Sorghum Sudan Research Articles

Impact of different nutrient sources on forage yield, nutritive value and economics of sorghum sudan grass hybrid-Oat cropping system

It is imperative to develop integrated fertilization strategies for various forage crops that enhance the competitive ability of the crop, increase crop production and reduce the risk of nonpoint source pollution from fertilizers. The objectives of this study were to determine the effect of different sources of nutrients on performance of sorghum sudan grass hybrid-oat cropping system. Significantly highest plant height, shoots per square meter, leaf stem ratio and dry matter accumulation of sorghum sudan grass hybrid and oat was observed with FYM @10 t ha−1+Azotobacter+PSB. Not surprisingly, plant height, shoots per square meter, leaf stem ratio and dry matter accumulation increased with increasing fertilizer levels with highest values recorded with 100% RDF. Moreover, significantly highest total green and dry forage yields and gross as well as net returns were recorded in FYM @10 t ha−1+Azotobacter+PSB as well as 100% RDF. FYM @10 t ha−1+Azotobacter+PSB resulted in higher benefit cost ratio, while, significantly highest benefit cost ratio was also recorded with 100% RDF. The system productivity and production efficiency showed its maximum value in FYM @10 t ha−1+Azotobacter+PSB as well as highest level of NPK fertilization.

95 Multi-Specie cover crop bale grazing effect after annual forage grazing on yearling steer grazing and feedlot performance, muscling, carcass measurements and carcass value

Abstract Yearling crossbred steers (n = 144) were randomly assigned to native range (NR) or annual forage (ANN>: native range plus field pea-barley, corn, 13-species cover crop) to evaluate grazing season extension by feeding (“Grazing”) cover crop bales (field pea, forage barley, clover, sorghum sudan 12.8% CP, 54.4% NDF, 31.4% ADF, 59.0% TDN) before feedlot entry to measure the effect on steer grazing and subsequent feedlot performance and economics. Grazing was extended 43.6 days (177.9 to 221.5 days). ANN plus bale grazing ADG was 0.95 kg/day; NR was 0.77 kg/day (P = 0.01). Ending ANN grazing gain was 43.0 kg heavier (P = 0.001). Grazing muscling was measured using ultrasound. The ratio for REA:45.4 kg live weight did not differ (P = 0.53). End grazing ANN steer REA (P = 0.002) and percent intramuscular fat (IMF) were greater (P = 0.05) than NR steers. End grazing marbling score did not differ (489.0 vs. 470.0). In the feedlot, steers were fed 95.7 days. The ANN steer feedlot arrival weight was heavier (P = 0.04), but ending weight did not differ between ANN and NR treatments (717.6 vs. 684.0 kg; P = 0.19). ANN steer hot carcass weight (HCW) was 25.6 kg heavier (P = 0.03). The NR steer dressing percent was greater (P = 0.01) and muscling (REA:HCW) was greater for the NR steers (P = 0.007), resulting in improved USDA yield grade (P = 0.01). Quality grade did not differ (98.6% Choice or better; P = 1.00). ANN steer HCW resulted in $92.26 more per carcass (P = 0.031) than NR. Grazing medium forage quality cover crop bales is an effective method for increasing gain and live animal muscle and intramuscular fat quality before feedlot entry, and ANN steer weight advantage entering the feedlot carried over to greater ending HCW and subsequently, greater carcass value.

Short communication: Influence of sorghum cultivar, ensiling storage length, and microbial inoculation on fermentation profile, N fractions, ruminal in situ starch disappearance and aerobic stability of whole-plant sorghum silage

In recent years, the interest to grow sorghum for silage has increased, with greater prominence in areas where water supply and or availability is an issue for plant growth. Therefore, the objective of this study was to evaluate the effects of sorghum cultivars (forage or sudan), storage length and microbial inoculation with heterofermentative and facultative homofermentative inoculants on the fermentation profile, DM loss, aerobic stability and ruminal in situ starch disappearance of whole-plant sorghum silage. Whole-plant sorghum (279 ± 37 g/kg DM for forage and 232 ± 29 g/kg DM for sudan) was ensiled in quintuplicate 20 L plastic buckets untreated (CON) or after the following treatments: Lactobacillus plantarum CH6072, L. plantarum LSI, and Pediococcus pentosaceus P6 at 1 × 105 cfu/g of fresh forage (LPPP); L. buchneri LB1819 and Lactococcus lactis O224 at 1.5 × 105 cfu/g (LBLL). Silos were allowed to ferment for 0, 15, 30 or 90 d. Lactic acid and total acids were greatest in sudan sorghum silage, and total acids were greatest in LPPP and lowest for LBLL. Ammonia-N (as g/kg of total N) was greatest with sudan sorghum. The acetic acid was greatest in forage sorghum inoculated with LBLL, intermediate in sudan sorghum inoculated with LBLL, and linearly increased in both cultivars with storage length from 15 to 90 d. Silage aerobic stability was greater for LBLL compared to CON and LPPP. Ruminal in situ starch disappearance was increased with ensiling time, and linearly increased from d 15–90. Microbial inoculation with L. buchneri and Lactococcus lactis increased the acetic acid concentrations, improved aerobic stability, and reduced the DM loss by discarded visible spoilage, at the expense of higher DM loss by gases. This effect was more evident in forage sorghum compared to sudan sorghum.

Evaluation of genetic diversity, agronomic traits, and anthracnose resistance in the NPGS Sudan Sorghum Core collection

BackgroundThe United States Department of Agriculture (USDA) National Plant Germplasm System (NPGS) sorghum core collection contains 3011 accessions randomly selected from 77 countries. Genomic and phenotypic characterization of this core collection is necessary to encourage and facilitate its utilization in breeding programs and to improve conservation efforts. In this study, we examined the genome sequences of 318 accessions belonging to the NPGS Sudan sorghum core set, and characterized their agronomic traits and anthracnose resistance response.ResultsWe identified 183,144 single nucleotide polymorphisms (SNPs) located within or in proximity of 25,124 annotated genes using the genotyping-by-sequencing (GBS) approach. The core collection was genetically highly diverse, with an average pairwise genetic distance of 0.76 among accessions. Population structure and cluster analysis revealed five ancestral populations within the Sudan core set, with moderate to high level of genetic differentiation. In total, 171 accessions (54%) were assigned to one of these populations, which covered 96% of the total genomic variation. Genome scan based on Tajima’s D values revealed two populations under balancing selection. Phenotypic analysis showed differences in agronomic traits among the populations, suggesting that these populations belong to different ecogeographical regions. A total of 55 accessions were resistant to anthracnose; these accessions could represent multiple resistance sources. Genome-wide association study based on fixed and random model Circulating Probability (farmCPU) identified genomic regions associated with plant height, flowering time, panicle length and diameter, and anthracnose resistance response. Integrated analysis of the Sudan core set and sorghum association panel indicated that a large portion of the genetic variation in the Sudan core set might be present in breeding programs but remains unexploited within some clusters of accessions.ConclusionsThe NPGS Sudan core collection comprises genetically and phenotypically diverse germplasm with multiple anthracnose resistance sources. Population genomic analysis could be used to improve screening efforts and identify the most valuable germplasm for breeding programs. The new GBS data set generated in this study represents a novel genomic resource for plant breeders interested in mining the genetic diversity of the NPGS sorghum collection.

Impact of different cover crops and termination methods on collard yield

A three-year experiment was conducted in Cullman, AL, to determine the impact of iron clay pea, sunn-hemp, soybean, velvet Bean, sorghum Sudan, and pearl millet cover crops terminated with two methods (rolling and flail mowing) on collard (brassica oleracea var. acephala, L.) yield. Overall, each of the three growing seasons (2013, 2014, and 2015) produced significant differences in cover crop biomass production among cover crops. Across three growing seasons sorghum Sudan and Pearl Millet generated the highest biomass (23,752 and 23,333 kg ha -1 respectively). During the same period, sunn hemp produced 10,908 kg/ha -1 and soybean, velvet bean and iron clay pea produced lower biomass (6,754, 6,068, and 4,360 kg ha -1 , respectively). Termination rates of cover crops used in this study were mostly below 90%. Termination rates above 90% have been recommended by agricultural extension services to plant cash crop into cover crop residue. In all three growing seasons volumetric soil moisture content during evaluation have showed that plots with rolled residue consistently held more VMC than the standing cover crops, indicating that rolled cover crop residue better preserved soil moisture content. Collard green yield was significantly different in each growing season for different covers and termination methods. Averaged over three growing seasons, the highest collard yield was observed for iron clay pea (12,623 kg ha -1 ), Velvet bean (11,020 kg ha -1 ) and sunn hemp (10,802 kg ha -1 ). Data suggest that higher collard yield was obtained with legume cover crops with the benefit of released nitrogen into the soil and utilized by collards. In addition, across all years, the average collard green yield was higher for cover crops which were flail mowed (11,875 kg ha -1 ) compared to rolled/crimped cover crops (7,349 kg ha -1 ).

Comparison of Different Weedicides on Multi-cut Sorghum Sudan Grass Hybrid for Productivity Enhancement and Control of Grassy Weeds

Comparison of Different Weedicides on Multi-cut Sorghum Sudan Grass Hybrid for Productivity Enhancement and Control of Grassy Weeds

Dominance of limited arbuscular mycorrhizal fungal generalists of Sorghum bicolor in a semi-arid region in Sudan

ABSTRACT Despite the economic importance of sorghum in Sudan, its productivity is low. Arbuscular mycorrhizal fungi (AMF) enhance sorghum growth, survival, and nutrient uptake, and their manipulation may have potential in mitigating biotic and abiotic stresses during droughts. However, information on the AMF community in Sudan and the host-AMF specificity at the sorghum genotype level are unknown. We investigated the AMF community structure of 19 sorghum genotypes by next-generation sequencing in a semi-arid region. A total of 102 AMF operational taxonomic units (OTUs) were detected comprising four families: Glomeraceae (85.3%), Claroideoglomeraceae (10.8%), Paraglomeraceae (2.9%), and Diversisporaceae (1%). Among them, appearance ratio of three OTUs (2.9%) belonging to Rhizoglomus was more than 75%, whereas 75 OTUs had lower appearance ratio than 25%, indicating that the AMF community comprised a small number of generalist and a large number of rare OTUs. Non-metric multidimensional scaling and permutational multivariate analysis of variance showed no AMF specificity of the sorghum genotypes. The community assembly was strongly influenced by neutral processes, but 11 OTUs had higher relative frequency than expected by neutral model. The result includes the possibility that adaptability of AMF to soil environment and positive selection by host plant also affect the AMF community assembly. Our work showed that only a few Rhizoglomus species dominated without host plant genotype specificity in a semi-arid Sudanese cropland. Further research on functional analysis of the dominant AMF species may reveal the importance of the dominant AMF species for sorghum cultivation in Sudan.

53 Comparison of digestibility of forages in Jersey steers supplemented with a yeast fermentation product on a high and low quality forage diet

Abstract The objective of this study was to determine the effect on digestibility of forages using a daisy jar system with inoculum from steers supplemented with the yeast fermentation product Saccharomyces cerevisiae. Forages tested included ryegrass, wheat, orchard grass, alfalfa, and sorghum sudan hays. Samples were ground through a 1mm screen, placed in Ankom F57 bags, and run in triplicate to increase statistical significance. Two ruminally cannulated jersey steers were used in a switchback design. Animals were housed in a dry lot pen. The study consisted of 2 three-week periods, 2-week standardization followed by a 1-week test period. Diets offered for period 1 were steer A = 100% alfalfa hay w/o yeast product and steer B = 100% wheat hay w/o yeast product. Diets offered for period 2 were steer A =100% alfalfa hay +15g/h/d yeast product and steer B =100% wheat hay +15g/h/d yeast product. During the test week, rumen fluid contents were collected from each donor via rumen cannula approximately 4 h after feeding and taken to the lab to be composited. The samples were incubated for 0 h, 24 h, 48 h, 72 h, and 96 h. At the end of the incubation period bags were collected and cold shocked to stop microbial digestion. Samples were dried at 55oC and stored for later analysis. Model included trt (+/-yeast), forage, hr, and interactions forage*hr and forage*trt. No significant differences were observed (P = 0.38) on DM digestibility or NDF digestibility (P = 0.76) with the supplementation of yeast fermentation product. Forage*Trt was significant (P = 0.03 DMdig, P = 0.02 NDFdig). Implications of this study are the inclusion of a Saccharomyces cerevisiae fermentation product at a rate of 15g/h/d may not impact overall forage NDF or DM digestibility but may impact types of forage differently in an in vitro system using composited inoculum from donors on a forage diet.

145 Digestibility of forages in ruminally cannulated Jersey steers supplemented with liquid glycerol on a wheat straw forage diet

Abstract The purpose of this study was to determine the impact of supplementation of glycerol at a rate of 15% of DMI on forage digestibility on a diet of mature wheat hay. Forages tested included bermuda hay, wheat hay, alfalfa hay, and sorghum sudan hay. Samples were ground through a 2mm screen and placed in Ankom forage in-situ bags. Samples were run in triplicate to reduce error and increase statistical significance. Two ruminally cannulated steers were used in a 2x2 Latin square design for the study with ad libitum access to wheat hay and water. Animals were housed in a dry lot pen for the study. Diets offered were Control = wheat hay and Treatment= control + glycerol at 15% of daily DMI. The study consisted of 2 three-week periods. Each period had a 2-week standardization followed by a 1-week test period. During the test period, forage bags were placed in each steer for 0 h, 48 h, 72 h, 96 h, and 144 h for fermentation. At the end of the incubation period, bags were collected and cold shocked to stop microbial digestion. The samples were then dried at 55°C and stored for later analysis for NDF. A significant impact on NDFdig by treatment (P < 0.0001) was observed. NDFdig was 59.2% w/ glycerol versus control at 49.13% overall. In addition, there was a significant difference between steers (P = 0.0001) on glycerol treatment (51.95% versus 66.45% NDFdig between steer A and B), indicating difference in ruminal population efficiency between individual animals. No significant difference (P = 0.98) between steers on the control treatment was observed. Implications of this study are the inclusion of dietary glycerol in the diet of ruminants on a low-quality forage diet may increase energy level and improve ruminal digestibility and animal response may be dependent on the unique ruminal environment of individual animals.

54 Digestibility of forages in ruminally cannulated Jersey steers supplemented with liquid glycerol on a wheat straw forage diet

Abstract The purpose of this study was to determine the impact of supplementation of glycerol at a rate of 15% of DMI on forage digestibility on a diet of mature wheat hay. Forages tested included bermuda hay, wheat hay, alfalfa hay, and sorghum sudan hay. Samples were ground through a 2mm screen and placed in Ankom forage in-situ bags. Samples were run in triplicate to reduce error and increase statistical significance. Two ruminally cannulated steers were used in a 2x2 Latin square design for the study with ad libitum access to wheat hay and water. Animals were housed in a dry lot pen for the study. Diets offered were Control = wheat hay and Treatment= control + glycerol at 15% of daily DMI. The study consisted of 2 three-week periods. Each period had a 2-week standardization followed by a 1-week test period. During the test period, forage bags were placed in each steer for 0 h, 48 h, 72 h, 96 h, and 144 h for fermentation. At the end of the incubation period, bags were collected and cold shocked to stop microbial digestion. The samples were then dried at 55°C and stored for later analysis for NDF. A significant impact on NDFdig by treatment (P < 0.0001) was observed. NDFdig was 59.2% w/ glycerol versus control at 49.13% overall. In addition, there was a significant difference between steers (P = 0.0001) on glycerol treatment (51.95% versus 66.45% NDFdig between steer A and B), indicating difference in ruminal population efficiency between individual animals. No significant difference (P = 0.98) between steers on the control treatment was observed. Implications of this study are the inclusion of dietary glycerol in the diet of ruminants on a low-quality forage diet may increase energy level and improve ruminal digestibility and animal response may be dependent on the unique ruminal environment of individual animals.

Voluntary intake and plane of nutrition of sheep fed hydroponic fodder varieties

Voluntary intake and plane of nutrition of adult sheep fed six varieties of hydroponic fodder i.e. Sorghum Sudan Grass, cowpea, horse gram, maize, jowar and barley as a sole feed was evaluated using four Nellore Jodipi rams. The average yield of fodder after 7 days of sprouting from 1 kg of seed was higher (P less than 0.01) from maize and barley than from jowar seeds and it was 7.17, 8.07, 7.10, 9.13, 5.38 and 8.22 respectively from Sorghum Sudan Grass, cowpea, horse gram, maize, jowar and barley. The DM was 10.2 to 12.5 % among the fodder varieties with the CP and CF content ranging from 13.7 to 41.0% and 16 to 24%, respectively. The NFE was lower in cowpea and horse gram fodder and it was higher, 61.94% in maize fodder. Sorghum Sudan Grass fodder contained lower lignin of 3.03% while it was higher in cowpea, 10.94%. The DMI (% body weight) was 0.34, 1.11, 0.70,1.31,0.41 and 1.06 from barley, maize, cowpea, horse gram, jowar and Sorghum Sudan Grass, respectively and was lower than the recommended 2.6 to 2.8 % of body weight for maintenance of adult sheep. The DCP was 9.98, 34.49, 23.9, 9.34, 17.91 and 12.73 while the TDN was 45.83, 75.79, 68.08, 77.57, 64.07 and 77.63 % in Sorghum Sudan Grass, cowpea, horse gram, maize, jowar and barley fodder, respectively. The nitrogen, calcium and phosphorus balance of sheep was negative in all varieties. It was concluded that economic fodder production was possible with maize and hydroponic fodder as a sole feed did not meet maintenance requirements.

Economic Consideration and Model Development Spatial Trade for Sorghum and Millet Staple Food in Sudan

Economic Consideration and Model Development Spatial Trade for Sorghum and Millet Staple Food in Sudan

ANTIOXIDANT DEFENSES OF IRRIGATED FORAGE SORGHUM WITH SALINE AQUACULTURE EFFLUENT

ABSTRACT The objective of this work was to evaluate the biomass production and antioxidant enzymatic system activity of irrigated forage sorghum with saline aquaculture effluent under different leaching fractions. The experiment was conducted in the Caatinga Experimental Field of the Embrapa Semiarido, in Petrolina, State of Pernambuco, Brazil. The experimental design was a complete randomized block in a split-plot arrangement with four replications, consisting of three forage sorghum varieties (Volumax, F305 and Sudan) and four leaching fractions (0, 5, 10 and 15%). The vegetal materials were collected when the plants were at the soft-dough stage. The biomass production and activity of the enzymes superoxide dismutase, catalase and ascorbate peroxidase were evaluated. Irrigation with saline aquaculture effluent with leaching fraction of 15% results in low salinity level in the root zone and higher biomass production of forage sorghum Sudan and F305, in semiarid conditions. The antioxidant system was activated in the three sorghum varieties to prevent accumulation of reactive oxygen species, with the synchrony between the enzymes superoxide dismutase and catalase resulting in a better productive response of the varieties Sudan and F305.

Living Mulch Performance in a Tropical Cotton System and Impact on Yield and Weed Control

Cotton (Gossypium hirsutum L.) is a major crop in the Vidarbha region of central India. The vertisol soils on which much of the cotton is grown have been severely degraded by the tropical climate, excessive tillage and depletion of organic matter. Living mulches have the ability to mitigate these problems but they can cause crop losses through direct competition with the cotton crop and unreliable weed control. Field experiments were conducted in 2012 and 2013 at four locations in Vidarbha to study the potential for growing living mulches in mono-cropped cotton. Living mulch species evaluated included gliricidia [Gliricidia sepium (Jacq.) Kunth ex Walp.], sesbania [Sesbania sesban (L.) Merr.], sorghum sudan grass [Sorghum bicolor (L.) Moench × Sorghum bicolor (L.) Moench ssp. Drummondii (Nees ex Steud.) de Wet & Harlan] and sunnhemp (Crotalaria juncea L.). Living mulch height was controlled through mowing and herbicides were not used. Living mulches generated 1 to 13 tons ha−1 of dry matter across sites and years. Weed cover was negatively correlated with both living mulch biomass and cover. Where living mulches were vigorous and established quickly, weed cover was as low as 7%, without the use of herbicides, or inter-row tillage. In a dry year, living mulch growth had a negative impact on cotton yield; however, in a year when soil moisture was not limiting, there was a positive relationship between cotton yield and living mulch biomass. Use of living mulches in cotton production in the Vidarbha region of India is feasible and can lead to both effective weed suppression and acceptable cotton yields.

Effect of water regime on seed germination and vigor of five sorghum (Sorghum bicolor (L.) Moench) genotypes growing in the field

Received: 2016-04-05 | Accepted: 2016-05-29 | Available online: 2017-09-30 http://dx.doi.org/10.15414/afz.2017.20.03.45-48 This study was designed to examine the effect of water regime on seed quality of five sorghum genotypes. Two laboratory experiments were conducted in two successive seasons (2014 2015-2015 2016) at the Regional Seed Center Laboratory, Agriculture Research Station (ARC), Elobied. The laboratory treatments were conducted as factorial experiments in a Randomized Complete Block Design (DCBD) with four replications. The estimated quality included seed germination test. The results showed that water regimes had significant effects on germination (%). The highest seedling length was recorded by well-watered plant. The highest seedling growth rate was recorded by plants under well-watered regime. Also the results revealed that genotypes were differing in germination percent, seedling length and seedling growth rate. The results indicated that Taggat genotypes scored the highest values of most seeds quality trials were measured in this study and it might be suitable for high quality and production under rain-fed condition. Keywords: germination, seed vigor, sorghum, Sorghum bicolor (L.) Moench, water regime References ABDALLA, H.M. and GAMAR, Y.A. (2011) Climate change: Selection of sorghum genotype with wide adaptation, AG-17, for rain-fed areas of Sudan. In International Journal of Agri. Science , vol. 1, no. 3, pp. 144–555. ACHAKZAI, A.K.K. (2009) Effect of water stress on imbibitions, germination and seedling growth of maize cultivars. In Sarhad J. Agric. , vol. 25, no. 2, pp. 165-172. ACHAKZAI, A.K.K. and BAZAI, Z.A. (2007) Effect of water stress on seedling growth of maize cultivars: In mannitol plus culture solution. In Int. J. Biol. & Biotech . vol. 4, n. 1, pp. 37–42. AGHAALIKHANI, M., ETEMADI, F. and AJIRLO, A.F. (2012) Physiology basis of yield difference in grain sorghum ( Sorghum bicolor L. Moench) in a semi-arid environment. In Journal of Agricultural and Biological Science , vol. 7, no. 7, pp. 18-24. AHMED, E.E. and ALAMAM, S.H. (2010) Sorghum ( Sorghum bicolor (L.) Moench.). Seed Quality as Affected by Type and Duration of Storage. In Sudan. Agric. Biol. J. N. Am ., vol. 1, no. 1, pp. 1–8. DELOUCHE, J.C. (1969) Planting seed quality. Beitwide cotton production . New Orleans: USDA. FOUGEREUX, J. et al. (1997). Water stress during reproductive stages affects seed quality and yield of pea ( Pisum sativum ). In J. Crop Sci , vol. 37, pp.1247–1252. HAMID, B.H. (2001) Overview of sorghum and millet in Sudan. Khartoum: Ministry of Science and Technology, ARC, Sudan. HARRINGTON, J.F. (1971) The necessity for high quality vegetables. In J. Hortscience , vol. 6, pp. 550–551. KENGA, R. et al. (2006) Genetic and phenotypic association between yield components in hybrid sorghum (S orghum bicolor (L.) Moench) populations . Zaria: Institute of Agricultural Research for Development (IRAD), Ahamadu Bello University, Department of Plant Science/IAR. MOOSAVI, S.G. et al. (2011) Effect of Irrigation Intervals and Planting Patterns on Yield and Qualitative Traits of Forage Sorghum. In Advances in Environmental Biology , vol. 5, no. 10, pp. 3363–3368. SAMARAH, H. and ALQUDAH, A. (2009) Effects of late-terminal drought stress on seed germination and vigor of barley ( Hordeum vulgare L.). In Archives of Agronomy and Soil Science , in press. YOUNESI, O. and MORADI, A. (2009) The effect of water limitation in the field on sorghum seed germination and vigor. In Australian Journal of Basic and Applied Sciences , vol. 3, no. 2, pp. 1156– 1159.

Sowing methods and varying seed rates of cowpea on production potentialof sorghum, sudan grass hybrid and cowpea: A review

Forage requirement of livestock is generally met through low quantity and quality of crop residues often not enough for maintenance of animal health and productivity in India. Cereal-legume intercropping has been recognized as a beneficial crop production system for higher fodder production per unit area per unit time, especially, under rainfed conditions. Sorghum sudan grass hybrid and cowpea are some of the potential fodder crops which can provide good nutrition to livestock with higher forage yields and improve the fertility status of soil when grown in association. This paper reviews all the literature on various aspects of intercropping of cereals and legumes, mainly sorghum and cowpea, for better understanding and future strategies for improved production as well as quality of fodder.

Improving Productivity of Managed Potato Cropping Systems in Eastern Canada: Crop Rotation and Nitrogen Source Effects

Strategies to improve sustainability are important in intensively managed potato (Solanum tuberosum L.) systems. This study has assessed rotation systems and N sources to mitigate potato yield and soil organic matter decline in Prince Edward Island (PEI), Canada. Three‐year potato rotation systems were initiated in 2006: continuous potato (CP); potato–barley (Hordeum vulgare L.) underseeded with red clover (Trifolium pratense L.)–red clover (PBR); and potato–barley–sorghum sudan grass ([Sorghum bicolor L.) used as green manure])/winter rape (Brassica napus subsp. rapifera) (PBSW); and potato–barley–canola ([Brassica napus susbsp. napus] used as green manure)/winter rape (PBCW). Three different N sources (mineral N fertilizer, liquid hog manure, and lobster flake) were applied in a split‐plot fashion during the potato phase. Potatoes were grown in 2006, 2009, 2012, and again in 2013 to evaluate residual effects. In 2012, total N or total C in the whole soil, in particulate organic matter or in the slurry fractions were not affected by N sources or rotation systems. The PBSW and PBCW rotations generated significantly higher potato yields in 2009 and 2013, whereas the CP rotation produced significantly lower potato yields in 2 of 4 yr. The addition of lobster flake suppressed yield compared with other N sources in 3 of 4 yr. The PBR rotation, which is common in PEI can increase nitrate losses over winter. Alternatively, the PBSW and PBCW rotations may represent a good substitute to the PBR rotation as they can increase potato yield while minimizing nitrate losses.

Effect of Nitrogen and Phosphorus Fertilizer on Yield and Nutritional Quality of Jumbo Grass (Sorghum Grass x Sudan Grass)

Effect of Nitrogen and Phosphorus Fertilizer on Yield and Nutritional Quality of Jumbo Grass (Sorghum Grass x Sudan Grass)

Chemical fractionation of Cu, Zn, Cd, Cr, and Pb in sewage sludge amended soils at the end of 65-d sorghum-sudan grass growth

Heavy metals are potentially toxic to human life and the environment. Metal toxicity depends on chemical associations in soil. Understanding the chemical association of trace elements in soils amended with biosolids is very important since it determines their availability within rhizosphere and mobility beyond the rhizosphere. A sequential extraction method was used to determine the various chemical associations [labile (exchangeable + sorbed), organic, carbonates, and sulfides] of Cu, Zn, Cd, Cr, and Pb at the end of sorghum-sudan grass growth (65d) in Candler fine sand (pH = 6.8) and in Ogeechee loamy sand (pH = 5.2) amended with wastewater treatment sludge (WWTS) obtained from two different sources at application rates of 0, 24.7, 49.4, 98.8, and 148.2 Mg ha−1. Results of this study indicated that irrespective of the soil type, Cu, Cd, Cr, and Pb in the labile fractions (exchangeable + sorbed) were in the range of 0–3.0 mg kg−1 and the amount for Zn was in the range of 0.2–6.6 mg kg−1. Therefore, their availability to plants and mobility beyond rhizosphere would be substantially low unless further transformations occur from other fractions. Results also indicated that the presence of substantial amounts of trace elements studied were in sulfide (HNO3) fraction and in organic (NaOH) fraction irrespective of soil type with the exception of Pb which was mainly present as carbonate (Na2EDTA) fraction and the remaining Pb equally as sulfide (HNO3) and organic (NaOH) fractions. Furthermore, results indicated that Cd was mainly present as carbonate (Na2EDTA) fraction. Irrespective of soil type, source and rate of WWTS application, summation of quantities of various fractions of all the trace elements studied through sequential extraction procedure were 1 to 25 % lower than that of total recoverable quantities of these trace elements determined on acid digestion described by US EPA method 3050 B. It was further evident that growing sorghum sudan grass for 65-d following the application of WWTS either depleted labile fractions or shifted the solid phases containing the trace elements in soils away from those extractable with more severe reagents, such as 4M HNO3 to those extractable with milder reagents such as dilute NaOH and Na2EDTA.

Propionibacterium acidipropionici P1691 and glucogenic precursors improve rumen fermentation of low-quality forage in beef cattle2

Cattle grazing dormant western rangelands may have a high ruminal acetate to propionate ratio (A:P) and may have low tissue clearance of acetate. Increasing propionate production could shift this ratio and improve animal performance. In Exp. 1, the effect of Propionibacterium acidipropionici P169 (PA) on forage digestibility and VFA production was evaluated in vitro using 2 substrates: 100% dormant warm-season grass extrusa and 50% sorghum-Sudan hay with 50% ground corn (DM basis). The objective of Exp. 2 was to evaluate the effect of PA or calcium propionate supplementation on digestibility, ruminal fermentation, acetate clearance, and BW change. Twelve 2-yr-old, pregnant Brangus heifers (BW = 416 ± 85 kg) were assigned to 1 of 3 treatments. All cattle were fed a basal ration of Old World Bluestem hay (Bothriochloa ischaemum; 5.8% CP and 76.5% NDF, DM basis) at 1.5% BW from d -10 to d 49. Treatments included a protein supplement (CON; 36% CP and 35% RUP, DM basis; 454 g/animal fed twice daily), CON plus 6 × 10(10) cfu PA/animal (BACT), and CON plus 80 g calcium propionate (PROP). After initiation of treatments (d 0), rumen fluid was collected via oral lavage every 3 d and analyzed for VFA, pH, and ammonia. Glucogenic potential of treatments was evaluated with an acetate tolerance test on d 49. In Exp. 1, PA addition increased (IVDMD; P < 0.001) and total VFA (P < 0.001) of 100% dormant warm-season grass extrusa but not 50% sorghum-Sudan hay with 50% ground corn (P ≥ 0.28). The addition of P169 decreased (P < 0.001) acetate, increased propionate (P < 0.001), and decreased A:P ratio (P < 0.001) for both substrates. In Exp. 2, total tract OM and NDF digestibility and ruminal pH, total VFA, and acetate did not differ (P ≥ 0.13) among treatments. Propionate concentration was least (P = 0.001) for CON, intermediate for P169, and greatest for PROP. Conversely, A:P ratio was greatest (P < 0.004) for CON, intermediate for P169, and least for PROP. Acetate clearance did not differ (P = 0.69) among treatments. Propionibacterium acidipropionici P169 increased IVDMD and total VFA of low-quality forage. Supplementation with PA and calcium propionate salts increased propionate and decreased A:P in the rumen. Supplementation of PA represents a potential way to increase ruminal propionate concentration when dormant forages are fed.