SOUTH DAKOTA
SOUTH DAKOTA STATE UNIVERSITY AND THE USDA-ARS NORTHERN GRAIN INSECT RESEARCH LABORATORY (NGIRL).
Plant Science Department, Brookings, SD 57007 U.S.A.
A.M.H. Ibrahim, S.A. Kalsbeck, R.S. Little, S. Malla, Howard J. Woodard, Anthony Bly, Ron Gelderman, Jim Gerwing, and Gary Erickson (South Dakota State University); and L. Hesler, W. Riedell, and S. Osborne (USDA-ARS-GIRL).
A.M.H. Ibrahim, S.A. Kalsbeck, R. S. Little, and S. Malla.
Crop Report and Testing Sites. Winter wheat production in 2003 was estimated at 59.34 million bushels, up 227 % from last years drought-impacted production and is the third largest production in the state's history. Producers harvested 1.38 million acres (1.6 million planted acres), for a state average of 43 bu/acre, which is 14 bushels above last year's and is the second highest yield in the state's history. Overall, the excellent winter survival rate at most locations was due to a mild winter and further aided by an early mild spring with adequate rainfall.
In 2003, the winter wheat breeding program conducted testing at eight sites throughout South Dakota. These environments included Aurora and Brookings (Brookings Co.), Platte (Douglas Co.), Highmore (Hyde Co.), Selby (Walworth Co.), Winner (Tripp Co.), Wall (Pennington Co.), the Northeast Research Farm near Watertown (Codington Co.), Kennebec (Lyman Co.), and both irrigated and dry land environments at the Dakota Lakes Research Farm east of Pierre (Hughes Co.). Crop performance testing also was conducted at an additional nine sites west of the Missouri River in cooperation with Bruce Swan and John Rickertson (SDSU West River Agricultural Research and Extension Center, Rapid City).
Autumn stand establishment at most testing locations was average. Late planting at Selby and the Northeast Experiment Station resulted in limited plant development and were abandoned in the spring. Extreme drought and cropping history lead to the abandonment of the dry land nursery at Dakota Lakes. Limited subsoil moisture at all west river locations was aided by May and June temperatures that were 4-5°F below normal and supplemented by above normal rainfall. Plants produced very few tillers at the Central Crops and Soils Research Station in Highmore but compensated by good grain filling aided by a mid-June rainfall. Conversely, plants in the nurseries at Wall and Winner had excellent plant tillering but less than average grain yield due to poor grain filling caused by limited post-anthesis moisture. At Platte, Brookings, and Kennebec, yield and test weight was above the 3-year average due to timely rainfall during plant development. One experimental variety yielded 99 bu/acre at Brookings
Foundation Seed Increase. Two lines are being increased for foundation seed.
SD97W604 (SD89333, Gent/Siouxland//Abilene) is a HWWW with high yield potential, early maturity, and excellent noodle quality. SD97W604 ranked at the top in 2003 South Dakota Crop Performance Testing (CPT) Variety Trial. SD97W604 ranked above all available HWWW lines in 4-year grain yield average, Polyphenol Oxidase (PPO) enzyme levels, and winter survival ability. SD97W604 has exhibited moderate adult-plant and seedling resistance to prevalent races of stem rust and has been postulated to carry Sr24 and Sr31 genes based on tests conducted by the USDA Cereal Disease Laboratory, St. Paul, MN. In tests done in the greenhouse at South Dakota State University, SD97W604 has exhibited resistance to RCR and was moderately resistant to TPMK and bulk mixture of stem rust races. SD97W604 is moderately resistant to field leaf rust and is tolerant to tan spot. SD97W604 was tested in 1999 in coöperative baking tests conducted by the USDA/ARS Hard Winter Wheat Quality Lab (HWWQL). Baking scores were poor. The T1BL·1RS rye translocation in SD97W604, which confers disease resistance, also is responsible for poor baking quality, confirmed by 4 years of predictive sedimentation tests and mixograph tests from two locations. Protein levels for SD97W604 have ranged from well above average to well below average in four years of testing. SD97W604 has low PPO levels, which is essential for good noodle quality, an attribute desired of HWWW cultivars. Flour yield of SD97W604 is above average. Results of noodle-making tests indicate that SD97W604 possess excellent noodle quality. SD97W604 has a short coleoptile, a trait typical of most of the experimental and released white wheat currently available. As breeding for white wheat in South Dakota progresses, lines with longer coleoptiles will be selected and advanced. SD97W604 has fair to good resistance to preharvest sprouting and will be best adapted to west of the Missouri river environments. SD97W604 is on large-scale increase with intention to release in 2004.
SD92107-5 (Brule//Bennett/Chisholm/3/Arapahoe) is a reselection from the cultivar Harding for better yielding ability and test weight. This line significantly yielded better than its sibling Harding in the last 4 years of CPT testing, and has a good disease package similar to it. However, SD92107-5 possesses better resistance to stem rust races than Harding. SD92107-5 is targeted for production systems where the potential for winter injury is of greatest concern, especially in the northern half of the state and conventional summer fallow production systems (with minimal or no crop residue at planting) across South Dakota. Across locations and years, SD92107-5 has shown superior performance in situations where winter injury has been an important factor in yield rankings and has shown good yield performance compared to other winter-hardy varieties after a mild winter. SD92107-5 has very good baking quality, similar to its sibling, and has better test weight. SD92107-5 will be purified this year with intention to increase in 2004 and release in 2005.
Fusarium head blight. We made significant progress in evaluating germ plasm and developing segregating populations that possess enhanced scab resistance. We have been evaluating elite breeding lines, introduced germ plasm, regional nurseries, commercial cultivars, and segregating populations in our mist-irrigated scab nursery since 1999. Approximately 6000 plants were evaluated for scab resistance during the 1999 season. One-thousand five hundred of the plants were kept and were planted into the field in 2000 (as F3:4 progeny rows). Forty-four lines were selected out of 1,500 based on agronomic performance and were planted in 2001-02 season in the early yield trial nursery (as F3:5 lines). These lines also were planted in the greenhouse to confirm resistance. Heads were also picked from the best promising F3:4 progeny rows and planted in the mist-irrigated nursery to obtain scab reaction data prior to line entry in the preliminary yield trials the following year. In the 2001-02 growing season, we planted 3,631 progeny rows, with resistant sources, under normal winter wheat production practices in Dakota Lakes, SD. These progeny rows were planted in spring wheat stubble with supplementary irrigation. The best 291 lines were advanced to the F3:5 yield trials and observation rows of these were evaluated in the mist-irrigated nurseries in the field and greenhouse in 2003. We have used marker-assisted selection (in collaboration with Yang Yen, SDSU Molecular Biologist) as a complementary tool to our traditional breeding methods, to evaluate resistance in our promising advanced generations (AYT and CPT).
We investigated planting schemes between 2001 and 2003 to determine if direct seeded row materials are affected differently than transplanted hill plots when they are inoculated with FHB. Preliminary results suggested that there were indeed significant correlations between the two methods. We also started using point inoculation to evaluate winter wheat lines and varieties for scab tolerance under greenhouse conditions in 2002.
Mr. Subas Malla joined our program in the autumn of 2002 to pursue and M.S. degree. He is assisting with the breeding program and conducting independent research regarding the genetics of scab resistance in hard winter wheat germ plasm.
White wheat. In previous years, our breeding efforts for HWWW have centered on making crosses between adapted red lines and unadapted white germ plasm. We incorporated resistance to prevalent races of stem rust and increased the winter survival ability of HWWW. We also increased coleoptile length of our HWWW germ plasm and decreased PPO activity (a predictive measure of noodle-making quality) without sacrificing bread-making qualities. In 2003, for both red and white germ plasm in advanced nurseries, we increased coleoptile length by an average of 1 cm. The percentage of white lines (40 %) with coleoptiles longer than the cultivar Harding was twice that of red lines (20 %) in 2003 advanced nurseries (the coleoptile length of Harding is considered to be a standard for acceptable emergence following deep planting). In 2004, few of the long coleoptile lines were advanced to the AYT nursery with the result that only 2 of 7 white lines and 3 of 36 red lines had coleoptiles at least as long as Harding. However, in the 2004 preliminary yield trial (PYT) nursery, 40 % of both red and white lines had coleoptiles at least as long as Harding. Preharvest sprouting resistance is one of our biggest challenges and commands our intense effort. Nuplains and Trego, the only two elite HWWW cultivars with acceptable adaptation for some environments in South Dakota, have been identified as very good lines for sprouting resistance. Of the tested experimental lines entered into 2003 and 2004 advanced nurseries, 96L9643-3 rated very good both years; SD97W671-1 rated good in 2003 and fair to good in 2004; and SD97W604 (2004 potential release) and SD00W087 rated fair to good both years. Of other experimental lines entered into 2004 advanced nurseries, nine SD01W lines as well as SD97W609 (2004 potential release), SD97W604-1 and SD99W015 rated very good for sprouting tolerance. The headrow nursery in Dakota Lakes Research Farm consisted of 3,933 white progenies in 1998, 5,340 in 1999, 1,635 in 2000, 7,502 in 2001, 1,954 in 2002, 11,707 in 2003, and 4,915 in 2004. The early yield trial (EYT) nursery had 125 HWWW entries in 1998, 182 in 1999, 174 in 2000, 117 in 2001, 99 in 2002, 141 in 2003, and 270 in 2004. The PYT nursery had 44 HWWW entries in 1999 and 2000, 40 in 2001, 26 in 2002, 29 in 2003, and 39 in 2004. The AYT nursery had 3 experimental HWWW entries in 1998, 26 in 1999, 22 in 2000, 10 in 2001, 11 in 2002, 14 in 2003 and 8 in 2004. The CPT nursery had 3 experimental HWWW entries in 2000 and 2001, 5 in 2002, 4 in 2003 and 5 in 2004. The number of white samples examined in routine quality tests more than doubled from 1998 to 2003. Tests included protein, test weight, computerized mixographs, sedimentation, PPO activity, sprouting tolerance, and coleoptile length in addition to seedling stem rust, and field WSMV and scab screening. Two lines, SD97W604 (SD89333 (Gent/Siouxland//Abilene) and SD97W609 (Abilene/Karl), are on foundation and breeder seed increase, respectively, with potential release in 2004 and 2006, respectively.
Development of combined meal PPO and sedimentation test for HWWW. We developed a protocol that simultaneously measures meal sedimentation and PPO activity for early generation quality screening during the short turnaround period between harvest and planting. Our regular sedimentation tests were usually conducted with 1 gram of ground meal from a 10-gram sample to predict gluten strength, whereas our PPO assay (predictive measure of noodle discoloration) was conducted with five whole-seed samples. A final combined protocol was selected based on correlations with standard tests for sedimentation, PPO, and computerized mixograph data. The combined protocol was built on the meal SDS-sedimentation protocol, with adjustments in temperature, MOPS (3-(N-Morpholino) propane-sulfonic acid) buffer concentration, lactic acid concentration, and the timing of steps. In this combined protocol, 4 ml of 10 mM L-DOPA (L-3,4-dihydroxyphenyl alanine) replaced 4 ml of water, whereas various levels of lactic acid were tested. PPO color development improved with time and was acceptable at 42 minutes. Use of the most promising combined protocol (5 ml lactic acid, 4 mL 10 mM L-DOPA in 150 mM MOPS buffer, with ambient temperature of 24 C. and measurement of sedimentation at 41 min and color at 42 min) provided acceptable PPO and sedimentation scores. The stability (CV% = 12.8) of PPO values in the combined protocol was greatly improved compared to that (CV% = 22.3 %) of the 5-grain visual PPO test. The stability of the sedimentation portion (CV% = 3.4) of the combined protocol matched that of the standard meal sedimentation test (CV% = 4.5). Both sedimentation tests were highly correlated with mixograph scores loading on a factor associated mainly with mixing tolerance. Highly skewed results for meal PPO and sedimentation obscured distinctions among higher values. All protocols (standard or new) produced highly significant location-by-entry interactions, indicating a need to test over multiple environments before using data for screening purposes. Further tests will be conducted on seed harvested from 2005 Advanced Yield Trials to confirm the repeatability of the combined protocol.
L. Hesler, W. Riedell, and S. Osborne (USDA-ARS-NGIRL).
Research continues on ways to limit infestations of cereal aphids, other arthropod pests, and diseases in wheat. We are determining the mechanisms and levels of resistance to bird cherry-oat aphids among wheat and related grasses. We are also evaluating how agronomic practices affect infestations of cereal aphids and other insects. For instance, with Dr. Robert Berg, SDSU Southeast Research Farm, we found that spring cereals grown under minimum tillage have greater infestations of bird cherry-oat aphid than under conventional tillage. With Dr. Marie Langham (SDSU, plant virologist), we are determining how planting date of wheat affects insect infestations, incidence of viral diseases, and plant growth and yield. We also are collaborating with Dean Kindler and Norman Elliott (USDA-ARS-PSWCRL, Stillwater, OK) to develop rearing methods, determine host plant suitability, and characterize plant damage by the rice root aphid, another member of the cereal aphid complex and vector of BYDV.
Howard J. Woodard, Anthony Bly, Ron Gelderman, Jim Gerwing, and Gary Erickson.
Crop rotation, tillage method, and crop residue management study at Brookings, SD. A site located on the Old Larsen Farm near Brookings was selected for the rotation study. The soil type at this site is the Divide series. Plots were established in August 1999. Crop rotations established in 2000 were corn/soybean, spring wheat/soybean, and corn/soybean/spring wheat. No-till and conventional tillage blocks were established for each crop rotation. Conventional tillage plots were tilled with a disk/chisel plow and leveled with a disk in November and April, respectively. Residue management plots were included in the plot design for each crop rotation and tillage system as either completely removing all loose residues (residue removal) or leaving the residues in place (residue maintenance). In the residue removal plots all of the loose residues across the whole plot were removed. The plot design is a strip-split-split randomized complete block with four replications. Plot size is 30' x 30'. Preplant, composite soil samples were taken from each replication for nutrient recommendations.
Oxen HRSW was seeded at 1.2 million pure live seeds on 10 April, 2003. Nitrogen fertilizer (70 lbs/acre) as urea and chloride (40 lbs/acre) as KCl was broadcast applied to the wheat plots on 23 April, 2003. Corn (Dekalb 4446 RRBt) was planted at 28,800 seeds/acre on 28 April, 2003. Nitrogen (reps 1 and 2 = 100 lbs/acre, and reps 3 and 4 = 38 lbs/acre) was broadcast applied as urea to corn plots on 3 June, 2003. Sulfur (10 lbs/acre) was broadcast applied to reps 1 and 2 corn plots as gypsum on 3 June, 2003. Spring wheat was sprayed with Puma (7 oz/acre), Buctril (1 pt/acre), and MCPA Ester (1.25 oz/acre) on 23 May, 2003, for weed control. Spring wheat was harvested on 13 August, 2003, with a plot combine. Wheat straw was gathered from a 125 ft2 subsection of each plot, weighed and a subsample obtained for nutrient analysis. Straw was returned to the residue maintenance plots and removed from the residue removal plots on August 15, 2003. Grain test weight and crude protein was measured by standard NIR techniques. Dependent variable statistics were computed with SAS.
Statistical analysis of data was performed for each crop. Analysis by tillage method and residue management was performed. ANOVA showed that no treatment or interaction significantly influenced grain yield or protein. Statistical analysis by tillage system or residue maintenance showed no significant influences with either residue management treatment or tillage method. Tillage method significantly influenced residue weight (Table 1). No-till had higher residue weight. Statistical analysis by residue maintenance showed that where residues are maintained on the plot that no-till had significantly higher residue dry matter weights. When residues are removed there is no significant difference between tillage systems. Overall spring wheat grain yields were very good.
Comparison of liquid and dry nitrogen fertilizer materials influence on grain protein and yield of hard red spring wheat at Brookings, SD. Increases in grain protein from applications of foliar N have been reported. Postpollination applications have been shown to be the most effective. Some researchers have said that broadcast application of dry fertilizers would be more effective than liquids because it is root uptake that is responsible for getting N into the plant. They say that foliar N applications are washed off and subsequently taken up by the roots anyway. Therefore, a research project was initiated to evaluate the influence of dry and liquid forms of UAN (urea ammonium nitrate) and AMN (ammonium nitrate) fertilizers applied after pollination on hard red spring wheat grain protein and yield.
A research site on the Agronomy research farm near Brookings, SD was selected. This site had been fallowed for three years. A combination of tillage and Roundup had been used on this site for weed control. A composite of 15 preplant soil samples from 0-6 and 6-24 inch depths were taken prior to planting to evaluate soil nutrient status. The Oxen HRSW was no-till seeded in 7-in rows at 1.2 million pure live seeds/a on 10 April, 2003. Nitrogen fertilizer (70 lbs/a) as urea and chloride (45 lbs/a) as KCl (0-0-60-45 Cl) was broadcast on all plots after planting. Plot width was 5 feet and length 25 feet. All plots were sprayed with Buctril (1 pt/acre), Puma (7 oz/acre), and MCPA ester (1.25 oz/acre) on 23 May, 2003 for broadleaf and grass weed control. An adequate number of plots were established to accommodate five treatments in four replications. The five treatments were a check, dry or liquid ammonium nitrate (AMN) and dry or liquid urea ammonium nitrate (UAN).
The treatment applications were applied after pollination at 30 lbs N/acre. Liquid UAN and dry AMN are common fertilizer materials. However, dry UAN and liquid AMN are not. To get dry UAN, common urea and ammonium nitrate fertilizers were used. This mixture is quite hydrophilic, therefore the usability of mixing them was not feasible. The correct amounts of urea and ammonium nitrate were calculated to represent the proportions in liquid UAN. The urea and ammonium nitrate were weighed and applied separately to each plot by hand. Dissolving the correct amount of AMN in water easily created liquid AMN. The rate of application for both liquid fertilizer materials was 20 gpa. The liquid UAN solution was a 1:1 blend with water. The dry and liquid fertilizer treatments were applied on 3 July, 2003. Precipitation is monitored at the Agronomy farm by standard weather service equipment. Rain was received 1 and 6 days after treatment application (0.16 and 1.13 inches, respectively). There should have been plenty of time for the foliar treatment applications to be absorbed by plant foliage since the rain 1 day after application was small as well as enough rain 6 days later to incorporate the dry fertilizer into the soil for root absorption. Grain was harvest from the plots with a small-plot combine on 8 August, 2003. Grain weight was recorded for yield calculations and a subsample retained for test weight, kernel weight, and grain protein determination. Dependent variable statistics were evaluated with SAS.
Plant stand and growth was excellent due to very good growing conditions. Composite soil test results from a two-foot sampling depth showed that nitrate levels were 108 lbs/acre, sulfur levels were 58 lbs/acre, and there was only 16 lbs/acre chloride available. Six inch soil test for Olsen P was 24 ppm (very high), extractable K was 840 ppm (very high), and pH was 6.4. ANOVA of dependent variables showed that treatment did not significantly influenced grain protein, test weight, yield, or kernel weight. Grain yield was very good and was between 61 and 65 bu/acre for all treatments. Grain protein was very high and probably due to an over supply of nitrogen. The grain yield was good but not enough for the 108 and 70 lbs of N that was available from soil test and fertilizer N application. Orthoganol contrasts for grain yield did not show any significant results for the comparisons made, however there were significant results for grain protein. The liquid N fertilizer materials (mean = 16.3 %) significantly increased grain protein in comparison the check (mean = 15.6) and the dry fertilizer materials (mean = 15.9). These results are very similar to what was concluded from 2001 and 2002 data.
This data would suggest that plant tissues are absorbing N from foliar applications of liquid fertilizer materials and not being washed off and taken up by the roots. The liquid UAN fertilizer material significantly increased grain protein when compared to the check and other dry fertilizer materials.
Nitrogen application timing and rate influence on HRSW grain protein and yield near Aurora, SD, in 2003. The nitrogen requirement for spring wheat is estimated at 2.5 lbs N/bu grain. If the spring wheat plant does not have access to N by a specific growth stage, grain yield reductions will occur. A recent management trend in the upper Great Plains for spring wheat has been to apply N at many different growth stages. This trend has come from Europe where the grain-fill period is much longer than in South Dakota and is known as 'spoon feeding.' Because our growing season and grain-filling period is much shorter than for Europe, a research study was initiated to measure the influence of N application timing on HRSW grain yield and protein.
A research site near Aurora, SD, was selected that had been under no-till since 1993. The prior crop was soybeans and rotated with corn since 1993. Composite soil samples from the 0-6 and 6-24-in soil depths were taken prior to planting for nutrient analysis. Five application timings for nitrogen were used that included planting, tillering, jointing, boot, and heading growth stages. The N application rate was kept low (50 lbs/acre) as to not over estimate N requirement of the plants and therefore overshadow any treatment differences. A control and high N rate (100 lbs/acre) were also included in the treatments. The nitrogen was applied as broadcast ammonium nitrate. Oxen hard red spring wheat was no-till planted on 14 April, 2003, at 1.2 million pure live seeds/acre. At planting, 75 lbs P2O5 as 0-46-0 was applied with the seed in 7-in rows. Sulfur (21 lbs/acre) was applied to all plots on 1 May, 2003, as broadcast gypsum. The N application timings were applied on 6 May (tillering), 9 June, (jointing), 16 June (boot), and 26 June (heading). Weeds were controlled with Buctril (1 pt/acre), Puma (7 oz/acre), and MCPA ester (1.25 oz/acre) and applied on 23 May, 2003. Plots were harvested with a small plot combine on 1 August, 2003. After harvest, 0-24 inch soil samples were taken for residual NO3-N analysis. Grain protein was measured with near-infrared reflectance. Dependent variable statistics were determined with SAS.
Soil test results (0-6") showed 3.5 % organic matter, 23 ppm Olsen P, 211 ppm extractable K, and 0.3 mmho/cm salts. Soil test results (0-24") showed 16 lbs/acre NO3-N, 32 lbs SO4-S, and 284 lbs/acre Chloride. N application timing significantly influenced grain protein and yield. The N applied at planting and tillering had the highest grain yield. As N was applied later in the growing season, yield was significantly reduced. Grain protein was the highest with treatments that yielded the lowest except the check plot which did not have enough N for yield or protein. Typically, the highest grain yielding wheat has the lowest protein except when an abundance of N is available. The high N rate (100 lbs N/acre) did not have the lowest protein because only six more bushels of grain were gained from the addition of 50 lbs N/acre resulting in a sufficient amount of N available for protein which was similar to lower yielding treatments. N rate significantly increased grain yield (0, 50, and 100 lbs N/acre, yielded 47, 70, and 76 bu/acre respectively). A very good relationship occurred between grain yield and protein for the N timing applications. Late N application was not available for dry matter accumulation but was available for increasing the N (protein) content of the grain.
Sulfur influence on spring wheat at Aurora, SD. Crop sulfur (S) deficiencies have increased in the past years. Many corn fields have shown S deficiencies. Soybeans have rarely been S deficient. There is little work with S and spring wheat. Therefore a research project was initiated to investigate whether spring wheat would respond to S application.
A research site near Aurora, SD, was chosen that had a low S soil test. A RCB design with two treatments was used. The treatments were either with or without S application. The S-treated plot received 25 lbs S/acre as gypsum, which was surface broadcast after planting the spring wheat. Nitrogen fertilizer (90 lbs/acre) was applied to all plots as surface broadcast ammonium nitrate after planting. Oxen spring wheat variety was no-till planted on 14 April, 2003, at 1.2 million pure live seeds/acre in 7-in rows. Phosphorus (75 lbs/acre) was applied with the seed as 0-46-0. Weed control was accomplished by spraying all plots with Buctril (1 pt/acre), Puma (7 oz/acre), and MCPA ester (1.25 oz/acre) on 23 May, 2003. Grain was harvested with a small plot combine on 1 August, 2003. Grain yield statistics were completed with SAS. Postharvest soil samples (0-24 in) were obtained for NO3-N and SO4-S analysis.
Sulfur did not significantly influence spring wheat grain yield. Yields were very good. A yield increase to sulfur was expected since the preplant SO4-S soil test (0-24 in) was only 14 lbs/acre. Postharvest soil test analysis showed equal amounts of NO3-N and SO4-S in the 0-24-in soil layer for each treatment.
Managing cultural practices for high yield wheat in northeast South Dakota. Many cultural practices are available to growers that under certain circumstances, increase wheat yield. Some individuals have recommended using many of these practices together to attain higher wheat yield. Often, the use of such practices would not be recommended by standard agronomic principles. These individuals claim that the combined use of these practices will result in higher wheat yield. Due to this theory, a research project was conducted to determine the combined and individual effect of several cultural practices for increased wheat grain yield.
A research site was selected on the Northeast Research Farm near South Shore, SD. The soil type is a nearly level silty clay loam soil (Brookings) that is common to North East South Dakota. Composite soil samples of the 0-6 and 6-24 inch depths were obtained during the autumn of 2002 and analyzed for nitrate-nitrogen, phosphorus (Olsen method), potassium, pH, organic matter, salts, zinc, sulfur, manganese, copper, chloride, calcium, and magnesium. The five cultural practices chosen for evaluation were soil fertility with a sulfur comparison, split application of nitrogen, seeding rate, foliar fungicide, and fungicide seed treatment. The five cultural practices were employed to compare with standard recommended methods for successful wheat production. The soil fertility comparison was made between standard nutrient recommendations determined from soil test results for a 60 bu/acre yield goal and nutrient applications for 100 bu/acre yield goal. The split application of nitrogen was evaluated by splitting the N for the 100 bu/acre yield goal into 3 timings, planting, tillering and boot growth stages. The standard seeding rate of 1.2 million pure live seeds (PLS)/a was compared to 2.2 million PLS/acre. Applying 4 oz/acre Tilt at flag leaf and 4 oz/acre Folicur at heading was the treatment used for disease control. The fungicide seed treatment used was Raxil XT (0.16 oz/100 lbs seed). The treatments used to test these cultural practices were determined so that comparisons of each practice with an appropriate check could be made as well as the combined effect of all the practices. Treatments were randomized in a complete block design with four replications. The fertility comparison treatments were split in each block with filler plots to minimize any border effect from the high N rate applied for the 100 bu/acre yield goal.
Ingot HRSW was no-till planted on 8 April, 2003, into soybean residue. All plots were sprayed with a herbicide tank mix of Puma (7 oz/acre), Buctril (1pt/acre), and MCPA Ester (1.25 oz/acre) on 23 May, 2003. Weed control was excellent. The second and third nitrogen application splits were applied on 23 May and 11 June, respectively. Tilt (4 oz/acre) and Folicur (4 oz/acre) were applied on 11 June and 1 July, respectively. Plots measured '5 x 15' feet and were harvested with a small plot combine on 31 July, 2003. Grain protein was determined with standard NIR technique. Grain yield and protein were adjusted to 13 % grain moisture. Mean determination and separation was accomplished with SAS. Orthogonal contrasts for each cultural practice were performed to determine if the individual practice had an effect on the measured parameter.
Preplant soil test analysis showed that nitrate-nitrogen was limiting for both the 60 and 100 bu/acre yield goals. Nitrogen was applied at a rate of 85 lbs/acre and 185 lbs/acre as urea for the recommended and maximum soil fertility treatments, respectively.
Phosphorus (P) was in the high (14 ppm) category and therefore no P was applied to the recommended plots, but 30 lbs/acre P2O5 was applied with the seed as 0-46-0 to the maximum soil fertility treatments. Potassium (K) was also in the very high (187 ppm) category and none would have been recommended. However since there was only 10 lbs/a chloride (Cl-) in the top two feet, 38 lbs/acre Cl- was applied to both the recommended and maximum soil fertility treatments. This Cl- application resulted in 50 lbs/acre K applied to all plots. Soil pH was 6.3 and salts were 0.3 mmho/cm. Zinc was in the medium category (0.54 ppm). Since wheat has not been shown to respond to zinc application, none was applied to the recommended treatment plots. Zinc was applied to the maximum soil fertility plots at 0.5 lbs/acre with the seed as zinc sulfate. The sulfur test showed 18 lbs/acre in the top 2 feet. Sulfur was applied to the recommended soil fertility plots, but another recommended soil fertility treatment was added that had no sulfur application. Sulfur at 56 lbs/acre was applied to the maximum soil fertility plots as gypsum (calcium sulfate). This gypsum application also resulted in 69 lbs/acre calcium applied to the maximum soil fertility plots. The calcium soil test was considered very high (2,798 ppm) and, therefore, none was applied to the recommended soil fertility plots. Manganese and copper were considered high (36.5 and 0.89 ppm, respectively) and therefore none was applied to the recommended soil fertility plots but 2 lbs/acre and 0.5 lbs/acre manganese and copper respectively were applied with the seed in the maximum soil fertility plots as the sulfate form. Magnesium was very high and none was applied to the recommended soil fertility plots or maximum soil fertility plots because individuals recommending practices for high yield wheat say that magnesium levels are already too high and calcium should be applied as gypsum to balance the high magnesium.
There was a significant treatment effect on grain yield, which ranged from 41.7 to 53.2 bu/acre. Twelve treatments make it hard to distinguish what is happening so orthogonal comparisons were used to separate meaningful treatment comparisons. Grain test weight was significantly higher for the recommended soil fertility treatment plots when compared to the maximum soil fertility treatment plots. Grain protein was significantly higher for the maximum soil fertility treatments plots when compared to the recommended soil fertility plots because of the extra nitrogen that was applied. The check plot without nitrogen had significantly lower protein when compared to the maximum and recommended fertility treatment plots.
Orthogonal contrasts for soil fertility treatment showed that grain test weight was significantly higher with the recommended treatments, grain protein was higher for the maximum treatments and grain yield was not different. Seeding rate and foliar fungicide application significantly influenced grain test weight, protein and yield. However, the differences between the seeding rate and fungicide treatments for grain test weight and protein are really insignificant when considering any price dividends that could be received. Increasing the seeding rate from 1.2 to 2.2 million seeds/acre decreased the grain yield 4 bu/acre. Applying foliar fungicide increased yield 4.8 bu/acre. Split N application did not significantly influence any of the dependent variables. Sulfur application significantly decreased grain test weight, had no effect on protein and significantly increased grain yield. The sulfur application seemed to decrease grain test weight only because we see that as yield increases, grain test weight decreases.
Soil fertility and testing studies on spring wheat and corn in Brown County, South Dakota. Evaluating and improving soil test recommendations is important and constantly needed to provide farmers with accurate and up to date information. Farmers are getting recommendations from many sources with little or no knowledge of product success. Crop sulfur deficiencies have been more common in South Dakota during the last few years, especially with no-till. Gypsum has been promoted to balance the ratio of calcium and magnesium by outside salesman. Therefore, several studies were initiated to evaluate the influence of chloride, sulfur, and gypsum application on spring wheat and phosphorus, sulfur and gypsum application on corn in Brown Co, SD.
Two sites each for spring wheat and corn were located in farmer fields. Nutrient treatments were surface broadcast applied after the farmers planted and applied their planned fertilizer applications. Conventional tillage was used on sites 1 and 2, strip tillage on site 3 and no-till on site 4. The farmers did not apply the nutrients evaluated with these projects except for nitrogen. Nitrogen was applied to all treatment plots to offset the nitrogen applied with the ammonium sulfate treatment. Sulfur was applied as ammonium sulfate (NH4SO4) (21-0-0-24), chloride as potash (0-0-60), and phosphorus as triple super phosphate (0-46-0). Gypsum is calcium sulfate (CaSO4) and contains 18 % sulfur and 23 % calcium by weight. Plot dimensions were '20 x 20' feet. Composite soil samples from the 0-6 and 6-24 inch soil depths were obtained from the research area for nutrient analysis. Grain yield was determined from hand harvesting 25 and 100 ft2 from each spring wheat and corn plot, respectively. Statistics were determined with SAS.
Chloride, sulfur, and gypsum application did not significantly influence grain yield, protein or test weight at site 1. Grain yield was very good. Sulfur application did not significantly influence grain yield at site 2. Grain protein and test weight was significantly lower with sulfur application at this site. Grain yield was lower than average because of heavy foxtail pressure. Phosphorus, sulfur, or gypsum application did not significantly influence corn yield at sites 3 or 4. A check of the farmer's corn yield at site 3 also verified that further nutrient applications did not significantly improve grain yield. Sites 2 and 4 had the lowest sulfur soil test and should have shown a grain yield response to sulfur application. Yields were higher with sulfur application at sites 2 and 4 but could not be determined to be significantly different from plots without sulfur application. Additional nitrogen application at sites 1, 2, and 4 above the farmer's applied rate did not significantly increase grain yield, which indicates that the farmer's applied rate did not limit crop productivity.