H. J. Woodard

Relationship of nitrogen management to winter wheat yield and grain protein in South Dakota

Abstract The effects of nitrogen (N) management systems on Rose and Arapahoe hard red winter wheat (Triticum aestivum L. Emend. Thell.) were measured. Nitrogen fertilizer rates of 0,55,110, and 165 kg N ha‐1 were surface broadcast as a full N rate application atpreplant or were split‐applied as two half N rates applied in the fall and spring. Supplemental N was also applied as a foliar spray treatment after anthesis at either 0 kg N ha‐1 or 33 kg N ha‐1 as a diluted urea‐ammonium nitrate solution. The grain yield of Arapahoe was generally higher than Rose across treatments, but protein was slightly lower. Splitting the N application lowered yield somewhat in both varieties compared to the entire N rate applied at preplant, but grain protein increased by nearly 0.8% with the split application over the preplant application. Grain protein also increased up to 1.6% with a late season foliar N application despite some leaf damage compared to no foliar N. Grain yield was correlated to many agronomic parameters ...

Effects of tillage, nitrogen placement, and wheel compaction on denitrification rates in the corn cycle of a corn‐oats rotation

Abstract Denitrification rates under various tillage systems were determined in the corn (Zea mays L.) cycle of a corn‐oats (Avena sativa L.) rotation. Denitrification was measured directly with an in‐situ soil cover method which supplied the soil with acetylene (C2H2) and evacuated the nitrous oxide (N2O) produced. Denitrification rates were measured in both a field or non‐wheel track (NWT) area and in a compacted wheel track (WT) area for the no‐till (NT), chisel plow (CH), moldboard plow (MP) tillage systems after nitrogen (N) was applied by broadcast/incorporation with 112 kg N/ha as ammonium nitrate. Nitrogen was also applied to the NT treatment by injection with modified anhydrous ammonia knives prior to planting. Most of the cumulative N loss occurred over a 22 day period following heavy rainfall in June. Denitrification was greatest on days after rainfall events for the NT systems. Cumulative N loss was estimated at 25, 16, and 11 kg N/ha from May 29‐September 8 for NT, CH, and MP treatments, resp...

Ameliorating caustic properties of aluminum extraction residue to establish a vegetative cover

High pH, electrical conductivity (E.C.), and extractable Na levels in the residue remaining after aluminum was extracted from bauxite were greater than can support vigorous plant growth. These caustic properties must be ameliorated so that vegetation could be established on the surface of large disposal ponds. Fresh residue was added to 14 field lysimeters of dimensions 3 m long × 3 m wide × 1 m deep. Internal drainage was enhanced in some lysimeters and restricted in others. Gypsum applied at the rate of 7.5% of the weight of the top 15 cm of residue in selected lysimeters. These management issues were studied to determine how their influence would lower chemical properties to support vegetation. Residue samples were removed annually for 5 years after the lysimeters were established to determine changes in pH, E.C., and extractable Na and Al over time. Plant species C. dactylon (bermudagrass), Atriplex nummalari (oldman saltbush), and Atriplex canescens (fourwing saltbush) were planted either as seeds or transplants beginning the third year after lysimeter establishment. Residue pH, E.C. Na, and Al decreased annually, but more gradually in restricted drainage. Species survival in the enhanced drainage treatments was more vigorous with gypsum amendments beginning in the third year after lysimeter establishment. This coincided with a decrease in the mean pH below 9.5 and decrease in mean E.C. below 10 dS/m. Extractable Na and Al did not seem to influence survivability. Survival of seeded and transplanted C. dactylon was greater than the two Atriplex spp. each year. This study proved that the caustic properties of this residue could be lowered enough to support vegetation, but not without appropriate drainage. The addition of gypsum amendments and appropriate amounts of supplemental water would accelerate the timeframe for vegetation establishment probably at a level commensurate with the application rate of both inputs in a well-drained system.

Contribution of biofertilizers and fertilizer nitrogen to nutrient uptake and yield of egyptian winter wheat

ABSTRACT Nutrient uptake and grain and straw yield of Egyptian winter wheat (Triticum aestivum L. Merr.) were evaluated for two site-years after the seed inoculation with two biofertilizer products, Phosphorien, containing the phosphorus (P)-solubilizing bacteria Bacillus megatherium, and Nitrobien, containing a combination of nitrogen (N)-fixing bacteria Azotobacter chroococcum and Azospirillum liposerum. Ammonium nitrate and polymer-coated urea fertilizers were applied to plots alone and together with the biofertilizers at rates of either 83 kg N ha−1 or 186 kg N ha−1 for comparison. The highest grain yield (5.76–6.74 Mg ha−1) and straw yield (11.49–13.32 Mg ha−1) occurred at the highest fertilizer rates with N fertilizer. There was a slight additional increase in grain and straw yields when a biofertilizer was applied along with N fertilizer. A slightly higher grain and straw yield was measured with the polymer-coated urea treatment than with the ammonium nitrate treatment. The biofertilizer materials were not as effective as N fertilizers in producing grain (4.02–4.09 Mg ha−1) or straw (7.71–8.11 Mg ha−1) for either year, although the Nitrobien + Phosphorien combination increased these parameters over the N-fertilizer control. The effect of the Nitrobien biofertilizer in increasing grain yields was equivalent to a urea application rate of about 13 kg N ha−1. Biofertilizer inoculations increased iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) concentrations in wheat tissue (at boot stage), but these higher levels did not influence grain or straw yield.

Generation of corn tissue norms from a small, high-yield data base

Abstract The purpose of this study was to determine the practicality of generating plant tissue norms with analytical data from a few, extremely high‐yield observations. A set of ear leaf tissue norms for corn (Zea mays L.) were developed from a set of data consisting of 10 observations of field‐grown corn with yields greater than 18 Mg ha‐1. The norms thus generated were compared with norms generated from 8494 observations from a wide geographical area. Norms for several elements (P, K, Mg, S, Mn, and B) calculated from the two data bases were significantly different, while norms for the other nutrients (N, Ca, Fe, and Cu) were not. The norms generated from the limited data base were tested with data from an N3P3K3S3 factorial greenhouse experiment. Results of this test indicate that the norms developed from the limited, high‐yield data base were slightly better at predicting yield increases than those from the broader worldwide data base. The increase in accuracy seemed to be largely due to lower S norm...

Response of early corn growth to fertilizer phosphorus rates and placement methods

Abstract Previous research showed that applying fertilizer phosphorus (P) to the soil in concentrated subsurface bands increased P availability to crops compared to a surface application. Early growth responses of corn (Zea mays L.) plants were measured after 28 days of growth in pots in a greenhouse for single band, two single bands, injection, and surface fertilizer P placement methods. Fertilizer P was applied at the rates of 0, 12, and 24 mg P/kg soil for each method for three different soils. Shoot dry matter weight and nitrogen (N) and P uptake increased for all placement methods regardless of initial soil test P level. However, growth parameters were greater for the banded and injection methods. Response parameters were minimally influenced by the surface P application, but some fertilizer P from the surface application leached through small desiccation cracks after daily additions of water. This probably increased P availability slightly. Shoot dry matter production efficiency and shoot N/P ratio ...

Effect of phosphate and sulfate fertilizers on selenium uptake by wheat (Triticum aestivum)

The objective of this study was to investigate whether oxyanionic phosphate (P) and sulfate (S) fertilizer management could influence selenium (Se) uptake by wheat (Triticum aestivum) in medium and high Se areas. Field studies were established at two locations for two growing seasons in central South Dakota, USA. Phosphate fertilizer was applied using three different methods (banded with seed, surface-broadcasted in the fall, or surface-broadcasted in the spring) using six different P rates. Sulfate fertilizers were broadcasted at four rates in the fall. Selenium concentration in wheat grain was significantly influenced by the interaction of P application methods and rates, but it was dependent on location. Grain Se concentration decreased in high Se availability soil when P fertilizer was applied, due to the dilution effect. Grain Se concentration and uptake was significantly decreased as S applications increased due to the competition effect, but the depression was apparent in high Se availability soil. The results from this study showed that P and S fertilizer management can influence Se level in wheat grain grown in naturally high Se areas, even though overall grain Se level was strongly associated with location variation.

Selenium uptake response among selected wheat (Triticum aestivum) varieties and relationship with soil selenium fractions

Some South Dakota soils contain high levels of available selenium (Se) for crop uptake. A field study was conducted to determine if any popular wheat (Triticum aestivum) varieties demonstrate differential Se uptake. A total of 280 samples including eight winter wheat and ten spring wheat varieties were analyzed for grain Se concentration and uptake for two growing years. Soil samples were sequentially fractionated into (1) plant available (0.1 M KH2PO4 extractable) and (2) conditionally available (4 M HCl extractable) pools and analyzed separately for total Se. Selenium concentration in wheat grain had a wide variability and the mean value over two years was 0.63 µg Se g−1. Grain Se concentration and Se uptake were not significantly different by wheat varieties tested in this study. Grain Se concentration was significantly correlated with soil Se levels, soil pH, and orthophosphate-P content within a location, but grain Se concentration was strongly influenced by geographical location in which different amounts of soil Se bioavailability occurred.

The relationship of soil and leaf nutrients to rice leaf oranging

Abstract A symptom called leaf‐oranging, indicating a deficiency of many nutrients, occurs in paddy rice (Oryzasativa L.) when production expands into some upland soils. Rice (Gui Chou cv.) was grown in culture pots in a flooded, weathered, upland soil (Nacogdoches) and compared to rice growth in a flooded soil currently used for paddy rice production (Dacosta) in Texas to understand the soil and plant factors involved in leaf‐oranging. Fertilizer rates of 0, 10, and 100 mg N/kg as (NH4)2SO4 were applied to each soil along with phosphorus (P) and potassium (K) fertilizer. The orange Leaf Index (OLI), a measure of leaf‐oranging, was determined weekly and increased to 60–70% for plants grown in the upland soil but its progression was delayed by higher N treatments. No leaf‐oranging was observed in the paddy soil. The soil evoking leaf‐oranging was low in silicon (Si) and high in iron (Fe). In addition, analysis of leaves from these plants showed 19–25% higher leaf ammonium‐nitrogen (NH4‐N), 9–137% higher ma...

Assessment of Soil Potassium Sufficiency as Related to Quantity‐Intensity in Montmorillonitic Soils

Abstract No studies have been conducted to evaluate the potassium (K) quantity‐intensity (Q/I) relationships that exist in eastern South Dakota soils and how that may affect K fertility interpretations. The objectives of this study were to i) evaluate the K status of smectite‐dominant soils through quantity‐intensity relationships and (ii) relate the findings to current research on soil K release and plant availability. Soil and plant tissue samples were collected from eight different corn production fields across east‐central South Dakota. Samples were collected from areas where corn plants did or did not exhibit K deficiency symptoms. Quantity‐intensity plots were developed and used to derive the typical Q/I parameters. Little difference existed in Q/I parameters and the form of Q/I plots among field sites. The ARe K and ΔK0 values ranged from 0.0013 to 0.0113, and −0.47 to 0.18 cmolc kg−1, respectively, and most sites were considered K insufficient. The predominant phyllosilicate present in the clay‐sized fraction was montmorillonite with an estimated 17% tetrahedral charge. These soils would not be expected to contribute much plant‐available, nonexchangeable K and would be in need of frequent K fertilization. Presumably, these and similar soils, upon K exhaustion, rely heavily on K released from K‐bearing silt‐sized particles and may be highly dependent on surface‐controlled dissolution processes for labile K replenishment. Additional research needs to be conducted concerning the release kinetics of K from K‐bearing minerals of these soils.