Typical Corn Research Articles

Morphological Character and Clorophyl Content Index of Corn Infected with Dowry Disease on Land Applied With Slow Realease Fertilizer Based on Corn Cob Biochar

Downy mildew is a significant disease of corn plants caused by the pathogenic fungus Peronosclerospora maydis, with attack rates reaching 95%. The application of slow-release fertilizer based on corn cob biochar is expected to increase the resistance of corn plants. Similarly, Bacillus sp. and Pseudomonas sp. are known as antagonistic microorganisms. Bacteria can produce antibiotic compounds that hydrolyze fungal cell walls, siderophores, and other antibiotic properties that inhibit pathogen growth. This study aims to determine the morphological characteristics of downy mildew-infected corn on biochar-applied land. Treatments were arranged factorially in a Factorial Randomized Block Design repeated four times. The treatment was the application of slow-release fertilizer from biochar mixed with NPK fertilizer, namely control, slow-release fertilizer, slow-release fertilizer + cow urine, and slow-release fertilizer + cow urine + bacteria (Azobacter and Bacillus). The results showed that slow-release fertilizer gave the best growth to both normal and downy mildew-affected maize plants. The stomata of typical corn leaves were more open with regular vascular bundles, while those affected by downy mildew had more closed and irregular stomata. The chlorophyll content index in downy mildew-affected maize can also improve by applying biochar-based slow-release fertilizer.

Effects of Perilla Seed Meal on Productive Performance, Egg Quality, Antioxidant Capacity and Hepatic Lipid Metabolism of Wenchang Breeder Hens.

The aim of this study was to investigate the effects of adding perilla seed meal (PSM) to the diet on reproductive performance, egg quality, yolk fatty acids, antioxidant capacity and liver lipid metabolism in breeding hens. A total of 192 31-week-old yellow-feathered hens were randomly divided into 4 treatments with 6 replicates of 8 birds for 8 weeks. The chickens were fed a typical corn-soybean meal diet containing 0% (control), 0.3%, 0.6%, and 1% PSM. The results showed that PSM can change the productivity of laying hens. Adding 0.6% PSM to the feed reduced the mortality rate of chickens. Adding 1% PSM improved the fertilization rate and hatching rate of chickens. Regarding egg quality, the albumen height and Haugh unit were improved in the 0.6% PSM group. The content of MUFAs and PUFAs in the egg yolk was increased in all the PSM groups, while SFAs were only increased in the 0.6% PSM group. Among the indicators related to lipid metabolism, serum GLU decreased in all the PSM groups. The 0.6% PSM group had a reduction in serum and liver TG, as well as reductions in serum LDL-C and ALT. The same results were observed for the abdominal fat percentage in the 0.6% PSM group. Liver lipid metabolism-associated gene expression of FAS and LXRα was decreased in all the PSM groups, and the mRNA expression of ACC and SREBP-1c was significantly reduced in the 0.6% PSM group. HE staining showed that the vacuoles in the liver tissue gradually decreased with increasing PSM doses, especially the 1% PSM dose. Lipid droplets with a similar trend were observed using Oil Red O staining. In the results of the antioxidant capacity test, the serum T-AOC was increased in the 0.6% and 1% PSM groups, and the SOD in both the serum and liver was significantly increased in all the PSM groups. The expression of antioxidant-related genes such as Nrf2, NQO-1, HO-1, CAT and GSH-Px was significantly upregulated in the 1% PSM group. In conclusion, the PSM diet improved the lipid metabolism and antioxidant capacity of breeding hens. PSM reduces mortality and improves fertilization and hatchability in the late laying period of chickens, resulting in greater benefits. We recommend adding 0.6% PSM to layer feed, which improves the physical condition of the hens and brings higher economic benefits.

Radish management and grazing effects on weed control and corn response

AbstractPlanting cover crops (CCs) may improve soil health, protect from soil erosion, interrupt disease and pest cycles, minimize weed infestations, provide grazing opportunities, and increase commodity crop yields. In upstate Missouri, field research (2012 and 2013) evaluated the effect of tillage (reduced and no‐till), planting date (nonseeded, early, and late Sept.) of radish (Raphanus sativus L.), grazing (grazed and nongrazed radish) on winter annual weed control, and radish and corn (Zea mays L.) response. The experiment was a split–split plot design with grazed and nongrazed radish as the main plot, tillage as the subplot, and radish planting time as the sub‐subplot with four replicates. The results of this research during 2011–2012 were under extreme drought and 2012–2013 under flash drought conditions. Early planted radish produced greater tuber and foliage mass and reduced winter annual weed dry weights compared to late planting. Grazing in the autumn during dry years did not affect weed control and corn yield. The use of CCs during drought conditions can help alleviate forage shortages for livestock producers, but early planting of radish is critical for autumn grazing. Late‐planted radish treatments resulted in greater corn grain yield than the early planted radish and nonseeded control in 2013; however, there was no impact of planting date and tillage on corn yield in 2012. When planted early, weed control and winter‐kill characteristics of radish make it a favorable CC prior to corn, but radish growth was poor when planted following typical corn harvest dates in upstate Missouri.

Physical Properties of Moist, Fermented Corn Kernels

A novel approach to producing corn stover biomass feedstock has been investigated. In this approach, corn grain and stover are co-harvested at moisture contents much less than typical corn silage. The grain and stover are conserved together by anaerobic storage and fermentation and then separated before end use. When separated from the stover, the moist, fermented grain had physical characteristics that differ from typical low-moisture, unfermented grain. A comprehensive study was conducted to quantify the physical properties of this moist, fermented grain. Six corn kernel treatments, either fermented or unfermented, having different moisture contents, were used. Moist, fermented kernels (26 and 36% w.b. moisture content) increased in size during storage. The fermented kernels’ widths and thicknesses were 10% and 15% greater, respectively, and their volume was 28% greater than the dry kernels (15% w.b.). Dry basis particle density was 9% less for moist, fermented kernels. Additionally, the dry basis bulk density was 29% less, and the dry basis hopper-discharged mass flow rate was 36% less. Moist, fermented grain had significantly greater kernel-to-kernel coefficients of friction and angles of repose compared to relatively dry grain. The friction coefficient on four different surfaces was also significantly greater for fermented kernels. Fermented corn kernels had lower individual kernel rupture strengths than unfermented kernels. These physical differences must be considered when designing material handling and processing systems for moist, fermented corn grain.

Evaluation of carinata meal or cottonseed meal as protein sources in silage-based diets on behavior, nutrient digestibility, and performance in backgrounding beef heifers.

Changing climatic conditions are imposing risks and diminishing yields in agriculture. Sorghum (Sorghum bicolor) silage is a feasible option for backgrounding beef cattle in terms of economic risk management and animal productivity when compared with corn (Zea mays) silage, due to its drought adaptability. Similarly, Brassica carinata meal has proven to be a viable alternative as a protein supplement in forage-based beef cattle systems, when included at 10% of the diet dry matter (DM). However, research is scarce regarding its inclusion in silage-based diets for backgrounding animals. The objective of this trial was to compare a processor-chopped sorghum silage (SS) against a typical corn silage (CS) in a digestibility and performance trial while supplementing two protein sources; one traditionally used like cottonseed meal (CSM) and one novel like B. carinata meal (BCM). A total of 84 Angus crossbred heifers (307 ± 33 kg BW) were evaluated in a randomized block design with a 2 × 2 factorial treatment arrangement with type of silage and protein source as factors. Diets were fed ad libitum, consisting of 89% silage source plus 10% protein source, and 1% mineral inclusion on DM basis. The experimental period consisted of 14 d of adaptation followed by 5 d of apparent total tract digestibility measurements and 56 d of animal performance and intake behavior measurements. Heifers fed SS showed greater number of daily meals but decreased meal sizes (P ≤ 0.05), not differing in meal length (P > 0.10) when compared with CS. Dry matter and organic matter (OM) digestibility showed a silage type × protein source interaction (P ≤ 0.01), where in CS diets, OM tended to be more digestible with CSM vs. BCM, and it did not differ between protein sources in SS based diets. There was an effect of protein (P ≤ 0.01) on ADF digestibility, where CSM was greater than BCM. No effect of treatment was observed (P ≥ 0.10) on DM intake. Average daily gain (ADG) and gain-to-feed ratio were greater for CS than SS (P ≤ 0.01) regardless of protein source. Although heifers fed CS had greater feed efficiency and digestibility, SS can still be considered a viable option for backgrounding beef heifers, obtaining adequate ADG rates of 0.945 kg/d. Lastly, BCM did not differ from CSM in terms of feed efficiency and animal performance, proving to be a viable alternative protein source in silage-based diets.

Effects of thifluzamide on soil fungal microbial ecology

Thifluzamide, a succinate dehydrogenase inhibitor fungicide, has been used extensively for many diseases control and has the risk of accumulation in soil ecology. In order to study the ecotoxicity of thifluzamide to soil fungal communities, typical corn field soils in north (Tai’an) and south (Guoyang) China were treated with thifluzamide (0, 0.1, 1.0 and 10.0 mg/kg) and incubated for 60 days. Thifluzamide exposure promoted soil basal respiration, and significantly reduced the number of soil culturable fungi and the abundance of soil fungi (RT-qPCR) in middle and late treatment period (15, 30, 60 days). Illumina Mi-Seq sequencing revealed that thifluzamide could reduce fungal alpha diversity (Sobs, Shannon, Simpson indexes) and change fungal community structure. FUN Guild analysis showed that the relative abundance of Undefined Saprotroph increased after the thifluzamide treatment, whereas that of Plant Pathogen decreased, and we concluded that exposure to thifluzamide could change the function of soil fungi. This study evaluated the soil ecological risk caused by thifluzamide’s release into soil, providing a basis for its rational application.

Mass Transport Limitations and Kinetic Consequences of Corn Stover Deacetylation

Alkaline pretreatment of herbaceous feedstocks such as corn stover prior to mechanical refining and enzymatic saccharification improves downstream sugar yields by removing acetyl moieties from hemicellulose. However, the relationship between transport phenomena and deacetylation kinetics is virtually unknown for such feedstocks and this pretreatment process. Here, we report the development of an experimentally validated reaction–diffusion model for the deacetylation of corn stover. A tissue-specific transport model is used to estimate transport-independent kinetic rate constants for the reactive extraction of acetate, hemicellulose and lignin from corn stover under representative alkaline conditions (5–7 g L−1NaOH, 10 wt% solids loadings) and at low to mild temperatures (4–70°C) selected to attenuate individual component extraction rates under differential kinetic regimes. The underlying transport model is based on microstructural characteristics of corn stover derived from statistically meaningful geometric particle and pore measurements. These physical descriptors are incorporated into distinct particle models of the three major anatomical fractions (cobs, husks and stalks) alongside an unsorted, aggregate corn stover particle, capturing average Feret lengths of 917–1239 μm and length-to-width aspect ratios of 1.8–2.9 for this highly heterogeneous feedstock. Individual reaction–diffusion models and their resulting particle model ensembles are used to validate and predict anatomically-specific and bulk feedstock performance under kinetic-controlled vs. diffusion-controlled regimes. In general, deacetylation kinetics and mass transfer processes are predicted to compete on similar time and length scales, emphasizing the significance of intraparticle transport phenomena. Critically, we predict that typical corn stover particles as small as ∼2.3 mm in length are entirely diffusion-limited for acetate extraction, with experimental effectiveness factors calculated to be 0.50 for such processes. Debilitatingly low effectiveness factors of 0.021–0.054 are uncovered for cobs—implying that intraparticle mass transfer resistances may impair observable kinetic measurements of this anatomical fraction by up to 98%. These first-reported quantitative maps of reaction vs. diffusion control link fundamental insights into corn stover anatomy, biopolymer composition, practical size reduction thresholds and their kinetic consequences. These results offer a guidepost for industrial deacetylation reactor design, scale-up and feedstock selection, further establishing deacetylation as a viable biorefinery pretreatment for the conversion of lignocellulosics into value-added fuels and chemicals.

First Report of Fusarium cf. longipes Associated with Maize Stalk Rot in China.

In a field survey from 2017 to 2019, Fusarium stalk rot symptoms including discolored, disintegrated stalk pith tissues and lodged plants were observed in maize hybrid lines Fuyu1611, Jidan66, and Danyu8439 grown in fields in Anshan (40o49'39''N, 122 o34'6''E), Liaoning province. Its incidence ranged from 15% to 20% and caused a yield loss of up to 30%. Infected pieces of stem tissues were dissected and then sterilized with 1% NaOCl for 1 min, 70% ethanol for 1 min, rinsed 3 times with sterilized ddH2O, and dried with filter paper in hood. Three pieces were placed onto Potato dextrose agar (PDA) and incubated at 25 °C for 5 days. The colonies were single-spore subcultured on PDA at 25 °C for 2 weeks (Leslie and Summerell 2006). Morphological features were observed on PDA and carnation leaf agar (CLA). The average mycelial growth rate was 4.5 to 10.3 mm/day at 25 °C on PDA. The colonies produced aerial mycelia, varying from dense white to grayish-rose, and secreted red pigments in the agar (Fig. 1A; 1B). Macroconidia produced on CLA were long and relatively slender, commonly 4- to 7-septate, averaging 85.6 × 5.2 μm, with thick walls and pronounced dorsiventral curvature with a distinctly foot-shaped and elongated basal cell and an apical cell that was whip-like (Fig. 1C). Microconidia were rarely observed on PDA or CLA. Morphological characteristics of the isolates were similar to the features of Fusarium longipes as previously described (Leslie and Summerell 2006). The portions of three phylogenic loci (EF1-α, RPB1, RPB2) were PCR amplified using the primer pairs EF1/EF2 (O'Donnell et al, 1998), lonR1F/lonR1R (5-TTTTCCTCACCAAGGAGCAGATCATG-3 and 5-CCAATGGACTGGGCAGCCAAAACGCC-3) and lonR2F/lonR2R (5-TATACATTTGCCTCCACTCTTTCCCAT-3 and 5-CGGAGCTTGCGTCCGGTGTGGCCGTTG-3) and sequenced. The consensus sequences were submitted to GenBank (MT513215 and MT997083 for TEF, MT513213 and MT997088 for RPB1; MT513214 and MW020572 for RPB2). BLASTn searches indicated that the nucleotide sequences of the three loci of the two isolates shared 94.52% to 99.69% identity with sequences of F. longipes strains deposited in the GenBank, Fusarium-ID and Fusarium MLST databases (Supplementary Table 1, 3, 4). A phylogram inferred via maximum likelihood analysis of the combined EF-1α, RPB1, RPB2 partial sequence data of Fusarium species (Supplementary Table 2) was inferred using the CIPRIES website (https://www.phylo.org). Isolates LNAS-05-A and LNAS-09-A clustered with F. longipes, with 98% bootstrap support (Fig. 2). Pathogenicity tests were conducted on three-leaf-stage seedlings and flowering-stage c.v. Zhengdan958 and B104 plants according to previously described methods (Ye et al., 2013; Zhang et al. 2016) with minor modifications. Three days after the roots of the seedlings were inoculated with 1 × 106 macroconidia solution, the leaves and stems exhibited typical wilt symptoms (Fig. 1D). Twenty flowering-stage maize plants were drilled individually at the second or third node above the soil using an electric drill (Bosch TSR1080-2-Li) to create a hole (8 mm in diameter). An approximately 0.5 mL mycelia plug (125 mL homogenized hyphal mats + 75 mL sterilized ddH2O) was injected into the hole and covered with Vaseline. Sterilized PDA plugs were used as a control. The stalk tissue of the split internodes turned dark brown and the brown area expanded above and below the injection site by 14 dpi. All of the inoculated plants developed characteristic stalk rot symptoms, whereas no symptoms were observed in the controls (Fig. 1E). The pathogen was re-isolated, and its identity was confirmed by sequencing the above mentioned loci. F. longipes was generally regarded as a tropical Fusarium species (Leslie and Summerell 2006). This is the first report that F. cf. longipes can cause stalk rot of maize under filed condition in a temperate, typical corn belt region of China.

Effects of typical corn kernel shapes on the forming of repose angle by DEM simulation

Corn kernel shape is an important feature to improve the accuracy of simulation results, also the repose angle is often used to calibrate model parameters in simulation. In this study, the effects of the corn kernel shapes on the behavior during corn kernels accumulation were investigated in detail. Firstly, the DEM models of three typical shapes of corn kernels were developed. Secondly, the influences of the corn kernel shapes on the process for forming repose angle were investigated, such as corn kernels distance change, energy conversion, and the contact number between corn kernels. Results show that the corn kernel shape has a significant effect on the repose angle formation. The irregular shape of corn kernels limit their rolling when adding the corn kernel length in one or two directions. In addition, the irregular shapes of corn kernels increase the contact number and extend simulation time. Regular shape corn kernels need to be mixed with irregular shape corn kernels to improve its flowability. Finally, observation of the trajectory of corn kernel repose angles indicates that spherical corn kernels contact the bottom plate early, and forming small cone first, then the cone becomes bigger to change the direction of other corn kernels from top to bottom. Keywords: corn kernel shape, energy conversion, repose angle, DEM DOI: 10.25165/j.ijabe.20221502.5670 Citation: Shi L R, Zhao W Y, Yang X P. Effects of typical corn kernel shapes on the forming of repose angle by DEM simulation. Int J Agric & Biol Eng, 2022; 15(2): 248–255.

Cover crop grazing impacts on soil properties and crop yields under irrigated no‐till corn–soybean management

AbstractCover crop (CC) grazing can be a strategy to reintegrate livestock with crops, but how this integration affects soils and crop yields is unclear. We studied the impact of cattle grazing an oat (Avena sativa L.) CC in the fall on soil properties of a silt loam in a field‐scale irrigated no‐till corn (Zea mays L.)–soybean [Glycine max (L.) Merr.] experiment in eastern Nebraska. Each rotation was present each year in two adjacent fields. During the 5‐yr study, Field I was grazed two times, and Field II was grazed three times. Grazing occurred on each field every other year. Treatments were arranged in a split‐plot design with corn harvest (corn silage and high‐moisture corn [HMC]) as main plots with no CC, nongrazed CC, and grazed CC as split plots. Corn silage was harvested 15 d before HMC; HMC was harvested about 25 d before typical corn harvest time. Cover crop grazing reduced aboveground CC biomass without affecting soil penetration resistance, bulk density, aggregate stability, hydraulic properties, organic matter concentration, particulate organic matter concentration, microbial biomass, and corn and soybean yields compared with nongrazed CC. Likewise, compared with no CC, nongrazed CC had no effect except for some improvement in soil microbial properties. However, corn silage harvest negatively affected most near‐surface soil properties but not crop yields compared with HMC. Cover crop did not generally offset the negative impacts of corn silage on soil properties. In conclusion, CC grazing had no impact on soil properties and yields, but corn silage adversely affected soil properties.

Fungal pretreatment parameters for improving methane generation from anaerobic digestion of corn silage

Corn silage was treated by white rot fungi (WRF) to investigate the effect of pretreatment on material’s ability to produce methane in anaerobic digestion (AD). The selective fungi Pleurotus ostreatus and Dichomitus squalens promoted biogas generation, whereas the non-selective Trametes versicolor and Irpex lacteus had negative effect. Cumulative methane production after 10-day pretreatment with P. ostreatus at 28 °C rose 1.55-fold. The longer pretreatments of 30 and 60-days had smaller effect. When the pretreatment with P. ostreatus was carried out at 40 °C a high H2S release affected the AD process. Effect of WRF action dependent on the type of corn silage. With typical corn silage, the lignin depolymerisation raised the methane generation from 0.301 to 0.465 m3kgVS-1. In contrast, extensive decomposition of hemicellulose in hybrid corn silage deteriorated the effect of pretreatment on methane production.

Efficacy of Cover Crops for Pollinator Habitat Provision and Weed Suppression.

Pollinator declines have been documented globally, but little information is available about native bee ecology in Midwestern U.S. agriculture. This project seeks to optimize pollinator support and weed suppression in a 3-yr crop rotation with a fallow growing season. During fallow, one of five cover crop treatments (T1: crimson, red, and ladino clover and Bob oats [Fabales: Fabaceae - Trifolium incarnatum L., Trifolium pratense L., Trifolium repens L., and Cyperales: Poaceae - Avena sativa]; T2: crimson clover and oats; T3: red clover and oats; T4: ladino clover and oats; T5: no cover crop; T6/control: winter wheat [Cyperales: Poaceae - Triticum aestivum] L.) was seeded in one-half of 25 agricultural fields, whereas wheat was left unharvested in the other half as a comparison. Treatments that provide season-long floral resources support the greatest bee diversity and abundance (T1), and treatments with red clover support declining (Hymenoptera: Apidae) Bombus species (T1 and T3). Late-season floral resources may be important, yet limited (T1 and T4), and some species of agricultural weeds provide floral resources. Floral diversity may be less important than flower abundance or timing for pollinator diversity (T1-T4). Weed diversity was greatest in the no cover crop treatment (T5), least in winter wheat (T6), and intermediate in cover crop treatments (T1-T4) with no differences in weeds of economic concern. Wheat suppresses weeds but does not provide floral resources for pollinators. These results may also be applicable to marginal lands taken out of cultivation or field margin pollinator plantings in a typical corn-soybean rotation. Floral resource availability across the landscape is critical to maintain pollinator diversity.

Bioconcentration, Potential Health Risks, and a Receptor Prediction Model of Metal(loid)s in a Particular Agro-Ecological Area

To investigate the bioconcentration and potential health risks of metal(loid)s in a particular agro-ecological area, 230 pairs of soil and corresponding crop grain samples were collected from typical corn and wheat plants. The geo-accumulation index (Igeo), bioconcentration factors (BCF), health risk assessment (the target hazard quotient), and Receptor Prediction Model (PCS-SMLR) analysis were adopted to study the spatial distribution, assess the health risks, and predict the relationship between metal(loid)s and soil properties. It was found that the mean concentrations of Cu, Zn, Pb, Hg, and Cd in the study area’s agricultural soils exceeded the background soil concentrations, especially for Cd (0.2 mg/kg), Meanwhile, the corresponding Cd concentration in wheat samples was higher than the food quality limit. The results of the Igeo showed that the samples with a value higher than 0 for Cd and Hg accounted for 47.83% and 33.48%, respectively. The results of BCF of Cu, Zn, Cd, and As were higher in wheat than in corn, except for Ni. The target hazard quotient (TTHQ) of health risk of wheat, corn, and soil were higher for children (2.48) than adults (1.78), showing a potential health risk for individuals who mostly consume wheat. In addition, the PCS-SMLR analysis of the BCF prediction model for Cu, Zn, As, and soil properties showed differences in terms of the influences from wheat and corn. These results provide valuable information that not only can help local residents improve the staple food structure, but also can get provide a reference metal(loid)s concentration level for agricultural soils in the study area and restore a sustainable agro-ecological environment.

Characteristics of cheese analogue from corn extract added by papain and pineapple extract

Corn extract is an alternative ingredient which can substitute cow’s milk in making cheese analogue. The addition of pineapple and papain extract aims to produce cheese analogue with the physical and chemical desired. This study aims to 1) find out the optimum formula of additional papain and pineapple extract to produce extract corn-substituted cheese analogue, 2) Knowing the sensory, physical and chemical characteristics of cheese from corn milk produced from the best formula. The experimental design in this study was determined by Response Surface Methodology (RSM) using Central Composite Design with 2 factors studied, which are the amounts of pineapple extract (31.72-88.28 ml) and papain extract (89.64-150 mg). Variables observed include yield, moisture content, soluble protein, soluble solid and sensory variables. The optimum formula for producing cheese analogue substituted by corn extract is the addition of 40 ml pineapple extract and 130.82 mg papain extract. The yield of the formula is 19.2%. The cheese analogue has 5.908% of dissolved protein content, 12°Brix of dissolved solids and 24.3% of moisture content. The sensory characteristics (scale 1-5) of cheese analogue are whitish yellow (3.44), typical corn aroma (3.5), good taste (3.5), easy to spread (4.28) and preferred (3.5)

Assessment of In‐Season Soil Nitrogen Tests for Corn Planted into Winter Annual Cover Crops

Core Ideas The Solvita 1‐d CO2 mineralization test could be a new tool to improve in‐season N rate recommendations for corn. Solvita and soil NO3–N tests may be useful for predicting the level of early‐season N mineralization from winter cover crops (WCCs). Soil NO3–N collected at the V4 growth stage of corn at 0 to 15 cm was positively correlated (R2 = 0.45) with corn check yield. Neither the Solvita nor the presidedress nitrate test detected WCC N mineralization consistently enough to use them in rate recommendations. Environmental and economic goals encourage the use of soil N tests to improve fertilizer N (FN) management in corn (Zea mays L.). Recently, the Solvita 1‐d CO2 burst test, which proposes to estimate soil potentially mineralizable N (PMN), has been promoted as a tool for FN recommendations. We aimed to compare the Solvita test with the established presidedress nitrate test (PSNT) for estimating optimum sidedressed FN rates in a typical corn crop rotation in the Mid‐Atlantic United States that includes winter annual cover crops (WCCs). Research was conducted at eight locations from 2012 to 2014. Three WCC treatments [cereal rye (Secale cereale L.), hairy vetch (Vicia villosa Roth ssp. villosa) or a cereal rye–hairy vetch mix] were the main plots and 10 FN rates were the subplots. The WCCs affected preplanting (PP) Solvita results at one location, V4 NO3–N at 0 to 15 cm (PSNT15) at four locations, and V4 NO3–N at 0 to 30 cm (PSNT30) at two locations. Correlations between soil N test parameters and relative corn yields ranged from 0.31 to 0.13. Values for PSNT15 and PSNT30 correlated positively with corn check yields (r = 0.41 and 0.39 respectively). Solvita did not provide additional information to PSNT for predicting preplanting PMN, V4 PMN, or corn check yields. The advantages of the Solvita test were its simplicity, speed of analysis, and lower coefficient of variation relative to the PSNT. Neither method was consistently effective for predicting WCC effects on soil N or relative corn yield.

Degradation dynamics, residues and risk assessment of Dufulin enantiomers in corn plants and corn by LC/MS/MS

ABSTRACTThe degradation dynamics and terminal residues of dufulin enantiomers were investigated in two typical corn plants. A convenient and precise chiral method by high-performance liquid chromatography coupled with tandem triple quadrupole mass spectrometry (HPLC/MS/MS) using a Chiralpak IC column was developed and validated for measuring dufulin enantiomers in corn plants and corn. The two enantiomers of dufulin quickly dissipated in the corn plant, and no noticeable stereoselectivity was observed during degradation or in the final residues. After 30% rac-dufulin wettable powder with a 1- to 1.5-fold dose of the recommended value was sprayed two to three times on corn plants, the residue levels of S-(+)-dufulin and R-(-)-dufulin in corn from both sites were lower than or equal to 0.0520 mg kg–1 on days 7, 14 and 21 after the last application. The dietary risk assessment indicated that dufulin did not exhibit obvious dietary health risks in corn samples when good agricultural practices were implemented. The findings from this study may be used to better understand the chiral profiles of dufulin in the environment and the effect of dufulin residues in corn on health.

NUTRITIONAL EVALUATION OF FORMIC ACID AND ITS SALT AND PROBIOTICS IN BROILER DIETS

An experiment was conducted to determine the effect of adding formic acid (FA) , sodium diformate (SDF) and probiotics [(Lactobacillus acidophilus (LA)] or Lactic acid bacteria and enzymes (LAE) to a typical corn soybean meal diets on growth performance, some blood parameters, carcass traits, ileum bacterial counts and economic efficiency of broiler chicks. A total number of 150 one-day-old Arbor Acers broiler chicks were classified into 5 equal groups, each was subdivided into 3 replicates with 10 chicks. The control group was fed basal (starter, grower and finisher) diets without supplementation (T1), while the other groups (T2: T5) were fed the basal diets supplemented with 2 g (SDF)/ kg diet (T2); 2 ml (FA)/ kg diet (T3); 1 g (LA)/ kg diet (T4) and 1 g (LAE)/ kg diet (T5), respectively. Feed and water were supplied ad-libitum, throughout the whole experiment which lasted till 35 days of age. The results indicated that: Productive performance of broiler chicks; live body weight, daily weight gain, daily feed intake, feed conversion ratio, protein conversion ratio and energy conversion ratio were not affected significantly by different dietary treatments at whole experimental period, but numerically (T2 and T3) represented the best feed conversion ratio being (1.56 and 1.57), respectively, without significant differences among treatments compared with that fed control diet (1.62). Plasma total protein, albumin and uric acid were significantly different compared to control group. Carcass traits indicated that different dietary treatments (T2: T5) had no effects on carcass characteristics compared with control group. Feed additives used, in the current study tended to increase values of total bacterial count and lactic acid bacteria, but the values of coliform and salmonella counts were decreased in comparison with the control group. Economical evaluation showed that, relative economic efficiency, was improved when broiler chicks fed 2 g (SDF)/ kg diet (T2) or 2 ml (FA)/ kg diet (T3) and the values were 5.49 and 4.77% more, respectively when compared with that fed control diet. It could be concluded that, supplementation of basal diets with FA or SDF enhanced productive economic efficiency of broiler chickens, without affecting carcass traits.

EFFECT OF GUANIDINO ACETIC ACID WITH OR WITHOUT AMINO ACIDS AND FEED ENZYME ON PERFORMANCE, CARCASS CHARACTERISTICS AND ECONOMIC EFFICIENCY IN BROILERS FED A CORN/SOY- BASED DIETS

The aim of this study was to evaluate the effect of adding Guanidino acetic acidmixture (GAA), Amino Acids (A.A.; Meth. + Lys. + Thr. + Arg.) or both (GAA + A.A.) and b-mannanase (Hemicell HT) to a typical corn soybean meal diets on growth performance, carcass characteristics and economical efficiency of broiler chicks. A total number of 225 day old Hubbard broiler chicks were classified into 5 equal groups, each was subdivided into 3 replicates with 15 chicks. The control group was fed basal (starter, grower and finisher) diets without supplementation, while the other groups (T1), (T2), (T3) and (T4) were fed the basal diets supplemented with 600mg G.A.A/kg.; 1450 mg A.A. kg. diet or both (600mg GAA + 1450 mg A.A.) and300mg b-mannanase/kg diet, respectively. Diets and water were provided I. throughout the experimental period (1-35) days of age. The results indicated that: Live body weight, daily weight gain and daily feed intake for the broiler chicks fed basal diets supplemented with GAA + A.A., (T3) or b-mannanase, (T4)reflected the highest significant results than those fed control basal diets at 1-35 days of age. Chicks fed T1, T2 and T3 diets had significant better FCR compared with those fed control or T4 diets. The best protein (PCR), energy (ECR) conversion ratio and the highest performance index (PI) and production efficiency factor (PEF) were recorded for the group supplied with GAA + A.A., (T3) compared with other dietary treatments. The group of chicks fed AA mixture recorded significantly higher percentages of dressing and ready to look comparing to control group. While, the same group (T2) showed lower value of giblets % as comparing to unsupplemented treatment. Economical evaluation, the chicks fed basal diets supplemented with different feed additives (T1-4) supported the calculated economic efficiency percentages compared to control group and the corresponding increasing values were 15.73, 1.35, 35.89 and 14.14% respectively.

Field scale measurement of greenhouse gas emissions from land applied swine manure

Greenhouse gas emissions (GHGs) from swine production systems are relatively well researched with the exception of emissions from land application of manure. GHGs inventories are needed for process-based modeling and science-based regulations. Thus, the objective of this observational study was to measure GHG fluxes from land application of swine manure on a typical corn field. Assessment of GHG emissions from deep injected land-applied swine manure, fall and reapplication in the spring, on a typical US Midwestern corn-on-corn farm was completed. Static chambers were used for flux measurement along with gas analysis on a GC-FID-ECD. Measured gas concentrations were used to estimate GHGs flux using four different models: linear regression, nonlinear regression, first order linear regression and the revised Hutchinson and Mosier (HMR) model, respectively for comparisons. Cumulative flux estimates after manure application of 5.85 × 105 g•ha–1 (1 ha = 0.01 km2) of CO2, 6.60 × 101 g•ha–1 of CH4, and 3.48 × 103 g•ha–1 N2O for the fall trial and 3.11 × 106 g•ha–1 of CO2, 2.95 × 103 g•ha–1 of CH4, and 1.47 × 104 g•ha–1 N2O after the spring reapplication trial were observed. The N2O net cumulative flux represents 0.595% of nitrogen applied in swine manure for the fall trial.

Drainage water management effects over five years on water tables, drainage, and yields in southeast Iowa

Subsurface drainage improves row crop production but also short circuits nitrate-nitrogen (NO₃-N) pathways in the soil with significant losses to surface waters. The objective of this study was to evaluate the effect of shallow, controlled, conventional, and undrained drainage treatments on depth to water table, drainage volume and NO₃-N loads, soil water content and storage in the soil profile, and crop yields. This research was conducted at the Iowa State University Southeast Research Farm near Crawfordsville, Iowa, from 2007 to 2015. We report on years five through nine here. The site consisted of eight large field plots with each of the four drainage treatments replicated twice. One-half of each plot was planted with corn (<i>Zea mays</i> L.) and the other half with soybeans (<i>Glycine max</i> [L.] Merr.). The corn and soybean halves were rotated every year in accordance with a typical corn–soybean rotation. The undrained treatment had a shallower water table than the other treatments and had a significantly higher number of days during the growing season when the water table was within 30 cm (12 in) of the ground surface than the other treatments. However, there was no difference in soil water contents in the top 80 cm (31.5 in) of the soil profile during the growing season between drainage treatments. Over the five-year study, controlled and shallow drainage reduced annual subsurface flows by 60% and 58%, respectively, while also reducing NO₃-N loads by 61% and 49%, respectively, as compared to the conventional drainage design. Crop yields were similar along the drainage designs but significantly lower in the undrained treatment. This study highlights the effectiveness of shallow and controlled drainage to reduce NO₃-N loads.