| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
a Dep. of Agronomy, Kansas State Univ., Manhattan, KS 66506
b Kansas Agric. Exp. Stn
* Corresponding author (chad.godsey{at}okstate.edu)
Received for publication March 16, 2006.
 |
ABSTRACT |
|---|
 TOPNOTES ABSTRACT INTRODUCTIONMATERIAL AND METHODSRESULTS AND DISCUSSIONCONCLUSIONSREFERENCES |
|---|
Abbreviations: DTPA, diethylenetriaminepenta-acetic acid • ECC, effective calcium carbonate • ICP, inductively coupled plasma • NT, no-till • OC, organic carbon • OM, organic matter
|
INTRODUCTION |
|---|
|
TOPNOTESABSTRACTINTRODUCTIONMATERIAL AND METHODSRESULTS AND DISCUSSIONCONCLUSIONSREFERENCES |
|---|
Moschler et al. (1973) found surface application of lime to be satisfactory in increasing corn grain yield in NT systems for a Frederick silt loam soil. On average, they found that surface application of limestone increased grain yield by 31.3% compared with the control. Vertical movement of limestone in the study was not measured because soil samples were collected to a depth of 20 cm in 10-cm increments. Research in Kentucky by Blevins et al. (1978) suggested that surface application of lime without incorporation is an efficient way to overcome soil acidity caused by N fertilization of NT corn. Movement of lime in this study was observed to a depth of 30 cm when limestone was applied at a rate of three times the lime requirement. Depth of limestone movement strongly correlated with lime application rate.
Edwards and Beegle (1988) considered the effects of surface application of limestone in a long-term NT system that had become acid (pH 4.5 in the surface 5 cm) in Pennsylvania. In their study, lime was surface-applied every year to every fifth year at rates of 0, 3360, 6720, and 10080 kg ECC ha–1. A rapid increase in soil pH was observed in the surface 5 cm of soil in the first 4 yr of the study, whereas changes below that were not observed until 4 yr after lime application. Nine years after limestone application, soil pH in the 5- to 15-cm depth had not reached the target pH of 6.5. Frequency of limestone application did not affect final soil pH or vertical movement of limestone in this study. Grain yield response from lime application generally was insignificant. Tissue analysis of corn leaves indicated that Ca uptake was increased significantly by limestone, whereas Mn uptake was significantly reduced. In addition, a reduction in Zn and Cu uptake was observed.
Conyers et al. (2003) also observed little movement of surface-applied limestone in southeastern Australia (precipitation of 570 mm yr–1) on a soil with 290 g kg–1 clay and 22 g kg–1 organic matter (OM). They observed an increase in pH 4 yr after limestone application at a depth of 10 cm, and application of limestone was not effective in increasing pH below that depth for a period of 8 yr.
Recent research in Brazil by Caires et al. (2005) evaluated the downward movement of surface-applied dolomitic limestone in NT systems and the effect on grain yields under crop rotation. Treatments consisted of 0, 2000, 4000, and 6000 kg dolomitic limestone ha–1, calculated to increase the base saturation to 50, 70, and 90%, respectively, in the surface 20 cm of soil, which was initially at 32%. Lime treatments significantly increased pH and base saturation, and decreased KCl-extractable Al in the 0- to 5- and 5- to 10-cm depths within the first year of lime application. After 2.5 yr, the same significant treatment differences were observed. They found the maximum economic yield was obtained at 4000 kg limestone ha–1.
A limited amount of data exists to identify the effects of surface application of lime in production systems receiving <1000 mm of annual rainfall. The objectives of this study were to (i) determine the vertical movement of surface-applied liming material, (ii) evaluate the effect of surface application of lime on specific soil chemical soil properties, and (iii) determine the correct application rate of lime for acidic soils under NT management.
|
MATERIAL AND METHODS |
|---|
|
TOPNOTESABSTRACTINTRODUCTIONMATERIAL AND METHODSRESULTS AND DISCUSSIONCONCLUSIONSREFERENCES |
|---|
|
In 2002, an additional NT field site [Marshall County (MS), 39°40' N, 96°20' W] (Table 1) in Kansas with below-optimal soil pH (<6.0) in the surface 15 cm was added to the experiment. This location had been in NT since 1996. At this site the recommended lime rate to raise pH to 6.8 was 8400 kg ECC ha–1. Nine treatments were imposed at this site that included an unlimed check and four rates of limestone and pelletized limestone (224 kg ECC ha–1, 25%, 50%, and 100% of the recommended rate). All treatments were hand-applied in the spring of 2002 as one-time applications, except the 224-kg ECC ha–1 treatment, which was applied annually for 3 yr (672 kg ECC ha–1 total). The final application of this treatment was made before soil sampling in 2005. Treatments were replicated three times in a randomized complete block design. Individual plot size was 4.5 m wide and 6 m in length. Crops grown at MS included soybean (2002 and 2004), corn (Zea mays L.) (2003), and winter wheat (2005). Wheat and soybean were planted in 19-cm rows at rates of 67 kg ha–1 and 246913 seeds ha–1, respectively. Corn was planted in 76-cm rows at a rate of 54320 seeds ha–1.
Individual limestone rates were on an ECC basis at all sites. The ECC of the commercially available limestone was 55% and that of the pelletized limestone was 86%. Plots were fertilized and treated by the cooperating producers as part of the entire field except for the treatments herein. At CLA, 90 and 82 kg N ha–1 were surface-applied to wheat in 2002 and 2004, respectively, and 63 kg N ha–1 to grain sorghum in 2004. No fertilizer was applied to soybean. At CLB, grain sorghum and wheat received 78 kg N ha–1 (surface applied) and soybean received 94 L 10–34–0 ha–1 applied over the row at planting each year the respective crops were grown. At MS, corn received 112 kg N ha–1 and 43 kg P2O5 ha–1 applied at planting 5 cm below and 5 cm to the side of the seed. Wheat received 56 kg N ha–1, while no fertilizer was applied to soybean.
Soil Sampling and Analysis
Samples were taken each spring to a depth of 15 cm and separated into 2.5-cm increments to monitor the movement of surface-applied limestone during the experimental period. In the spring of 2005 (the last year of the experiment), samples were taken to a depth of 30 cm; the surface 15 cm was separated into 2.5-cm increments and the lower 15 cm was separated into 7.5-cm increments. In all years, 14 2.5-cm-diameter soil cores were taken in each plot and then homogenized into a single sample for each plot and depth. Samples were analyzed for pH (1:1 soil–water) with a AS-3000 Dual pH Analyser (Labfit Pty Ltd., Burswood, Western Australia) (Watson and Brown, 1998); 1 M ammonium acetate-extractable K, Ca, and Mg (Warncke and Brown, 1998); Mehlich3-extractable P (Frank et al., 1998); KCl-extractable Al (Bertsch and Bloom, 1996); diethylenetriaminepenta-acetic acid (DTPA)-extractable Cu, Fe, Mn, and Zn (Whitney, 1998); and organic carbon (OC) by dry combustion using a LECO CN-2000 (LECO, St. Joseph, MI) (Nelson and Sommers, 1996). Calcium, Mg, K, Al, and DTPA-extractable micronutrient concentrations in the extracts were determined by inductively coupled plasma (ICP) atomic emissions spectrometry by using a Fison Model Accu-141 ICP (Fison Instruments, Dearborn, MI). Mehlich3 P concentrations were determined colorimetrically with a QuikChem 8000 (QuikChem Methods, Lachat Instruments, Milwaukee, WI). Not all analyses were performed at each sample depth of samples collected in 2005, due to cost and time considerations.
Tissue Sampling and Analysis
In 2005, leaf tissue samples were taken from all sites and analyzed for N, P, and K after digestion with H2SO4–H2O2 (Linder and Harley, 1942; Thomas et al., 1967). Twenty samples were collected in each plot from every fifth plant in the non-harvested rows. Leaves at boot stage (Feekes growth stage 10) (Miller, 1999) for winter wheat were taken. The most recently developed trifoliate on soybean plants was collected at growth stage R5 (Iowa State University, 1994). All samples were dried at 60°C and ground to pass a 0.5-mm stainless steel sieve. Concentrations of N and P in the digest sample were measured with a Technicon Auto Analyzer II according to Technicon Industrial Method 334–74W/B+ (Technicon Industrial Systems, Tarrytown, NY). Potassium concentration in the digest was determined by using flame atomic emission (Model 3110, PerkinElmer Instruments, Norwalk, CT). In addition, Ca, Mg, Cu, Mn, Fe, Zn, and S concentrations were determined by using a perchloric digestion (Geiseking et al., 1935). Concentrations of analytes in the digest were determined by ICP.
Grain Yield and Analysis
Yield was determined by hand-harvesting a 6-m length of row from the middle of each small plot. For crops grown on 76 cm rows, the middle two rows were harvested, while for crops grown on 19 cm rows three rows of each plot were harvested. Grain was separated mechanically and then weighed. Corn, soybean, wheat, and grain sorghum yields were adjusted to 155, 130, 125, and 125 g kg–1 moisture content, respectively. A grain subsample was ground to pass a 0.5-mm stainless steel sieve and analyzed using methods identical to those described for tissue analysis.
Statistical Analysis
Data for soil, plant tissue, and grain were analyzed according to the GLM procedure in SAS (SAS Institute, 1998). Locations were analyzed separately each year. Soil sampling depths were analyzed separately (i.e., results from 2.5 cm depth increments were compared against each other and not to other depths). Contrasts were used to determine individual treatment differences and to determine differences between liming materials at a probability level of 0.05.
|
RESULTS AND DISCUSSION |
|---|
|
TOPNOTESABSTRACTINTRODUCTIONMATERIAL AND METHODSRESULTS AND DISCUSSIONCONCLUSIONSREFERENCES |
|---|
|
7 mg kg–1 in the 2.5- to 5-cm depth, compared with that of the control. All treatments receiving limestone had similar concentrations of KCl-extractable Al at all depths. Concentrations of KCl-extractable Al were <27 mg kg–1 (0.3 cmol kg–1), which is the critical level for KCl-extractable Al determined by Unruh (1988) for winter wheat in Kansas.
Site CLB
At CLB, lime movement to a depth of 7.5 cm was detected as indicated by increases in pH (Table 3). Evidence of limestone movement below the 7.5-cm depth was not observed at this site. Precipitation was similar to CLA during the 5 yr of the study. Application of 4480 kg ECC ha–1 increased pH by 1.2 and 0.9 units, compared with the control, at the 0- to 2.5- and 2.5- to 5-cm depths, respectively. At 0 to 2.5 cm, pH increased from 0.5 to 1.6 units for treatments receiving limestone, compared with the control. The 2240 kg ECC ha–1 rate of limestone increased pH by 1.0 units in the 0- to 2.5-cm depth and by 0.6 units in the 2.5- to 5-cm depth, compared with the control. But, at the 5- to 7.5-cm depth, the 2240-kg ECC ha–1 rate of limestone was similar to the control. Contrasts indicated no differences in pH when comparing pelletized lime and commercial limestone (P > F = 0.91, 0.30, and 0.45 for the 0- to 2.5-, 2.5- to 5-, and 5- to 7.5-cm depth, respectively). The 1120 kg ECC ha–1 rate of limestone was omitted from the contrast because this treatment inadvertently received an additional 1120 kg ECC ha–1 rate of limestone in the spring of 2004. This explains the greater pH in the surface 2.5 cm, compared with the 1120 kg ECC ha–1 rate of pelletized limestone.
|
Site MS
Movement of limestone only to the 5-cm soil depth was evident at the MS site (Table 4). The application of limestone increased pH in the surface 2.5 cm of soil by a minimum of 0.6 units with the 224 kg ECC ha–1 annual application and by a maximum of 1.5 units with the application of 8400 kg ECC ha–1. The application of limestone and pelletized limestone at 8400 kg ECC ha–1 increased pH compared with the control by an average of 0.9, at the 2.5- to 5-cm depth. Below-normal annual precipitation amounts of 385, 239, and 574 mm in 2002, 2003, and 2004 (Kansas State University Research and Extension, 2005), respectively, may have limited the movement of limestone at this site. Additionally, surface-applied lime has only had 3 yr to react, which may have influenced the limited movement observed. Response in pH change from the addition of limestone and pelletized limestone was similar at the 0- to 2.5- and 2.5- to 5-cm depths (P > F 0.75 and 0.93, respectively).
|
Figure 1 shows the annual changes in pH at all three sites, pH of the one-time 4480 kg ECC ha–1 treatment (CLA and CLB) or the 8400 kg ECC ha–1 treatment (MS) minus the pH of the control for each year after initial lime application. At CLA, little change in pH was observed from 2002 to 2004. However, in 2005, pH seemed to increase compared with the control, indicating additional reaction of limestone. Reaction of limestone at CLB seemed to be complete by 2003, as decreases in pH were observed since that time. Reaction of limestone at MS appears to still be occurring given the change that was observed from 2004 to 2005.
|
Application rates of limestone at these field sites failed to increase soil pH to 6.8 in the uppermost 15 cm of soil. Reasons for this failure may include low lime application rates, insufficient soil-to-limestone contact, and lack of moisture at soil surface. But, the failure to reach a target pH of 6.8 may also be an indication that the SMP buffer should be recalibrated for soils in NT management systems or that an alternative method for determining limestone requirement should be identified.
The type of liming material had no effect on any of the chemical soil characteristics measured at any of the three sites. This is not surprising since both pelletized limestone and commercial limestone were applied based on ECC. The only potential advantage of pelletized limestone, compared with commercially available limestone, is relative ease of application, which may or may not justify the higher cost. Also, the frequency of limestone application did not have an effect on any of the chemical characteristics at any of the sites.
Surface application of limestone at half of the full rate recommended by Kansas State University consistently decreased KCl-extractable Al to near-detection limits (2 mg kg–1) in the uppermost 7.5 cm of soil. Increasing the pH to alleviate Al toxicity at this depth is probably the most critical effect of liming because the seed is typically placed in the 0- to 5-cm zone at planting; pH lower in the soil profile (>15 cm from surface) usually increases and Al toxicity is less of a concern. At a depth of 7.5 to 15 cm, pH can either be as acid as the surface 7.5 cm or start to increase. Factors that determine soil acidity in the 7.5- to 15-cm depth include fertilizer placement, years in NT management, inherent soil characteristics, and natural acidification rate of the soil.
Lime source, rate, and frequency of application had no effect on Mehlich3 P extraction at any of the experimental sites. This is surprising because maximum P solubility occurs within a pH range of 6.0 to 6.5 (Lindsay, 1979). Mehlich3 P concentrations in the surface 2.5 cm of soil at CLA, CLB, and MS ranged from 113 to 131, 99 to 139, and 76 to 109 mg kg–1, respectively.
Ammonium acetate-extractable Ca was generally increased to a 5-cm soil depth with surface-applied limestone compared with the control. Limestone source did not affect Ca concentrations at any of the sites. Extractable Ca concentrations in the surface 5 cm of soil at CLA, CLB, and MS decreased an average of 900, 1235, and 1340 mg kg–1, respectively, when comparing the full recommended rate of lime to the control. Potassium and Mg were not affected by lime application (data not shown).
Data is not shown for DTPA-extractable Cu, Fe, Mn, and Zn because no unexpected differences among limestone treatments were observed at any of the experimental sites. Consistent decreases in extractable Cu and Fe from limestone application were observed at all sites. This is not unexpected because when pH increases, solubility of Cu, Fe, and Mn decreases (Lindsay, 1979). Extractable Cu concentrations decreased by an average of 0.3, 0.2, and 0.3 mg kg–1 in the surface 5 cm of soil at CLA, CLB, and MS, respectively, when comparing the full recommended rate of commercial lime to the control. Extractable Fe concentrations decreased by an average of 41, 50, and 28 mg kg–1 in the surface 5 cm of soil at CLA, CLB, and MS, respectively, when comparing the full recommended rate of commercial lime to the control. Application of lime caused a consistent decrease in DTPA-extractable Mn at Sites CLA and CLB in the surface 7.5 cm and 5 cm, respectively (Table 5). At the MS site a decrease in extractable Mn in the 0- to 2.5-cm soil depth was observed from the application of lime in the surface 2.5 cm of soil. Treatment differences in DTPA-extractable Zn were not detected. Extractable Zn concentrations ranged from 1.4 to 1.6, 1.2 to 1.6, and 1.6 to 2.9 mg kg–1 at Sites CLA, CLB, and MS, respectively, in the surface 2.5 cm of soil.
|
|
Plant tissue Mn concentration results agree with what Unruh (1988) observed. He found no consistent trends in Mn concentration of wheat (collected at boot stage) or grain sorghum plant tissue (collected at boot stage) growing on acid soils in south-central Kansas. Manganese concentrations did decrease in plant tissue two out of four site years in limed plots, but Mn concentrations would not have been considered deficient (Mills and Jones, 1996). Edwards and Beegle (1988) also observed reduced Mn uptake in corn after surface application of limestone. They also observed a reduction in Zn and Cu uptake, which we did not detect in our study.
Few differences were detected in nutrient concentrations of harvested grain. For three out of five site years, however, limestone applications decreased Mn concentrations in grain (data not shown). This occurred at CLB in 2005 (wheat), MS in 2004 (soybean), and MS in 2005 (wheat). Concentrations of Mn in grain corresponded to lower concentrations of Mn in soil and plant tissue.
Grain Yield
At CLA, soybean grain yields (Table 7), when grown were generally at (2000 and 2005) or below (2003) the county averages (National Agricultural Statistics Service, 2005), indicating the presence of other potential crop-production problems unrelated to soil acidity. One potential problem was the presence of an apparent clay pan in the rooting zone (25 cm below surface) which may have prohibited deep root development, making crops more sensitive to drought stress. Grain yields at CLB in Cowley County were generally higher than the county averages (National Agricultural Statistics Service, 2005). Measured grain yields at MS (Table 8) were low, and this was likely due to below-normal precipitation received at this site.
|
|
Given the lack of grain yield response, the application of limestone to soils above pH 5.5 seems uneconomical in corn, grain sorghum, soybean, and wheat production systems. A study by Warmann (1995) suggests limestone applications should be treated as a multiyear investment. An economic analysis performed by Warmann (1995) for south-central Kansas wheat producers found that an 86 kg ha–1 increase in wheat grain yield was needed annually for a 7-yr period to offset the $1.68 ha–1 associated with an application of 2240 kg limestone ha–1, assuming the price of wheat is $0.05 kg–1. But, this analysis assumed a reduction of P fertilizer application by $1.22 ha–1 yr–1 due to more P becoming available to the plant as pH increases. This may not be an accurate assumption because the data from this study found no differences in Mehlich3 P concentrations due to the application of limestone. If pH levels are <5, this may be an appropriate assumption.
Another consideration of liming NT managed acidic soils is the likelihood of herbicide carryover. For example, 6-chloro-N-ethyl-N'-(1-methylethyl)-triazine-2,4-diamine (atrazine) is strongly adsorbed to soil particles at low soil pH (<6), making it less available for breakdown. But, at high soil pH (>6.5), atrazine is extremely soluble in the soil, producing potentially toxic effects even when concentrations in the soil as a whole are very low. Scharf et al. (2002) observed a soybean yield loss of 336 kg ha–1 as a result of the application of atrazine to soils the previous year where limestone had been surface broadcast in Missouri. They estimated $4.1 million yr–1 of lost income in Missouri due to atrazine carryover on limed NT managed soils. Surface application of limestone could also increase the potential of atrazine entering surface waters through runoff because of the increased solubility of atrazine. Chinkuyu and Kanwar (1999) measured greater concentrations of atrazine in leachate as a result of limestone application in soil columns, compared with the unlimed soil. Issues regarding herbicide carryover should be considered when surface-applying lime to reduced or nontilled soils.
|
CONCLUSIONS |
|---|
|
TOPNOTESABSTRACTINTRODUCTIONMATERIAL AND METHODSRESULTS AND DISCUSSIONCONCLUSIONSREFERENCES |
|---|
Application of limestone at three field sites failed to increase the pH in the uppermost 15 cm to 6.8. Reasons for underestimation of the limestone requirement from the SMP may include low application rates and slow reaction between the soil and limestone. The failure to reach a target pH of 6.8 at two locations where the full recommended rate was applied may be an indication that the SMP buffer should be recalibrated for NT managed soils similar to the ones used in this study, or an alternative method for determining limestone requirement should be identified. The type of liming material had no effect on any of the chemical soil characteristics measured at any of the three sites. Also, frequency of limestone application did not have an effect on any of the chemical characteristics or grain yield at any of the sites. Delaying limestone application for NT corn, soybean, grain sorghum, and wheat until pH is below pH 5.5 seems reasonable as long as soils at depths > 7.5 cm are not extremely acid (pH < 5.5). Proper management of NT acid soils is an important part of making these systems sustainable.
|
NOTES |
|---|
|
TOPNOTESABSTRACTINTRODUCTIONMATERIAL AND METHODSRESULTS AND DISCUSSIONCONCLUSIONSREFERENCES |
|---|
|
REFERENCES |
|---|
|
TOPNOTESABSTRACTINTRODUCTIONMATERIAL AND METHODSRESULTS AND DISCUSSIONCONCLUSIONSREFERENCES |
|---|
This article has been cited by other articles:
|
|
 |
|
  M. J. Schlossberg, F. C. Waltz Jr., P. J. Landschoot, and B. S. Park Recent Mechanical Cultivation of Lawns Enhances Lime Application Efficacy Agron. J., May 7, 2008; 100(3): 855 - 861. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Crop Science | Vadose Zone Journal | |||
| Journal of Natural Resources and Life Sciences Education |
Soil Science Society of America Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||
