bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Acid Soil Infertility Factors on Growth and Nodulation of Soybean1
Authors: Alva A. K. , Edwards D. G. , Asher C. J. , Suthipradit S. 
Published: July 2010

AbstractGrowth of a legume in acid soils can be limited by the effects of infertility factors on the growth of the host plant per se or on nodulation and nodule function. Effects of varying solution pH (4.5, 5.0, 5.5) and external calcium (Ca) concentration (0.05, 0.5, 2.5 mM) on growth and nodulation of soybean [Glycine max (L.) Merr. cv. Fitzroy] were investigated in a solution culture experiment. Total dry matter production was not influenced by pH; however, shoot growth increased while root growth decreased with increasing solution pH. Increase in Ca concentration significantly increased shoot dry weight at pH 5.0 and 5.5. At pH 4.5, appearance of the first nodule was delayed, and nodule number and nodule dry weight per plant were lower than at higher pH. Nodule number and dry weight per plant were not affected by Ca concentration at pH 4.5 but increased significantly with increasing Ca concentration at pH 5.0. At pH 5.5, nodule number per plant decreased, but nodule dry weight increased as Ca concentration increased from 0.5 to 2.5 mM. Further experiments were conducted at pH 4.5 with 0.5 mM Ca concentration to investigate the effects of monomeric aluminum (Al) activity (∑ aA1 mono) on the growth of soybean supplied with adequate inorganic N and on growth and nodulation of plants inoculated with Bradyrhizobium japonicum. Shoot and root weights declined linearly with increase in ∑ aAl mono, with the critical ∑ aAl mono (90% of yield in Alfree treatment) ranging from 5 to 9 µM. Nodulation was totally inhibited in solutions with ∑ aAl mono ≥ 27.8 µM. The critical ∑ aA1 mono for nodule number and for nodule dry weight per plant were approximately 0.4 µM.
Utilization of DRIS for Diagnosis of Nutrient Deficiencies in Winter Wheat1
Authors: Amundson R. L. , Koehler F. E. 
Published: July 2010

AbstractThe diagnostic recommendation integrated system (DRIS) has been regarded by some to be capable of providing nutrient diagnoses via foliar analyses regardless of the origin or age of the plant. This study had two objectives designed to address this claim. First, to determine if nutrient ratio norms currently available for wheat (Triticum aestivum L.), based on hard red winter wheat from Kansas, South Dakota, and Canada, could be used by the DRIS procedure to accurately diagnose deficiencies for N, P, K, and S in soft white irrigated winter wheat (cv. Daws) grown in central Washington state. Second, since DRIS diagnoses are based on a set of nutrient ratios assumed to be relatively invariate with age, to determine if a sampling date/time dependency existed for six specified nutrient ratios. Using the set of published DRIS norms developed from wheat grown in the Midwest, nutrient diagnoses calculated on irrigated winter wheat grown in central Washington tended to overestimate N deficiencies and underestimate P deficiencies at early heading and tillering, respectively, relative to parallel diagnoses by DRIS based on a corresponding set of norms. This second set of norms was derived from tissue analyses of winter and spring wheat grown on a Haploxeroll, an Argixeroll, two Argialbolls, and a Camborthid in Washington state. A statistical analysis of nutrient ratios from winter wheat grown in eastern Washington indicated that six ratios (N/P, K/N, K/P, N/S, P/S, and K/S) each exhibited significant sampling date/time dependence. Consequently, nutrient diagnoses provided by the DRIS procedure may not yet be independent of the origin and age of plant.
Grain and Forage Sorghum Production with No‐Tillage on Dryland
Authors: Unger Paul W. 
Published: July 2010

AbstractGrain sorghum [Sorghum bicolor (L.) Moench] is adapted to the Southern and Central Great Plains, but water stress at critical reproductive stages can sharply reduce grain yields of the crop on dryland. In contrast, forage sorghums (S. bicolor sudanense or saccharatum) have no such critical stages and, hence, do not require such timely rainfall to attain good yields. This study compared growth, production, water use, and water‐use efficiency of grain and forage sorghums under no‐tillage conditions on dryland from 1984 to 1986. All cultivars attained similar heights at 30 d after planting, but forage sorghums were taller at later times. Average total dry matter (TDM) production by grain and forage sorghums (8.14 vs. 8.61 Mg ha−1) was not significantly different. Total (grain plus stover) crude protein production was higher for grain than for all forage sorghums except ‘Sugar Dan’. Total digestible energy (DE) and metabolizable energy (ME) production also were higher for grain sorghum. Grain sorghum stover, however, has low nutrient value and usually is not harvested. When only grain of grain sorghum is considered, nutrient production (crude protein, DE, and ME) was lower than that for forage sorghums. Water‐use efficiency for TDM and nutrient production was lower for grain than for forage sorghums because grain sorghum had a longer growing season, which resulted in higher growing season precipitation and total water use than that for forage sorghums. In conclusion, forage sorghums are viable alternative crops to grain sorghum on dryland in the Southern Great Plains where forages can be used by the cattle (BOS spp.) industry.
Evaluation of the Salinity Tolerance of Russian‐Thistle, a Potential Forage Crop
Authors: Fowler J. L. , Hageman J. H. , Suzukida M. , Assadian H. 
Published: July 2010

AbstractRussian‐thistle (Salsola spp.) has economic potential as a forage for arid‐lands agriculture. It is drought and heat tolerant, uses water efficiently, and may be salt tolerant. Laboratory and greenhouse studies were conducted to determine the salinity tolerance of Russian‐thistle in three developmental stages: (i) germination, (ii) juvenility, and (iii) reproductivity. Treatment solutions were prepared using NaCl and CaCI2 in a 2:1 molar ratio. The effect of salinity (electrical conductivities of 0.1, 10.1, 18.8, 26.7, and 33.8 dS m−1) and temperature (5, 10, 15, 20, 25, and 30°C) on germination was determined under laboratory conditions. Salinity response during juvenility and reproductivity was studied under greenhouse conditions using sand culture irrigated with salinized nutrient solutions with electrical conductivities of approximately 1.3, 10.5, 18.2, 26.7, and 33.2 dS m−1. Germination percentages, fresh and dry biomass yield (total aboveground production), water content, ash content, and mineral composition of the ash were measured. A variable response to salinity was observed among the stages of plant development. Russian‐thistle was less salt tolerant during germination than at later growth stages. Germination generally declined linearly with increasing salinity at all temperatures. However, final germination was significantly reduced only at 30°C. Continuous exposure to salinity from the seedling stage through early flowering increased dry biomass yield by 56 and 24% over the control at treatment solution salinities of 10.5 and 18.2 dS m−1, respectively, 64 d after planting. In contrast, when the initial exposure to salinity occurred during the transition from the vegetative to the flowering stage, yield decreased linearly as salinity increased, with no yield enhancement at any salinity level. The reason for this differential response to salinity in the two growth stages was not determined.
Centipedegrass Decline and Recovery as Affected by Fertilizer and Cultural Treatments
Authors: Johnson B. J. , Carrow R. N. , Burns R. E. 
Published: July 2010

AbstractCentipedegrass [Eremochloa ophiuroides (Munro) Hack.] turf is often over‐fertilized, resulting in “centipede decline.” The purpose of this research was to determine the influence of fertilizer programs and cultural treatments on centipedegrass recovering from decline and for several years after recovery. Treatments were arranged in a split‐block statistical design with subunits in strips. Primary strips were seven cultural treatments and subunit strips were five fertilizer programs. The soil type was a Cecil sandy loam (clayey, kaolinitic, thermic Typic Hapludult). Centipedegrass with decline (50%) recovered to an acceptable turfgrass quality and density after 2 yr of annual treatments with 100–44–83 N‐P‐K rates (kg ha−1) applied in April. Scalping, topdressing, and vertical mowing did not improve turfgrass recovery during the first 2 yr of the study. Quality was improved by a 200–88–166 N‐P‐K rate (kg ha−1) for the first 3 yr, but thereafter, the grass lost density and was chlorotic. There was no benefit from additional K applied in late August to plots previously treated with a 100–44–83 N‐P‐K rate in April. Topdressing with soil improved spring growth, qualtiy, and shoot density more than did vertical mowing or scalping. Thatch increased by 18% with annual 100–44–83 N‐P‐K treatments, and similar thatch levels occurred with the 200–88–166 N‐P‐K treatment. Topdressing with soil decreased thatch accumulation 48% compared to untreated turf. Vertical mowing twice per year provided 15 to 17% thatch control, and scalping none. Fertilization at the 100–44–88 N‐P‐K rate plus annual topdressing provided the best turfgrass quality, shoot density, and lowest thatch accumulation.
Effect of Zinc Deficiency on Alcohol Dehydrogenase Activity and Nutrient Uptake in Rice
Authors: Moore P. A. , Patrick W. H. 
Published: July 2010

AbstractZinc deficiency in rice (Oryza sativa) usually occurs after flooding. A greenhouse experiment was conducted to determine if the metabolic disorders associated with Zn deficiency in flooded rice are due to decreases in alcohol dehydrogenase (ADH) or glutamate dehydrogenase (GDH) activities, or both, in the roots, since Zn is a cofactor in these enzymes. ‘Saturn’ rice, a variety characterized as being susceptible to Zn deficiency, was grown in 20 pots containing 3 kg of Crowley silt loam soil (fine, montmorillonitic, thermic Typic Albaqualf). Half of the pots received 1 mg Zn/kg as ZnEDTA; the other half served as controls. Five days after flooding the control plants showed signs of Zn deficiency. The plants were harvested 17 d after flooding. Aboveground dry matter production by the fertilized plants (x̄=0.91 g) was significantly greater than that of the Zn‐deficient control plants (x̄=0.24 g). Plant tissue analysis revealed that Zn‐deficient plants accumulated divalent cations at the expense of monovalent cations, possibly indicating the increased production of a divalent charge‐specific carrier. Root GDH activities of the control and fertilized plants were not significantly different. However, ADH activities in the roots of plants that had received Zn were more than twice as high as those in control plants. Root ADH activity was also correlated with Zn concentration in the leaves (r=0.78**). It is hypothesized that decreases in the ADH activity of Zn‐deficient flooded rice result in less ATP production, thereby reducing vital metabolic activities of the roots.
Animal Performance on Limpograss‐Aeschynomene and Nitrogen‐Fertilized Limpograss Pastures
Authors: Rusland G. A. , Sollenberger L. E. , Albrecht K. A. , Jones C. S. , Crowder L. V. 
Published: July 2010

AbstractIn vitro digestible organic matter (IVDOM) concentration of ‘Floralta’ limpograss [Hemarthria altissima (Poir.) Stapf et C. E. Hubb.] is high compared to many tropical grasses, but low crude protein (CP) concentration in Floralta may limit animal performance. Aeschynomene (Aeschynomene americana L.) grows well in association with limpograss and may improve animal performance on limpograss‐based pastures. This study compared steer (Bos spp.) average daily gain (ADG), carrying capacity (CC), and gain per hectare from midsummer to early fall on limpograss pastures that were overseeded with aeschynomene (LA) or fertilized with N (LN). Soils were primarily Pomona sands (sandy, siliceous, hyperthermic Ultic Haplaquods). Seasonal ADG (84 d in 1984, and 126 d in 1985 and 1986) was higher for LA than for LN pastures in 1984 (0.69 vs. 0.36 kg), 1985 (0.55 vs. 0.27 kg), and 1986 (0.85 vs. 0.54 kg). Handplucked herbage of aeschynomene had mean CP and IVDOM concentrations of approximately 250 g kg−1 dry matter (DM) and 720 g kg−1 organic matter (OM). Handplucked limpograss CP was marginal for growing steers, averaging 92 and 88 g kg−1 DM in 1985 and 1986, respectively. Mean seasonal CC over the 3 yr of grazing was higher for LN than for LA pastures (2210 vs. 1700 kg liveweight ha−1 d−1). In 1985 and 1986, however, mean seasonal CC did not differ between systems, but from early July to mid‐September LN pastures had higher CC (2240 vs 1540 (1985) and 2450 vs 1930 (1986) kg liveweight ha−1 d−1]. Mean gain per hectare per year was higher for LA than for LN pastures (377 vs. 264 kg) over the 3 yr of grazing. Although LN pastures are easier to manage and have a longer grazing season, these data indicate that gain per animal and gain per hectare can be increased during midsummer through early fall by growing aeschynomene with limpograss.
AGASSISTANT: an Artificial Intelligence System for Discovering Patterns in Agricultural Knowledge and Creating Diagnostic Advisory Systems
Authors: Fermanian T. W. , Michalski R. S. , Katz B. , Kelly J. 
Published: July 2010

AbstractAGASSISTANT is a non‐specialist artificial intelligence system for automatically determining, refining, and evaluating diagnostic rules and patterns for agricultural decision problems. It has the ability to create general decision rules from examples of expert decisions. It can provide advice using these self‐created rules or rules supplied by a system creator, and can also serve as a tool for developing expert or advisory systems. AGASSISTANT was first applied to build WEEDER, a system for identifying 37 grass weed or turf species commonly found in turfs in the USA. To evaluate WEEDER's potential for exclusive identifications, a program was developed to produce all possible combinations of variable values which lead to an exclusive identification of any grass represented in the system. For most grasses, there were multiple ways (x̄ = 4) of identifying each grass exclusively among all other grasses. Each identification required the selection of a value for an average of five variables. The maximum number of variable value decisions required for an identification was seven and the minimum was four. More than one‐half (59%) of the identifications required a decision on five or less variables. WEEDER was found to be as efficient in the number of decisions required for an identification as the theoretical maximum efficiency (5 leads) for a dichotomous key covering the same species. WEEDER represents an improvement over current methods of plant identification (e.g. identification keys) due to its ability to identify specimens through multiple sets of plant variables, use uncertain knowledge, allow the user to answer questions in any order, and be easily modified to reflect local differences in plant populations. AGASSISTANT provided the total environment for the initial representation and organization of the WEEDER knowledge base and serves as its final delivery medium.
Plant Tissue Tests for Predicting Nitrogen Fertilizer Requirements of Winter Wheat
Authors: Roth G. W. , Fox R. H. , Marshall H. G. 
Published: July 2010

AbstractField experiments were conducted to evaluate three plant tissue tests for estimating the need for supplemental nitrogen (N) fertilization of ‘Tyler’ winter wheat (Triticum aestivum L. em Thell) in Pennsylvania. The tests were used between Feekes growth stages (GS) 3 and 6, and measured stem nitrate concentration, whole‐plant Kjeldhal‐N concentration, and crop N uptake. The accuracy of a test for predicting N deficiency was evaluated in four to eight experiments conducted on either Hagerstown (fine, mixed, mesic, Typic Hapludalfs) or Murrill (fine‐loamy, mixed, mesic Typic Hapludults) soils. Spatial variability of the test procedures was evaluated at GS 4 in a 0.25 ha area of a production wheat field. In a third study the temporal variability of each test procedure was monitored during 37 and 25 d periods in 1985 and 1986, respectively. The whole‐plant N concentration accounted for the most variation in relative yields, had the lowest spatial variability, and appeared to be best suited for the current wheat management system in Pennsylvania. The wholeplant N concentrations necessary to produce 90% of the maximum yields or critical levels, were 39.0, 35.0, and 26.5 g N kg−1 for GS 4, 5, and 6, respectively. The stem nitrate tissue test was most sensitive to short‐term changes in the soil N supply. The critical level for the stem nitrate test did not fluctuate more than 10% between growth stages and averaged 2.15 g kg−1 NO3−N. The N uptake test was the weakest predictor of N deficiency, had the largest spatial variability, and was affected by factors that limited crop dry matter production.
Carbohydrate, Nitrogen, and Phosphorus Concentrations of Spring Wheat Leaves and Stems
Authors: Frank A. B. , Bauer A. , Black A. L. 
Published: July 2010

AbstractTillers which produce a spike on spring wheat (Triticum aestivum L.) contribute greatly to grain yield. Management practices and environmental factors influence tiller survival, but mechanisms that contribute to survival are not well understood. Leaves and stems from the main plant and all tillers grown in the field under two N and two water levels were separated and analyzed for water soluble carbohydrates (WSC), N, and P concentration. Concentrations of WSC were greater in stems than in leaves for all treatments, with concentrations in stems increasing rapidly as plants developed, while concentration of WSC in leaf tissue changed only slightly during development. Main plant stems had higher WSC than tiller stems and WSC of tiller stems decreased as tiller position increased from the main stem to T3. Leaf and stem N and P concentrations decreased for all treatments as plants developed morphologically. On most sample dates, leaf tissue had higher N concentrations than stems, but stems had higher P concentrations than leaves. Results were not conclusive as to the role of N, P, or WSC in determining tiller number and survival in spring wheat, but the tissue analyses suggest that WSC concentrations in stems are an important factor in determining total tiller number and survival. The plants that are most vigorous during vegetative development have a greater potential to produce tillers that survive and contribute to grain yield.
Mitscherlich‐Bray Equation Used to Correlate Soil Phosphorus and Potato Yields
Authors: Payton F. V. , Rhue R. D. , Hensel D. R. 
Published: July 2010

AbstractVery little is known about the response of potato (Solanum tuberosum L.) to P in northeast Florida where potato is a major winter crop. The purpose of this study was to correlate tuber yields with Mehlich‐I extractable soil and fertilizer P. Dolomitic lime was applied to an Ellzey sand (sandy, siliceous, hyperthermic Arenic Ochraqualfs) in 1977 at rates of 0.0, 2.2, 4.5, and 9.0 Mg ha−1, and resulted in average soil pH levels of 4.8, 5.4, 6.1, and 6.5 during the 5 yr of the study. In 1978 four rates of P were superimposed on lime treatments to establish a range of residual soil P levels for use in subsequent years of the study. In the following years, plots were fertilized with either no P (residual) or with P at planting. Data from 1981 were used to estimate the various parameters of the MB model, which related tuber yields to a linear function of soil and fertilizer P referred to as total effective P (TEP). Between 1979 and 1982 the percent yield was found to decrease with time by 20 to 70%, depending on the soil pH and Mehlich‐I P level. The decrease in relative yield was more rapid at pH 6.5 than at 5.4. The decrease in yield appeared to be the result of a decrease in availability of residual soil P, which was not accompanied by a decrease in Mehlich‐I extractable P.
Using Time‐Domain Reflectometry to Measure Soil Water in Hawaiian Sugarcane
Authors: Grantz D. A. , Perry M. H. , Meinzer F. C. 
Published: July 2010

AbstractTime‐domain reflectometry (TDR) has been suggested as a convenient technique for quantifying soil water in agronomic experiments. Sampling protocols and installation techniques remain to be described and the validity of a “universal” calibration equation remains to be tested in Ferich volcanic soils. Thus, TDR was evaluated in this study for measurement of volumetric soil‐water content in an extensive sugarcane field in Hawaii. Matched pairs of probes, 0.359 m and 0.725 m long, were installed vertically at various distances from the drip irrigation line at six locations in a well‐watered field. This sampling protocol resolved the diurnal depletion of soil water due to evapotranspiration and the decline in soil water wilh distance from the drip inrigation line, both occurring largely within the surface 0.36 m of soil. Independent measurements of soil‐water content using gravimetric methods confirmed the accuracy of the TDR determinations and validated a universal calibration for Ferich Hawaiian soils. A rapid technique was developed to install probes, which remained functional throughout the 2‐yr crop cycle. Use of spaced arrays of TDR probes is safer, more convenient, and more suited to automation of data acquisition, reduction, and analysis, than conventional methods of assessing volumetric water content.
Plant and Nitrogen Yield of Barley‐Field Pea Intercrop in Cryoboreal‐Subhumid Central Alberta
Authors: Izaurralde R. C. , Juma N. G. , McGill W. B. 
Published: July 2010

AbstractGrowing legumes with cereals may increase both yield and protein of livestock‐feed crops as well as the quantity of N returned to soil. This study examined: (i) if barley‐field pea intercropping has advantage over sole barley (Hordeum vulgare L.) for grain and N yield and (ii) the interactions between fertilizer N and seeding densities of barley and field pea (Pisum sativum L.). In 1986 and 1987, crop and N yields of barley and barley‐pea were compared on a Malmo silt loam (Typic Cryoboroll) and a Breton loam (Typic Cryoboralf). In 1987, fertilizer N (0 and 80 kg N ha−1) and seeding density (0, 86,172, 258 seeds m−2 of barley; and 0, 25, 50, 75 seeds m−2 of field pea) effects on intercrop yield were determined on the Malmo soil. In 1986, intercropped‐barley yields at both sites were similar to sole crop yields due to low pea competition; but in 1987, they were 35 to 40% lower than sole crop yields. In three of four location‐years, grain‐N yield was higher in the intercrop than in sole barley. Nitrogen returned to soil in barley‐pea residues was at least 22% higher than in barley straw. Of the intercrop components, only barley‐straw yield increased when fertilized with 80 kg N ha−1. Peagrain yields were not affected by barley seeding rates; but barley yields decreased linearly when pea density increased from 0 to 75 seeds m−2. Fertilizer N did not interact with seeding densities of barley and pea. Area × Time Equivalent Ratios indicated an advantage of intercropping over sole cropping in N but not in plant yield. Barley‐pea intercrops, each species seeded at half its sole rate, appear to increase N production in grain and straw over sole cropping under both soil‐climate conditions.