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Evaluation of soil test phosphorus extractants in Idaho soils
Get PDFEvaluation of soil-phosphorus (P) tests is critical to ensure the accuracy of fertilizer recommendations to optimize crop yield while minimizing negative environmental consequences. Olsen-P is the most commonly used soil-P test for alkaline calcareous soils found in Idaho and the Western United States. The Bray-1 test is commonly used in the Pacific Northwest (PNW) on neutral to acidic soils but underestimates P in alkaline calcareous soils. Mehlich-3 has been evaluated throughout various regions in the United States. Little data evaluating the test exists on soils in the Western United States. Additionally, the comparatively newly developed H3A test, a component of the soil health tool, has not been widely evaluated on alkaline calcareous soils. Soil samples from the 0- to 30-cm depth were collected from agricultural fields throughout Idaho and analyzed using Bray-1, H3A, Mehlich-3, and Olsen P extractants. Results suggested that Olsen P was strongly correlated with Mehlich-3, while Bray-1 and H3A were not correlated with Olsen P. Both the Bray-1 and H3A test underestimated extractable P when compared with the Olsen P test, whereas the Mehlich-3 overestimated. A threshold point in calcium carbonate (i.e., inorganic carbon (IC)) of 6.7 and 5.1 mg kg-1 for the Bray-1 and H3A was obtained, respectively, that indicated inorganic carbon concentrations at or above these levels result in underestimation of extractable soil P. Thus, Mehlich-3 was very strongly correlated to Olsen P and could be evaluated for use in alkaline calcareous soils whereas Bray-1 and H3A have notable issues that would limit their applicability
Dairy-CropSyst: Gaseous emissions and nutrient fate modeling tool
Get PDFDairy confined animal feeding operations (CAFO) are required to implement nutrient management plans for minimizing the risk of water resource degradation and report gaseous emissions when exceeding certain threshold values. Although tools exist to aid in completing such tasks, few integrate the impact of on-farm manure treatment unit operations such as anaerobic digestion, solids separation, and nutrient recovery. Furthermore, existing tools do not estimate the nutrient value of recovered products and effluent leaving the dairy system or the nutrient fate after effluent is applied to crop fields. Dairy-CropSyst is a decision support tool for researchers and CAFO managers aimed at evaluating the effects of different manure treatment unit operations on gaseous emission and nutrient fate in dairy systems. The model tracks nutrients through the dairy system, including inorganic and organic forms of carbon, nitrogen, and phosphorus. This is accomplished by integrating established transformation and emission equations, performance parameters of manure treatments from industrial data and literature, and using a cropping system model for the land application evaluation. Predicted and observed emission values for greenhouse gases (GHG) and ammonia from different dairy unit operations were found in good agreement. The use of Dairy-CropSyst has the potential to assist the dairy industry in decision making on manure management treatment strategies and as a tool for reporting GHG and ammonia emissions
Rhizomania and storage rot resistance in USDA-ARS plant introduction lines evaluated in Idaho, 2018
Get PDFRhizomania caused by Beet necrotic yellow vein virus (BNYVV) and storage losses are serious sugar beet production problems. To identify sugar beet germplasm lines with resistance to BNYVV and storage rots, 30 USDA-ARS Beta vulgaris Plant Introduction (PI) Lines and four check cultivars were screened. The lines were grown in a sugar beet field infested with BNYVV during the 2018 growing season in a randomized complete block design with 6 replications. At harvest on 15 October 2018, roots were dug and evaluated for rhizomania symptoms and also placed in an indoor commercial sugar beet storage building. After 119 days in storage, samples were evaluated for the percentage of root surface area covered by fungal growth or rot. Rhizomania symptom development in the field was uniform and other disease problems were not evident in the plot area. The BNYVV susceptible check had 97% foliar symptoms and a high root disease severity rating. The three resistant checks had 0 to 6% foliar symptoms and the lowest root ratings. Based on root ratings, only 2 PI Line entries were not significantly more susceptible than the resistant checks and most lines were not different from the susceptible check. However, entry 3 (Ames 8447) was the only entry that had both a low foliar rating and was also among the lowest for storage rot. The root rating for entry 3 may have been affected by poor inherent root shape and may not necessarily represent a lack of resistance to BNYVV. The foliar rating and resistance to storage rot both suggest entry 3 should be reevaluated for resistance to BNYVV. Entry 3 may serve as a starting point for identifying additional sources of resistance to BNYVV and storage rots
Biochar, manure, and sawdust alter long-term water retention dynamics in degraded soil
Get PDFBiochars are porous but more recalcitrant that non-pyrolyzed organic materials, hence when biochar is added to soil it may cause more persistent alterations to soil water dynamics as compare to other materials. In this 6-yr, outdoor, large-pot study, we amended an irrigated calcareous silt loam with a single, one-time, 1 or 2% dry wt. (22.4, 44.8 Mg ha-1) application of either hardwood biochar, manure, sawdust, or acidified sawdust, a combined 1% biochar+2% manure treatment, and an untreated control. Each year the soils were hand-tilled and planted to a local crop. Soil water retention and plant available water (PAW, g H2O per g dry soil, being that retained between potentials of -10 to -1500kPa) were measured on spring soil samples. Across all years, the combined 1% biochar+2% manure produced the greatest PAW (0.262), with PAW in all treatments following the order of: 1% biochar+2% manure > all 2% rates > all 1% rates > control (0.222). In most years, the 2% treatments increased soil PAW relative to the control, i.e. their PAW ratios exceeded unity. The PAW ratios for 2% rates varied with amendment and year (P<0.0001). PAW ratios for: i) 2% manure peaked in yr 1 and declined to a minimum in yr 3; ii) 2% biochar, 2% sawdust, and 2% acid sawdust were least in yr 1 and peaked between yr 3 and 5; and iii) 1% biochar+2% manure was consistently near a maximum during the study period. Biochar effects on PAW were no more persistent than that of non-pyrolyzed amendments during the 6-yr study. Several factors influenced soil PAW development in addition to the quantity of the added highly porous amendment. Results suggest that water repellent properties and particle size distribution of the added organic material substantially influenced water retention dynamics in amended soils
Foliar insecticides for the control of curly top in Idaho sugar beet, 2018
Get PDFCurly top caused by Beet curly top virus (BCTV) 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. The neonicotionoid seed treatments currently supplement this resistance to provide early season control. In order to identify other management options seven foliar insecticides were screened in 2018 on a commercial sugar beet cultivar approved for production. The plots were arranged in a randomized complete block design with eight replications. A curly top epiphytotic was created by releasing six viruliferous beet leafhoppers per plant at the eight-leaf growth stage on 19 June. Foliar symptoms were evaluated on 24 July and 5 September 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 non-treated check. Based on visual ratings, root yield, and estimated recoverable sucrose, the foliar insecticides provided little or no influence on the control of curly top. However, the yields for all treatments except the insecticide seed treatment check indicate that the cultivar was severely infected during the study. These data show that sugar beet production in areas with curly top would likely suffer considerably without the neonicotinoid seed treatments. One non-check treatment (Truvia) led to a significant reduction in black bean aphid colonies. This treatment will be investigated further as a potential product that can be recommended for aphid control in commercial crops and for home owners as well
Soil carbonate analysis using the solvita compost maturity gel system
Get PDFSoil fertility and nutrient-management programs across Idaho and the western United States need to consider the effective comparison of various extractants for nutrient analysis. Common extractants for primary (potassium; K), secondary (calcium; Ca, magnesium; Mg, sulfur; S) and micro (zinc; Zn, copper; Cu, manganese; Mn, iron; Fe, aluminum; Al, boron; B, sodium; Na,)-nutrients vary (e.g., ammonium acetate, AA, Olsen). The desire to develop relationships among common tests in the region and those of multinutrient extractants used or proposed in other geographical regions has increased due to the interest in soil health measurements (Mehlich-3; M-3 and Haney, Haney, Hossner, Arnold; H3A). To investigate these multinutrient tests, 46 primarily alkaline soils were sampled from the 0 to 30-cm depth in agricultural fields in Idaho.
The majority of nutrients were highly related and relationships were developed. However, for Ca issues were noted for M-3 due to high levels of calcium carbonate in the soil interfering with the test on alkaline soils. Additionally, issues were noted for specific micronutrients when both acidic and alkaline soils were combined in the analysis, but were improved when they were separated. Thus, this research provides specific correlation equations that could be used for comparison among tests as well as provides evidence of the potential suitability of multinutrient extractants in the region
Interaction of rhizoctonia solani and leuconostoc spp. causing sugar beet root rot and tissue pH changes in Idaho
Get PDFRhizoctonia root and crown rot in sugar beet is a serious yield limiting disease problem caused by an interaction between Rhizoctonia solani and Leuconostoc spp. in Idaho. To better understand this synergistic interaction, the two most common Leuconostoc haplotypes were paired with 17 R. solani strains representing the range of genetic diversity established previously in Idaho. The interaction study was conducted by inoculating sugar beet roots in the field using a plug assay in 2017 and repeated in 2018. The study had 54 treatments established by inoculating with the Leuconostoc and R. solani strains individually and in combination and comparing them versus a water check by measuring subsequent root rot and pH changes. The rot data for both years was evaluated together since years did not differ (P <0.0001). With the bacterial and 13 of 17 fungal strains inoculated individually, rot (8 mm or less) was minor enough that it did not differ from the water check (0 mm). In the top 20 ranking treatments with the most rot, there was only one non-combination treatment, R. solani strain F514. When comparing the bacterial strains in combination with the fungal strains, L. mesenteroides strain L12311 (17 mm of rot) had significantly (P < 0.0001) more rot than L. pseudomesenteroides strain L12487 (13 mm). The R. solani anastomosis group (AG), 2-2 IIIB strains (16 mm of rot) led to significantly (P <0.0001 to 0.0073) more rot than strains associated with other AG: 2-2 IV (11 mm), 4 HG-I (5 mm), and 4 HG-II (3 mm). With strains from the three phylogenic groups within AG-2-2 IIIB, rot ranged from 15 to 17 mm and did not differ (P = 0.1275 to 0.5565). The pH for sugar beet root tissue associated with at least 30 mm of rot was lower (4.2 ± 0.45 in 2017 and 4.0 ± 0.25 in 2018) than tissue with < 2 mm of rot (6.2 ± 0.17 in 2017 and 6.4 ± 0.14 in 2018). Both the isolations and pH changes suggest Leuconostoc spp. along with bacterial and yeast contaminants dominate in rotted root tissue but without R. solani AG-2-2 IIIB strains being present when rot initiates, Leuconostoc strains caused very little damage
Comparison of soil-test extractants for potassium, calcium, magnesium, sulfur, and micronutrients in Idaho soils
Get PDFSoil fertility and nutrient-management programs across Idaho and the western United States need to consider the effective comparison of various extractants for nutrient analysis. Common extractants for primary (potassium; K), secondary (calcium; Ca, magnesium; Mg, sulfur; S) and micro (zinc; Zn, copper; Cu, manganese; Mn, iron; Fe, aluminum; Al, boron; B, sodium; Na,)-nutrients vary (e.g., ammonium acetate, AA, Olsen). The desire to develop relationships among common tests in the region and those of multinutrient extractants used or proposed in other geographical regions has increased due to the interest in soil health measurements (Mehlich-3; M-3 and Haney, Haney, Hossner, Arnold; H3A). To investigate these multinutrient tests, 46 primarily alkaline soils were sampled from the 0 to 30-cm depth in agricultural fields in Idaho. The majority of nutrients were highly related and relationships were developed. However, for Ca issues were noted for M-3 due to high levels of calcium carbonate in the soil interfering with the test on alkaline soils. Additionally, issues were noted for specific micronutrients when both acidic and alkaline soils were combined in the analysis, but were improved when they were separated. Thus, this research provides specific correlation equations that could be used for comparison among tests as well as provides evidence of the potential suitability of multinutrient extractants in the region
Experimental sugar beet cultivars evaluated for rhizomania resistance and storability in Idaho, 2017
Get PDFRhizomania caused by Beet necrotic yellow vein virus (BNYVV) and storage losses are serious sugar beet production problems. To identify sugar beet cultivars with resistance to BNYVV and evaluate storability, 7 experimental cultivars were screened by growing them in a sugar beet field infested with BNYVV in Kimberly, ID during the 2017 growing season in a randomized complete block design with 6 replications. At harvest on 2-3 October 2017, roots were dug and evaluated for symptoms of rhizomania and also placed in an indoor commercial sugar beet storage building. After 147 days in storage, samples were evaluated for surface rot, weight loss, and sucrose loss. Surface root rot ranged from 16 to 85%, weight loss ranged from 17 to 28%, sucrose losses ranged from 25 to 87%, and estimated recoverable sucrose ranged from 596 to 8,518 lb/A. Given these response ranges, selecting cultivars for rhizomania resistance and combining this resistance with storability will lead to considerable economic benefit for the sugar beet industry
Mechanisms responsible for soil phosphorus availability differences between sprinkler and furrow irrigation
Get PDFFrom a historical perspective, human-induced soil erosion and resulting soil phosphorus (P) losses have likely occurred for thousands of years. In modern times, erosion risk and off-site P transport can be decreased if producers convert from furrow to sprinkler irrigation, but conversion may alter nutrient dynamics. Our study goal was to determine soil P dynamics in furrow- (in place since the early 1900s) versus sprinkler-irrigated (installed within the last decade) soils from four paired producer fields in Idaho. Furrow- and sprinkler-irrigated soils (0–5 cm; Aridisols) contained on average 38 and 20 mg/kg of Olsen-extractable P (i.e., plant-available P), respectively; extractable P values over 40 mg/kg limit Idaho producers to P application based on crop uptake only. Soil samples were also analyzed using a modified Hedley extraction. Furrow-irrigated soils contained greater inorganic P concentrations in the soluble+aluminum (Al)-bound+iron (Fe)-bound, occluded, and amorphous Fe bound pools. Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy was unable to detect Feassociated P but indicated greater amounts of apatite-like or octacalcium phosphate-like P in furrow-irrigated producer soils, while sprinkler-irrigated fields had lower amounts of apatite-like P and greater proportions of P bound to calcite. Findings from a controlled USDA-ARS sprinkler- versus furrow-irrigation study suggested that changes in P dynamics occur slowly over time, as few differences were observed. Overall findings suggest that Fe redox chemistry or changes in calcium (Ca)-associated P in flooded conditions altered P availability under furrow irrigation, even in aridic, calcareous soils, contributing to greater Olsen extractable P concentrations in long-term furrow-irrigated fields