bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water Economy and Saline Water Use by Drip Irrigation1
Authors: Singh S. D. , Gupta J. P. , Singh Panjab 
Published: July 2010

AbstractIn arid regions water is scarce and efficient use of poor quality water by means of drip irrigation has become a necessity. Drip irrigation with good quality water at 1.0, 0.75, and 0.5 and with saline water at 1.0 times the daily evapotranspiration (ET) rate was compared with furrow irrigation using sweet water applied at the rate 1.0 ET with respect to the yield of potatoes (Solanum tuberosum L.) on a loamy sand soil. Drip irrigation with sweet and with saline water at the rate equal to 1.0 ET was also evaluated with respect to the yield of tomatoes (Lycopersicon esculentum Mill.). Water was applied daily by drip irrigation and at intervals of about 7 days by furrow irrigation in amounts equal to 63% of Class A pan evaporation.Drip irrigation at a rate less than the ET rate decreased the yield of potatoes compared with the rate equal to ET. To obtain identical yields, drip irrigation required 50% less water than furrow irrigation. Saline water at 3,000 μmhos/cm applied by drip irrigation did not limit yields but at 10,000 μmhos/cm it reduced potato yields by 91% and tomato yields by 35%. The soil water content was about 15% beneath the emitter, 7% at a point 20 cm from the lateral, and 3 to 4% near the wetting front located 40 cm from the lateral. The wetted zone, extending 20 cm on either side of the lateral, could be used for twin‐row configurations. Salts were concentrated in the surface 15 to 20 cm of soil at the midpoint between the emitters and towards the wetting front. Salts were not leached to lower soil horizons with the treatments used in these experiments.
Alfalfa Root Development and Shoot Regrowth in Compact Soil of Wheel Traffic Patterns1
Authors: Grimes D. W. , Sheesley W. R. , Wiley P. L. 
Published: July 2010

AbstractReduced growth and fewer plants are common in wheel paths of post harvest equipment in alfalfa (Medicago sativa L.) fields of the San Joaquin Valley. Up to 70% of the soil surface may be covered by equipment wheels in a single harvest. Field and glasshouse studies were conducted to quantify plant and soil responses to wheel traffic in confined paths scheduled to simulate harvest operations. Three field compaction treatments simulated harvest, postharvest, and harvest plus postharvest wheel traffic. A no‐traffic area served as a control treatment. Compaction of a sandy loam soil (Typic Xerorthents) in traffic zones reduced root‐length density (cm of root per cm3 of soil) as much as 60% in a 15‐to‐30‐cm depth zone. Postharvest traffic reduced plant population and yield by damaging crowns and regrowth shoots. Field observations on soil‐compaction root‐growth relations were substantiated by a glasshouse study that char. acterized alfalfa root‐length density (Rd, cm of root per cm3 of soil) as a function of soil bulk density (Ds, g cm−3) and time (T, days) as Rd = −23.51 +27.88Ds +0.2210T −9.135D,s 2 −0.0003548T3 −0.08360DsT, R2 = 0.84. Root growth in a field study was enhanced by delaying the harvest for newly established seedings.
Seed and Fertilizer Patterns with Spinning and Oscillating Spreaders1
Authors: Wolf D. D. , Smith E. S. 
Published: July 2010

AbstractSeeding and fertilization represent common operations where broadcast distributors increase efficiency of forage production and pasture renovation. The successful use of broadcast units has been something of an art with procedures based largely on trial and error experiences of the operator. In this paper we describe two broadcast delivery methods for application of fertilizers and forage seeds. Spinner and oscillating delivery methods were used to establish spread patterns and effective swath widths for phosphate (20% P) and potash (50% K) fertilizers, and seeds of red clover (Trifolium pratense L.), and tall fescue (Festuca arundinacea Schreb.) A mixture of P fertilizer, red clover, and tall fescue (100:12:6 ratio), typical of that appropriate for pasture renovation, was also tested. Both the spinner and oscillating units produced satisfactory spread patterns when properly adjusted. The spinner unit required adjustment for each material delivered to produce a symmetrical spread pattern while no changes were required with the oscillating type. The effective swath width was selected as the maximum width for a 15% coefficient of variation among rates at 0.6 m intervals across the field. The fertilizer‐seed mixture did not segregate seriously during delivery and the effective swath width was selected to achieve uniform coverage of the component with the smallest pattern.
Control by Tillage and Persistence of Volunteer Sunflower and Annual Weeds1
Authors: Robinson Robert G. 
Published: July 2010

AbstractVolunteer sunflower (Helianthus annuus L.) is a major problem in crop rotations which include sunflower. This research was conducted to determine if the problem persists beyond the crop following sunflower and to learn if tillage methods affect populations of volunteer sunflower and annual weeds. Sunflower fields were harvested with a combine in 1973 and 1974 at Rosemount, Minn. Volunteer sunflower and annual weed numbers/ha were determined following five primary tillage treatments in combination with May and June planting of pinto bean (Phaseolus vulgaris L.) and a secondary preplanting rototiller treatment. Counts were made shortly after emergence in permanent 1‐m2 quadrats through 1977. Plots were rogued to prevent sunflower or weeds from producing seed. The weed seed population in the soil continued to supply weed plants every year, and there was no reduction in the last years of the trials. But volunteer sunflower populations in the 2nd year dropped to 2% of the first year's populations and were nearly 0 in the third and fourth years. Three treatment combinations that eliminated volunteer sunflower in 1 year were: no tillage in October followed by disk, plow, rototill in the spring; disk in October followed by plow, rototill in the spring; and rototill in October and again in the spring. Volunteer sunflower plants in the 1st year after sunflower were most numerous following rototilling in October and least numerous following no tillage in October. Weed plants were most numerous following moldboard plowing in October. About 90% of the volunteer sunflower emerged by 11 to 13 June.
Effects of Natrustoll Soil Horizons on Germination, Emergence, and Growth of Four Grasses1
Authors: McGinnies William J. , Ludwig Jim R. 
Published: July 2010

AbstractRehabilitation of low‐value saltgrass [Distichlis stricta (Torr.) Rydb.] meadows involves elimination of the existing vegetation and establishment of palatable forage grassy. The seeded forage grasses have frequently failed to become established in field plantings on Natrustoll (Solonetz) soils, particularly where the B and C horizons have been brought to the surface by plowing. To determine how soil material from the Natrustoll soil horizons affects grass establishment, soil from A, B, and C horizons was placed in pots in a greenhouse, and emergence, establishment, and growth of four promising range grasses were measured. We found that Agropyron elongatum, A. desertorum, Elymus junceus and Bromus inermis could readily be established on soil from the A and B horizons of the Natrustoll soil found in the saltgrass meadows. On the C horizon, all species would germinate and emerge (although germination and emergence were slower), but only A. elongatum could become established. Herbage yields on the C horizon were less than 5% of yields on A or B horizons. We attributed the poor establishment and yield on the C horizon to its saline‐alkali nature (a pH of 8.8, a conductivity of 12.6 mmho/cm, and a sodium adsorption ratio of 78.6).
Large Crabgrass Control in Turfgrasses with Fall‐applied Herbicides1
Authors: Johnson B. J. 
Published: July 2010

AbstractHerbicidal control of both winter and summer annual weeds in turfgrasses usually requires fall and spring treatments which utilize excessive amounts of chemicals. Management studies were conducted for 3 years on common bermudagrass [Cynodon dactylon (L.) Pers.] at Griffin and Kentucky bluegrass (Poa pratensis L.) at Blairsville, Georgia, to determine the effectiveness of fall and fall + reduced spring rates of herbicides applied for large crabgrass [Digitaria sanguinalis (L) Scop.] control to minimize chemicals applied. The experiments were conducted on Cecil (Typic Hapludult) sandy loam at Griffin and Hatboro (Typic Fluvaquents) sandy loam at Blairsville.Bensulide [0,0‐diisopropyl phosphorodithioate S‐ester with N‐(2‐mercaptoethyly)benzenesulfonamide] was the only herbicide that consistently controlled at least 82%, of large crabgrass the summer after fall treatment. All other herbicides required fall and repeated spring treatments for consistent control.
A Hand‐Held Grafting Device for Making Uniform Wedge Cuts1
Authors: White M. C. 
Published: July 2010

AbstractThe design of a hand‐held device for making uniform wedge cuts for reciprocal grafts is described. The Plexiglas device uses two changeable stainless‐steel, single‐edge razor blades to simultaneously cut a uniform wedge and its receptacle in a plant stem. This reduces considerably both plant handling and the time required to perform numerous reciprocal grafts. In plants of similar age and stem diameter, the uniform cuts should allow more efficient tissue matching and increased survival of the grafted plants.
Fertilization of Switchgrass in the Greenhouse with Various Levels of N and K1
Authors: Smith Dale 
Published: July 2010

AbstractSwitchgrass (Panicum virgatum L.) is a warm‐season, native grass that may have value in humid areas for summer pasture. The objective of this research was to obtain additional information on its response to N and K fertilization. Soil cores of ‘Forestburg’ switchgrass were removed from the field before spring growth started and transplanted into plastic pots in a warm greenhouse (27 to 35 C). The soil was a Dodge silt loam (Typic Argiudoll) with low levels of N and K. Potted plants were fertilized with 0,50,100,200, and 400 kg/ha of N as NH4NO3 in all combinations with 0 and 200 kg/ha of K as KCl. Plants were harvested 52 days later at near anthesis. Fertilization with N significantly increased the dry matter yields (g/pot) of herbage and of stem base tissue (stubble), percentage and content (mg/pot) of N in the herbage, and content of total nonstructural carbohydrates (TNC) in the stubble. Fertilization with N decreased significantly the percentage of K in the herbage, but did not influence the content of K in the herbage and the percentage of TNC in the stubble. Fertilization with K significantly increased stubble dry matter yields, but did not influence the yields of herbage. Fertilization with K significantly increased the percentage and content of K in the herbage and content of TNC in the stubble, but did not influence the percentage and content of N in the herbage or percentage of TNC in the stubble. It was concluded that the vegetative growth of switchgrass is very responsive to N fertilization to the highest rate applied (400 kg/ha), but was not affected greatly by fertilization with K.
Laboratory and Field Response of Preconditioned Upland Cottonseed to Minimal Germination Temperatures1
Authors: Fowler J. L. 
Published: July 2010

AbstractHydration of cottonseed (Gossypium hirsutum L.) prior to germination is known to desensitize the seed to chilling injury. Little has been reported, however, on the effects of these hydration treatments on germination and subsequent growth of cotton subjected to minimal germination temperatures, especially in the field. This study evaluated the effect of pregermination hydration treatments on stand establishment, seedling vigor, yield, and earliness of the crop. Hydration of ‘Acala 1517‐70’ cottonseed in water or saturated CaSO4 solution for 6 hours at 31 C, or in hot water for 1.5 min at 85 C and dried overnight in ambient air, stimulated germination and seedling elongation at 14 C in the laboratory. Preconditioned seed responded similarly at 14 C after chilling at 5 C for 24 hours. The effects of these treatments on emergence, seedling vigor, crop earliness, yield, and fiber properties were field evaluated ova a 2‐year period using several planting dates to provide a range of weather conditions. No advantages of using hydrated seed were demonstrated in the field tests as hydration of cottonseed decreased seedling vigor and, under favorable germination conditions, reduced stands.
Crude Protein Levels in Turfgrass Clippings1
Authors: Turgeon A. J. , Stone G. G. , Peck T. R. 
Published: July 2010

AbstractLeaf clippings are a by‐product of turfgrass culture and they are frequently collected and discarded where a high level of turfgrass quality is desired. The purpose of this investigation was to determine the value of turfgrass clippings as a source of protein for animal feed.Clippings were collected during mowing in seven different field experiments and crude protein (CP) levels were calculated from a measurement of total N (CP = N ✕ 6.25) by the Kjeldahl procedure. In some studies, nitrate N and ammonium N levels were measured in clippings. All turfgrasses were growing in an Aquic Argiudoll (Flanagan silt loam) soil. The CP content of the clippings varied with species, cultivars, mowing height and nitrogen (N) fertilization rate. Among 53 Kentucky bluegrass (Poa pratensis L.) cultivars maintained under the same cultural regime, CP levels varied from 22.0 to 32.7%. Comparing eight perennial ryegrass (Lolium perenne L.) cultivars, CP varied from 26.3 to 30.2%. The CP levels of clippings from ‘Kenblue’‐type Kentucky bluegrass and ‘Kentucky‐31’ tall fescue (Festuca arundinacea Schrebs.) turfs, that were each maintained under different cultural intensities, were inversely proportional to the mowing height and directly proportional to the N fertilization rate. (The highest CP level measured was 38.7% in early October.) The level of NO3‐N in the Kentucky bluegrass clippings varied with mowing height and frequency, fertilizationn rate, and season. The highest level measured was 0.16% which is below that considered toxic to ruminants. These experiments have shown that turfgrass clippings can be an important source of protein for use in some animal feeds, and that high concentrations of crude protein can occur depending upon season, turfgrass cultivars, and mowing and fertilization practices.
Research Plot Planter with Wide Versatility1
Authors: Knapp W. R. , Trenchard G. D. 
Published: July 2010

AbstractField research with small grains or row crops often involves a number of different treatments at planting. Since no presently available, or previously described, individual planter provides all the flexibility needed for a wide range of experiments, a planting unit was constructed that permits simple changes in species, cultivars, seeding rates, row spacing, and fertilizer rates and materials. The three‐point hitch mounted unit consists of a steel framework with seven double disk coulters, two fertilizer boxes, a cone‐spinner and distributor, and an operator's seat. The planter can be adjusted to plant plots ranging from 1 to 75‐m long at any seeding rate and with row spacings of 16, 36, 54, and 72 cm. Fertilizer rates of 20 to 800 kg/ha can be applied through each box. A number of crop species, including forages, have been successfully planted with the machine over the past 2 years. The unit is easily transported and can plant as many as 100 8‐m long plots/hour.
Heat Stress as a Special Purpose Alternative to Clipping in Alfalfa1
Authors: Venuto B. C. , Laude H. M. 
Published: July 2010

AbstractRegrowth in alfalfa (Medicago sativa L.) usually is studied following cutting. The possibility that regrowth after a different type of defoliation might reveal useful information led to the present greenhouse and chamber study. By exposing plants for 5 or 6 hours to heat reaching 52 C, aerial tissues were killed but crown buds survived to regrow. The heat‐stressed plants were delayed from 7 to 14 days in attaining the shoot numbers of clipped plants, but this regrowth appeared morphologically normal and initially was not influenced by the living residual leaf or buds found on stems below a cutting height. Certain attributes of regrowth, following high temperature exposure may prove useful in future research. When plants 50 to 92 days of age received the same stress, the older plants produced shoots in regrowth more rapidly than did the younger. Within an age group, those plants in flower when stressed produced more shoots than did those not yet showing flower buds when stressed. Individual plants with larger shoot numbers before either clipping or heat stress produced more shoots during regrowth.
Influence of Nutrition on Stripe Smut Severity in Kentucky Bluegrass Turf1
Authors: Hull R. J. , Jackson N. , Skogley C. R. 
Published: July 2010

AbstractStripe smut, caused by the fungus Ustilago striiformis (West.) Niessl., is highly destructive to several fine turf cultivars of Kentucky bluegrass (Poa pratensis L.). while there is evidence that turf management practices can modify disease injury, the role of nutrient status in disease development is uncertain. Stripe smut severity and fertility management was studied using ‘Merion’ Kentucky bluegrass plots fertilized with four nutrient combinations (N:O:O, N:P:O, N:O:K, and N:P:K) applied at three rates (12:2:4, 24:4:8, and 48:8:16 g N, P, and K per m2 per year). A natural infection of stripe smut occurred throughout the plot area in 1972 and persisted through 1975. After infection, a close correlation between turf quality and disease incidence was noted. Heavily infected plots, as indicated by disease scores and counts of infected tillers, were those fertilized at high rates with incomplete fertilizers. Grass receiving high rates of N‐P‐K fertilizer was less diseased than that receiving high N alone or N plus P or K. Tiller counts revealed stand thinning in all plots as the disease continued but low fertility plots contained more plants than heavily fertilized plots. Stripe smut severity in susceptible Kentucky bluegrass cultivars is influenced by fertility level and balance.
Long‐Term Potassium Requirements of Nitrogen‐fertilized Smooth Bromegrass1
Authors: George J. R. , Pinheiro M. E. , Bailey T. B. 
Published: July 2010

AbstractNitrogen fertilization of smooth bromegrass (Bromus inermis Leyss.) has been extensively studied, but relatively little is known about its K requirements. A field study was conducted on a Clarion loam (Typic Hapludoll) site in central Iowa to evaluate the long‐term K requirements of smooth bromegrass grown under high N fertility and intensive harvest management. Forage yield and percent K was observed over 4‐ and 3‐year periods, respectively. Changes in soil exchangeable K and pH at 0 to 7.5‐ 7.5‐ to 15‐, and 15‐ to 30‐cm soil depths were monitored during 1970–75 and 1970–73, respectively. Ammonium nitrate (33.5‐0‐0) was applied at rates of 0, 125, and 500 kg N/ha in 1970, and 0, 250, and 500 kg N/ha during 1971–74 (N0, N1, and N2 treatments, respectively). Applications were made as single levels in 1970. Rates were split in subsequent years, with half applied in early spring and the rest after the second harvest. Potassium treatments consisted of a check and 125 kg K/ha applied each year in early spring as Cl‐ and S‐ containing sources (KC1 vs. K2SO4 and K2SO4 • MgSO4).Nitrogen fertilization produced more of a linear than quadratic increase in bromegrass yield. Yields were not increased by K fertilization even when soil exchangeable K approached “minimal” levels. No yield differences among K sources were observed, suggesting that yields were not enhanced by either Mg or S contained in the K sources.Nitrogen fertilization reduced forage percent K concentrations. Potassium fertilization without N had no effect, whereas, NK fertilization increased forage percent K. Differences in forage percent K among K sources occurred only in 1972 with higher concentrations observed for KC1 compared with K2SO4 and K2SO4 • MgSO4.Fertilization with N reduced soil exchangeable K. Decreases were most evident for the 0‐ to 7.5‐cm soil layer, but were significant to a depth of 15 cm. Potassium fertilization without N increased K in the 0‐ to 7.5‐cm soil layer. Soil K decreased 47% when no K was applied, suggesting that a severely N deficient bromegrass sward, if harvested, requires some applied K to maintain soil K concentrations. When both N and K were applied, soil K decreased to 137 kg/ha in the 0‐ to 7.5‐cm soil layer. These trends observed over time suggest that bromegrass obtains most of its K from surface soil layers.Fertilization at N1 and N2 levels reduced pH in the 0‐ to 7.5‐cm soil layer from 6.3 to 6.0 and 6.2 to 5.3, respectively. Most of the pH change developed during the 1st year as evidenced by linear regression coefficients of —0.0017, —0.0020, and —0.0025 pH units/kg N/ha applied in 1971, 1972, and 1973, respectively. Fertilization with K produced little change in surface soil pH. No effect of N and K fertilization on soil pH was observed below the 7.5‐cm depth.
Effect of Prices and Moisture Stress on Nitrogen Rates that Maximize Two Economic Criteria for Corn1
Authors: Escamilla Emilio , Voss Regis , Webb J. R. 
Published: July 2010

AbstractFertilizer rates, which maximize certain economic criteria for crop production, are affected by the yield response to fertilizer, the ferti1izer:crop‐price ratio, the crop price, and the cost of production. The purpose of this study was to evaluate the effects of different fertilizer N:crop‐price ratios (P,), corn (Zea mays L.) prices (Py), and moisture‐stress levels (S) on the rates of fertilizer N that maximize net return (m) and rate of return (M) to total investment in corn production per unit of land area.Fifteen site‐years of data were used from two continuous‐corn fertilizer rate experiments conducted under different crop management and environmental conditions. Moisture stress had a different effect in each experiment on yield and yield response to N.Net return from corn production and the rate of return to investment per hectare at the economic optimum N rate were affected by all factors considered. They were affected more by decreasing Py by half from 13.77 to 6.88¢/kg than by increasing the Pr ratio fourfold from 2.8 to 11.2 on a kg N:kg corn‐price basis. Only a severe deleterious effect of moisture stress on yields and yield reponse to N decreased the net return and rate of return more than decreasing the price of corn.At a constant PrM, decreasing the corn price caused the N rate that maximized M to increase and approach the economic optimum N rate. At a constant N price and a decreasing corn price, the economic optimum N rate decreased, but the N rate that maximized M remained static. In either case, these two N rates approached each other. A deleterious moisture‐stress effect also caused both N rate to decrease but approach each other.These results suggest that, if there are increasing production costs and(or) decreasing crop prices, an overreduction of a divisible responsive input such as fertilizer N on corn could markedly affect the return to total investment on per‐land‐area basis.