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| Registros recuperados: 92 | |
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| Lentz, R.D.; Ippolito, J.A.; Spokas, K.A.. |
| Aluminum-based water treatment residuals (Al-WTR) have a strong affinity to sorb phosphorus. In a proof-of-concept greenhouse column study, Al-WTR was surface-applied at 0, 62, 124, and 248 Mg/ha to 15 cm of soil on top of 46 cm of sand; Al-WTR rates were estimated to capture 0, 10, 20, and 40 years of phosphorus from an urban watershed entering an engineered wetland in Boise, Idaho, USA. Creeping red fescue (Festuca rubra) was established in all columns; one set of columns received no Al-WTR or plants. After plant establishment, once per week over a 12-week period, ~1.0 pore volumes of ~0.20 mg phosphorus/L was added to each column. Infiltration rates were measured, leachate was collected and analyzed for soluble phosphorus, and fescue yield,... |
| Tipo: Article |
Palavras-chave: Chemistry; Soil quality. |
| Ano: 2015 |
URL: http://eprints.nwisrl.ars.usda.gov/1592/1/1550.pdf |
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| Lentz, R.D.. |
| High water infiltration rates in unlined canals, reservoirs, and the inflow end of furrows relative to outflow ends result in excessive seepage losses and reduced furrow irrigation application uniformity. This study evaluated the use of cross-linked, anionic, polyacrylamide hydrogel (XPAM), a water-absorbing, swellable polymer solid, for reducing infiltration and seepage losses though soil. Experiments 1 and 2 measured the influence of soil treatments on seepage rate in soil columns under constant-head conditions: Exp. 1 treated five soils with 0, 2.5, 5, and 10 g kg -1 XPAM; Exp. 2 applied combined XPAM (0-5 g kg-1) and NaC1 (0-5.1 g kg-1) treatments to a silt loam soil, and separately tested the effect ofXPAM granule size and treated soil layer... |
| Tipo: Article |
Palavras-chave: Polyacrylamide; Cross-linked (hydrogel) PAM; Mass Import - autoclassified (may be erroneous). |
| Ano: 2007 |
URL: http://eprints.nwisrl.ars.usda.gov/62/1/1226.pdf |
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| Sojka, R.E.; Lentz, R.D.; Shainberg, I.; Trout, T.J.; Ross, C.W.; Robbins, C.W.; Entry, J.A.; Aase, J.K.; Bjorneberg, D.L.; Orts, W.J.; Westermann, D.T.; Morishita, D.W.; Watwood, M.E.; Spofford, T.L.; Barvenik, F.W.. |
| Tipo: Conference or Workshop Item |
Palavras-chave: Water-soluble PAM (WSPAM); Mass Import - autoclassified (may be erroneous). |
| Ano: 2000 |
URL: http://eprints.nwisrl.ars.usda.gov/943/1/1022.pdf |
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| Lentz, R.D.; Lehrsch, G.A.. |
| The use of solid dairy manure for sugarbeet production is problematic because beet yield and quality are sensitive to deficiencies or excesses in soil N, and soil N availability from manure varies substantially depending on the year of application. Experimental treatments included combinations of two manure rates (0.33 and 0.97 Mg total N ha-1) and three application times, and no manure treatments (control and urea fertilizer). We measured soil net N mineralization and biomass, N uptake, and yields for sprinkler-irrigated sugarbeet. On average, the 1-year-old, low-rate manure, and 1- and 2-year-old, high-rate manure treatments produced 1.2-fold greater yields, 1.1-fold greater estimated recoverable sugar, and 1.5-fold greater gross margins than that of... |
| Tipo: Article |
Palavras-chave: Sugarbeet; Manure; Nitrogen. |
| Ano: 2012 |
URL: http://eprints.nwisrl.ars.usda.gov/1454/1/1419.pdf |
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| Lentz, R.D.; Ippolito, J.A.; Spokas, K.A.. |
| Few multiyear field studies have examined the impacts of a one-time biochar application on net N mineralization and greenhouse gas emissions in an irrigated, calcareous soil; yet such applications are hypothesized as a means of sequestering atmospheric CO2 and improving soil quality. We fall-applied four treatments, stockpiled dairy manure (42 Mg/ha dry wt.); hardwood-derived biochar (22.4 Mg/ha); combined biochar and manure; and no amendments (control). Nitrogen fertilizer was applied in all plots and years based on treatment’s pre-season soil test N and crop requirements, and accounting for estimated N mineralized from added manure. From 2009 to 2011 we measured greenhouse gas fluxes using vented chambers, net N mineralization (NNM) using buried bags,... |
| Tipo: Article |
Palavras-chave: Corn; Manure; Chemistry; Nitrogen; Soil. |
| Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1558/1/1514.pdf |
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| Lehrsch, G.A.; Lentz, R.D.; Westermann, D.T.; Kincaid, D.C.. |
| High water application rates beneath the outer spans of center pivot sprinkler systems can cause runoff, erosion, and nutrient losses, particularly from sloping fields. This study determined runoff, sediment losses, and loads of nutrients (dissolved organic C, Nitrate-N, ammonium-N, total phosphorus [TP], ferric-oxide strip phosphorus [FeO P], dissolved reactive phosphorus [DRP], K, Ca, Mg, and Na) in sprinkler runoff for two years after a single application of either stockpiled or composted dairy manure. The two-year field investigation studied five treatments, including a non-amended control, in each of six blocks, with each block situated under a different span of a moving-lateral sprinkler system. In October 1999, we incorporated 29.1 or 71.7 Mg/ha... |
| Tipo: Article |
Palavras-chave: Sprinkler irrigation; Composted manure; Runoff. |
| Ano: 2014 |
URL: http://eprints.nwisrl.ars.usda.gov/1559/1/1515.pdf |
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| Lentz, R.D.. |
| Researcher’s seek a more renewable and natural alternative for water soluble anionic polyacrylamide (PAM), a highly-effective, petroleum-derived polymer used in agriculture to control erosion and reduce water seepage from unlined irrigation structures. This study evaluated two anionic polymers: a bacteria-produced polysaccharide (biopolymer) with 10-20 Mg/mol molecular weight (MW) and 30% charge density, and a PAM (12-15 Mg/mol MW, 30% charge density) to compare their ability to flocculate soil colloids, stabilize soil aggregates, and influence effective hydraulic conductivity (seepage loss). The biopolymer most effectively flocculated the colloids at a concentration of 1 mg/L, but was still 30% less effective than PAM at 1 mg/L and 50% less effective than... |
| Tipo: Article |
Palavras-chave: Water-soluble PAM (WSPAM); Erosion control; Erosion; Soil; Water. |
| Ano: 2015 |
URL: http://eprints.nwisrl.ars.usda.gov/1583/1/1539.pdf |
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| Lentz, R.D.; Lehrsch, G.A.. |
| Use of dairy manure to supply crop nutrients is gaining broader acceptance as the cost of fertilizer rises; however, there are concerns regarding manure’s effect on water quality. In 2003 and 2004, we measured sediment, NO3-N, NH4-N, K, dissolved reactive P (DRP), and total P (TP) concentrations in runoff from furrow irrigated field plots (6-7 irrigations/y). Annual treatments included: (M) 13 to 34 Mg/ha stockpiled dairy manure; (F) 78 to 195 kg N/ha inorganic N fertilizer; or (C) control--no amendment. Available N in manure applied each year was similar to amounts applied in fertilizer. Constituent concentrations (mg/L) in runoff ranged widely: sediment, 10 to 50,000; NO3-N, 0 to 4.07; NH4-N, 0 to 2.28; K, 3.6 to 46.4; DRP, 0.02 to 14.3; and TP, 0.03 to... |
| Tipo: Article |
Palavras-chave: Manure; Runoff. |
| Ano: 2010 |
URL: http://eprints.nwisrl.ars.usda.gov/1400/1/1370.pdf |
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| Registros recuperados: 92 | |
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