Xeric Haplocalcid Research Articles

Digital assessments of soil organic carbon storage using digital maps provided by static and dynamic environmental covariates

AbstractUnderstanding the vertical and lateral distribution of soil organic carbon (SOC) and soil organic carbon density (SOCD) is indispensable for soil use and environmental management because of their vital role in soil quality assessments. Primarily, they are needed in calculating soil organic carbon storage (SOCS). The objective of this research was to provide digital maps of SOC and SOCD variation as well as their uncertainties at multiple standardized depths (H1: 0–5, H2: 5–15, H3: 15–30, H4: 30–60 and H5: 60–100 cm) using a parsimonious model with optimized terrain‐related attributes and satellite‐derived data. SOCS were evaluated at soil subgroup levels. An area of about 808 km2 with varying elevation, plant cover and lithology from the Miandoab region, West Azerbaijan Province, Iran was selected as a case study area. A total of 386 soil samples were collected from 104 profiles comprising various soil genetic horizons. A continuous spline function was then fitted to the target properties in advance of creating a dataset at five standard depth intervals (following the GlobalSoilMap project). These were then grouped into three classes including top (H1), middle (H2, H3 and H4) and bottom (H5) depths to ease interpretation. Static and dynamic covariates (30‐m resolution) were derived from a digital elevation model (DEM) and a suite of Landsat‐8 spectral imageries, respectively. Four candidate models including stepwise multiple linear regression (SMLR), random forest (RF), cubist (CU) and extreme gradient boosting (XGBoost) Tree were tested in this study. Finally, the digital maps at 30‐m resolution of SOC and SOCD and their uncertainties were prepared using the best‐fit model and the bootstrapping method, respectively. Four soil subgroups (Gypsic Haploxerepts, Typic Calcixerepts, Typic Haploxerepts and Xeric Haplocalcids) were identified across the study area. The covariates had variable contributions on the evaluated models. The XGBoost Tree model generally outperformed other models for prediction of SOC and SOCD (R2 = 0.60, on average). Regardless of soil subgroups, the uncertainty analysis showed that the SOCD map had a low prediction interval range value indicating high accuracy. Additionally, the highest SOCS and SOCD was observed at the top followed by middle and bottom depths in the study area. All subgroups exhibited a decreasing trend of SOCD with increasing depth. A similar trend was also observed for SOCS. The highest SOCD (on average) was observed in Gypsic Haploxerepts (4.71 kg C/m2) followed by Typic Calcixerepts (4.46 kg C/m2), Typic Haploxerepts (4.45 kg C/m2) and Xeric Haplocalcids (4.40 kg C/m2). Overall, the SOCS normalized by area within soil order boundaries was greater in Inceptisols than Aridisols across the study area. The findings of this study provide critical information for sustainable management of soil resources in the area for agricultural production and environmental health in the Miandoab region of Iran.

Chemical weathering indices applied to soils developed on old lake sediments in a semi-arid region of Turkey

Climate is a major influence on weathering processes affecting soil parent materials. Important contributors to soil formation in arid and semi-arid climatic zones are the diurnal cycles of solar heating and cooling that cause mechanical or physical disintegration of rock or parent materials, and wind-blown sands that score and abrade exposed rock surfaces. By using the Soil Taxonomy classification system, the initial aim of this study was to carry out a pedological evaluation for four soil profiles, classified as Xeric Haplocalcid and Xeric Haplocambid, formed on different parent materials (limestone, marl and old alluvial deposits) under the same conditions, including topography and vegetation, in a semiarid region. The second stage was the exploration of the similarities and differences in the classifications resulting from either the pedogenic processes, or from other factors, by determining the degree of soil weathering using geochemical data. To achieve this, soil samples were collected from the horizons to investigate their mineralogical, geochemical and physiochemical properties. The study also considered other features, such as the pedogenic evolution of soils, through the use of weathering indices, namely the Chemical Index of Alteration (CIA), Chemical Index of Weathering (CIW), Base/R2O3 Ratio, Weathering Index of Parker (WIP) and Plagioclase Index of Alteration (PIA). The results clearly showed that soil development at the Altınova State Farm at Konya in the Central Anatolia region of Turkey is due to slow pr ogressive weathering. For this case, the main indicators are secondary calcium carbonate illuviation and weak structural development with a weathering ratio of silicon to aluminium greater than two in all profiles.

A model for field-based evidences of the impact of irrigation on carbonates in the tilled layer of semi-arid Mediterranean soils

Carbonates constitute a significant proportion of the soil mass in many semi-arid soils. Due to their solubility, they can be affected by changes in the soil water regime. This needs to be taken into account when assessing the environmental and agronomical impacts of the adoption of irrigation. To gain knowledge on the importance of the effect of irrigation on carbonates dynamics in the tilled layer (0–20cm) of agricultural soils, we conducted a two-step study embracing field observations and numerical simulation. First, carbonates storage and their size distribution were quantified for two different situations (irrigation and non-irrigation) in three irrigation districts with different time under irrigation (Valtierra (19years), Miranda (5years) and Funes (12years)) in Navarre (Spain). Soil sampling was designed to ensure homogeneous comparisons in the most characteristic soil types at each site (Xeric Haplocalcid, Typic Calcixerept and Xeric Haplocalcid, respectively). Carbonates concentration was systematically lower with irrigation in the finest (<50μm) soil fraction: 22.2±1.4g carbonates 100g−1 fraction without irrigation for 16.1±0.9 with irrigation in Valtierra, 26.7±1.1 for 19.1±3.8 in Miranda and 27.8±2.9 for 22.7±1.5 at Funes1. However, the net annual balance of total carbonates-C between irrigated and non-irrigated condition was neutral at the three sites. This can be explained by agricultural management affecting carbonates in the sand-size fraction, including the addition of carbonates with fertilizers, and coarse carbonate particles brought to the surface by tillage.In a second step, a simplified model was developed for use with easily available data in most irrigation districts, and numerical simulations of the geochemical interactions between the soil, the soil solution and irrigation water were run using actual soil and soil solution data from the tilled layer of another pair of plots in Funes (Funes2). Sensitive analysis was also conducted to investigate the potential impact of water quality and crop types as sources of variability on the model outputs. The modelling results showed annual values of carbonates-C loss in the range between 13.52 and 12.06gm−2year−1 in the studied depth under irrigation, depending on the quality of irrigation water, for 0.46gm−2 without irrigation. These data were within the range of carbonates budgets found in the literature but one order of magnitude lower than the observed results in the fine fraction in the field. Overall, our results showed that irrigation can significantly alter carbonates dynamics in semi-arid Mediterranean land, which implies that human use can significantly alter the mineral phase of these soils in a relatively short time lapse. Simple geochemical models can be a useful approach to evaluate changes in the carbonates balance at the local and regional scale when irrigation is applied, although they have to be improved to account for other factors related to agricultural management and local geochemical conditions.

Effect of Phosphorus Placement Methods and Rates on Sugarbeet Production under Strip Tillage in Southern Idaho

The use of strip tillage in the sugarbeet production systems of the Pacific Northwest is increasing, and data is needed about options for P placement and application rates for those options. The effects of P application methods (surface and subsurface band) and application rates (0–205 lb/acre P2O5) were evaluated in 2009 and 2010 on sugarbeet grown under strip tillage at the USDA‐ARS Northwest Irrigation and Soils Research Laboratory, in Kimberly, ID. The soil at the study sites was a Portneuf silt loam (coarse‐silty mixed superactive, mesic Durixerollic Xeric Haplocalcids) that had low bicarbonate‐extractable P concentrations of 3.7 ppm in 2009 and 6.0 ppm in 2010. In general, yields did not differ between the application methods for P fertilizer application; however, yields increased as the P rate increased and were not maximum even at the highest application rate in this study (&gt;205 lb/acre P2O5). Across all treatments and years, the harvested roots removed an average equivalent of 14.3% of the applied fertilizer P, and the entire plant extracted an average equivalent of 22.8% of the applied fertilizer P. Regardless of the application methods used in this study, the results do not provide evidence that the current P fertilizer recommendations from the University of Idaho and the Amalgamated Sugar Company (TASCO) should be changed for strip tillage.

Compost and Manure Effects on Sugarbeet Nitrogen Uptake, Nitrogen Recovery, and Nitrogen Use Efficiency

To maximize recoverable sucrose from sugarbeet (Beta vulgaris L.), producers must effectively manage added N, be it from urea or organic sources such as manure or composted manure. Our study's objective was to determine the effects of a one‐time application of stockpiled and composted dairy cattle (Bos taurus) manure on sugarbeet N uptake, nitrogen recovery (NR) and nitrogen use efficiency (NUE). First‐year Site A treatments included a control (no N), urea (202 kg N ha−1), compost (218 and 435 kg estimated available N ha−1), and manure (140 and 280 kg available N ha−1). Site B treatments were a control, urea (82 kg N ha−1), compost (81 and 183 kg available N ha−1), and manure (173 and 340 kg available N ha−1). Compost and manure were incorporated into two silt loams, a Greenleaf (fine‐silty, mixed, superactive, mesic Xeric Calciargid) near Parma, ID, in fall 2002 and 2003 and a Portneuf (coarse‐silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid) near Kimberly, ID, in fall 2002 with sugarbeet planted the following spring. At each site, N uptake of sugarbeet tops, but not roots, was similar whether fertilized with urea or organic N, regardless of rate. Incorporating equal organic amendment rates to 0.05 rather than 0.10 m increased whole‐plant N uptake 1.13‐fold, to 163.3 kg N ha−1. In general, NR varied among fertilizer sources such that urea &gt;&gt; manure &gt; compost. Where similar available N rates were supplied, NUE ranged from 44.1 to 83.5 kg sucrose kg−1 available N, not differing among inorganic and organic N sources within site‐years.

Sugarbeet Yield and Quality When Substituting Compost or Manure for Conventional Nitrogen Fertilizer

To grow sugarbeet (Beta vulgaris L.) profitably, producers must effectively manage added N, whether from inorganic or organic sources. Our objective was to determine if equivalent sugarbeet root and sucrose yields could be achieved when substituting dairy cattle (Bos spp.) manure, either composted or stockpiled, for conventional N (urea) fertilizer. First‐year treatments at Site A (Parma, ID) included a control (no N), urea (202 kg N ha−1), compost (218 and 435 kg estimated available N ha−1), and manure (140 and 280 kg available N ha−1). Site B (Kimberly, ID) treatments were a control, urea (82 kg N ha−1), compost (81 and 183 kg available N ha−1), and manure (173 and 340 kg available N ha−1). Compost and manure were incorporated into two silt loams, a Greenleaf (fine‐silty, mixed superactive mesic Xeric Calciargid) at Parma in fall 2002 and 2003 and a Portneuf (coarse‐silty, mixed superactive, mesic Durinodic Xeric Haplocalcid) at Kimberly in fall 2002. Sugarbeet was planted the following spring. Sucrose yield averaged across years and organic N rates at Site A was 12.24 Mg ha−1 for urea, 11.88 Mg ha−1 for compost, and 11.20 Mg ha−1 for manure, all statistically equivalent. Doubling the organic N rates at Site A increased the yield of roots up to 26% and sucrose up to 21%. Applying organic amendments in place of urea affected neither root nor sucrose yields but, at one location, decreased sugarbeet quality, though without hindering sucrose recovery. Sugarbeet producers can use compost or manure to satisfy crop N needs without sacrificing sucrose yield.

Drought Tolerance Selection of Sugarbeet Hybrids

Increased water demands and drought have resulted in a need to indentify crop hybrids that are drought tolerant, requiring less irrigation to sustain yields. This study was conducted to assess differences in drought tolerance among a group of genetically diverse sugarbeet hybrids. The study was conducted over three consecutive growing seasons (2008-2010) at the USDA Northwest Irrigation and Soils Research Laboratory in Kimberly, Idaho on a Portneuf silt loam soil (coarse-silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid). Drought tolerance was evaluated by measuring sucrose yield production of six breeding hybrids of Klein Wanzlebener Saatzucht (KWS SAAT AG) and one commercial hybrid (Betaseed Inc.) under six water input treatments. Hybrid drought tolerance was evaluated by linear regression analysis (slope and intercept) of yield versus water input, calculation of a drought stress index (DSI), and comparison of yield potential under full irrigation. The water input treatments were based on a percentage of estimated crop evapoatransipration (ETc). Water input treatments were 125% ETc (W1), 100% ETc (W2), 75% ETc (W3), 50% ETc (W4), 25% ETc (W5) and rain-fed (W6). Irrigation was applied three times a week to meet the desgnated rate. There were significant differences in overall yield potential and in the sucrose yield response to water among hybrids. Greater drought tolerance or greater difference in sucrose yield between hybrids was seen at the lowest water input treatment (intercept difference). Greater drought tolerance was observed for the KWS-05 hybrids compared to the commercial hybrid. Based on these results there exist genetic diversity among existing sugarbeet breeding hybrids.

Switchgrass Biochar Affects Two Aridisols

The use of biochar has received growing attention because of its ability to improve the physicochemical properties of highly weathered Ultisols and Oxisols, yet very little research has focused on its effects in Aridisols. We investigated the effect of low or high temperature (250 or 500°C) pyrolyzed switchgrass () biochar on two Aridisols. In a pot study, biochar was added at 2% w/w to a Declo loam (Xeric Haplocalcids) or to a Warden very fine sandy loam (Xeric Haplocambids) and incubated at 15% moisture content (by weight) for 127 d; a control (no biochar) was also included. Soils were leached with 1.2 to 1.3 pore volumes of deionized HO on Days 34, 62, 92, and 127, and cumulative leachate Ca, K, Mg, Na, P, Cu, Fe, Mn, Ni, Zn, NO-N, NO-N, and NH-N concentrations were quantified. On termination of the incubation, soils were destructively sampled for extractable Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Zn, NO-N, and NH-N, total C, inorganic C, organic C, and pH. Compared with 250°C, the 500°C pyrolysis temperature resulted in greater biochar surface area, elevated pH, higher ash content, and minimal total surface charge. For both soils, leachate Ca and Mg decreased with the 250°C switchgrass biochar, likely due to binding by biochar's functional group sites. Both biochars caused an increase in leachate K, whereas the 500°C biochar increased leachate P. Both biochars reduced leachate NO-N concentrations compared with the control; however, the 250°C biochar reduced NO-N concentrations to the greatest extent. Easily degradable C, associated with the 250°C biochar's structural make-up, likely stimulated microbial growth, which caused NO-N immobilization. Soil-extractable K, P, and NO-N followed a pattern similar to the leachate observations. Total soil C content increases were linked to an increase in organic C from the biochars. Cumulative results suggest that the use of switchgrass biochar prepared at 250°C could improve environmental quality in calcareous soil systems by reducing nutrient leaching potential.

Biochars Impact on Soil-Moisture Storage in an Ultisol and Two Aridisols

Droughts associated with low or erratic rainfall distribution can cause detrimental crop moisture stress. This problem is exacerbated in the USA’s arid western and southeastern Coastal Plain due to poor rainfall distribution, poor soil water storage, or poorly-aggregated, subsurface hard layers that limit root penetration. We hypothesized that soil physical deficiencies may be improved by biochar applications. Research indicates a single biochar will not serve as a universal supplement to all soils; consequently, biochars may need to be designed with physico-chemical properties that can ameliorate specific soil physical deficiencies. We conducted a laboratory study that examined the effect of biochar on soil moisture retention and aggregate formation. Eight biochars were made from four feedstocks at two different pyrolysis temperature classes ( 500°C; 932°C) and were characterized for their physical and chemical properties. In addition, we included a biochar made using fast pyrolysis of hardwood wastes. All biochars were mixed at 2% w/w with either a Norfolk loamy sand (Fine-loamy, kaolinitic, thermic Typic Kandiudults), a Declo silt loam (Coarse-loamy, mixed, superactive, mesic xeric Haplocalcids), or a Warden silt loam (Coarse-silty, mixed, superactive, mesic xeric Haplocambids). Amended soils were laboratory incubated in pots for up to 127 days. About every 30 days, bulk density was measured and then each pot was leached with 1.2 to 1.3 pore volumes of deionized water. Gravimetric and volumetric soil moisture contents were determined after free drainage had ceased and again 2 and 6 days after leaching. The Norfolk-treated soils were later dry-sieved, and the sum by weight of their 0.5- to 1.0-mm aggregates was determined. In general, the biochar surface area and surface tension increased when produced under higher pyrolytic temperatures (>500°C). After leaching, Norfolk soils treated with switchgrass biochars had the most significant increase in soil moisture capacities. Similar increases were found in the Declo and Warden soils. Formation of 0.5- to 1.0-mm aggregates in the Norfolk loamy sand varied with biochar. Biochars enhanced the moisture storage capacity of the Ultisol and Aridisols thereby potentially reducing the on-set of crop moisture stress; however, the effect varied considerably with biochar feedstock and pyrolysis temperature.

Interactive Effects of Copper on Alfalfa Growth, Soil Copper, and Soil Bacteria

Copper sulfate (CuSO4) foot baths are a management practice used by dairy farms in an effort to control hoof infections. As an unintended consequence, agricultural soils experience Cu accumulation when spent foot baths are disposed of in wastewater lagoons utilized for irrigation purposes. We investigated the effect of Cu applications (up to 1000 mg kg-1) to a Xeric Haplocalcid (Declo series) and a Typic Calciaquoll (Logan series) on alfalfa (Medicago sativa) growth and Cu concentration, soil total and diethylenetriaminepentaacetic acid (DTPA)-extractable Cu, and the soil bacterial community diversity using ribosomal intergenic spacer analysis (RISA). Copper application up to 250 mg kg-1 did not affect alfalfa growth; above 500 mg Cu kg-1 alfalfa did not grow. The 100 and 250 mg kg-1 Cu application rates increased alfalfa Cu content grown in Declo soil, while the 250 mg kg-1 Cu application rate increased alfalfa Cu content when grown in the Logan soil. Regardless of initial application rate, 48 to 80% of the added Cu was still plant-available at the end of the study. Comparing DTPA-extractable Cu to alfalfa Cu concentrations, 63 or 95 mg kg-1 of DTPA-extractable soil Cu for the Declo and Logan soils, respectively, would be detrimental in terms of cattle dietary Cu intake. For Declo soils, bacterial diversity remained relatively stable across all Cu application rates; Logan soils saw a peak in bacterial diversity at the 50 mg kg-1 Cu application rate. Cluster analysis revealed differences in the bacterial RISA profiles between the lower and higher Cu application rates. To prevent excessive alfalfa Cu accumulation and negative impacts on the soil bacterial community, it is suggested available soil Cu not exceed 63 mg kg-1 in agroecosystems associated with these soil series.

Dairy Manure Nitrogen Availability in Eroded and Noneroded Soil for Sugarbeet Followed by Small Grains

Efficient recycling of abundant manure resources from regional dairy industries in the semiarid West requires a better understanding of N availability in manure‐amended soils. We measured net N mineralization using buried bags, and crop biomass, N uptake, and yields for sprinkler‐irrigated, whole (noneroded) and eroded Portneuf soils (coarse‐silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid) subject to a one‐time manure application. Treatments included a control, fertilizer, two rates of composted dairy manure (28.4, 64.3 Mg ha−1, dry wt.), and two rates of stockpiled dairy manure (23.3, 45.7 Mg ha−1, dry wt.) applied in the fall before the Year 1 cropping season. Plots were planted to sugarbeet (Beta vulgaris L.), winter wheat ( Triticum aestivum L.), and spring barley (Hordeum vulgare L.) during the 3‐yr study. Overall, net N mineralization rates were low to moderate during winter through spring, decreased in early summer due to N immobilization, then increased to a maximum in late summer, followed by a decrease in fall. The mean mineralization rate (as a percentage of the added organic N) for Years 1, 2, and 3 was −4.2 (N immobilization), 4.3, and 4.8% for compost and 17.4, 17.0, and 11.4% for manure, respectively. Relative to controls, compost and manure treatments as a group increased total 3‐yr net N mineralization more for eroded (1.77×) than for whole soils (1.55×). At higher rates, manure also increased immobilization and mineralization in 30‐ to 60‐cm soil depths (below the zone of incorporation). To optimize the use of N mineralized in southern Idaho's manure‐amended soils, one should consider the type manure employed and the erosion status of the soil receiving the amendment.

Zeolite Soil Application Method Affects Inorganic Nitrogen, Moisture, and Corn Growth

Adoption of new management techniques that improve soil water storage and soil N plant availability yet limit N leaching may help improve environmental quality. A benchtop study was conducted to de- termine the influence of a single urea fertilizer rate (224 kg N ha j1 ) applied with band or fully mixed zeolite (clinoptilolite) application rates (up to 90 Mg ha j1 )o n NH 4-N and NO3-N concentrations in a Portneuf silt loam (coarse-silty, mixed, mesic, durinodic Xeric Haplocalcid). Two ad- ditional greenhouse experiments were carried out to test the soil moisture status and corn (Zea mays L.) growth in a Wolverine sand (mixed, frigid Xeric Torripsamment). Mixing urea fertilizer into silt loam soil resulted in greater urea mineralization as compared with band application of fertilizer + zeolite, and the mixed zeolite was more effective at sorbing and pro- tecting NH4-N against nitrification. Increasing the rate of mixed zeolite into sandy soil increased the soil moisture content, and mixed zeolite soils contained 1.3% more soil moisture as compared with band zeolite appli- cations. After 6 weeks of corn growth in amended sandy soil, zeolite application at 22 Mg ha j1 seemed to increase corn weight compared with controls. However, increasing zeolite rate up to 90 Mg ha j1 caused a decrease in corn weight, likely caused by the elevated zeolite Na content (3%). Fully mixing zeolite into soil reduced the rate of nitrification likely because of NH4 + adsorption in the zeolite mineral lattice. Thus, mixing

Oilseed Radish Effects on Soil Structure and Soil Water Relations

Oilseed radish (Raphanus sativus spp. oleifera) reduces sugarbeet cyst nematode (Heterodera schachtii) populations. Fall-incorporated radish biomass may also increase the yield and quality of subsequently grown sugarbeet (Beta vulgaris L.) by improving soil physical and hydraulic properties. This field study determined radish effects on nearsurface soil aggregate stability, water-stable aggregate size distribution, bulk density, and field-saturated water content, as well as infiltration and hydraulic conductivity measured at water supply potentials of -40, -20, and +0 mm H 2 O. In 2003 and 2004 in Twin Falls, ID, radish were grown in a Portneuf silt loam (Durinodic Xeric Haplocalcid) for about 10 weeks in the fall, then incorporated later that fall by disking, followed by moldboard plowing. In early May of the following year, sugarbeet were planted, irrigated, then harvested for yield and quality. In the spring and fall of each sugarbeet growing season, soil samples were collected from two depths, 0 to 5 and 5 to 50 mm, on which we measured aggregate stability and size distribution by wet sieving. Soil cores were collected from 0 to 34 mm to measure bulk density. Also in spring and fall, we used ponded and tension infiltrometers placed in the row to measure steadystate, unconfined infiltration rates and, from those rates, to

Sprinkler Irrigation Effects on Infiltration and Near-Surface Unsaturated Hydraulic Conductivity

Sprinkler irrigation alters soil hydraulic properties both at and below the soil surface, yet its effects are not well characterized. We evaluated the effects of sprinkler irrigation on infiltration and near-surface hydraulic conductivity (K) measured under tension in a poorly structured, recently roller-harrowed Portneuf silt loam (Durinodic Xeric Haplocalcid). The experimental design was a randomized complete block with two treatments (pre- and post-irrigation) and four replications. We used two half-circle spray heads to apply 127 mm of water at 70 mm h-1 in one irrigation to duplicate 1 2 m plots. Unconfined (three-dimensional) infiltration rates at steady-state were measured at potentials of -55, -35, and -15 mm of water before and about 10 days after irrigation. Irrigation increased surface bulk density (0 to 34 mm) by 18% and increased the saturation ratio by 35%. At -15 mm, the unconfined infiltration rate was 53 mm h-1 before, but 16 mm h-1 after irrigation. At -35 and -55 mm, irrigation decreased infiltration by 68%. Irrigation also decreased infiltration nearly 5-fold through pores with diameters ranging from 0.55 to 0.86 mm. At each measured potential, irrigation tended to decrease hydraulic conductivity by 48%, on average. Sprinkler droplet impact consolidated unprotected soil and greatly reduced tension infiltration. Our findings provide useful input data regarding this and similar soils for models requiring hydraulic properties. In addition, our results provide valuable insight for managing infiltration and avoiding runoff during a growing season when surface properties change as recently tilled soils are sprinkler irrigated.

Changes in Soil Test Phosphorus and Phosphorus in Runoff From Calcareous Soils Receiving Manure, Compost, and Fertilizer Application With and Without Alum

Intensification of the dairy industry in southern Idaho has led to the overapplication of manures and a buildup of soil phosphorus (P), which is a potential threat to water quality in the region. As the use of alum has been shown to reduce both soluble manure P and runoff P from alum-treated manures, the objective of this study was to determine if surface applications of alum to dairy manure and compost before soil incorporation would reduce P losses under furrow irrigation on a calcareous soil. The effects of manure, compost, and fertilizer application with and without alum treatment on soil P, runoff P, and aluminum under furrow irrigation, crop yield, tissue P concentrations, and P removal during a 4-year period were investigated in Kimberly, Idaho, on a Portneuf silt loam (coarse-silty, mixed superactive, mesic Durinodic Xeric Haplocalcids). Fertilizer and manure addition had the greatest potential to increase soluble P in soils compared with compost, which translated to greater soluble P losses with irrigation in some instances. The addition of alum to manure did not have any effect on soil-extractable P or soluble P losses from furrow irrigation and therefore, when surface applied to manure before incorporation, is not a good best management practice for stabilizing P in manure-treated calcareous soils.

Phosphorus Mobility in Soil Columns Treated With Dairy Manures and Commercial Fertilizer

The concentration of animal production in some areas of the United States has led to concern about the environmental fate of manure-derived phosphorus (P) in soils. A column study was conducted to quantify P leaching in a calcareous soil treated with monoammonium phosphate (MAP), two solid dairy manures (D1S and D2S), and two liquid dairy manures (D1L and D2L). A control with no P application was also included. Treatments were applied at 166 kg P ha−1 to columns packed with 20 cm of a Warden fine sandy loam (coarse-loamy, mixed superactive, mesic Xeric Haplocalcids) in a completely randomized design with four replications and housed in a climate-controlled growth chamber. Simulated irrigation water was added to the columns at a rate of 47.4 mm (450 mL) during 13 events during a 9-week period, with leachate collected, volume recorded, and concentrations of total organic carbon (TOC) and total P (TP) determined for each event. At the end of the leaching events, each soil column was divided into eight 2.5-cm segments. Then, soil was air-dried, ground, and analyzed for TP, total carbon, calcium (Ca), iron, and manganese, and water-soluble P. The masses of TP and TOC in leachate were in the order D1L = D2L > MAP = D1S = D2S = Control. There was a positive linear relationship between the cumulative mass of TOC and cumulative mass of TP lost in leachate over all manure treatments (r2 = 0.98). The masses of TP and water-soluble P for treatments in the entire soil columns were in the order MAP > D1L = D2L > D1S = D2S = Control. Masses of P and C in leachate and soil show that P mobility in soil was in the order liquid dairy manures > MAP > solid dairy manures. At the end of the study, the total C was greater in the surface 2.5 cm of the soil columns for the solid manure treatments compared with the other treatments/depth combinations. The greater leaching of P in the liquid manure treatments compared with the solid manure treatments may be caused by a combination of factors including microbial activity, organically complexed metals, coating of P adsorption sites on clay particles by organic C compounds, and P-Ca and P-aluminum reactions.

Soil erosion rates in rangelands of northeastern Patagonia: A dendrogeomorphological analysis using exposed shrub roots

Soil erosion is an important process of land degradation in many rangelands and a significant driver of desertification in the world's drylands. Dendrogeomorphology is an alternative to traditional methods for determining soil erosion rate. Specifically, the vertical distance between the upper portion of exposed roots and the actual soil surface can be used as a bioindicator of erosion since plant establishment. In this study, we determined (i) the soil erosion rate from exposed roots of the dwarf shrub Margyricarpus pinnatus [Lam.] Kuntze in two ecological sites in the northeastern rangelands of Patagonia and (ii) the relationship between shrub age and upper root diameter. We selected two ecological sites, a pediment-like plateau and a flank pediment, where the dominant soils were Xeric Haplocalcids and Xeric Calciargids, respectively. The soil erosion rates in the pediment-like plateau and in the flank pediment were 2.4 and 3.1 mm yr − 1 , respectively. Data clearly indicate a high rate of soil erosion during the mean 8-year life span of the dwarf shrubs in degraded patches, which represent ~ 10% of surface cover in the study area. Simple linear regression analysis yielded a highly significant predictive model for age estimation of M. pinnatus plants using the upper root diameter as a predictor variable. The measurement of ground lowering against datable exposed roots represents a simple method for the determination of soil erosion rates. In combination with other soil surface features, it was used to infer the episodic nature of soil erosion. This approach could be particularly useful for monitoring the effects of land management practices on recent soil erosion and for the establishment of records in regions where historical data regarding this process are scarce or absent.

Whey utilization in furrow irrigation: Effects on aggregate stability and erosion

Improving soil structure often reduces furrow erosion and maintains adequate infiltration. Cottage cheese whey, the liquid byproduct from cottage cheese manufacture, was utilized to stabilize soil aggregates and reduce sediment losses from furrow irrigation. We applied either 2.4 or 1.9 L of whey per meter of furrow (3.15 or 2.49 L m −2, respectively) by gravity flow without incorporation to two fields of Portneuf silt loam (Durinodic Xeric Haplocalcid) near Kimberly, ID. Furrows were irrigated with water beginning four days later. We measured sediment losses with furrow flumes during each irrigation and measured aggregate stability by wet sieving about 10 days after the last irrigation. Overall, whey significantly increased aggregate stability 25% at the 0–15 mm depth and 14% at 15–30 mm, compared to controls. On average, whey reduced sediment losses by 75% from furrows sloped at 2.4%. Whey increased the aggregate stability of structurally degraded calcareous soil in irrigation furrows.

Carbon and nitrogen stable isotope ratios can estimate anionic polyacrylamide degradation in soil

Water-soluble anionic polyacrylamide (PAM) is applied to millions of hectares worldwide as a highly effective erosion-preventing and infiltration-enhancing polymer, when applied at rates of 1 to 2 kg ha − 1 (i.e., 1 to 10 g m − 3 ) in furrow water. PAM degradation has not directly been measured in soil. We tested the ability of stable isotopes of C and N at natural abundance to estimate PAM degradation rates. Values of δ 13C were related to anionic PAM concentration in a positive curvilinear relationship in a low-C, low-N, Durinodic Xeric Haplocalcid (Portneuf series) soil. The other soils with higher organic C or N concentrations did not show significant relationships between PAM concentrations and δ 13C values. The δ 15N values were not related to anionic PAM concentration in any of the soils tested. When 2691 active ingredient (ai) kg PAM ha − 1 was applied to the Durinodic Xeric Haplocalcid soil, 49% and 74% of the PAM was degraded after 6 and 12 yr respectively. When 5382 kg ai PAM ha − 1 was applied to the Durinodic Xeric Haplocalcid soil, 13% was degraded after 6 yr, and 73% of the PAM was degraded after 12 yr. We calculated PAM degradation rate based on δ 13Cfor the Durinodic Xeric Haplocalcid soil to be 9.8% yr − 1 . Further testing using labeled PAM is necessary to estimate degradation rates in higher C soils, and to determine what portion of the C is released from decomposing PAM is emitted to the atmosphere, incorporated into soil organic matter and living microbial biomass.

Compost and Manure Effects on Fertilized Corn Silage Yield and Nitrogen Uptake under Irrigation

Dairy manure increases the yields of dry bean (Phaseolus vulgaris L.) and spring wheat (Triticum aestivum L.) from eroded, furrow‐irrigated soils and may increase corn (Zea mays L.) silage yield from steeper eroded areas under sprinkler irrigation. In a 2‐year field study in southern Idaho on Portneuf silt loam (coarse silty, mixed, superactive, mesic Durinodic Xeric Haplocalcid), the effects of a one‐time, fall application of 29 or 72 Mg ha−1 of dry manure or 22 or 47 Mg ha−1 of dry compost on subsequent silage yield and nitrogen (N) uptake from previously eroded, sprinkler‐irrigated hill slopes were evaluated. In October 1999, stockpiled or composted dairy manure was disked to a depth of 0.15 m into plots with slopes from 0.8 to 4.4%. After planting field corn in 2000 and 2001, a low‐pressure, six‐span traveling lateral sprinkler system was utilized to apply water at 28 mm h−1 in amounts sufficient to satisfy evapotranspiration to 6.4‐×36.6‐m field plots. Yields in 2000 were 27.5 Mg ha−1, similar among all rates of all amendments and a fertilized control. In 2001, compost applied at oven‐dry rates up to 47 Mg ha−1 increased yield compared to controls. Silage yield in 2001 increased initially then decreased with increasing manure applications. Where compost or manure was applied, regardless of rate, 2‐year average N uptake was 15% greater than controls. Regardless of treatment or year, yields decreased linearly as soil slope increased.