Bahman Eghball

Soil Properties as Influenced by Phosphorus- and Nitrogen-Based Manure and Compost Applications

posting has some disadvantages that include nutrient and C loss during composting, the cost of land, equipManure or compost application based on N needs of corn (Zea ment, and labor required for composting, and odor assomays L.) may result in soil accumulation of P, N, and other ions, ciated with composting. since the manure or compost N/P ratio is usually smaller than the corn N/P uptake ratio. This study was conducted from 1992 to 1996 Manure application in excess of crop requirements to evaluate the effects of annual or biennial application of Nand can cause a significant buildup of P, N, and salt in soil. P-based composted and noncomposted beef cattle (Bos taurus ) feedAfter 18 yr of manure application, surface soil cation lot manure on soil properties. Fertilized and unfertilized checks were exchange capacity, total organic C, and total N increased also included. Soil surface (0–15 cm) pH significantly increased with with increasing rate of manure application (Gao and N-based manure (MN) or compost application (CN), but decreased Chang, 1996). Schlegel (1992) found that soil P, K, and with NH4–N fertilizer application as compared with the check. Soil organic matter increased with increasing rate of combulk density was unaffected by manure or compost application. After posted beef cattle feedlot manure applied from 1987 4 yr of manure and compost applications, soil surface (0–15 cm) C to 1990, while increasing rates of synthetic N fertilizer and N concentrations and quantities were greater for Nthan P-based application decreased soil P and K, but had no effect management systems. About 25% of applied manure C and 36% of applied compost C remained in the soil after 4 yr of application, on soil organic matter content. In this study, soil nitrate indicating greater C sequestration with composted than noncomposted levels were unaffected by compost application but inmanure. No significant difference was observed between fertilizer and creased with chemical fertilizer application. In another check plots for soil total C or N. Soil properties in the 15to 30study, eleven annual applications of cattle feedlot macm increment were unaffected by the applied treatments except soil nure increased soil organic matter, total N, NO3, total electrical conductivity (EC). Residual soil NO3 to a depth of 1.2 m was P, available P, soluble Na, Ca Mg, Cl, SO4, HCO3, greater for inorganic fertilizer than manure and compost treatments in and Zn (Chang et al., 1991). About 1 Mg ha 1 NO3–N drier years. Soil property changes were greater for the annual or accumulated at the recommended application rate of biennial N-based than P-based manure or compost applications, re30 Mg ha 1 yr 1 after 11 yr of application. Davis et al. flecting the differences in application amounts. (1997) showed that residual soil NO3–N after heavy manure application was greater in heavy-textured soils than sandy soils. Chang and Janzen (1996) found that B cattle feeding is concentrated in the Central losses of N through leaching and volatilization were less and Southern Great Plains. At any one time, there for rainfed than irrigated treatments when annual beef are at least 10 million head of beef cattle on feed in the cattle feedlot manure was applied. The proportion of United States (USDA, 1997) generating manure that manure N mineralized was independent of manure rate contains 529 900 Mg N, 157 000 Mg P, and 482 000 Mg K and irrigation, and during 20 yr of manure application, each year, based on manure N, P, and K concentrations ≈56% of manure N was mineralized. (Overcash et al., 1983). In addition to nutrients, beef Soil pH may be influenced by manure application. cattle feedlot manure also contains ≈15% C that can be Eghball (1999) found that application of beef cattle used to improve soil physical and chemical properties. feedlot manure or compost increased the soil surface Carbon in manure is likely to have far greater value (0–15 cm) pH while N application as NH4NO3 signifithan the nutrients it contains if applied to a low organic cantly reduced the pH (from 6.4 to 5.6). The increase matter or eroded soil. in soil pH with manure and compost application was Composting manure is a useful method of producing attributed to a beef cattle diet that contains ≈15 g CaCO3 a stabilized product that can be stored or spread with kg 1. Manure and compost effects on soil pH depends little odor or fly-breeding potential. The other advanon the initial soil pH level. Chang et al. (1991) reported tages of composting include killing pathogens and weed that the EC and sodium absorption ratio of soil inseeds, and improving handling characteristics of manure creased and soil pH decreased with increasing rate of by reducing manure volume and weight. However, commanure application (soil pH in the 0–15 cm was 7.8 and manure had a mean pH of 7.3). In another study, manUSDA-ARS, Dep. of Agron. and Hortic., Univ. of Nebraska-Lincoln, Lincoln, NE 68583. Joint contribution of USDA-ARS and Univ. of Abbreviations: CN, compost application for corn N needs; CP, comNebraska Agric. Res. Div., Lincoln, NE, as paper no. 12996. Received post for corn P needs; EC, electrical conductivity; MN, manure applica29 Mar. 2001. *Corresponding author (beghball1@unl.edu). tion for corn N needs; MN2Y, manure for corn N needs for 2 yr; MP, manure application for corn P needs. Published in Agron. J. 94:128–135 (2002).

Liming effects of beef cattle feedlot manure or compost

Abstract Soil pH can be increased by manure or compost application because feed rations usually contain calcium carbonate. This study was conducted from 1992 to 1996 to evaluate effects of phosphorus (P) and nitrogen (N)‐based manure and compost application management strategies on soil pH level. Composted and uncomposted beef cattle (Bos taunts) feedlot manure was applied to supply N or P needs of corn (Zea mays L.) for either a one‐ or two‐year period. Phosphorus‐based manure or compost treatments also received additional fertilizer N (ammonium nitrate) to provide for a total of 151‐kg available N ha‐1 yr‐1. Fertilized and unfertilized checks also were included. Manure and composted manure contained about 9 g CaCO3kg‐1 resulting in application rates of up to 1730 kg CaCO3 ha‐1 in 4 years. The surface soil (0–150 mm) pH was significantly decreased with ammonium nitrate application compared to soil in the unfertilized check or to soil receiving manure or compost. Soil pH was significantly increased with t...

Leaching of Phosphorus Fractions Following Manure or Compost Application

Phosphorus (P) leaching in manure‐amended soil can be influenced by the P fractions added when manure or composted manure is applied. This study was conducted to determine leaching of different P fractions following beef cattle feedlot manure or compost application. Manure and composted manure were applied to meet the nitrogen (N) or P needs of corn (Zea mays L.) for either a one or two‐yr period. Fertilized plots and unfertilized control plots were also used. The P‐based treatments also received additional N fertilizer. Soil P fractions were determined for various soil depth increments. After 4 years of manure and compost applications, leaching of plant‐available P was observed to a soil depth of 30 cm. The differences among treatments for total and inorganic P were significant only at the 0 to 15 cm soil depth increment. Greater concentrations of total, available, and inorganic P fractions were observed for the N‐based manure and compost treatments as these management strategies received more P than P‐based. More than 70% of beef cattle manure or composted feedlot manure P was inorganic. Water‐soluble P was a small fraction of total P in beef cattle feedlot manure or composted manure (< 13%). Leaching of plant‐available P following manure and compost applications can pollute the ground water if P comes in contact with ground water, especially in areas with shallow and/or fluctuating ground water and in areas with till drainage. #Joint contribution of USDA‐ARS and University of Nebraska Agricultural Research Division, Lincoln, NE, as paper No. 13435.

LONG–TERM MANURE AND FERTILIZER APPLICATION EFFECTS ON PHOSPHORUS AND NITROGEN IN RUNOFF

Long–term manure and fertilizer applications to a soil can increase phosphorus (P) and nitrogen (N) transport in runoff. This study was conducted to determine P and N transport in runoff following long–term (since 1953) manure and fertilizer applications. Duplicate soil samples (32) were collected in 1998 from the top 0.1 m of selected plots of a long–term manure and fertilizer applications field experiment and later placed in 1 m 2 soil pans in the laboratory. Manure and fertilizer were mixed with 16 of the soil samples, while no treatment was applied to the other half (long–term residual effect). Simulated rainfall was then applied to the soil during initial and wet (24 hours later) events. Manure added just before simulated rainfall resulted in significantly greater concentrations of dissolved P (DP), bioavailable P (BAP), particulate P (PP), total P (TP), NO3–N, and NH4–N than when the last manure application was the previous year in 1997. Soil test P level was not a significant factor in DP loss when manure was applied just before rainfall. When the last manure application was the previous year, similar concentrations of DP, BAP, PP, and TP were measured on the manure and no–manure treatments. Concentrations of NO3–N and NH4–N in runoff were not influenced by long–term fertilizer application, but significantly increased with increasing N application rate when N was applied just before rainfall. Phosphorus concentration in runoff decreased with time of runoff up to 45 minutes, after which the P concentration remained constant. NO3–N and total N concentrations continued to decrease for the entire runoff period. Manure and fertilizer should not be applied when the probability of rainfall immediately following application is great.

Interactive effects of water and nitrogen stresses on nitrogen utilization efficiency, leaf water status and yield of corn genotypes

Abstract Information on the combined effects of N and water stresses on corn (Zea mays L.) is of importance for selecting nitrogen efficient and drought tolerant genotypes. Greenhouse and field experiments were conducted to determine the interactive effects of N and water stresses on N utilization efficiency (NUE), leaf water status and yield of diverse corn genotypes. Three genotypes which normally rank differently for NUE in the field, were grown to the 9‐leaf stage in the greenhouse with four N rates of 0, 30, 60, and 90 mg/kg and two water regimes (stressed for 8‐d, and unstressed). In the field experiment, four genotypes with different NUE history, were grown with N rates of 0, 60, 120, and 180 kg/ha, and water regimes of irrigated and dryland. Maximum grain yield was obtained at different N rates for different genotypes and for different water regimes. The genotypes differed significantly in NUE as expected, but also for water use efficiency (WUE) in both experiments. Nitrogen x water regime interac...

Viability of Weed Seeds Following Manure Windrow Composting

Introduction of weed seeds is a concern when using animal manure as a nutrient source on croplands. The viability of weed seeds can be reduced through composting. Experiments were conducted in 1996 and 1997 to determine the effects of manure windrow composting on seed viability of eight weed species. Weed seeds were placed in nylon bags and buried at 25 and 75-cm within the composting windrows of dairy manure and beef cattle feedlot manure with or without water addition. After one turning a week later, the seeds of most weed species survived the composting conditions in the dairy cattle manure. Following the four to five month dairy manure composting process, all weed seeds lost viability except for 14% of the velvetleaf (Abutilon theophrasti) seeds. This occurred even though the temperature within the composting dairy manure windrow never reached 60°C, which is considered necessary for weed seed destruction. In the watered beef feedlot manure, all weed seeds lost viability after one turning. However, seeds of most species survived after the first turning of the unwatered beef feedlot manure. The temperature in the feedlot manure windrows with water addition was higher and stayed high longer than other manure windrows. Composting process that generates high temperature (≥60°C) can destroy seed viability after only one turning. When the composting materials are moist for most of the composting period, the viability of weed seeds can be reduced even though the critical temperature is not achieved possibly because of compost phytotoxins.

Spatial and temporal variability of soil nitrate and corn yield: Multifractal analysis

1997). Ferguson et al. (2002) found reduction in soil nitrate concentration due to variable rate fertilizer N High levels of residual soil NO3–N can contaminate ground water application in only 3 out of 12 site-years as compared by leaching through the soil. Our objective was to reduce the level and spatial variability of residual soil NO3–N while maintaining optiwith uniform N application. Machado et al. (2000) indimum corn (Zea mays L.) production by variable rate N fertilizer cated that management zones for variable rate fertilizer application. The experiment was located on a 60-ha sprinkler-irrigated and water applications should be based on information corn field in central Nebraska and included four N management pracabout soil elevation, texture, and soil nitrate. Spatial tices: uniform rate, variable rate (VRAT), variable rate at 75% of dependence of soil NO3–N was found to be time depenrecommended amount (VRAT @ 75%), and variable rate plus 10% dent in irrigated salad crops (Bruckler et al., 1997). (VRAT 10%). VRAT @ 75% decreased the amount of residual Fractal analysis can provide insight into the spatial or NO3–N in the soil while maintaining similar grain yield to the other temporal variability of crop or soil parameters. Fractal treatments, indicating over-application of N with treatments receiving analysis has been shown to be useful in a variety of the recommended rate. Increasing the recommended rate by 10% (VRAT 10%) did not increase corn yield or residual soil NO3–N. scientific disciplines. The use of fractals for numerical Based on multifractal spectrum, no consistent pattern of spatial varianalysis of soil and plant parameters is still a relatively ability of soil NO3–N was observed for each treatment across years. new technique. It has been used for characterizing soil Spatial variability in corn grain yield was much lower than that for structure (Eghball et al., 1993b; Perfect and Blevins, soil NO3–N, indicating noneffectiveness of using soil NO3–N spatial 1997), soil chemical and physical parameters (Burrough, distribution for variable rate N application unless some areas in the 1983), root morphology (Eghball et al., 1993a), temporal field are severely N deficient. Variable rate N application did not yield variations (Eghball and Power, 1995; Eghball and reduce variability of residual soil NO3–N or corn grain yield as comVarvel, 1997), and spatial variability of soil and crop pared with uniform N. Multifractal analysis quantitatively characteryield (Eghball et al., 1997, 1999). Fractal analysis was ized the extent and pattern of spatial and temporal variability in corn grain yield and residual soil nitrate. found to be useful in characterizing soil and plant parameters that was not possible or very difficult to do before. Fractal dimension (D) of a curve can have a value between 1 and 2, giving a quantitative indication R developments in agricultural technology have of the function’s shape or roughness. made site-specific fertilizer application a reality. Multifractal analysis has been proposed for determiVariable rate (site-specific) N application should pronation of spatial variability of soil parameters (Folovide the plant with the appropriate amount of N while runso et al., 1994; Kravchenko et al., 1999, 2000). Multireducing the quantity and variability of residual soil fractal parameters were found to reflect many of the NO3–N after harvest. One may also expect to find a more major aspects of variability in soil properties, provided homogeneous yield response across the field following a unique quantitative characterization of the data spatial adoption of variable rate N application. By reducing distribution, and multifractal parameters were useful in variability and quantity of residual soil NO3–N, its leachchoosing an appropriate interpolation procedure for maping and subsequent ground water contamination potenping soil properties (Kravchenko et al., 1999). Multitial should be reduced. Eghball et al. (1999) found that the extent of variability in residual soil NO3–N was sigfractal analysis was used to characterize particle-size nificantly reduced following adoption of variable rate distribution of soils with wide range of particle sizes N application in a continuous corn system under gravity (Posadas et al., 2001). A single fractal dimension might irrigation. The residual soil NO3–N to a depth of 0.9 m not be sufficient to characterize soil spatial variability was high (avg. 6.8 mg kg 1, max. 12.0 and min. 2.4) across because of the heterogeneous nature of soil parameters. the field before initiation of variable rate N application. A set of fractal dimensions, called a multifractal specAfter 1-yr variable rate N application, average residual trum, is referred to as multifractal analysis (Frisch and soil NO3–N was 5.0 mg kg 1 with a maximum of 7.9 and Parisi, 1985). Multifractal analysis needs to be evaluated a minimum of 3.7. In another study where residual soil to determine its usefulness in comparing spatial variabilNO3–N was low (avg. 4.0 mg kg 1, max. 7.8 and min. ity of soils treated with different treatments. The objec1.5), variable rate N application did not significantly tive of this study was to characterize and compare spatial reduce residual soil NO3–N variability (Eghball et al., and temporal variability of residual soil NO3–N and corn grain yield in a variable rate N study using multifractal analysis. B. Eghball, J.S. Schepers, and M.R. Schlemmer, USDA-ARS, 121 Keim Hall, Univ. of Nebraska, Lincoln, NE 68583; and M. Negahban, Dep. of Eng. Mechanics, Univ. of Nebraska, Lincoln, NE 68583. Joint Abbreviations: adiff, the distance between minimum and maximum contribution of the USDA-ARS and the Univ. of Nebraska Agric. a values of each multifractal spectrum; CEC, cation exchange capacity; Res. Div., Lincoln, NE, as paper no. 13618. Received 9 Feb. 2002. VRAT, variable rate; VRAT @ 75%, variable rate at 75% of the *Corresponding author (beghball1@unl.edu). recommended amount; VRAT 10%, variable rate of the recommended amount plus 10%. Published in Agron. J. 95:339–346 (2003).

Runoff and Erosion Following Field Application of Beef Cattle Manure and Compost

Manure or compost from beef cattle feedlots can be excellent sources of nutrients and organic matter when added to soils. This study was conducted to determine the effect of a single application of manure and compost on runoff and erosion under no-till and tillage conditions. Tillage consisted of a single disking operation up and down the slope on a Sharpsburg soil which was cropped to grain sorghum or wheat the previous season. Manure and compost were applied at rates required to meet corn fertility requirements. Additional experimental treatments included the application of inorganic fertilizer and an untreated check. The addition of manure or compost to the no-till plots containing sorghum or wheat residue resulted in significant reductions in residue cover. However, residue cover following tillage was unaffected by the earlier addition of manure or compost. Runoff and erosion from simulated rainfall were not significantly influenced by the single application of manure or compost. On the no-till sorghum residue treatments, total solids transport represented 5.1% and 3.3% of the mass of applied manure and compost, respectively. Total solids transport was 1.3% and 1.4% of the mass of applied manure and compost, respectively, on the no-till wheat residue treatments.

Automated Gas Sampling System for Laboratory Analysis of CH4 and N2O

Analyzing the flux of CH4 and N2O from soil is labor intensive when conventional hand injection techniques are utilized in gas chromatography. An automated gas sampling system was designed and assembled from a prototype developed at the National Soil Tilth Laboratory in Ames, IA. The sampler was evaluated for accuracy and precision when attached to a Varian1 3700 gas chromatograph configured with flame ionization and electron capture detectors. The automated gas sampling system is easy to operate and provides acceptable results (standards ranging from 1.0–5.0 ppmv CH4 and 0.342–2.0 ppmv N2O had coefficients of variation ranging from 1.7–5.6%) while providing an economical approach for analyzing large numbers of gas samples with minimal labor and equipment cost. 1Mention of commercial products in this paper is solely to provide specific information for the reader. It does not constitute endorsement by the USDAs Agricultural Research Service or the University of Nebraskas Agricultural Research Division over other products that may be suitable. †This paper is a joint contribution of the U.S. Department of Agriculture and University of Nebraska-Lincoln. Published as Journal Series Number 13107.

Fractal analysis of spatial and temporal variability

Abstract Characterizing spatial and temporal variability is important in variable rate (VRAT) or long-term studies. This study was conducted to compare spatial variability of soil nitrate in a VRAT nitrogen (N) application study and temporal variability of soybean (Glycine max L.) yield in a long-term organic vs. inorganic study. In the VRAT study, conventional uniform N application was compared with variable rate and variable rate minus 15% N. In the long-term experiment, soybean yields under organic (manure application), fertilizer, and fertilizer plus herbicide systems were studied from 1975 to 1991. Semivariograms were estimated for soil nitrate in the VRAT and for soybean yield in the long-term study. The slope of the regression line of log semivariogram vs. log lag (h, distance or year) was used to estimate the fractal dimension (D), which is an indication of variability pattern. The intercepts (log k) of the log–log lines, which indicate extent of variability, were also compared between treatments. There was no significant effect of the N treatments on the D-values in the VRAT study. The extent of spatial variability for residual soil nitrate became significantly less after imposing N application regimes. The variable rate N application had lower log k-values than uniform application indicating reduced soil nitrate variability with VRAT N application. In the long-term study, all three management systems had similar D and log k-values for soybean yield indicating similar temporal yield variability for the three systems. The three management systems used did not change temporal effects on soybean yield. Rainfall during July and August accounted for 65% of variability in soybean grain yield. Fractal and covariance analyses can be effectively used to compare treatments or management systems for spatial or temporal variability.