Stephen C. Mason

Importance and Effect of Nitrogen on Crop Quality and Health

Publisher Summary This chapter discusses the importance and effect of nitrogen on crop quality and health. Nitrogen is often the most limiting factor in crop production. Hence, application of fertilizer nitrogen results in higher biomass yields and protein yield and concentration in plant tissue is commonly increased. Nitrogen often affects amino acid composition of protein and in turn its nutritional quality. In cereals, abundant supply of nitrogen decreases the relative proportion of lysine and threonine, thus, reducing the biological value of the protein. Increasing nitrogen supply generally improves kernel integrity and strength, resulting in better milling properties of the grain. In oil seed crops, protein levels are increased upon nitrogen fertilization, whereas oil concentration is decreased. Effects of nitrogen fertilization on oil composition and quality are inconsistent.

Weed Management in a Glyphosate Resistant Soybean System: Weed Species Shifts

With increased reliance on glyphosate for weed control, weed species composition shifts are likely. Changes in relative abundance could arise from differential tolerance or resistance to, or avoidance of, glyphosate. This study characterized the potential changes in seedbank composition of a mixed population of summer annual weeds due to glyphosate application timing. Seven weeds common in soybean fields in the Midwest were introduced at known densities and treated with glyphosate at several treatment timings. Common lambsquarters, common sunflower, common waterhemp, eastern black nightshade, ivyleaf morningglory, shattercane, and woolly cupgrass were selected to represent a range of emergence patterns and tolerances to glyphosate. Seedling emergence and seed production were monitored. Differences in herbicide tolerance and avoidance, through markedly different weed emergence patterns, were strong contributors to projected changes in weed species composition. Lessened sensitivity to glyphosate allowed some emerged species, such as ivyleaf morningglory, to better survive the herbicide. Late emergence allowed others, such as shattercane and ivyleaf morningglory, to avoid glyphosate applications. Such mechanisms may allow specific species to increase in a continuous glyphosate system. Nomenclature: Glyphosate; common lambsquarters, Chenopodium album L.#3 CHEAL; common sunflower, Helianthus annuus L. # HELAN; common waterhemp, Amaranthus rudis Sauer # AMATA; eastern black nightshade, Solanum ptycanthum Dun. ex DC. # SOLPT; ivyleaf morningglory, Ipomoea hederacea [L.] Jacq. # IPOHE; shattercane, Sorghum bicolor [L.] Moench # SORVU; woolly cupgrass, Eriochloa villosa [Thunb.] Kunth # ERBVI; soybean, Glycine max (L.) Merr. ‘Asgrow 3003RR’. Additional index words: Differential sensitivity, fecundity, herbicide tolerance, population dynamics, relative abundance. Abbreviations: DAP, days after planting; POST, postemergence; SBt, seedbank at time = 0; SBt+1, seedbank at time = 1 yr.

Velvetleaf (Abutilon theophrasti) and Green Foxtail (Setaria viridis) Response to Corn (Zea mays) Hybrid1

Abstract: A 2-yr study was conducted near Mead, NE, to determine the interaction of six corn (Zea mays) hybrids having different heights and leaf angles and four herbicide rates on velvetleaf (Abutilon theophrasti) and green foxtail (Setaria viridis) biomass rating and seed production. Corn hybrid grain yields averaged over herbicide rates differed by up to 1,100 kg/ha in 1993 and 3,000 kg/ha in 1994, yet similar grain yield reductions occurred for all hybrids as herbicide rate decreased. Corn hybrids differed in suppression of weed growth and seed production, but suppression differences among hybrids were not consistent across years. Plots with the very tall, erect-leaf hybrid had 7.4 velvetleaf plants/m2, whereas other hybrids had 8.6 to 10.1 plants/m2. Plots with the very tall, erect-leaf hybrid also produced the lowest quantity of velvetleaf seeds of 23,100 seeds/m2 versus 25,100 to 30,700 seeds/m2 for plots with other hybrids. Erect-leaf hybrids suppressed weeds more effectively than horizontal-leaf hybrids. Corn hybrids had less effect on early- Fand late-season weed densities and biomass ratings and on seed production than herbicide application. Selection among current corn hybrids as a tool in integrated weed management will have a small or inconsistent influence on weed suppression. Nomenclature: Alachlor, 2-chloro-N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide; atrazine, 6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine; green foxtail, Setaria viridis #3 SETVI; velvetleaf, Abutilon theophrasti Medik. # ABUTH; corn, Zea mays L. Additional index words: Grain yield, herbicide, integrated weed control, reduced input, weed seed production, weed competition, ABUTH, SETVI. Abbreviations: GDD, growing degree days; IFS, Illinois Foundation Seed.

Crop Rotation and Soil Amendment Alters Sorghum Grain Quality

Soybean [Glycine max (L.) Merr.] rotation enhances grain sorghum [Sorghum bicolor (L.) Moench] yield, but infl uence on grain quality has not been measured. The objective was to determine the effect of cropping sequence (CS) and soil amendment (SA) on grain yield and quality. Sorghum grain yield and quality, soil NO3–N and water were measured in a rotation study in 2003 and 2004 on a Sharpsburg silty clay loam (fi ne, smectitic, mesic Typic Argiudoll). Cropping sequences were continuous sorghum, and sorghum rotated with non-nodulating and nodulating soybean. Soil amendments consisted of no amendment, manure (17–26 Mg dry matter ha−1 yr−1), and N (84 kg ha−1 yr−1). CS × SA interaction effects were found for most parameters. Rotation with non-nodulating soybean without SA increased yield by 2.6 to 2.8 Mg ha−1 over continuous sorghum without SA. Rotation without SA with nodulating soybean further increased yield by 1.7 to 1.8 Mg ha−1 over rotation with non-nodulating soybean. Grain N increased by 0.5 to 1.0, 2.5 to 5.0, and 3.3 to 4.9 g kg−1 for N application to continuous sorghum and sorghum rotated with non-nodulating and nodulating soybean, respectively. Tangential abrasive dehulling device (TADD) removal indicated that continuous sorghum without SA produced the softest grain with 43 to 44% TADD removal, and sorghum rotated with nodulating soybean with manure produced the hardest grain with 22 to 27% TADD removal. As food end-use opportunities for sorghum grain evolve, use of crop rotation and SA application will be important to produce grain with desirable quality attributes. Crop Rotation and Soil Amendment Alters Sorghum Grain Quality Nanga Mady Kaye, Stephen C. Mason,* David S. Jackson, and Tom D. Galusha Dep. of Agronomy and Horticulture, and Food Science and Technology, Univ. of Nebraska, Lincoln, NE 68583-0915. Paper No. 14668 of the Journal Series of the Nebraska Agric. Res. Div. Research supported by USAID Grant No. DAN 1254-G-0021 through INTSORMIL, the International Sorghum and Millet Collaborative Research Program. Received 25 May 2006. *Corresponding author (smason1@unl.edu). Abbreviations: CS, cropping sequence; SA, soil amendment; TADD, tangential abrasive dehulling device. Grain sorghum is an important grain crop in the Central Great Plains due to its drought tolerance (Sander and Frank, 1980), high nutrient use effi ciency (Maranville et al., 1980), and use for livestock feed. During the past 50 yr, sorghum grain yields have increased by 139% largely due to improved hybrids and soil water management (Unger and Baumhardt, 1999). Due to interest in using sorghum grain for human food (Shayo et al., 2001; Johnson, 2005) and industrial products (Buff o et al., 1998, Johnson, 2005) research eff orts are presently underway to develop sorghum hybrids with improved kernel characteristics (Maunder, 2005). Rotating soybean with sorghum has been shown to increase grain yield (Gakale and Clegg, 1987; Roder et al., 1989a, Peterson and Varvel, 1989), alter soil stored water (Roder et al., 1989a), increase soil N (Bagayoko et al., 1992), improve soil physical properties (Gakale and Clegg, 1987), and reduce yield variability (Varvel, 2000). None of these studies addressed crop rotation or N supply infl uences on grain quality. One tool to help separate biologically fi xed N from other rotation eff ects is the inclusion of nodulating and non-nodulating soybean isolines into a crop rotation as previously done by Maloney et al. (1999), Gentry et al. (2001), and Bergerou et al. (2004). Manure as a soil amendment in sorghum studies has improved soil physical properties (Eghball, 2000), increased water and Published in Crop Sci 47:722–729 (2007). doi: 10.2135/cropsci2006.05.0346

Weed management in glyphosate resistant soybean : Weed emergence patterns in relation to glyphosate treatment timing

Knowing when weed species are likely to emerge can aid in developing effective integrated weed management programs. When using nonresidual herbicides such as glyphosate for weed control, treatment timing is critical. This study characterized the emergence patterns of common lambsquarters, common sunflower, common waterhemp, eastern black nightshade, ivyleaf morningglory, shattercane, and woolly cupgrass in soybean, in relation to common glyphosate application timings. Approximately 90% or more of common lambsquarters, common sunflower, and common waterhemp seedlings emerged before the end of May, both in 2000 and 2001. Both ivyleaf morningglory and shattercane emerged from late April to mid-August, allowing these species to avoid glyphosate applications timed to prevent early-season weed competition. Avoidance through periodicity in emergence underscores the importance of integrating multiple tactics to ensure that difficult to manage weeds are not selected for in this management system. Nomenclature: Glyphosate; common lambsquarters, Chenopodium album L.#3 CHEAL; common sunflower, Helianthus annuus L. # HELAN; common waterhemp, Amaranthus rudis Sauer # AMATA; eastern black nightshade, Solanum ptycanthum Dun. ex DC. # SOLPT; ivyleaf morningglory, Ipomoea hederacea (L.) Jacq. # IPOHE; shattercane, Sorghum bicolor (L.) Moench # SORVU; woolly cupgrass, Eriochloa villosa (Thunb.) Kunth # ERBVI; soybean, Glycine max (L.) Merr. ‘Asgrow 3003RR’. Additional index words: Cohorts, germination, growing degree days, heat units, integrated weed management, periodicity. Abbreviations: DAP, days after planting; IWM, integrated weed management; POST, postemergence.

Soil fertility and crop yields in long-term organic and conventional cropping systems in Eastern Nebraska

Organic agriculture aims to build soil quality and provide long-term benefits to people and the environment; however, organic practices may reduce crop yields. This long-term study near Mead, NE was conducted to determine differences in soil fertility and crop yields among conventional and organic cropping systems between 1996 and 2007. The conventional system (CR) consisted of corn (Zea mays L.) or sorghum (Sorghum bicolor (L.) Moench)‐soybean (Glycine max (L.) Merr.)‐sorghum or corn‐soybean, whereas the diversified conventional system (DIR) consisted of corn or sorghum‐ sorghum or corn‐soybean‐winter wheat (wheat, Triticum aestivum L.). The animal manure-based organic system (OAM) consisted of soybean‐corn or sorghum‐soybean‐wheat, while the forage-based organic system (OFG) consisted of alfalfa (Medicago sativa L.)‐alfalfa‐corn or sorghum‐wheat. Averaged across sampling years, soil organic matter content (OMC), P, pH, Ca, K, Mg and Zn in the top 15 cm of soil were greatest in the OAM system. However, by 2008 OMC was not different between the two organic systems despite almost two times greater carbon inputs in the OAM system. Corn, sorghum and soybean average annual yields were greatest in either of the two conventional systems (7.65, 6.36 and 2.60 Mg ha - 1 , respectively), whereas wheat yields were greatest in the OAM system (3.07 Mg ha - 1 ). Relative to the mean of the conventional systems, corn yields were reduced by 13 and 33% in the OAM and OFG systems, respectively. Similarly, sorghum yields in the OAM and OFG systems were reduced by 16 and 27%, respectively. Soybean yields were 20% greater in the conventional systems compared with the OAM system. However, wheat yields were 10% greater in the OAM system compared with the conventional DIR system and 23% greater than yield in the OFG system. Alfalfa in the OFG system yielded an average of 7.41 Mg ha - 1 annually. Competitive yields of organic wheat and alfalfa along with the soil fertility benefits associated with animal manure and perennial forage suggest that aspects of the two organic systems be combined to maximize the productivity and sustainability of organic cropping systems.

Skip-Row Planting Patterns Stabilize Corn Grain Yields in the Central Great Plains

The highly variable climate of the central Great Plains makes dryland corn (Zea mays) production a risky enterprise. Twenty-three field trials were conducted across the central Great Plains from 2004 through 2006 to quantify the effect of various skip-row planting patterns and plant populations on grain yield in dryland corn production. A significant planting pattern by plant population interaction was observed at only one of 23 trials, suggesting that planting pattern recommendations can be made largely irrespective of plant population. In trials where skip-row planting patterns resulted in increased grain yields compared to the standard planting pattern treatment (every row planted using a 30-inch row spacing), the mean grain yield for the standard planting treatment was 44 bu/acre. In those trials where skip-row planting resulted in decreased grain yield compared to the standard planting pattern, the mean yield was 135 bu/acre. The plant two rows, skip two rows planting pattern is recommended for riskaverse growers in the central Great Plains where field history or predictions suggest likely grain yields of 75 bu/acre or less. Planting one row and skipping one row is recommended for growers with moderate risk-aversion and likely yield levels of 100 bu/acre or less.

Factors affecting the alkaline cooking performance of selected corn and sorghum hybrids.

ABSTRACT Dent corn (Zea mays L.) and sorghum (Sorghum bicolor L. Moench) sample sets representative of commonly grown hybrids and diverse physical attributes were analyzed for alkaline cooking performance. The influence of kernel characteristics including hardness, density, starch properties (thermal, pasting, and crystallinity), starch content, protein content, and prolamin content on alkaline cooking performance was also determined. Corn nixtamal moisture content was lower for hard, dense kernels with high protein contents; sorghum nixtamal moisture content was lower for kernels with low moisture contents and low starch relative crystallinities. Statistically significant (P < 0.05) regression equations showed that corn nixtamal moisture content was influenced by TADD (tangential abrasive dehulling device) index, kernel moisture content, starch content, and protein content; sorghum nixtamal moisture content was influenced by starch relative crystallinity, kernel moisture content, and abrasive hardness in...

Soil and cropping system research in semi-arid West Africa as related to the potential for conservation agriculture

Semi-arid West Africa faces challenges to increase sorghum and pearl millet production to meet food needs for a growing human population while increasing soil carbon (C), nutrient levels, and water holding capacity that are documented benefits of conservation agriculture. This review focuses on the wealth of research on cropping systems, tillage, crop residue, nutrient, and weed management as related to conservation agriculture. It also identifies needs for multidisciplinary, integrative research to assist the transition from current production systems to conservation agriculture. Crop residue use as livestock feed, or fuel are major constraints to adoption of conservation agriculture, which could be reduced by wood production in agroforestry systems, alternate energy sources, and increased forage supply. Crop residue and grain yields are related, thus improved crop, soil, water, nutrient, and weed management to increase grain yield would also increase the supply of crop residue with potential for ‘left over’ crop residue being available for soil mulching. Incorporating indigenous shrubs and/or cover crops could also increase crop residue supply. Species diversity can be increased through crop rotation, agroforestry, cover crops, and intercrops. Higher grain and stover yields and increased profit potential for resource-poor farmers in West Africa will be required before wide-scale adoption of conservation agriculture will be possible.

Sorghum Malt and Traditional Beer (Dolo) Quality Assessment in Burkina Faso

Sorghum malt and dolo quality evaluation criteria and parameters affecting quality were surveyed in six cities in Burkina Faso through questionnaires addressed to malt processors, dolo processors, retailers, and consumers. The major quality criteria for malt quality assessment were perceived to be taste and presence/absence of roots in the malt. Taste, alcohol content, and wort sufficiently cooked were perceived as major criteria for the dolo quality assessment. The major parameters affecting malt quality were perceived to be malt production period, proportions of grain and the amount of water entering malting, presence of pesticide residues in the malting grains, and age of grain. Processing method, yeast source, proportions of the components (crushed grain, water, mucilage, yeast) entering dolo production, malt quality, wort temperature at time of inoculation, amount of energy available for cooking, wort and sediment boiling time, quality of mucilage, malt with non-sweet taste, presence/absence of roots in the malt, and ease of filtering crushed malt were perceived as major parameters affecting the dolo quality. These results will be used in the improvement of the dolo supply chain in Burkina Faso by providing more reliable information for training programs for efficient dolo brewing processes, development of best cropping practices to improve grain quality, and providing better selection criteria for sorghum breeding programs.