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Effect of deficit irrigation timing on sugarbeet
Get PDFIncreased water demands and drought have resulted in a need
to determine the impact of deficit water management in irrigated sugarbeet (Beta vulgaris L.) production. This study was conducted over 3 yr at USDA-ARS in Kimberly, ID, on a Portneuf silt loam soil. Eight irrigation treatments consisted of crop evapotranspiration (ETc) rates combined with application timing. Treatments were: W1 Even: approximately (≈) 100% ETc evenly throughout the growing season; W2 Even: ≈65% crop evapotranspiration; W2 Early: ≈100% ETc early in season, ≈55% ETc the remainder of the season; W2 Late: rain-fed from emergence to end of July, ≈100% ETc the remainder of the season; W3 Even: ≈40% ETc; W3 Early: ≈100% ETc early in season, ≈25% the remainder of the season; W3 Late: rain-fed through mid-August, ≈100% ETc the remainder of the season, and rain-fed: no post emergence irrigation. Results showed that within deficit irrigation treatments, higher yields were obtained when water was applied evenly throughout the season (Even) or ≈100% of ETc was applied early with deficit irrigation later in the season (Early). Thus, the W2 Even and W2 Early treatments had 31.6, 32.9, and 28.2% greater estimated recoverable sucrose (ERS) yields compared to the W2 Late treatment in 2011, 2012, and 2016, respectively. Across all years, ERS yields increased at rates ranging from 17.3 to 22.0 kg ha–1 mm–1 actual crop water evapotranspiration (ETa). Generally, sugarbeet with greater water stress early in the season followed by ≈100% ETc later had lower yields and sucrose content (late treatments)
Greenhouse gas emissions from an irrigated dairy forage rotation as influenced by fertilizer and manure applications
Get PDFInformation is needed regarding the effect of nitrogen source on greenhouse gas (GHG) emissions from irrigated semiarid agricultural soils. We report nitrous oxide, carbon dioxide, and methane emissions from a silage corn (Zea mays L.) (2013)–barley (Hordeum vulgare L.) (2014)–alfalfa (Medicago sativa L.) (2015) rotation under conventional tillage and sprinkler irrigation. We evaluated the effectiveness of an enhanced-efficiency fertilizer (SuperU, a stabilized granular urea with urease and nitrification inhibitors) to reduce nitrous oxide emissions compared with granular urea and to determine GHG emissions from fall-applied dairy manure or composted dairy manure and spring-applied dairy manure. Nitrogen was applied during the first 2 yr of the study. SuperU plots emitted 53% less nitrous oxide than urea with corn, whereas no emission reductions occurred in 2014 with barley. The nitrous oxide -N emission losses as a percentage of total nitrogen applied were 0.21 and 0.04% for urea and SuperU in 2013, respectively, with losses of 0.05% from both urea fertilizers in 2014. On average, nitrous oxide fluxes from fall and spring manure were statistically similar and greater than the other nitrogen treatments in 2014 and a lasting manure treatment effect on emissions occurred under alfalfa. Carbon dioxide fluxes were greatest from fall- and spring-applied manure during the first 2 yr. Methane fluxes were negative, indicating microbial oxidation, and no differences occurred among the treatments. Corn, barley, and alfalfa yields were similar among all nitrogen treatments. This work demonstrates that SuperU can reduce nitrous oxide emissions from irrigated cropping systems in the semiarid western United States without affecting yields
Methane emissions from dairy lagoons in western U.S.
Get PDFMethane (CH4) generation from dairy liquid storage systems is a major source of agricultural greenhouse gas emissions. However, there has been little on-farm research conducted to estimate these emissions and determine the factors that may affect these emissions. Six lagoons in south-central Idaho were monitored for one year, with CH4 emissions estimated by inverse dispersion modelling. Lagoon characteristics thought to contribute to CH4 emissions were also monitored over this time period. Average emissions from the lagoons ranged from 30 to 126 kg/ha/d or 22 to 517 kg/d. While there was a general trend for greater emissions during the summer, when temperatures were greater, events such as pumping, rainfall, freeze/thaw of lagoon surfaces, and wind events significantly increased CH4 emissions irrespective of temperature. Lagoon physicochemical characteristics such as total solids, chemical oxygen demand, and volatile solids were highly correlated with emission. Methane prediction models were developed using volatile solids, wind speed, air temperature and pH as independent variables. The USEPA methodology for estimating CH4 emissions from manure storage was used for comparison of on-farm CH4 emissions from one of the lagoon systems. The USEPA method underestimated CH4 emissions by 48%. An alternative methodology, using volatile solids degradation factor, provided a more accurate estimate of annual emissions from the lagoon system and may hold promise for applicability across a range of dairy lagoon systems in the U.S
Irrigation Management
Get PDFCompetition for limited water supplies continues to restrict water available for irrigation. Irrigated agricultural must continually improve irrigation management to continue producing food, fiber and fuel for a growing world population. Precision irrigation is the process of applying the right amount of water at the right time and place to obtain the best use of available water. Precision irrigation management is needed on large irrigation projects so water delivery matches irrigation needs and on individual fields to apply the right amount of water at the right time and place. Technology is commercially available to precisely apply water when and where it is needed by crops, however, user-friendly decision tools are still needed to quantify specific irrigation needs and control water application within fields. Integrating information from various sensors and systems into a decision support program will be critical to highly managed, spatially varied irrigation
Beet curly top virus strains associated with sugar beet in Idaho, Oregon, and a Western U.S. collection
Get PDFCurly top of sugar beet is a serious, yield limiting disease in semi-arid production areas caused by Beet curly top virus (BCTV) and transmitted by the beet leafhopper. One of the primary means of control for BCTV in sugar beet is host resistance but effectiveness of resistance can vary among BCTV strains. Strain prevalence among BCTV populations was last investigated in Idaho and Oregon during a 2006-2007 survey, but changes in disease severity suggested a need for reevaluation. Therefore, 406 leaf samples symptomatic for curly top were collected from sugar beet plants in commercial sugar beet fields in Idaho and Oregon from 2012 to 2015. DNA was isolated and BCTV strain composition was investigated based on polymerase chain reaction (PCR) assays with strain specific primers for the Severe (Svr) and California/Logan (CA/Logan) strains and primers that amplified a group of Worland (Wor)-like strains. The 2006-2007 ID/OR BCTV positive sugar beet samples (59% had mixed infections) included: 87% Svr, 7% CA/Logan, and 60% Wor-like. The BCTV strain distribution in the new survey (16% had mixed infections) averaged 2% Svr, 30% CA/Logan, and 87% Wor-like. Whole genome sequencing (GenBank accessions KT276895 to KT276920 and KX867015 to KX867057) with overlapping primers, found that the Wor-like strains included Wor, Colorado (CO), and a previously undescribed strain designated Kimberly1 (Kim1). Results confirm a shift from Svr being one of the dominant BCTV strains in commercial sugar beet fields in 2006-2007 to becoming undetectable at times during recent years
Beet curly top resistance in USDA-ARS Ft. Collins germplasm, 2016
Get PDFFifty-one sugar beet (Beta vulgaris L.) germplasm lines produced by the USDA-ARS Ft. Collins sugar beet program and three commercial check cultivars [SV2012RR (susceptible) and HM PM90 and Beta G6040 (resistant)] were screened for resistance to Beet curly top virus (BCTV). The curly top evaluation was conducted at the USDA-ARS North Farm in Kimberly, ID which has Portneuf silt loam soil and had been in barley in 2015. The field was plowed in the fall and in the spring, it was fertilized (90 lb N and 110 lb P2O5/A) and roller harrowed on April 4. The germplasm was planted (density of 142,560 seeds/A) on May 16. The plots were two rows 10 ft long with 22-in row spacing and arranged in a randomized complete block design with four replications. The field was sprinkler irrigated, cultivated, and hand weeded as necessary. Plant populations were thinned to about 47,500 plants/A on June 16. Plants were inoculated at the four- to six-leaf growth stage on June 20th with approximately six viruliferous (contained at least the following BCTV strains: Cal/Logan, CO, Severe, and Worland) beet leafhoppers per plant. The beet leafhoppers were redistributed three times a day during the first two days and then twice a day for five more days by dragging a tarp through the field. The plants were sprayed on June 30th with Lorsban 4E (1.5 pints/A) to kill the beet leafhoppers. Plots were rated for foliar symptom development on July 13th using a scale of 0 to 9 (0 = healthy and 9 = dead), with the scale treated as a continuous variable (Plant Dis. 90:1539-1544). Data were analyzed in SAS using the general linear models procedure (Proc GLM), and Fisher’s protected least significant difference (LSD; a = 0.05) was used for mean comparisons. Curly top symptom development was uniform and no other disease problems were evident in the plot area. The resistant and susceptible checks performed as expected for the visual ratings. Based on the visual rating, seven entries (1, 14, 15, 32, 40, 44, and 51) were not significantly different from the resistant check. These germplasm will be retested and, if resistance is confirmed, they may be incorporated into the USDA-ARS germplasm improvement program as sources of resistance to BCTV. These results and germplasm will be accessible to interested parties through the USDA-ARS, NPGS GRIN database (http://www.ars-grin.gov/npgs/index.html)
Effects of tillage and irrigation management on sugarbeet production
Get PDFIncreased water demands and drought have resulted in a need to determine the impact of tillage and deficit water management practices in irrigated sugarbeet (Beta vulgaris L.) production. This study was conducted over three growing seasons (2012, 2013, and 2015) at the USDA-Agricultural Research Service, Northwest Irrigation and Soils Research Laboratory in Kimberly, ID on a Portneuf silt loam soil. Treatments consisted of two tillage treatments (strip tillage [ST] and conventional tillage [CT]) and four water input treatments (approximately 100, 75, 50 and 25 percent of estimated crop ET [ETd]) using a linear move irrigation system. Estimated recoverable sucrose (ERS) yield, root yield, sucrose concentration and brei nitrate concentration were statistically the same for ST and CT across all water input levels. However, there was a significant tillage by water interaction for root yield in 2012. The significant interaction was a result of ST at the W3 (approx. 57 percent ETd) water input level having a higher root yield (72 Mg/ha) compared to the CT treatment (63 Mg/ha). Water input had significant effects on ERS and root yields. In general, as water input increased, ERS and root yields increased. Estimated recoverable sucrose and root yields in 2012, 2013, and 2015 were maximized at the ETd rates of 75, 97 and 58 percent, respectively. Data from this study supports the use of ST in sugarbeet production at various water input rates ranging from full irrigation to deficit irrigation. This support is based on equal yield potential with CT, tillage cost savings compared to CT, and agronomic and environmental benefits associated with increased soil surface residue
Spatial and temporal variation in physicochemical properties of dairy lagoons in south-central Idaho
Get PDFThere are large quantities of wastewater generated on dairies in south-central Idaho, which can be a source of valuable nutrients as well contribute to air quality and climate change issues via ammonia (NH3) and greenhouse gas (GHG) emissions. The objective of this study was to examine the range of lagoon water properties among dairies in the region and to determine how they varied spatially and temporally. Twenty-seven lagoons were sampled twice in a blind trial to determine physicochemical characteristics, while 6 lagoons were sampled (3 to 27 times) over a longer period of time to determine how these characteristics changed with time and space. Lagoon properties measured consisted of total solids (TS), volatile solids (VS), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), total ammoniacal nitrogen (TAN), total phosphorus (P), total potassium (K), temperature, pH, dissolved oxygen (DO), and specific conductivity. Results indicate that all lagoon characteristics varied greatly between dairies and with sampling date. Seasonal trends indicated that N decreased from spring to fall, while specific conductivity, total P, total K, and in some instances TS and VS increased over the same time period. There was an effect of housing on these properties with freestall dairies having higher concentrations of TS, VS, COD, TKN, TAN, and specific conductivity than dry-lot dairies. There was little effect of dairy size on physicochemical characteristics measured. These results suggest that it is important to account for nutrients applied with lagoon waters in nutrient budgets in order to prevent over-application of N and K which could lead to N leaching and forage quality issues. In addition, capturing the temporal variation in lagoon properties is important to accurately model seasonal variations in NH3 and GHG emissions
Soil quality improvement through conversion to sprinkler irrigation
Get PDFConversion from furrow to sprinkler irrigation is a recommended conservation practice for improved water use efficiency (and/or erosion control), but effects on soil quality indicators were unknown. Several soil quality indicators were therefore quantified within a northwestern U.S. Conservation Effects Assessment Project (CEAP) watershed after changing from long-term furrow to sprinkler irrigation. Four on-farm sites were identified where producers were growing irrigated barley (Hordecum vulgare L.) using both irrigation practices. Climate, soil type, and management were similar between sites. Soil samples were collected from the upper and lower ends of furrow irrigated fields at three in-field positions (bed, shoulder, and furrow); fields converted to sprinkler irrigation were sampled where the upper and lower ends were when the field was furrow irrigated. Soil quality indices (physical, chemical, biological, nutrient, and overall) were computed using the Soil Management Assessment Framework (SMAF). Regardless of in-field position, furrow irrigated field bottoms had higher soil quality index scores than field tops due to long-term erosional deposition. Within sprinkler irrigated fields, soil quality indices for field tops and bottoms showed minimal differences. Overall, when all sampling locations and in-field positions were combined, soil quality was similar for both irrigation methods. However, as compared to furrow irrigation, sprinkler irrigation had greater soil quality indices in the field tops, suggesting that sprinkler irrigation improved soil quality of historically eroded furrow irrigated fields
Beet curly top resistance in USDA-ARS Kimberly sugar beet germplasm lines, 2016
Get PDFCurly top caused by Beet curly top virus is a widespread disease problem vectored by the beet leafhopper in semiarid sugar beet production areas. Host resistance is the primary defense against this problem, but resistance in commercial cultivars is only low to intermediate. In order to identify novel sources of curly top resistance, 11 sugar beet lines were screened in a disease nursery in 2016. The lines were arranged in a randomized complete block design with six replications. A curly top epiphytotic was created by releasing six viruliferous beet leafhoppers per plant at the four- to six-leaf growth stage on 20 Jun. Foliar symptoms were evaluated on 20 Jul using a scale of 0-9 (0 = healthy and 9 = dead) in a continuous manner. Curly top symptom development was uniform and no other disease problems were evident in the plot area. The disease pressure in the test was moderately severe with good symptom development in the susceptible check. Based on the overall visual rating, KDH13 and KDH4-9 performed the same as the resistant check. Additionally, ELISA data also indicated that these two lines had significantly lower or similar virus titer as the resistant check. These germplasm lines will be released to the general public, so they can be utilized to improve resistance in commercial sugar beet cultivars