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Mg and K effects on cation uptake and dry matter accumulation in tall fescue (Festuca arundinacea)
Get PDFHiMag tall fescue (Lolium arundinaceum (Schreb.) S.J. Darbyshire = Festuca arundinacea Schreb) was selected for high Mg concentration in the herbage to reduce grass tetany risk to ruminants; however, the mechanism of increased Mg uptake into shoots is unknown. The objective was to determine cation concentrations of roots, crowns, and leaves in plants of cv. HiMag and its parents, cv. Kentucky 31 and cv. Missouri 96, grown in nutrient solution for 42 days, and determine if cation ratios in roots, crowns, and leaves are different, indicating a difference due to translocation. Treatments were “basal” (1.5 mM K and 0.5 mM Mg), “K” (3.2 mM K), “Mg” (1 mM Mg), and “K + Mg” (3.2 mM K and 1 mM Mg). For HiMag, Mg was lower in roots (Trial 2 only), not different in crowns, and greater in leaves than Kentucky 31 and Missouri 96. Doubling the K and Mg of the nutrient solution from basal levels resulted in a 44% reduction of root Mg in Kentucky 31 and Missouri 96, compared to a 17% reduction in root Mg for HiMag. The K inflow rate in HiMag for the basal treatment was lower than that in Kentucky 31 and Missouri 96. These results provide evidence for a process that limits K uptake and an active Mg translocation mechanism in tall fescue. HiMag was apparently selected for traits that promote translocation of Mg from roots to shoots
Influence of rhizomania on sugarbeet storability
Get PDFRhizomania caused by Beet necrotic yellow vein virus (BNYVV) and storage losses are serious sugar beet production problems. To investigate the influence of BNYVV on storability, six sugar beet cultivars varying for resistance to BNYVV were grown in 2005 and 2006 in southern Idaho fields with and without BNYVV infested soil. At harvest, samples from each cultivar were placed in an outdoor pile as a randomized complete block design with 4 reps in Twin Falls, ID and were removed on 40-day intervals starting the end of October. After 144 and 142 days in storage, sugar reduction across cultivars averaged 20 and 13% without and 68 and 21% with BNYVV for the 2005 and 2006 roots, respectively. In the December samplings, frozen root area was 1 and 2% without and 25 and 41% with BNYVV for the 2005 and 2006 roots, respectively. Root rot was always worse with stored roots from BYNVV infested soil in December, January, and February samplings. In another series of studies an indoor storage facility was utilized to generate a more uniform environment. Research in this environment suggested this approach may lead to a more reliable cultivar screen for storability than work conducted outdoors. Cultivars that performed well in these assays possessed both resistance to rhizomania and good storability
Fecal phosphorus excretion and characterization from swine fed diets containing a variety of cereal grains
Get PDFTwenty crossbred barrows weighing 35.8±3.1 kg, were fed 1 of 5 diets (N = 4) to determine the effects
of different cereal grains on fecal P excretion and composition. The diets contained 97.15% corn, wheat, high
fat-low lignin oat, normal barley or low phytate barley with the cereal grain supplying the sole source of dietary
phosphorus. The diets were fed for a 7 day acclimation period followed by a three-day fecal collection. Total
tract digestibility coefficients were determined for dry matter, phosphorus and phytate using the indicator
method. Fecal phosphorus was characterized using solution state Phosphorus Nuclear Magnetic Resonance
spectroscopy (31P-NMR). Water Soluble Phosphorus (WSP) and the ratio of WSP to total phosphorus
(WSP:TP) were determined in the feces. Digestibility coefficients for phosphorus and phytate ranged from
0.11 (corn) to 0.46 (wheat) and 0.94 (oat) to 1.00 (corn and low-phytate barley), respectively. There was very little
phytate phosphorus excreted in the feces regardless of the type of cereal grain fed (< 6% of total phosphorus)
and phytate degradation was not related to the level of endogenous phytase in the diet. There was a negative
relationship between the fecal WSP:TP ratio and the concentration of phosphate monoesters in the feces. In
summary, our results indicate that the majority of the phosphorus in the feces of pigs fed cereal grains is
present in the form of inorganic phosphate and only trace amounts of phytate are excreted intact. The amount
of phytate in the excreta was not related to the amount of phytate or endogenous phytase in the grain. Further
research should be conducted with diets more typical of those used in commercial swine production to confirm
these findings, as the high inorganic phosphate content and WSP:TP ratio in manure from swine could increase
the potential for off-site phosphorus losses when swine feces are applied on agricultural lands
Application of anaerobically digested biosolids to dryland winter wheat: 2006-2007 results
Get PDFThe application of biosolids to lands in EPA Region 8 (includes Colorado) is the major
method of biosolids disposal, with 85% of the material being reused (USEPA, 2003). This
disposal method can greatly benefit municipalities and farmers by recycling plant nutrients in an
environmentally sound manner (Barbarick et al., 1992).
Our long-term biosolids project, now in its twenty-sixth year, has provided valuable
information on the effects of continuous biosolids applications to dryland winter wheat.
Previous research has shown that Littleton/Englewood biosolids is an effective alternative to
commercial nitrogen (N) fertilizer with respect to grain production and nutrient content of
winter wheat (Barbarick et al., 1992). However, as with other N fertilizers, application rates of
biosolids exceeding the N needs of the crop result in an accumulation of soil nitrate-nitrogen.
Excess soil nitrate-nitrogen may move below the root zone or off-site and contaminate
groundwater or surface waters. The potential benefit of biosolids is that they contain organic N,
which can act like a slow-release N source and provide a more constant supply of N during the
critical grain-filling period versus commercial N fertilizer
Phytate utilization and phosphorus excretion by broiler chickens fed diets containing cereal grains varying in phytate and phytase content
Get PDFEighty, 12-day-old, male broiler chicks, were fed one of four diets to determine the effects of
feeding grains varying in phytate phosphorus (P) and intrinsic phytase activity on ileal and excreta
P digestibility and composition. The diets contained approximately 970.7 g grain kg−1 (maize, high
fat–low lignin oat, normal barley or low-phytate barley) with the cereal supplying the sole source of
dietary P. The diets were fed for a 7-day acclimation period followed by a 2 day excreta collection
while ileal digesta was collected at slaughter on day 21. The coefficients of ileal apparent digestibility
(CIAD) for P and phytate P ranged from 0.79 (normal barley) to 0.86 (maize and low-phytate barley)
and 0.76 (low-phytate barley) to 0.89 (maize), respectively. The CIAD for phytate P was significantly
greater in the maize and high fat–low lignin oat diets, while the low-phytate barley diet had the lowest
coefficient (P>0.002). The coefficients of total tract apparent digestibility (CTTAD) for P and phytate
P ranged from 0.25 (maize) to 0.35 (low-phytate barley) and 0.90 (maize and low-phytate barley) to
0.96 (high fat–low lignin oat), respectively, with no significant differences between diets. There was
very little phytate P in excreta regardless of the type of grain fed (<0.13 of total P) with no significant
differences between diets. Phytate P degradation was not related to the level of intrinsic phytase in
the diet. In summary, current results indicate that, regardless of the type of grain fed, dietary phytate
P is highly digestible when large amounts of calcium and P are not added into poultry diets and little
phytate P is excreted
Phosphorus utilization and characterization of ileal digesta and excreta from broiler chickens fed diets varying in cereal grain, phosphorus level, and phytase addition
Get PDFBoth intrinsic and exogenous phytase
in poultry feeds can alter phytate utilization and the
solubility of P excreted. This experiment determined
the effects of feeding diets varying in cereal grain, P
concentration and phytase addition on phytate and P
utilization and P characterization of ileal digesta and
excreta. Twelve treatments, consisting of diets based
on corn, wheat, barley, or high fat-low lignin oat and 3
P treatments (low P with 0.30% nonphytate P; low P
+ 1,000 phytase units of phytase; high P with 0.45%
nonphytate P), were fed to 300 broilers using a factorial
design. Fresh excreta were collected at 20 and 21 d
and ileal digesta was collected at 21 d. Ileal digesta and
excreta were analyzed for total P, phytate P and Ca,
with P composition determined by solution 31P nuclear
magnetic resonance spectroscopy. Excreta samples were
also analyzed for water soluble P (WSP). Apparent ileal
digestibility coefficients for phytate P and total P
ranged from 0.03 to 0.42 and 0.56 to 0.71, respectively.
Diets supplemented with phytase had greater phytate P
hydrolysis than unsupplemented diets. Apparent total
tract digestibility coefficients for phytate P and total P
ranged from 0.10 to 0.73 and 0.43 to 0.61, respectively.
Across cereal grains, there was almost a 3-fold increase
in total tract phytate P hydrolysis with phytase supplementation.
The P composition of ileal digesta was predominantly
phytate P (70 to 88% of total P), whereas
excreta phytate P ranged from 26 to 76% of total P.
Excreta WSP ranged from 3.2 to 7.5 g kg−1 and was
least for the barley diets. There was a 25% reduction in
excreta WSP from the high P to the low P + phytase
diets and a 37% reduction from the high P to the low
P diets. As cereal grain had little influence on phytate
digestibility, it is unlikely that intrinsic phytase in grain
has much influence on phytate utilization by poultry.
Both total P and WSP in excreta were reduced by the
low P diet and the low P + phytase diet, irrespective
of cereal grain, which reduces the risk of P transfer to
water bodies when excreta are applied to land as fertilizer
BIOSOLIDS USE FOR RECLAIMING FLUVIAL MINE TAILINGS
Get PDFThis study was conducted to determine the effect of biosolids and lime on reclamation of a heavily contaminated metal site. Within the Superfund area near Leadville, CO, biosolids and lime were amended (1998) to a 1 ha site at rates of 240 Mg per ha each. In 2006, soil samples were collected on a 10 m x 10 m grid to a depth of 30 cm across the site. Basic soil analysis included pH, EC, total C and N, inorganic and organic C, and NO3-N and NH4-N. A sequential fractionation for metal contaminants of concern (Cd, Cr, Fe, Pb, Mn, and Zn) identified associations with: 1) soluble/exchangeable; 2) specifically sorbed/weakly bound; 3) non-crystalline Fe/Mn oxides; 4) crystalline Fe/Mn oxides and organically complexed; 5) residual organic; and 6) residual inorganic phases. Sequential extraction data was cross correlated with basic soil analysis. Basic soil analysis were affected by both lime and biosolids applications. Cadmium was found primarily in mobile phases, Cu, Fe, Pb, and Mn in more resistant phases, and Zn distributed equally among all soil fractions. Metals were negatively correlated with basic soil analysis. The greatest mobile-phase metal concentrations were observed at the site’s south end. This may have been due to a lack of uniformly applied or incorporated biosolids, or not enough lime applied to raise soil pH and complex metals in more immobile phases. If mobile phases were present over the entire site prior to reclamation, then a positive phase shift has occurred towards more immobile metal phases following reclamation
Nitrogen placement, row spacing, and water management for furrow-irrigated field corn
Get PDFBanding and sidedressing nitrogen (N) fertilizer on a never-irrigated side of a row of corn
(Zea mays L.) were hypothesized to maintain yield and decrease nitrate leaching. In a two—year
field study on a Portneuf silt loam (Durinodic Xeric Haplocalcid) in southern Idaho, we
evaluated effects on yield and N uptake of 1) urea placement (broadcast pre-plant vs. band at
planting), 2) row spacings (30-in vs. an offset 22—in spacing in which every pair of 22-—in rows
was positioned close to a furrow rather than each row on a bed center), and 3) water
management. Our water management, termed irrigated furrow positioning, consisted of every-
second furrow irrigation in which we applied water to either a) the same or b) the Opposite side
of the row with successive irrigations, the latter called alternating furrow irrigation. At season’s
end, we harvested 20 ft of row at three locations in each plot for silage and at three other
locations for grain. Grain yield was not affected by the positioning of the irrigated furrow.
However, averaged across years, grain yield from 22-in rows was 113 bu acre-1 from banded
plots, 5% greater (P<0.05) than broadcast plots. Two-year average grain yield from 30-in rows
was 107 bu acre-1, with no difference between banding and broadcasting. In the second year, N
uptake in grain averaged across row spacings was 72.3 lb acre-l from banded plots and 65.5 lb
acre-l from broadcast plots (P<0.01). Silage yield increased up to 26% and N uptake in silage
increased up to 21% from banding, compared to broadcasting, where we irrigated the same
furrow in the study’s second year. In both years, grain and silage yield and N uptake in grain
and silage were similar or greater where urea was banded on one side of a row rather than
broadcast
Physical, chemical and microbiological properties of an Andisol as related to land use and tillage practice
Get PDFThe effects of land use and management practice on soil physical, chemical and microbiological properties may provide essential information for assessing sustainability and environmental impact. This study compared the effects of 41 years of no-tillage (NT) with continuous apple orchard, with those of conventional tillage (CT) with wheat–soybean rotation and another of puddling (PD) with continuous rice on the characteristics of a pumice Andisol in a temperate region of northern Japan. Higher values for bulk density, penetration resistance, pH, C/N ratio, exchangeable Na (X-Na), Fe, and Mn were observed for PD than NT and CT. On the other hand, organic matter, EC, N, exchangeable K (X-K), exchangeable Ca (X-Ca) and Cu were significantly higher for NT than CT and PD. Highest content of Zn was found in CT compared to other practices. The three-phase composition at pF 2.0 was significantly affected by land use and tillage practices. The solid phase and liquid phase were greater under PD than under NT and CT, while air phase was greater under CT than under NT and PD. Significantly higher values for saturated hydraulic conductivity was found in CT than NT and PD. Total phospholipid fatty acid (PLFA) and PLFA for bacteria, aerobes and cyanobacteria were remarkably higher in NT than CT and PD, regardless of depth. On the other hand, PLFA for methane-oxidizing bacteria, sulfate-reducing bacteria and mycorrhizae were significantly higher in CT than NT and PD. PLFA for fungi was significantly higher in surface (0–10 cm) soils than subsurface (10–20 cm) soils regardless of treatments. Highest bacterial and fungal diversity evaluated by DNA band number in DGGE analysis based on PCR amplification of 16S rDNA and 18S rDNA fragments, respectively, were observed in surface soil of PD. The result suggests a linkage between microbial community and tillage practices in temperate Andisol. This study also justifies the need of measuring soil characteristics based on soil microbial communities
Curly top survey in the Western United States
Get PDFCurly top in sugar beet continues to be a challenging disease to control
in the western United States. To aid in development of host resistance and
management options, the curtovirus species composition was investigated
by sampling 246 commercial fields along with nursery and field trials in
the western United States. DNA was isolated from leaf samples and the
species were identified using species-specific polymerase chain reaction
primers for the C1 gene. Amplicons from 79 isolates were also sequenced
to confirm identifications. Beet severe curly top virus (BSCTV) and Beet
mild curly top virus (BMCTV) were widely distributed throughout the
western United States, while only a few isolates of Beet curly top virus
(BCTV) were found. In phylogenetic analysis, BSCTV, BMCTV, and
BCTV isolates formed distinct groups in the dendrogram. Seven isolates
not amplifiable with species-specific primers did amplify with curly top
coat protein primers, indicating novel curtovirus species or strains may be
present. Given the wide host range of the viruses responsible for curly
top, frequent co-infections, and genetic diversity within and among
species, establishing better host resistance, and controlling curly top will
continue to be a challenge