bluuebunny/crossref_metadata_2025 huggingface dataset:
Field Comparisons of Formamide, Urea‐Ammonium Nitrate Solution, and Ammonium Nitrate as Nitrogen Sources for Grasses and Wheat1
Authors: Hunter Albert S.
Published: July 2010

Formamide, HCONH2, closely related to urea, is a clear liquid containing about 31% N. It is a solvent for many fertilizer salts, lowers the salting‐out temperature of urea ammonium nitrate solutions (UANS) and makes possible higher concentrations of soluble N, and has a low vapor pressure and a high boiling point. Pot tests have indicated its possible utility as nitrogenous fertilizer but no reports of field plot tests were found. In this study it was compared with UANS and prilled ammonium nitrate (PAN) in 13 field plot experiments. Five of these were on established stands of grasses [(tall fescue (Festuca elatior var. arundinaceae), smooth bromegrass (Bromis inermis Leyss.), orchardgrass (Dactylis glomerata L.), reed canary‐grass (Phalaris arundinacea L.) and eight were on winter wheat (Triticum aestivum L.). All materials were surface‐applied in early April when grasses and wheat were approximately 8 to 13 cm tall, at rates of 28, 56, and 112 kg N/ha. Formamide and UANS were applied as sprays and PAN was surface‐applied in bands 30 cm apart. Observations were made on leaf tip‐burning and lodging. Yields and N contents of grasses and grain were determined. Formamide was an effective source of N but, in general, somewhat less effective than UANS or PAN, as evidenced by lighter green color of plants, lower yield of grasses, less lodging of wheat, and lower N content of wheat grain. Some early leaf tip‐burning on grasses resulted from formamide; no such effects of UANS or PAN were observed.
Effect of Origin, Moisture Content, Maturity, and Mechanical Damage on Seed and Seedling Vigor of Beans1
Authors: Wijandi Soesarsano , Copeland L. O.
Published: July 2010

Each year a substantial portion of the dry edible bean (Phaseolus vulgaris L.) acreage in the Upper Great Lakes region of Michigan, New York, and Ontario, Canada is planted with seed produced in the western United States, particularly Idaho and California. Most of the seed brought from the West is that of large‐seeded, colored bean cultivars although there is interest in increasing the use of western‐produced navy bean seed.

These studies compared the laboratory and field performance of hand‐threshed Michigan and Idaho‐grown seed of field beans (navy type), cultivar ‘Seafarer,’ following mechanical impaction at various moisture levels. Michigan‐produced seed exhibited less reduction in germination and seedling vigor than Idaho‐grown seed after impaction at comparable moisture levels.

The level of injury increased as the seed moisture content decreased, but was significant at all moisture levels. Planting injury to seed was reduced by pretreating with talc, graphite, and diesel fuel; however, diesel fuel adversely affected seed germination.

Significant reductions in germination and seedling vigor were observed in seed harvested prior to complete maturity.
Interactions between Rhizobium japonicum and Soybean Rhizosphere Bacteria1
Authors: Smith R. Stewart , Miller Robert H.
Published: July 2010

The success of soybean inoculation is influenced by the survival of Rhizobium japonicum as a free‐living soil bacterium. One factor affecting survival is the interaction of R. japonicum with other rhizosphere bacteria. The objective of this study was to observe interactions of R. japonicum and soybean rhizosphere bacteria with techniques of increasing complexity with and without the soybean host (Glycine max (L.) Merrill). Eight of nine rhizosphere isolates inhibited R. japonicum on agar. The degree of inhibition was dependent upon the strain of rhizobia, the bacterial isolate, and the agar medium. The interactions of R. japonicum and rhizosphere bacteria with the soybean host (Glycine max (L.) Merrill) were evaluated by observing soybean nodulation, plant weight, and plant elemental analysis. Nodulation was not affected by rhizosphere bacteria when plants were grown in vermiculite or in sterile soil. One rhizosphere isolate, which failed to inhibit R. japonicum on agar, caused severe soybean tap root injury under gnotobiotic growth in soil. Even with the root damage, nodulation was unaffected with this bacterium‐R. japonicum combination.
Portable Self‐Propelled Field Plot Forage Chopper for Agronomic Research1
Authors: Hunter Albert S. , Hoffman Lynn D. , Allshouse Gary W. , Kjelgaard William L.
Published: July 2010

A commercially available farm forage harvester was converted to a self‐powered and readily portable forage chopper for experimental plots of either row crops or hay. The original harvester was towed and powered by farm tractors. In conversion, the original axle was shortened and moved, a chassis frame was constructed, and the front axle and wheels of a 4‐wheel drive automotive vehicle were mounted under the rear of the chassis for propulsion and steering. An engine was mounted on the chassis for mechanical transmission of power to the header, cutter head, and blower and for hydraulic transmission of power to propulsion wheels and header lift. A working platform and control center for the driver was built directly above the cutter head. A rear platform was constructed for the bagging, sampling, transport, and weighing of harvested forage. No modification of essential features of row‐crop head or cutter‐bar (grass) head was required and their ready inter‐changeability was maintained. Outside‐to‐outside distance for the tires is about 112 cm (48 in); if row spacing is of the order of 75 cm (30 in), one row may be harvested without disturbing the others. The cutter bar unit harvests a swath of 137 cm (54 in).
Effect of Ridging and Earley‐Season Cultivation on Bean Yield1
Authors: Cartee Ray L. , Hanks R. J.
Published: July 2010

It has been observed! that small differences in the type and timing of ridging and subsequent early cultivation of beans (Phaseolus vulgaris L.) had seemingly large influences on yields. Since little information was available to substantiate or to give reasons for this observation, the study was undertaken.

Three ridging and cultivation treatments, imposed near planting time, were conducted to determine the effect on pinto bean yield. The ridging treatments were: preemergence (ridged just: before plants emerged), plantingridge (ridged at planting time), postemergence (ridged after plants emerged), and control. The preemergence treatment was cultivated once, after ridging just prior to the first irrigation. The planting‐ridge and postemergence treatments were cultivated twice after ridging and prior to the first irrigation, and the control treatment was not cultivated after planting except for furrowing prior to the first irrigation. The yields of both bean seed and total dry matter were significantly influenced by all treatments, with the following ranking: preemergence > planting‐ridge > postemergence > control. The treatment effect was correlated with soil water content above 15 on in early season and root rot infection but not with soil temperature. Similar consistent results were found for three planting dates. The planting date yields were ranked latest > intermediate > earliest.
Influence of Between and Within‐Row Spacing on Agronomic Characteristics of Irrigated Soybeans1
Authors: Basnet B. , Mader E. L. , Nickell C. D.
Published: July 2010

Several workers have reported on the effect of varying between and within‐row spacing on soybean (Glycine max (L.) Merr.) yield but few have used irrigated soybeans. We studied two row‐widths, and two in‐row spacings in a split‐split plot arrangement in 1969 and 1970 using five soybean cultivars on irrigated plots.

Plants in '46‐cm row width or 3.8‐cm within‐row spacing were taller, lodged more, and produced fewer nodes, branches, pods on branches, pods on main stem, and total seeds on a per plant basis. Height to the first pod increased as row‐width or in‐row spacing decreased. Spacings between or in rows affected neither seed weight nor quality.

Highest yields resulted at the lower plant density in narrow rows in 1969, and at the higher plant density in wider rows in 1970. Row‐width ✕ within‐row spacing and row‐width ✕ cultivar interactions were significant for some of the characteristics measured.
Response of Millet and Sorghum ✕ Sudangrass Crosses to Magnesium Fertilization1
Authors: Cummins D. G. , Perkins H. F.
Published: July 2010

In the southeastern United States, millet (Pennisetum glacum) often produces more forage than sorghum ✕ sudangrass crosses [Sorghum bicolor (L.) Moench] on sandy soils, while the reverse is often true on clay soils. Based on the hypothesis that difference in production may be related to different Mg requirements of the two crops, a study was made to (a) determine the critical levels of Mg for growth of millet and sorghum ✕ sundangrass crosses in the greenhouse, and (b) relate these results to field production. One greenhouse study was grown in sand using Hoagland's solution to develop different plant Mg levels. A second greenhouse study was grown on a Magnolia sandy loam with Mg rates ranging from 0 to 200 ppm. Two field studies were conducted with Mg rates ranging from 0 to 67.2 kg/ha, one on a Magnolia sandy loam and the other on a Lynchburg sand. In the greenhouse sand‐solution study, maximum yields occurred at 0.13 to 0.14% mg (whole plant samples) with both millet and sorghum ✕ sudangrass, whereas maximum yields in the greenhouse soil study occurred at 0.45% Mg (whole plant samples) in both crops. Maximum yields were higher in the sand‐solution study and forage contained lower Mg and higher K levels, compared to the soil study in which maximum yields were lower and were accompanied by higher Mg and lower K levels. Significant yield increases were not obtained due to added Mg in either field study, but Mg content in the plants increased with added Mg on the Magnolia soil. In the field, higher yields (the Magnolia soil) were accompanied by lower Mg and higher K levels in the plant tissue, whereas lower yields (the Lynchburg soil) were accompanied by higher Mg and lower K in the plant. Millet and sorghum ✕ sudangrass crosses used in these studies did not differ in their Mg requirements. Mg required for maximum growth varies according to environmental conditions affecting growth and K availability to the plants.
The Rhizotron — Lysimeter Research Facility at TVA, Muscle Shoals, Alabama1
Authors: Soileau J. M. , Mays D. A. , Khasawneh F. E. , Kilmer V. J.
Published: July 2010

A combined root observation laboratory (rhizotron) and lysimeter was constructed at TVA's National Fertilizer Development Center in 1973. This mainly belowground‐level facility consists of two rows of nine concrete bins, separated by an access area 3.3 m wide. Each bin holds an approximately 1.0 ✕1.2 ✕ 1.9 m volume of soil, has a transparent Plexiglas panel for root growth observations and treatment activities, and a 30 ✕30 cm porous ceramic filter plate at the bottom. A special feature of the facility is its automated, vacuum‐ controlled soil profile drainage and percolate sampling system; components of this apparatus are described in detail. The rhizotron ‐ lysimeter is being used to study crop root growth and the mobility of nutrients and heavy metals in soils and percolating water, as related to applications of municipal organic wastes and chemical fertilizers.
Effect of Row Direction on Sunflowers1
Authors: Robinson R. G.
Published: July 2010

The effect of row direction on sunflower (Helianthus annuus L.) performance was researched because young sunflowers are phototropic and after flowering ceases most heads face the east. Sunflowers planted in east‐west and north‐south rows in large, rectangular plots were compared in 1972 and 1973 at Rosemount, MN. Wheel‐spoke plant alignments in circular plantings were used to evaluate row directions in 1973. Row direction did not influence achene yield, weight, size, nor oil percentage, but plants lodged significantly more in EW than in NS rows both years. However, in the circular plantings, lodging differences did not occur.

Row direction effect on sunflowers is not an important consideration for commercial production. For some research plots, EW rows with plot labels on the east end are easiest to evaluate because most heads face the viewer.
Yield of Dryland Grain Sorghum as Affected by Antitranspirant, Nitrogen, and Contributing Micro‐watershed1
Authors: Fuehring H. D.
Published: July 2010

In the semi‐arid Great Plains yields of grain sorghum [Sorghum bicolor (L.) Moench] are almost always limited by lack of rainfall or soil moisture during some part of the growing season. The purpose of this study was to determine if minimal land shaping practices in combination with antitranspirant application would increase yield levels of dryland grain sorghum.

Variables were width of watershed, width of growing bed, applied N, and foliarly applied antitranspirant combined in a central composite experimental design. Use of contoured, compacted bare micro‐watersheds increased grain sorghum yields of adjacent growing beds considerably even in two relatively wet years. However, yields of the entire area (growing bed plus watershed) decreased. Atrazine (2‐chloro‐ethylamino‐6‐isopropylamino‐s‐triazine) as an antitranspirant at 0.2 to 0.3 kg/ha effectively increased sorghum grain yields under conditions of solid planting and adequate nitrogen. The antitranspirant‐nitrogen interaction was especially positive under conditions of moisture stress.

Since most grain sorghum is grown under conditions where moisture stress is likely, further work on the use of antitranspirants is warranted in order to establish the conditions of response.
Critical Level of Mg in Western Nigerian Soils as Estimated under Greenhouse Conditions1
Authors: Lombin L. G. , Fayemi A. A. A.
Published: July 2010

Widespread Mg deficiencies have not been reported in western Nigeria. But with continuous intensive cultivation, heavier fertilization especially with K, and the introduction of high yielding, responsive crop varieties Mg deficiency is likely to become a serious problem in the near future. Knowledge of the critical available Mg levels can be useful in conjunction with routine soil analysis data to monitor the onset of these deficiencies.

There is no previously published work on Nigerian soils that estimated the available Mg level below which response to Mg fertilization can be expected. The objective of this investigation therefore was to approximate this critical level under greenhouse conditions.

Twenty‐three Nigerian soils collected from various ecological zones and soil types were cropped to maize (Zea mays L.) in the greenhouse with and without Mg application. The maize tops were cut after 35 days, dried, weighed, milled, and analyzed for Mg. Using the dry matter weights relative yields were worked out for all the soils and the new Cate‐Nelson (6) statistical procedure used to estimate the critical level. This procedure involved a step‐wise splitting of the data into two groups using successive tentative critical levels to determine the level which maximized the overall predictive ability (R2) with the means of the two groups serving as the predictor values. An approximate critical level of 0.28 to 0.35 meq/100 g was obtained by this technique.

Tests on individual plot yields showed that 0.28 meg/100 g neutral N NH4OAc, extractable Mg was low enough for statistically signficant response to Mg application. All soils (except no. 10) that had less than 5% saturation of CEC responded to Mg application; those with more than 7% Mg saturation did not respond to Mg.

Mg deficiency symptoms were associated with soil Mg level of 0.17 meq/100 g or lower prior to planting and with plant Mg content of less than 0.1%. Although the critical level of available Mg approximated in this study (0.28 to 0.35 meq/100 g) is much lower than the average available Mg content (1.2 to 1.5 meq/100 g) of western Nigerian soils. Caution is nonetheless needed in evaluating the findings of the present study as greenhouse results may not necessarily reflect the true situations in the field.
Cultivar Blends in Safflower1
Authors: Abel George H.
Published: July 2010

Cultivar blends of safflower (Carthamus tinctorius L.) were evaluated to determine if there were any favorable competitive interactions for yield of seed or oil.

In a 50:50 blend of ‘Gila’ and ‘12417’ there was an average over‐compensation of 3.6% for seed yield and 3.9% for oil yield. For a 50:50 blend of ‘Dart’ and ‘1415430’ there was undercompensation for both seed and oil yield in the 1 year of testing. Generally, seed and oil yield of the blends did not exceed that of the better cultivar planted alone.
Yield and Composition of Soybean Seed as Affected by N and S Fertilization1
Authors: Ham G. E. , Liener I. E. , Evans S. D. , Frazier R. D. , Nelson W. W.
Published: July 2010

Soybeans (Glycine max (L.) Merr.) obtain nitrogen from soil and from symbiotic fixation when nodulated with effective strains of rhizobia. These two sources of N may need to be supplemented with fertilizer N for maximum seed yields. The objectives of the present study were to determine the effects of N and sulfur fertilization on soybean seed yield and other seed properties (protein, oil, amino acid, fatty acid, and S composition).

Chippewa 64 and a nodulating‐nonnodulating (nodnonnod) pair of isolines of Chippewa background were examined at three field locations over 2 years for yield response to different forms of fertilizer N (224 kg/ha) and to fertilizer S (224 kg/ha). Three readily available fertilizers (ammonium nitrate, urea, and urea + sulfur) and two slow release fertilizer (S‐coated urea and ureaformaldehyde) were mixed in the top 20 cm of soil before planting. The soils were Nicollet silty clay loam (Aquic Hapludoll), McIntosh silt loam (Aeric Calciaquoll) and Webster clay loam (Typic Haplaquoll).

Response to N fertilizer was greater with the nonnod isoline than with the other two lines. Nitrogen fertilization increased seed yield, weight per seed, seed protein percentage, and kg protein/ha. Plant height and lodging were either increased or unaffected, depending upon locations and/or year. Seed oil percentage decreased following N fertilization. However, total oil production usually increased due to larger yields. All sources of fertilizer decreased N2 fixation, plant nodule weight, nodule number, and weight per nodule.

Amino acids increased uniformly with protein increases but fatty acid composition was unchanged.

Sulfur fertilizer increased seed yield in one case and decreased seed yield in two cases depending on location and year. Total S percentage of the seed and S‐containing amino acids of the seed were not increased with S additions.

Increases in seed yield and/or seed protein percentage in the nodulating lines suggest N2 fixation failed to supply amounts of N essential for maximum seed yield and/or protein percentage. With the recent concern for energy, N2 fixation must be increased to provide the N needed for maximum seed yields of soybeans rather than relying on fertilizer N.
Factors Affecting the Development of Flue‐cured Tobacco Grown in Artificial Environments. V. Effects of Humidity and Nitrogen Nutrition1
Authors: Raper C. David , Smith W. Tony
Published: July 2010

Controlled environment rooms (CERs) were used to investigate effects of relative humidity on physical and chemical properties of mature, flue‐cured tobacco (Nicotiana tabacum L.) leaves. The relative humidities in separate CERs were monitored with a dewpoint hygrometer and maintained at 90% (high) or 65% (low) relative humidity. Plants were moved between the two CERs to evaluate effects of diurnal and seasonal variations in relative humidity. The apparent effects of humidity on leaf size and shape were dependent on age of the plants. For plants grown in continuous high humidity, leaf sizes were greater at lower and middle stalk positions, but were less at upper stalk positions, than for plants grown in continuous low humidity. The reduction of areas of upper leaves by high humidity was a residual response to the humidity during the initial 3 to 5 weeks after transplanting. Initial periods of high humidity, whether followed by low or high humidity, also resulted in abnormally elongated upper leaves. Furthermore, variations in total plant leaf areas which resulted from diurnal variations in humidity were highly correlated with total nitrogen content in leaf tissues. These results suggest that suppression of nitrogen uptake by high humidity during a critical period of leaf formation was directly involved. Humidity during later stages of growth apparently has effects on the chemical balance within tobacco plants unassociated with nitrogen accumulation. High humidity during the light period tended to increase both starch and alkaloid composition of leaves.
Degradation of Alachlor by Rhizoctonia solani1
Authors: Smith A. E. , Phillips D. V.
Published: July 2010

The direct effects of herbicides on fungi are reported to include: inhibition, stimulation, or no effect as determinated by growth, sporulation, spore germination, and pathogenicity. Also, certain fungi have been found to rapidly degrade herbicides present in the ecosystem. Research was conducted to determine the influence of 2‐chloro‐2′,2′‐diethyl‐N‐(methoxymethyl)acetanilide (alachlor) on the growth and development of Rhizoctonia solani Kuehn, and to quantify the rate of alachlor degradation by R. solani in nutrient media containing differing concentrations of sucrose. Alachlor did not influence sugar utilization or growth of R. solani. Fungal growth and degree of alachlor degradation were proportional to the amount of sugar in the media. Apparently R. solani does not utilize alachlor as a sole carbon source and degradation of this herbicide is dependent on the presence of some other source of carbon.
Relationship of Exchangeable Acidity to Yield and Chemical Composition of Alfalfa1
Authors: Janghorbani M. , Roberts S. , Jackson T. L.
Published: July 2010

This study was undertaken to help clarify the soil acidity‐plant response relationship in western Oregon in an effort to improve the efficiency in the use of lime and fertilizer. The objective of the study was to relate the lime and P response of ‘Du Puits’ alfalfa (Medicago sativa L.) to selected measures of soil exchange acidity and exchangeable Al and Mn.

Extractable acidity in soil samples from the A horizon of six representative soil series ranged from 0.3 to 8.1 meq/100 g of soil with a range of 0.2 to 7.9 meq/100 g exchangeable Al and somewhat lower amounts of Mn in the extracts.

Responses of alfalfa to applied lime and P treatment combinations in greenhouse experiments were recorded for five of the six soil series studied. Maximum yield response was obtained with applications of either 4 or 8 meq of lime per 100 g of soil which largely eliminated KCl exchangeable acidity and Al at approximately pH 6.0 or higher. There was evidence of lime × P interactions on those soils that were both strongly acid and low in P with lime treatments increasing the availability of soil P. Lime application decreased tissue concentrations of Al and Mn, but increased plant Ca and P.

It was concluded that the presence of exchange acidity and Al in the soils was indicative of a potential yield response to lime. The relatively large liming increments used in the study were not conducive to evaluating the precise amount of lime needed to react with a specified amount of exchange acidity or Al. The greatest benefit was derived from liming increments sufficient to neutralize the exchange acidity.
15N‐Labelled Single‐treatment Fertility Experiments1
Authors: Fried M. , Soper R. J. , Broeshart H.
Published: July 2010

There is only one way of measuring directly the uptake of nutrient from applied fertilizer as affected by timing, placement, fertilizer source, and environmental interactions. This is by isotope labelling of the fertilizer. The purpose of the present study is not only to demonstrate the effectiveness of this technique in field experiments, but to extend the technique to the direct measurement of these fertilizer efficiencies without interactions. A further extension permits the direct quantitative measurement of interactions.

The method has been referred to as “single‐treatment fertility experiments” because all treatments, as far as the plant soil or environment are concerned, are identical. The only difference is which of the fertilizer applications within a given treatment was isotopically labelled. Thus growth, nutrient uptake, amount, and pattern in all plots is identical within normal experimental variation. The presence of the label permits the quantitative measure of treatment effects without interaction.

The method has been successfully used in field experiments in various areas of the world with rice (Oryza sativa L.), maize (Zea mays L.), and wheat (Triticum aestivum L.), Problems quantitatively evaluated were: the relative effectiveness of NH4+ and NO3− as a source of N to rice at different placements; the effect of NH4+‐N in the fertilizer band on the uptake of P and of P on the uptake of NH4‐N; and the uptake of fertilizer N by corn, rice, and wheat as related to growth stage at which it was applied. Interactions can be directly and quantitatively measured by adding additional treatments.
Phosphorus Efficiency as Related to Iron Inefficiency in Sorghum
Authors: Brown J. C. , Jones W. E.
Published: July 2010

Sorghum (Sorghum bicolor L. Moench) is often grown on alkaline soils, and the plants frequently develop symptoms of Fe deficiency. The susceptibility is dependent on the ability of the plant to respond to Fe stress. This adaptive response is genetically controlled whereby H+ ions and a reductant are released from the roots. These make Fe available for uptake by the plant. Activation is greatest in Fe‐efficient plants and least in Fe‐inefficient plants. Phosphate accumulation and Fe‐stress response oppose each other in plant use of Fe. In this study, accumulation of phosphate and Fe‐stress response were evaluated as causes of Fe chlorosis in four sorghum cultivars that differ in uptake of P and in susceptibility to Fe chlorosis. The seedlings were first grown in a light chamber on a complete nutrient solution at, pH 4.3 until the plants were large enough for use. They were then transferred to nutrient solutions with Fe, P, NH4‐N or NO3‐N as variables. The pH of the nutrient solution, reductant in nutrient solution, and uptake of Fe and P by the plant were determined. The Fe‐efficient KS5 and ‘Pioneer 846’ sorghums released more reductant from their roots, took up more Fe, and contained less P than the Fe‐inefficient “B‐line” and ‘Wheatland’ cultivars. The release of H+ ions by roots was somewhat comparable in all four sorghum lines. On Bladen soil (pH 4.3—high in Al), KS5 and Pioneer 846 took up less P than the “B‐line” and Wheatland sorghum. Phosphorus efficiency in the four cultivars is “B‐line” ≥ Wheatland > Pioneer‐846 > KS5. In addition, KS5 developed iron chlorosis, which implies that KS5 cannot utilize either P or Fe in Bladen soil. Accumulation of P and insufficient Fe‐stress response both appear to be causative factors of Fe deficiency in “B‐line” and Wheatland sorghum.
Seasonal Development of, and the Effect of Inter‐plant Competition on, Soybean Nodules1
Authors: Weil R. R. , Ohlrogge A. J.
Published: July 2010

Research suggests that competition for photosynthate between nodules and seeds of soybeans [Glycine max (L.) Merr.] may be responsible for the apparent decline in symbiotic nitrogen fixation during the high N requirement pod‐filling period. A study was conducted in eight highly productive commercial fields to characterize the development of nodules during the growing season and to determine the effect on nodulation of thinning to one plant/m2 at a time (end of flowering period) when the response by the reproductive sink would be limited to a small increase in seed size.

The number and size of nodules increased rapidly during flowering, peaked in early pod‐filling, and declined thereafter. After flowering, the percentage of red nodulated declined while the percentage of green (inactive) nodules increased. Total nodule volume/plant and active (i.e., red) nodule volume/plant peaked in mid‐August and then dropped off rapidly.

The thinned plants showed significantly more nodule volume/plant, a greater percentage of red nodules, and a lower percentage of green nodules during pod‐filling, than did the plants growing at normal population densities. During that period, the thinned plants had 2 to 5 times as much active nodule volume/plant. The thinning treatment apparently postponed the decline in the nodules for several weeks. This effect was probably due to an increased supply of photosynthate available to the nodules at the lower plant density.
Effect of Soil and Foliar‐applied Manganese on the Micronutrient Content and Yield of Soybeans1
Authors: Randall G. W. , Schulte E. E. , Corey R. B.
Published: July 2010

Manganese deficiency of soybeans (Glycine max (L.) Merr.) will undoubtedly become more prevalent as soybean acreage increases along with strong emphasis on yield maximization. Thus, field experiments were conducted on two soils (Argiaquoll and a Hapludoll) in southern Wisconsin to evaluate sources, rates, and methods of application of Mn fertilizers on soybeans. Two sources, MnSO4 and Mn‐ethylenediaminetetraacetic acid (MnEDTA), were broadcast, row or foliar‐applied at various rates to Mn‐deficient soils and/or soybeans. Micronutrient concentrations, Mn uptake, and various production parameters were measured.

All rates and application methods of MnSO4 and foliar applications of Mn‐EDTA were effective in supplying Mn to the plant. Row applications of MnSO4 were somewhat more efficient than broadcast applications. Manganese applied at rates ranging from 5 to 22 kg Mn/ha as MnSO4 with the starter fertilizer in the row at planting time appeared to be most efficient soil treatments in increasing seed yields. The MnEDTA applied in the row reduced plant weight, leaf Mn, and soybean yields slightly. When Zn was not included in the starter fertilizer, leaf Zn and Cu were increased by the soil‐applied MnEDTA treatments. Leaf Fe was not affected by any of the Mn treatments.

Foliar applications of Mn were most effective when applied at the early blossom or early pod set stages or in multiple applications at these stages. Single applications of 2.24 and 4.48 kg Mn/ha as MnSO4 or 0.51 kg Mn/ha as MnEDTA caused some burning of the foliage.

Combined row and foliar methods of application also appeared to relieve Mn deficiency effectively. Small amounts of MnSO4 applied in the row corrected the Mn deficiency early in the season, whereas foliar applications adequately supplied Mn to the plant later in the growing season. This combination resulted in higher yields than with either row or foliar treatments applied alone.
Effect of Irrigation, Lime, and Fertility Treatments on the Yield and Chemical Composition of Soybeans1
Authors: Lutz J. A. , Jones G. D.
Published: July 2010

Data are available on the effects of surface applied plant nutrients on the yield, quality, oil, and protein contents of soybean [Glycine max (L.) Merr.] seed and on the chemical composition of the soybean leaves. Very little information is available, however, on the effects of irrigation and plow sole (30.5 cm) placement of plant nutrients on these same plant characteristics.

In order to determine the effects of irrigation and plow sole placement of P, K, lime, and micronutrients on the quality, yield, oil, and protein contents of soybean seeds and on the chemical composition of the leaves, a field experiment was conducted for 3 consecutive years. The experiment was located on Davidson clay loam (Rhodic Paleudults; clayey, kalonitic, thermic) at Orange, Va. Treatments included zero and 22.4 metric tons/ha lime, 336 and 672 kg/ha of EsMinel, and varying rates and ratios of P and K. The plowsole treatments were applied only when the experiment was initiated. The annual surface treatments on all plots have been 49 kg P/ha and 186 kgk/ha.

Soybean seed yields were increased each year with irrigation; the average annual increase being 514 kg/ha or 22%. Yields were unaffected by P and K treatments during the first 2 years, but in the third year, yields were lower where P and K had not been applied on the plow sole. Lime and micronutrients did not significantly affect soybean seed yields.

Irrigation increased the oil content each year but did not affect the protein content. Leaf P and K concentration were unaffected by irrigation but were affected by P and K applications. Leaf P concentration in 1972 and 1973 and K concentrations in 1972 were generally increased with increased rates of applied P and K respectively. Leaf Ca and Mg concentrations were increased with irrigation in 1971 but not in the other 2 years.

Irrigation had no real effect on the amounts of available P, K, Ca, and Mg in the soil. The total amounts of these elements increased with increased rate of application. Applied lime did not affect the acidity below the 30‐cm depth.
Effects of Uneven Spreading of Fertilizer on Crop Yields1
Authors: Lutz J. A. , Jones G. D. , Hawkins G. W. , Hutcheson T. B.
Published: July 2010

Bulk spreading of fertilizer does not always result in a uniform distribution over the entire area. The extent to which this distribution affects crop yield is unknown and should be investigated. As a result, nine experiments were conducted over a period of several years to determine the effects of uneven distribution of fertilizer on the yield of corn (Zea mays L.), barley (Hordeum vulgare L.), soybeans (Glycine max L.), and wheat (Triticum aestivum L.). The investigations were conducted in the three physiographic areas of Virginia (i.e., mountain, piedmont, and coastal plain). Soil types varied from thich surface phase sandy loams to a clay loam. Four spread patterns commonly obtained in farming operations and a no‐fertilizer treatment were used.

In 1970, corn on Frederick silt loam and Tatum silt loam responded to fertilization, but there was no significant differences among spread patterns on Lodi loam. Significant differences in yields among spread patterns on Davidson clay loam were observed. In 1971 there was an excellent barley response to fertilizer on Norfolk sandy loam, thick surface phase, and on Davidson clay loam, but no yield differences among spread patterns. Soybeans did not respond to fertilization on Davidson clay loam. Differences in corn yields among spread patterns on Nason silt loam were significant. Corn in 1972 on Groseclose silt loam and on Norfolk sandy loam, thick surface phase, did not respond to fertilization and hence there were no differences in yields among spread patterns. Differences in crop yields within spread patterns were observed on most of the soils.
Availability of Water Absorbed by Hardwood Bark Soil Amendment1
Authors: Spomer L. Art
Published: July 2010

This laboratory investigation determined the ‘availability’ of water absorbed by hardwood bark soil amendment. Water retention isotherms on a volumetric basis were determined on bark samples of seven different species (Fraxinus americana L., Populus deltioides Bartr., Acer rubrum L., Quercus rubra L., Platanus occidentalis L., Juglans nigra L., and Quercus alba L.) with a water pycnometer and a thermocouple psychrometer. Available water was assumed to be the volume held between 0 and −15 bars water potential. Maximum bark water content averaged about 40% of its wet volume; however, less than 25% of this water is released at water potentials between 0 and −15 bars. Hence, about three‐fourths of the water absorbed by bark is unavailable to plants.
Preharvest Desiccation of Grain Sorghum with Glyphosate1
Authors: Bovey R. W. , Miller F. R. , Baur J. R.
Published: July 2010

The need for an effective and nontoxic preharvest desiccant for grain sorghum (Sorghum bicolor (L.) Moench) has been recognized for many years. Studies were conducted to compare glyphosate [(N‐phosphonomethyl) glycine] to sodium chlorate and paraquat (1,1'‐dimethyl‐4,4'‐bipyridinium ion) on hybrids RS 626 and Tophand. Glyphosate was more effective than sodium chlorate or paraquat in reducing grain, leaf, and stem moisture content. Glyphosate reduced grain moisture content to 13% or lower within 1 week after treatment from original grain moisture content of 20, 30 or 40%. Glyphosate prevented growth of axillary buds of grain sorghum and killed all established johnsongrass and Coloradograss in treated agreas. Lodging of grain sorghum was insignificant for 3 weeks following glyphosate treatment, despite heavy rainfall and high wind velocity. Germination of treated grain was not affected by glyphosate at rates of 0.56 and 1.12 kg/ha. The low mammalian toxicity and the absence of phytotoxicity from soil residue suggests that glyphosate may be a valuable preharvest grain sorghum desiccant.
Performance of Selected Silage and Summer Annual Grass Crops as Affected by Soil Type, Planting Date, and Moisture Regime1
Authors: Fribourg H. A. , Bryan W. E. , Bell F. F. , Buntley G. J.
Published: July 2010

In order to better understand the relative performance of forages grown on soils of different characteristics, field experiments were conducted over a period of 5 years on two soils at each of six locations to determine the effects of soil mapping unit and climatic differences on the silage yield and grain content of corn (Zea mays L.) and grain and forage sorghums (Sorghum bicolor (L.) Moench) and on the forage production of a sorghum‐sudangrass hybrid (S. bicolor) and of pearmillet (Pennisetum americanum (L.) K. Schum). The soils at each location were selected for their differences in moisture supplying capacity. Climatic differences were obtained by location effects, planting dates, and irrigation. The 82 location‐treatment‐year conditions studied pointed to the dependence of yields of corn, grain and forage sorghums, and pearlmillet on soil and climatic environments. Higher yields resulted from the soil with the more desirable moistureholding characteristics in the “pair” at each location. Total silage stage dry matter production and grain content were usually higher from early plantings than from those made 5 to 6 weeks later; conversely, delay in planting resulted in relatively more green‐chop sorghum and pearlmillet dry matter production after August 1 than early plantings. Irrigation generally resulted in higher corn, grain and forage sorghum silage yields than natural rainfall alone, but it did not affect substantially production of green‐chopped sorghum and pearlmillet, illustrating the greater tolerance of these two crops to moisture stress. These results clearly indicate the interdependence of forage production with land selection.
Skip‐row Planting of Pima Cotton1
Authors: Kittock D. L.
Published: July 2010

Growers have been planting American Pima cotton (Gossypium barbadense L.) in skip‐row patterns without supportive research data on skip‐row effects on yield and quality of Pima cotton. The purpose of this research was to obtain such data on skip‐row planting for Pima cotton. Pima cotton was grown under irrigation in five skip‐row patterns in randomized blocks in each of 5 years. All skip‐row patterns increased lint yields on a planted‐area basis as compared to solid planted. Skipping single rows increased lint yield of a two‐row strip 20%. Skipping two rows increased lint yield an additional 8%. In plant‐6‐skip‐2 pattern, lint yield of outside rows was increased 28% over that of the center two rows. The second rows from the outside had 5% increase in lint yield. A tall cultivar benefited more from skip‐row than did a short cultivar. Skip‐row effect on outside rows was greater during years of high lint yield than during years of low yield (r = 0.90). In these tests the skip‐row yield increases were about 60% of those reported on Upland cotton (G. hirsutum L.). Outside rows and single rows had lower gin turn‐out, more trash in lint, and slightly higher lint percent. Skip‐row patterns had no effect on fiber quality.
Yield Potential of Soybean as Related to Soil Compaction Induced by Farm Traffic1
Authors: Nelson W. E. , Rahi G. S. , Reeves L. Z.
Published: July 2010

Injudicious traffic on the farm causes undesirable compaction of the soil, that might result in appreciable reduction in the yield of crops. The present studies were conducted for 3 years (1970 to 1972) on a Norfolk sandy loam soil (Typic Ochrult) to evaluate the effect of tractor traffic on the yield performance of soybean [Glycine max. (L.) Merr. ‘Bragg’]. There were five traffic combinations comprising zero, four, and eight tractor passes made on the outside only, and on both sides of a set of two 1.1 m wide plant rows. These combinations, 0‐0‐0, 4‐0‐4, 4‐4‐4, 8‐0‐8, and 8‐8‐8, were replicated three times. In the control plots (0‐0‐0), the distance between the tractor tire path and the outside of the plant row was maintained to a minimum of 38 cm. Penetration resistance indices and soil moisture content at different depths, development of root system, and the yield of soybean were determined during each crop season. Four and eight passes made either on the outside or both sides of the plant rows compacted the soil considerably, which seemed to affect the availability of soil moisture and the yield of soybean adversely. The plants in the control plots apparently made better utilization of soil moisture. This was evidenced by more developed and extensive root system, and higher yields of the soybean.
Seed Treatment of Mojave Desert Shrubs1
Authors: Graves Walter L. , Kay Burgess L. , Williams William A.
Published: July 2010

Information is needed for revegetation of barren scars left from destruction of native shrubs by recreational vehicles and right‐of‐way clearance. Numerous seed treatments were tested for improvement of field establishment of Mojave Desert shrubs and reduction of establishment costs.

Scarification, 4‐hour 60 C and 80 C dry heat, stratification, activated carbon, 3‐hour and 15‐hour soaking, 100 ppm and 1,000 ppm ethylene, hot water (5 min), 0.5 and 6% sodium hypochlorite, 3% thiourea, and 6% hydrogen peroxide were used on the following species considered promising for revegetation: 1) Larrea divaricata Cav., 2) Atriplex polyycarpa (Torr.) Wats., 3) Atriplex canescens (Pursh.) Hutt., 4) Hymenoclea salsola T. & C., 5) Ephedra nevadensis Wats., 6) Ambrosia dumosa (Gray) Payne Franseria dumosa), and 7) Lepidospartum squamatum Gray.

Activated carbon was the most effective treatment in improving fruit germination on 5 of 6 species tested (spp. 1, 2, 4, 5, 6). Stratification was effective on improving the germination of 3 of 6 species (spp. 2, 3, 6). Thiourea (3%) was effective in improving the germination of both the carpels and seeds of Larrea divayicata, The 15‐hour soaking, 100 ppm ethylene, 4‐hour 60 C, and scarification treatments improved the germination of only one species each. Treatments having no effect on germination were 3‐hour soaking, 6% hydrogen peroxide, and 1,000 ppm ethylene. The 4‐hour 80 C dry heat depressed the germination of 5 of the 7 species and 6% sodium hypochlorite depressed the germination on all species tested. Hot water (5 min) killed the embryos on all species tested.
Minimal Herbicide Treatments on the Establishment of Four Turfgrasses1
Authors: Johnson B. J.
Published: July 2010

Establishment of newly planted grasses for turf is influenced by weed competition. Since herbicides may reduce weed competition during the establishment period, an experiment was initiated to determine the effects of minimal vs. no herbicide treatment during the establishment of four turfgrass varieties and species. Herbicides as preemergence treatments were applied immediately after sprigging to centipedegrass [Eremochloa ophiuroides (Munro) Hacck.], ‘Emerald’ zoysia (Zoysia japonica × Zoysia tenuifolia Willd. ex Trin.), ‘Tifway’ and ‘Floraturf’ bermudagrasses (Cynodon sp.) in May and again the following March for experiments initiated in 1972 and 1973. The soil type was a Cecil sandy clay loam (Typic Hapludult). With the exception of Emerald zoysia, all turfgrasses grew well in untreated plots and competed successfully with the weeds after two growing seasons. Bensulide [0,0‐diisopropyl phosphorodithioate S‐ester with JV‐(2‐mercaptoethyl)benzenesulfonarnide] and terbutol (2‐ 6‐di‐tert‐butyl‐p‐tolyl methylcarbamate) generally caused more injury to the different turfgrasses than pronamide [3,5‐dichloro‐N‐(l,l‐dimethyl‐2‐propynyl)benzamide], DCPA (dimethyl tetrachloroterephthalate), or benefin (Nbutyl‐N V‐ethyl‐a,a,a‐trif luoro‐2,6‐dinitro‐p‐toluidine). Bensulide was the only herbicide that satisfactorily controlled grassy weeds during the first growing season both years.
Nitrate Accumulation in Radish as Affected by Nitrapyrin1
Authors: Mills Harry A. , Barker Allen V. , Maynard Donald N.
Published: July 2010

Ingestion of NO3‐N in vegetables represents a major source of dietary intake of NO3‐N and is potentially hazardous to human health. Radish (Raphanus sativus L.), when cultured in a NO3‐rich medium accumulates substantial quantities of NO3‐N. The main objective of this study was to evaluate the influence of a nitrification suppressor, 2‐chloro‐6‐(trichloromethyl)pyridine (nitrapyrin), on NO3‐N accumulation in radish plants. In one study, ‘Cherry Belle’ radish was grown in pot culture under greenhouse conditions and was fertilized with KNO3 or (NH4)2SO4 to provide 0, 200, 400, 600, or 800 mg N/pot of soil (1 kg) in a factorial arrangement with pH 6.5 and pH 7.5 and with no nitrapyrin and 50 mg nitrapyrin/pot. In a second study, the same cultivar was grown with 400 mg N/pot, an amount shown to be optimum for growth in the first study, and with nitrapyrin applications of 0, 5, 10, or 50 mg/pot.

Nitrate accumulation in the plants was less with (NH4)2SO4, fertilization than with KNO3 fertilization, and all nitrapyrin applications essentially eliminated the accumulation in both roots and shoots. Total N concentrations of shoots were significantly greater with NH4‐N than with NO3‐N nutrition although total N in roots was unaffected by N treatment. Shoot growth was greatest with NH4‐N nutrition, but root growth was restricted by NH4‐N nutrition relative to NO3‐N nutrition. Nitrapyrin as such had little effect on plant growth but appeared to increase the potential for NH4toxicity. Nitrapyrin caused significantly lower concentrations of NO3‐N in the soil with (NH4)2SO4 fertilization but increased soil NO3‐N levels with KNO3 treatments. Liming the soil had no effect on any of the factors considered in this study.
Chemical Control of Wild Allium Species1
Authors: Hardcastle W. S.
Published: July 2010

Wild Allium sp. often occur in pastures, lawns, and small grain fields in the Southeastern U.S. They are on the noxious weeds lists of several states in this area. Commonly two or more applications of 2,4‐D [(2,4‐dichlorophenoxy) acetic acid] per year for up to 3 years are the current recommended practice for their control. Single applications of glyphosate [N‐(phosphonomethyl) glycine] and 2,4‐D were made in February or April on wild garlic (Allium vineale L.) and wild onion (Allium canadense L.) growing in fields in the Piedmont and Limestone Valley regions of Georgia. Scape counts, 6 and 14 weeks after treatment, indicated that excellent control was obtained from treatments of 4.48 and 6.72 kg/ha glyphosate especially when a surfactant was used. The 2.24 kg/ha treatment rate usually equalled or surpassed the 2,4‐D treatments in control.