthent) with rates of feedlot manure at 0, 20, 40, and 60 metric tons/ha and sewage sludge at rates of 0, 10, 20, and 30 metric tons/ha combined factorially with 0, 50, 100, 150, and 200 mg N/kg of soil as (NH4)2SO4 was conducted using barley (Hordeum vulgare L.) and sudangrass (Sorghum sudanense (Piper) Stapf.) as test crops. The objectives were to measure the net mineralization of N in the organic materials, to compare the availability of N in the organic materials with the N in (NH4)2SO4 and to determine the critical levels for N and NO3 in barley. The available N from the organic materials was estimated from the amounts required to equal the N in (NH4)2SO4 in terms of barley forage production. Net mineralization was determined by soil analyses.Yields of barley forage were increased by additions of organic materials and (NH4)2SO4. The addition of either manure or sludge decreased the response to (NH4)2SO4. In a 2.5‐month period after application, the manure gave an average of 0.65 kg of available N/ton, whereas the sludge gave 7.05 kg of available N/ton. This represents 4.2% of the total N from the manure and 17.0% of the total N in the sludge. In a 10‐month period only 17.2 and 40.9% of the N in manure and sludge, respectively, had mineralized.The estimated critical levels of total N and NO3−‐N in barley forage were 2.0 and 0.12%, respectively. These values were independent of the N source. The minimum content of total N in barley forage at which NO3−‐N began to increase was about 2.0%. The level of NO3−‐N in plant tissue was more sensitive than total N to changes in N supply.
Moisture‐Stress Effects on the Yield Components of Two Soybean Cultivars1
Authors: Momen N. N. , Carlson R. E. , Shaw R. H. , Arjmand O. 
Published: July 2010

AbstractLimited soil moisture influences field crop performance by reducing plant height, the size of the assimilating leaf area, and the size and number of potential storage sites for produced dry matter. The effect of moisture stress on plants is complex and very dependent on the stage of development. Therefore, soybeans (Glycine max (L.) Merr.) cultivars ‘Hark’ and ‘Rampage’ were in grown in the field in large potometers filled with the top 15 cm of a Nicollet loam (Aquic Hapludolls, fineloamy mixed mesic). The plants were subjected to four independent moisture stress periods during critical reproductive stages of growth. Soil moisture was controlled by hand watering and the use of an automatic weather shelter, which covered the plots during periods of rainfall. Soil moisture was measured with a neutron soil‐moisture probe, and frequent leaf‐water potential and leaf diffusive resistance measurements were collected to document moisture stress. Final seed yield and components of yield were determined at maturity for all experimental units.Moisture stress significantly affected most components for both cultivars during the four stress periods, but important cultivar moisture stress interactions were difficult to identify. Although these two cultivars differed greatly in some specific components of yield (Le., seed number, seed size, etc.), compensation between the different yield components resulted in no consistent yield differences between these two cultivars.
Differential Cultivar Tolerance in Soybean to Phytotoxic Levels of Soil Zn. I. Range of Cultivar Response1
Authors: White M. C. , Decker A. M. , Chaney R. L. 
Published: July 2010

AbstractHeavy metals in waste materials added to agricultural soils can severely inhibit subsequent crop growth. This study was conducted to evaluate the variation in tolerance among cultivars of an agriculturally important plant species to phytotoxic levels of added soil Zn. Twenty soybean (Glycine max L. Merr.) cultivars were screened, through greenhouse pot studies, for their growth response to Zn at pH 5.5 and 6.5 on a Sassafras sandy loam (Fragiudult) amended with 1.31 (control), 131, and 262 ppm Zn. Significant differential responses were found, and the cultivars were grouped into several tolerance and uptake classes, based on the results of the pH 6.5, 262‐ppm Zn treatment: tolerant (9 to 18% leaf dry weight yield reduction [YR], 5 cultivars), normal (20 to 32% YR, 12 cultivars), sensitive (33 to 48% YR, 3 cultivars); accumulator (696 to 730 ppm trifoliolate leaf Zn, 5 cultivars), normal (549 to 675 ppm Zn, 11 cultivars), and excluder (389 to 540 ppm Zn, 4 cultivars). Soil Zn additions significantly increased root and foliar Mn contents to reported phytotoxic levels at both pH 5.5 and 6.5, but did not influence DTPA‐TEA extractable soil Mn. Significant cultivar differences in root and leaf Mn contents were observed. The results of this work illustrate the importance of cultivar selection, not only for field planting of Zn‐enriched soils, but also for its influence on experimental results.
Effects of Sulfur‐coated Urea on California Annual Grassland Yield and Chemical Composition1
Authors: Vaughn C. E. , Jones M. B. , Ruckman J. E. 
Published: July 2010

AbstractFall applications of N fertilizers on California annual grasslands are often accompanied by luxury N uptake, excessive N leaching losses, and N deficiencies the following spring. Sulfur‐coated urea (SCU), a slow‐release fertilizer, was applied to a grassland soil (Laughlin, fineloamy, mixed mesic, ultic haploxeroll) to determine whether it could supply adequate N and S and eliminate problems encountered with more soluble N fertilizers.Urea (U), urea with 100‐mesh elemental S (U + S), and two formulations of SCU were broadcast on resident annual grassland, dominated by annual bromes (Bromus spp.), wild oat (Avena barbata) broadleaf filaree (Erodium botrys), and clover (Trifolium spp.), in a climate with cool, rainy winters and hot, dry summers. Forage ield and N and S uptake were measured seasonally in the 1st year and annually the following 5 years. Seasonal growth distribution was similar from all fertilizers in the 1st year. However, U + S was significantly more productive and gave greater herbage S uptake than the SCU's and U throughout the first growing season, and greater N uptake in the first winter.Residual studies suggested the long‐term benefit of S fertilization; the U + S and SCU treatments were significantly more productive for the last 5 years. Residual N uptake responses were similar to the yields. Herbage S uptake was similar in the U and check treatments for the entire study. The more heavily coated SCU formulation gave greater S uptake than both U + S treatments in the 4th and 6th years after application.It was concluded that the SCU's were of no greater benefit than urea combined with fine S in fertilizing California annual grasslands. The slow release of N from SCU did not give any greater apparent residual N response. There was a long‐term response to the larger particles of S in SCU, but it is questionable that this would justify the extra cost of the fertilizer.
Transector: An Inexpensive Device to Measure Ground Cover and Botanical Composition of Swards1
Authors: Andrade J. M. S. , Ocumpaugh W. R. 
Published: July 2010

AbstractA need for an apparatus capable of simplifying the reading and recording of ground cover and botanical composition on 80 experimental grazing plots prompted the development and testing of the transector.The objective of this manuscript is to describe how to construct and use the device to measure ground cover and/or botanical composition of grazed swards. The transector is a device that uses the line interception method, developed over 25 years ago, to simplify the logistics of pasture sampling and subsequent data analysis. The transector is a lightweight, simple, inexpensive device that is easily constructed and maintained. The only essential materials neded for the transector are two pieces of aluminum patio extrusion. This device makes it possible to take direct readings along a 5‐m long line without moving the transector. Since this device permits a direct reading along the line, it also simplifies the subsequent accumulation of the data for determining ground cover or botanical composition percentages.
Use of Slow‐Release N Fertilizers on Native Mixed Prairie1
Authors: Power J. F. 
Published: July 2010

AbstractAlthough it is known that the native mixed prairie grasses will respond to N fertilization, little is known concerning the recovery and fate of different fertilizer N sources applied to this ecosystem. Possibly by using slow‐release N fertilizers, changes in stands of the different grass species could be controlled in a manner that would improve productivity. Consequently, a 4‐year field experiment was conducted at Mandan, North Dakota, to compare the effects of S‐coated urea and ureaformaldehyde with ammonium nitrate on production of mixed native prairie vegetation. In general, all fertilizers at all rates of application decreased Boulettoua gracilis (blue grama) density, while Agropyron smithii (western wheatgrass) density generally increased at rates above 56 kg N/ha annually. Dry matter production from all rates of N application was greatest for ammonium nitrate and least for ureaformaldehyde, with intermediate production for the S‐coated ureas. Fertilizer N recovery in harvested forage followed this same order. Assuming that about 100 kg fertilizer N was immobilized in grass roots, and that fertilizer N not accounted for in tops, roots, and soil inorganic N forms estimates gaseous losses, presumed gaseous losses varied from less than 10% of the amount of N applied as ammonium nitrate to about 60% for ureaformaldehyde. In general, the mixed prairie grasses used N from urea‐containing fertilizers less efficiently than that from ammonium nitrate.
Sulfur Nutrition of Rice. I. A Survey of Soils of South Sulawesi, Indonesia1
Authors: Blair Graeme J. , Mamaril C. P. , Pangerang Umar A. , Momuat E. O. , Momuat Christine 
Published: July 2010

AbstractRice (Oryza sativa L.) yields in South Sulawesi, Indonesia have declined in some areas despite the use of significant quantities of urea and triple superphosphate (TSP). Chlorotic plants were observed to be growing on these low‐yielding areas despite the application of N. A series of field trials were conducted to examine the S status of soils in the area.In these experiments S was applied in various forms and yields were measured from unfertilized, NP, and NPS treatments at each of 28 sites. Responses in rice grain yield to applied S were measured at 18 sites. The magnitude of the responses ranged up to 278% with an average grain yield response over the 28 sites of 18.6%. The widespread nature of the responses in soils derived from varying parent material and in different river basins suggest that some 60 to 70% of the agricultural areas of the province is deficient in S.