Published in Soil Sci. Soc. Am. J. 67:1920-1927 (2003).
© 2003 Soil Science Society of America
677 S. Segoe Rd., Madison, WI 53711 USA
DIVISION S-8—NUTRIENT MANAGEMENT & SOIL & PLANT ANALYSIS
Broadcast and Deep-Band Placement of Phosphorus and Potassium for Soybean Managed with Ridge Tillage
Rogerio Borges and
Antonio P. Mallarino*
Dep. of Agronomy, Iowa State Univ., Ames, IA 50011
* Corresponding author (apmallar{at}iastate.edu).
 |
ABSTRACT
|
|---|
The efficiency of broadcast and band P and K placement methods for ridge tilled soybean [Glycine Max (L.) Merr.] has not been extensively researched. This study evaluated grain yield, early plant growth, and nutrient uptake (V5–V6 stages), and soil-test responses to broadcast and deep-band (15–20 cm below the ridge surface) placements in 14 trials. Fertilizer rates were 0, 14, and 56 kg P ha-1 and 0, 33, and 132 kg K ha-1. A randomized complete-block design was used. Soil-test P (STP) was 7 to 61 mg kg-1 (Bray-P1 test, 15-cm depth) and soil-test K (STK) was 100 to 197 mg kg-1 (ammonium acetate test). Phosphorus increased yield (P 
0.1) at four sites. Band P was better at one site (30 kg ha-1) and broadcast P was better (40 kg ha-1) at another site. Both P placements increased dry weight (DW) at two sites. Yield and DW responses to P were observed when STP was <19 mg kg-1. Phosphorus increased plant P uptake at eight sites, and band P was better than broadcast P at three sites. Potassium increased yield at two sites, and only band K increased yield at one of these sites. Potassium increased DW at four sites, and increases were always larger for band K. Band K increased K uptake at 10 sites and broadcast K increased K uptake only at two sites. Soil-test P in ridges predicted P sufficiency better than mean STP from ridges and valleys at two sites. Although K fertilization seldom increased yield in this study, increased plant K uptake with banding compared with broadcasting suggests that banding may be more efficient for grain production in other conditions.
Abbreviations: DW, dry weight • STP, soil-test P • STK, soil-test K
|
INTRODUCTION
|
|---|
IN THE USA MIDWEST, soybean usually is grown in rotation with corn (Zea mays L.). Research for either soybean or corn managed with plow or chisel-disk tillage has shown that P fertilization seldom increases yield when STP is >20 mg kg-1 (Bray-P1 test) in the surface 15 to 20 cm of soil (deMooy et al., 1973; Rehm et al., 1981; Rehm, 1986; Walker and Raines, 1988; Mallarino et al., 1991a; Webb et al., 1992). Studies with K have shown less consistent results than for P, although both corn and soybean have shown little or no yield response to K in soils with STK >100 to 150 mg kg-1 (ammonium acetate test) (Hanway et al., 1962; deMooy et al., 1973; Rehm et al., 1981; Walker and Raines, 1988; Mallarino et al., 1991a,b).
After an extensive review, deMooy et al. (1973) concluded that the frequency of nonresponsive soils in conditions where a response was expected was higher for soybean than for corn. They explained this result by greater nutrient uptake efficiency of soybean for soil derived P and K and less sensitivity to periods with soil moisture deficiency. Long-term Iowa research (Mallarino et al., 1991a, Mallarino et al., 1991b; Webb et al., 1992) showed that STP and STK values needed to maximize soybean and corn yield were approximately similar, but the relative yield response to fertilization was greater and more consistent for corn. Perhaps influenced by these results, most corn-soybean producers apply the P and K requirements of the 2-yr rotation once before planting corn.
Current soil-test interpretations and sampling methods may, or may not, apply to reduced tillage systems such as no-tillage or ridge-tillage. Large accumulations of P and K occur in the surface 5 to 10 cm of the soil under reduced tillage systems (Kitchen et al., 1990, Karlen et al., 1991; Rehm et al., 1995; Bordoli and Mallarino, 1998; Varsa and Ebelhar, 2000; Borges and Mallarino, 2000, 2001). Fertilizer response studies in Illinois (Vasilas et al., 1988; Ebelhar and Varsa, 2000) and Ohio (Hudak et al., 1989) showed no differences between K fertilization needs of soybean managed with plow, chisel-plow, or disk tillage systems. Hairston et al. (1990) showed that no-till soybean responded more to band P and K than to broadcast fertilization in two of three Mississippi soils, while conventionally tilled soybean responded similarly to all placement methods. Recent Iowa research with no-till soybean (Borges and Mallarino, 2000; Buah et al., 2000) showed that P fertilization often increased yield in low-testing soils but band or broadcast placement methods did not differ. The study by Buah et al. (2000) showed no difference between planter-band and broadcast K placements. The study by Borges and Mallarino (2000) reported small and agronomically insignificant additional response to deep-band K (15- to 20-cm depth) or planter-band K compared with broadcast K in soils with STK optimum or higher for soybean managed with chisel-plow or disk tillage. Most referenced studies showed, however, that band K usually increased tissue P and K concentrations or uptake compared with the broadcast K mainly during early vegetative growth periods.
The area of soybean and corn managed with ridge tillage in the Midwest increased until the late 1980s but has remained approximately constant during the 1990s (CTIC, 2000). Ridge tillage leads to accumulation of P and K in the ridges during crop growth because of the tillage operations and limited movement of these nutrients in soil (Karlen et al., 1991; Rehm, 1992; Borges and Mallarino, 2001). The ridges are built when crops are 20 to 30 cm tall, and are left undisturbed until planting time of the next season when a device on specialized planters opens the ridge and transfers soil to interrow positions (i.e., valleys). This operation transfers soil and any fertilizer and residue from the ridges to the valleys, and several weeks later the ridge rebuilding operation reverses this action. Therefore, when P or K fertilizers are broadcast before planting, mixing of fertilizer and soil takes place in the valleys at planting and only weeks later in the ridge.
Banding of P and K below the seeding level depth could increase fertilizer-use efficiency, plant growth, and grain yield in soybean managed with ridge tillage. Research in Minnesota (Rehm, 1992) and Iowa (Borges and Mallarino, 2001) showed larger corn yield response to preplant deep-band K (15–20 cm below the ridge surface) compared with broadcast K application but little or no difference between P placement methods. These studies and others (Rehm et al., 1995) suggested that collecting soil samples only from ridge positions may predict P needs of ridge-tilled corn better than a random sampling from ridges and valleys. The objective of this study was to assess grain yield, early plant growth, and early P and K uptake of ridge-tilled soybean as affected by direct and residual P and K fertilization using preplant broadcast or deep-band application methods.
|
MATERIALS AND METHODS
|
|---|
Fourteen P-K response trials with soybean were evaluated in farmers' fields managed with ridge tillage during 3 yr. Summarized information about management practices and soil characteristics are shown in Tables 1 and 2. All fields had been planted to corn the previous year, and the fields had 2- to 7- yr histories of ridge tillage management. Crop and soil management practices (except P and K fertilization) were those used by each farmer. Plots in each trial were 18.3-m long and four to six rows wide. The row spacing was 96 cm except for Site 3 where it was 91 cm.
Treatments (14) were the factorial combinations of three P rates and two placement methods, the factorial combinations of three K rates and two placement methods, and one P-K mixture applied with the two placement methods. The P rates were 0, 14, and 56 kg P ha-1 (using granulated triple superphosphate) and the K rates were 0, 33, and 132 kg K ha-1 (using granulated KCl). The placement methods were broadcast and deep bands approximately 2.5 cm wide placed 15 to 20 cm below the surface of each ridge. Each P or K factorial had its own set of control treatments. The two broadcast controls (one for P and one for K) received no P or K and the ridge was not disturbed until the planting operation. The two deep-band controls (one for P and one for K) received a coulter-knife pass without fertilizer application. The P-K mixture applied 56 kg P ha-1 and 132 kg K ha-1. The high rates were the 2-yr P and K rates recommended by the Iowa State University Soil and Plant Analysis Laboratory for the corn-soybean rotation in low-testing soils. The low P and K rates were considered insufficient to maximize yield in low-testing soils or to maintain current STP and STK levels in Iowa (Voss et al., 1999). The broadcast treatments were applied by hand and the band treatments were applied with commercial deep banders. The banders placed the fertilizer either through a vertical slit opened from the top of the ridge or through one ridge shoulder. The coulter-knife combinations opened and closed narrow slits (2.5–5 cm) that caused the smallest possible disturbance of the ridge, and placed the band 5 to 7.5 cm below the planned seeding depth.
Soybean response to direct fertilizer application was evaluated in seven trials (Sites 1–7), and the treatments were applied in the fall (October or November) four to five months before planting, which is the P and K fertilization date used by most Midwest producers. The residual effects on soybean of similar treatments applied for the previous corn crops were evaluated in seven additional trials (Sites 8–14). The corn responses were published before (Borges and Mallarino, 2001).
Soil samples were collected immediately after harvest of the previous corn crop and before applying the treatments. In Sites 1 to 7, where direct fertilization effects were evaluated, composite soil samples were collected from each experimental area. In Sites 8 to 14, where residual fertilization effects were evaluated, composite samples were collected from each plot that had received the broadcast control treatment and from each plot that had received separate P and K rates either broadcast or deep-banded (the deep-band control treatment and the P-K mixture treatments were not sampled). In all instances, three 16-core (2-cm diameter) samples were collected from each sampling area to represent the 0- to 15-cm depth of the ridges, the 15- to 30-cm depth of the ridges, and the 0- to 15-cm depth of the valleys between the ridges. Samples were dried at 40°C and crushed to pass a 2-mm sieve. Soil-test P, STK, pH, and organic matter were determined for each sample following procedures recommended in several chapters of the North Central Region Publication 221 (Brown, 1998). Soil-test K was analyzed by the ammonium acetate test and STP by the Bray-P1 test. Table 2 shows mean STP and STK values and the corresponding Iowa State University interpretation classes for soybean at the time the study was conducted (Voss et al., 1999) for the experimental area of Sites 1 through 7 (before fertilization) and for the control plots of Sites 8 through 14 (because residual effects of treatments applied to previous corn crops were evaluated at these sites). The STP classes (expressed as mg P kg-1) are 0 to 8 for the very low class, 9 to 15 for the low class, 16 to 20 for the optimum class, 21 to 30 for the high class, and >30 for the very high class. Values for five (very low to very high) STK classes (expressed as mg K kg-1) are 0 to 60, 61 to 90, 91 to 130, 131 to 170, and >170.
The aboveground parts of 10 soybean plants were sampled from each plot at the V5 to V6 (15–20 cm tall) growth stages (Fehr et al., 1971) by excluding the central harvest area and avoiding plot borders. Plants were dried at 65°C, weighed, and ground to pass a 1-mm screen. Total P and K concentrations were determined by digesting 0.25 g from each sample with concentrated H2SO4 and H2O2 (Digesdahl Analysis System, Hatch Inc., Boulder, CO). The P in the digests was measured by colorimetry (Murphy and Riley, 1962) and the K was measured by flame photometry. Total P and K uptake were calculated for all treatments. Soybean grain yield was measured by cutting plants from 7.6-m sections of the two center rows of each plot and threshing with a stationary thresher. Grain moisture was measured by weighing about 0.5 kg of field-moist grain and weighing the grain again after drying it at 65°C for 6 d. Yield was adjusted to 130 g kg-1 moisture.
Completely randomized-block designs with three replications were used for all trials. Analyses of variance were performed for data from each site and across all sites assuming fixed block and treatment effects using SAS (SAS Institute, 2000). For yield and plant measurements, the treatments sums of squares was partitioned into (i) a comparison between the broadcast and deep-band controls, (ii) a P rate by placement complete factorial that excluded the P-K mixture (three rates, two placements, and an interaction), (iii) a similar K rate by placement factorial, and (iv) a set of single degree of freedom, nonorthogonal comparisons (one for each placement) between the P-K mixture and the equivalent high rate of P or K rate applied separately. Correlation and regression analysis were used to study relationships between yield response to fertilization and initial STP or STK. Analyses of variance were used to assess initial differences in STP and STK among plots of sites where the residual effects of treatments applied for a previous corn crop were evaluated (Sites 8–14).
|
RESULTS AND DISCUSSION
|
|---|
The deep-band control did not differ from the broadcast control (P 0.1) for grain yield, early plant growth, and P or K uptake in any trial. This result indicates no significant physical effects of the coulter-knife pass and, thus, means of the two controls will be shown. Also, grain yield, early plant growth, and nutrient uptake for the P-K mixture were always statistically similar (P 0.1) to equivalent P or K rates applied separately. Therefore, data for the P-K mixture are not shown in tables or discussed further and results for P and K treatments are discussed separately.
Phosphorus
One or more P fertilization treatments increased soybean grain yield (P 0.1) at two sites where fertilizer was applied for soybean (Sites 1 and 2) and at two sites (Sites 10 and 13) where fertilizer was applied for the previous corn crop (Table 3). Only the means of the two P rates are shown because statistically maximum yields (P 0.1) were always achieved with the lowest rate used with both placement methods. At Sites 1 and 13, the P placement methods did not differ. At Site 2, P applied with both placement methods increased yield but there was a small yield advantage (30 kg ha-1) for the deep-band method. At Site 10, there was a small yield advantage (40 kg ha-1) for the broadcast method, and nonorthogonal comparisons of each fertilized mean and the control (not shown) suggested that broadcast P increased yield but band P did not.
Soil of three responsive sites tested very low or low in STP and one tested optimum according to current Iowa interpretations (Table 2), which consider samples collected from a 0- to 15-cm depth from both ridge and valley positions. The lack of grain yield response at other low-testing sites was not expected. Although grain yield varied across locations, study of daily precipitation and air temperature data from the nearest weather station (distant from 3–10 km) to each trial (not shown) indicated no relationship between these measurements and crop response to P or to P placement method (soil moisture and temperature were not measured). Analyses included visual observations of rainfall amount and distribution over the growing season, as well as linear and curvilinear (quadratic) regression analyses between crop response and rainfall or temperature for seasonal, monthly, or weekly periods of time across sites. Such a lack of relationship between rainfall or temperature and crop response was also observed for ridge-tilled corn (Borges and Mallarino, 2001) and no-till soybeans (Borges and Mallarino, 2000).
One possible explanation for lack of response in some low-testing soils relates to the applicability of current STP interpretation classes to ridge tilled soybean. These classes were derived mainly from studies with soybean managed with plow or disk tillage, and in Iowa have been applied to ridge tilled soybean and soil samples collected across ridges and valleys. If the STP interpretations classes were determined by only the ridge sampling position, two low-testing nonresponsive sites (Sites 6 and 9) would be classified as optimum or high. Previous research with ridge-tilled corn (Rehm et al., 1995; Borges and Mallarino, 2001) showed significantly lower STP in the valleys than in ridge positions at comparable sampling depths. We found a similar result in this study (Table 2). Other researchers (Bauder et al., 1985, and Kaspar et al., 1991) have shown a 50% decrease in corn root growth within the surface 7.5-cm soil depth of trafficked valleys, which suggests a minor contribution of the nutrients in this soil volume to plant nutrient uptake under these conditions.
Observation of initial STP for soybean at sites where fertilizer was applied before a previous corn crop (Table 4) provides additional support for different assessment of plant-available P depending on the soil sampling position. Data for the low application rates are not shown because they seldom changed STP compared with values for the control. The high broadcast P rate never increased (P 0.1) STP of any ridge sampling position compared with the control, but almost always increased STP of the valleys. In contrast, band P almost always increased STP in the two ridge sampling positions and seldom increased STP of the valleys. Thus, the results showed that P banding was effective in minimizing P fertilization of the valleys and in increasing plant P availability in the ridge.
View this table:
[in this window]
[in a new window]
|
Table 4. Soil-test P for the control and high fertilizer rate treatments from seven trials that evaluated residual effects of P applied before the previous corn crop.
|
|
Although our study showed no large or frequent yield response of ridge tilled soybean to band P compared with broadcast P (even in low-testing soils), band P can potentially reduce P loss from fields with water runoff. Our results, and those from other research for ridge-tilled crops (Rehm et al., 1995; Borges and Mallarino, 2001), show that band P increased STP in the ridges but seldom increased STP in the valleys. Thus, because concentrated surface water flow occurs through valleys (mainly the trafficked ones), banding P (or other nutrients) into the ridges could potentially reduce nutrient loss from fields (Hamlett et al., 1990; Waddell et al., 1996).
Phosphorus fertilization increased early plant growth (P 0.1) only at Site 7, where fertilizer was applied for soybean, and at Site 10, where fertilizer was applied for a previous corn crop (Table 5). Only means of the two P rates are shown because the two rates never differed (P 0.1). The P placement methods did not differ at any site. Soil in both responsive sites tested in the Low STP class for either the ridge sampling position or the average of both ridge and valley positions. The responses at these two sites together with small nonsignificant yield increases at several other sites likely explain a statistically significant P effect across all sites. It is noteworthy that only one site (Site 10) showed statistically significant responses for both DW and yield.
View this table:
[in this window]
[in a new window]
|
Table 5. Dry weight at the V5-V6 growth stage of ridge tilled soybean as affected by P fertilization and placement.
|
|
In contrast to results for grain yield and early plant growth, the P treatments influenced P uptake at several sites, responses sometimes were observed even for high-testing soils, and there were significant interactions between P fertilization and placement method (Table 6). One or both P placement methods increased (P 0.1) P uptake at six sites where fertilizer was applied for soybean and at two sites where fertilizer was applied before a previous corn crop. The high P rate increased (P 0.1) P uptake over the low P rate only at Site 2 (for both placement methods). Phosphorus applied with the two placement methods increased P uptake at five sites (Sites 1, 2, 4, 7, and 10). At Sites 3, 5, and 9, the P uptake values, a significant interaction between P and placement method, and nonorthogonal comparisons of each broadcast mean and the control (not shown) indicated that only band P increased P uptake. The P uptake response was greater for band P than for broadcast P for means across all sites. Furthermore, the P uptake values and nonorthogonal comparisons of each broadcast means and the control (not shown) indicated that only the high rate increased P uptake. Thus, although effects sometimes were small and inconsistent for each individual site, this overall result suggests that the low fertilizer rate was more efficient in increasing P uptake when the P was banded.
View this table:
[in this window]
[in a new window]
|
Table 6. Phosphorus uptake at the V5-V6 growth stage of ridge-tilled soybean as affected by the P fertilization rate and placement.
|
|
Potassium
Potassium fertilization increased grain yield (P 0.1) only at Sites 10 and 13 (Table 7), where the K fertilizer was applied before a previous corn crop. Only the means of the two K fertilization rates are reported because the two K rates did not differ. At Site 10, the yield values and a significant interaction between fertilization and placement method indicate that only band K increased yield. At Site 13, the placement methods did not differ. The general lack of soybean response to K could have been expected because mean STK data over both ridge and valley sampling positions was optimum or higher, and STK for the ridges was even higher at most sites. However, Borges and Mallarino (2001) observed more frequent responses of ridge tilled corn for a similar range of soil series and STK values. The site that showed the largest response to K fertilization (Site 13) did not have the lowest STK level or the largest lateral or vertical STK stratification (Table 8). However, rainfall (April to August) at this location was among the lowest of all sites (not shown) and was 25% below the region long-term average. Bordoli and Mallarino (1998) showed larger response of no-till corn to K (especially to band K) when moisture was deficient. However, previous Iowa research with no-till soybean (Borges and Mallarino, 2000) and ridge-tilled corn (Borges and Mallarino, 2001) did not show a significant relationship between crop response to K and rainfall during any period of the growing season.
View this table:
[in this window]
[in a new window]
|
Table 8. Soil-test K for the control and high fertilizer rate treatments from seven trials that evaluated residual effects of K applied before the previous corn crop.
|
|
Observation of STK data at sites that evaluated fertilization for a previous corn crop (Table 8) showed that the high banded K rate usually increased (P 0.1) STK of the top 15-cm layer of ridges compared with the control and seldom increased STK of the valleys. Also, the broadcast method seldom increased STK at any ridge depth. However, and in contrast to results for STP, broadcast K usually did not increase STK of the valleys and band K usually did not increase STK in the 15- to 30-cm layer of the ridges. These contrasting results for STP and STK also were observed in a previous study with ridge-tilled crops (Borges and Mallarino, 2001). The differences between P and K cannot be explained with certainty. Soil-test data for both nutrients suggest high sampling error, which is a known problem with conservation tillage when band fertilization is used. Significantly larger K recycling with corn residues compared with P (Hanway et al., 1962) may explain a more limited impact of deep K placement on residual STK at the application depth.
Potassium fertilization influenced early plant growth at four sites (Table 9). One or both K placement methods increased DW (P 0.1) at Site 5 (where fertilizer was applied for soybean) and at Sites 9, 10, and 14 (where fertilizer was applied for a previous corn crop). The DW values and a significant interaction between K fertilization and placement method indicated that only band K increased DW at Sites 5, 9, and 14. At Site 10, the DW values, a significant interaction between K fertilization and placement method, and nonorthogonal comparisons of each fertilized mean and the control (not shown) indicated that the DW response was largest for band K compared with broadcast K. Site characteristics such as STK data for ridges and valleys, STK for different sampling depths, and rainfall or temperature (not shown) could not explain the reason for different responses across sites. Means and statistics across all sites show that only band K increased DW.
View this table:
[in this window]
[in a new window]
|
Table 9. Dry weight at the V5-V6 growth stage of ridge tilled soybean as affected by K fertilization and placement.
|
|
In contrast to effects of P fertilization on early plant growth, K fertilization influenced K uptake at 10 sites (Table 10). Potassium fertilization increased (P 0.1) K uptake at four sites where fertilizer was applied for soybean, and at six sites where fertilizer was applied for a previous corn crop. The K uptake response to band K was larger than the response to broadcast K at nine sites (the interaction between K fertilization and placement method was significant). Furthermore, the K uptake values and nonorthogonal comparisons of each broadcast mean and the control (not shown) indicated that only band K increased K uptake at six sites (Sites 1, 3, 4, 5, 9, and 14). In contrast with all other plant measurements, the high rate of band K often produced significantly higher K uptake than the low rate. Figure 1 describes the average interaction fertilizer rate by placement method for means of P and K uptake across the responsive sites. Although the broadcast placement method was less efficient than the deep-band placement in increasing both P and K uptake, the difference was larger for K.
View this table:
[in this window]
[in a new window]
|
Table 10. Potassium uptake at the V5-V6 growth stage of ridge tilled soybean as affected by the K fertilization and placement.
|
|
View larger version (21K):
[in this window]
[in a new window]
|
Fig. 1. Interaction of fertilization rate by placement method for early soybean P uptake (top) and K uptake (bottom). Data are means across responsive (P 0.1) sites (eight for P uptake and 10 for K uptake).
|
|
Large and frequent K uptake responses to band K compared with broadcast K at many sites indicated that the deep K placement increased fertilizer-use efficiency. However, this increased efficiency usually did not result in higher yield probably because most soils had high STK values. Frequent large K uptake responses, which were more frequent than P uptake responses, and were in sharp contrast with little or no yield response to K, show that young soybean plants have high limits for luxury uptake of K. This was also observed for ridge-tilled corn by Borges and Mallarino (2001), but corn K uptake responses to band K were more frequent than soybean responses for comparable soils and STK levels.
|
CONCLUSIONS
|
|---|
The results showed small and infrequent responses of yield, early growth, and P uptake of ridge-tilled soybean to P placement. Although means across all sites showed a higher P uptake increase from band P compared with broadcast P, this difference was inconsistent for individual sites and did not result in yield differences. The results suggested that STP from the ridges seldom is a better predictor of P availability for soybean compared with STP from valleys or both ridges and valleys. Although band P produced similar yield to broadcast P, its use could reduce P loss to surface water resources by reducing P accumulation near the soil surface.
Band K increased yield compared with broadcasted K only in one site. However, and in contrast to results for P, band K increased early K uptake considerably and frequently compared with broadcast K. Although initial STK levels and a general lack of yield response to K indicate that most soils had sufficient K for ridge-tilled soybean, the results suggest that a deep-band K placement could be more effective than a broadcast placement in soils with lower STK. Our results for soybean and results of previous studies with corn suggest that deep K banding would be beneficial for ridge-till producers because of economic reasons and that deep P banding could be beneficial for environmental reasons because of its potential to reduce P loss with surface runoff.
|
NOTES
|
|---|
Iowa Agric. Home Econ. Exp. Stn. Journal Paper no. 19897. Project 4062; R. Borges, now at: Dep. of Agronomy, 1575 Linden Drive, University of Wisconsin, Madison, WI 53706. Research supported in part by the Iowa Soybean Promotion Board.
Received for publication June 26, 2002.
|
REFERENCES
|
|---|
- Bauder, J.W., G.W. Randall, and R.T. Schuler. 1985. Effects of tillage with controlled wheel traffic on soil properties and root growth of corn. J. Soil Water Conserv. 40:382–385.
- Bordoli, J.M., and A.P. Mallarino. 1998. Deep and shallow banding of phosphorus and potassium as alternatives to broadcast fertilization for no-till corn. Agron. J. 90:27–33.[Abstract/Free Full Text]
- Borges, R., and A.P. Mallarino. 2000. Grain yield, early growth, and nutrient uptake of no-till soybean as affected by the phosphorus and potassium placement. Agron. J. 92:380–388.[Abstract/Free Full Text]
- Borges, R., and A.P. Mallarino. 2001. Deep banding phosphorus and potassium fertilizers for corn produced under ridge tillage. Soil Sci. Soc. Am. J. 65:376–384.[Abstract/Free Full Text]
- Buah, S.S.J., T.A. Polito, and R. Killorn. 2000. No-tillage soybean response to banded and broadcast and direct and residual fertilizer phosphorus and potassium applications. Agron. J. 92:657–662.[Abstract/Free Full Text]
- Brown, J.R. 1998. Recommended chemical soil test procedures for the North Central region. North Central Regional Publ. No. 221 (Rev.). Missouri Exp. Stn. Publ. SB 1001. Columbia. Also available online at http://www.muextension.missouri.edu/explore/specialb/sb1001.htm (verified 9 June 2003).
- CTIC. 2000. National crop residue management survey. Conservation Technology Information Center. West Lafayette, IN.
- deMooy, C.J., J.L. Young, and J.D. Kaap. 1973. Comparative response of soybeans and corn to phosphorus and potassium. Agron. J. 65:851–855.[Abstract/Free Full Text]
- Ebelhar, S.A., and E.C. Varsa. 2000. Tillage and potassium placement effects on potassium utilization by corn and soybean. Commun. Soil Sci. Plant Anal. 31:2367–2377.
- Fehr, W.R., C.E. Caviness, D.T. Burmood, and J.S. Pennington. 1971. Stage of development description for soybean. Crop Sci. 11:929–931.[Abstract/Free Full Text]
- Hairston, J.E., W.F. Jones, P.K. McConnaughey, L.K. Marshall, and K.B. Gill. 1990. Tillage and fertilizer management effects on soybean growth and yield on three Mississippi soils. J. Prod. Agric. 3:317–323.
- Hamlett, J.M., J.L. Baker, and R. Horton. 1990. Water and anion movement under ridge tillage: A field study. Trans. ASAE. 33:1859–1866.
- Hanway, J.J., S.A. Barber, R.H. Bray, A.C. Caldwell, M. Fried, L.T. Kurtz, K. Lawton, J.T. Pesek, K. Pretty, M. Reed, and F.W. Smith. 1962. North central regional potassium studies. III. Field studies with corn. Iowa Agric. Home Econ. Exp. Stn. Res. Bull. 503.
- Hudak, C., R. Stehouwer, and J. Johnson. 1989. An evaluation of K rate, placement, and tillage systems for soybeans. J. Fert. Issues 6:25–31.
- Karlen, D.L., E.C. Berry, T.S. Colvin, and R.S. Kanwar. 1991. Twelve-year tillage and crop rotation effects on yields and soil chemical properties in northeast Iowa. Commun. Soil Sci. Plant Anal. 22:1985–2003.
- Kaspar, T.C., H.J. Brown, and E.M. Kassmeyer. 1991. Corn root distribution as affected by tillage, wheel traffic, and fertilizer placement. Soil Sci. Soc. Am. J. 55:1390–1394.[Abstract/Free Full Text]
- Kitchen, N.R., J.L. Havlin, and D.G. Westfall. 1990. Soil sampling under no-till banded phosphorus. Soil Sci. Soc. Am. J. 54:1661–1665.[Abstract/Free Full Text]
- Mallarino, A.P., J.R. Webb, and A.M. Blackmer. 1991a. Corn and soybean yields during 11 years of phosphorus and potassium fertilization on a high-testing soil. J. Prod. Agric. 4:312–317.
- Mallarino, A.P., J.R. Webb, and A.M. Blackmer. 1991b. Soil test values and grain yields during 14 years of potassium fertilization of corn and soybean. J. Prod. Agric. 4:560–566.
- Murphy, J., and J.P. Riley. 1962. A modified single solution method for the determination of phosphate in natural waters. Anal. Chim. Acta. 27:31–36.
- Rehm, G.W. 1986. Effect of phosphorus placement on early growth, yield and phosphorus absorption by irrigated corn. J. Fert. Issues 3:12–17.
- Rehm, G.W., R.C. Sorensen, and R.A. Wiese. 1981. Application of phosphorus, potassium, and zinc to corn grown for grain or silage: Early growth and yield. Soil Sci. Soc. Am. J. 45:523–528.[Abstract/Free Full Text]
- Rehm, G.W. 1992. Response of ridge-till corn to potash fertilization. p. 139–143. In Proceeding 22nd North Central Extension-Industry Soil Fertility Conference. 18–19 Nov. 1992. St. Louis, MI. Potash & Phosphate Institute, Manhattan, KS
- Rehm, G.W., G.W. Randall, A.J. Scobbie, and J.A. Vetsch. 1995. Impact of fertilizer placement and tillage system on phosphorus distribution in soil. Soil Sci. Soc. Am. J. 59:1661–1665.[Abstract/Free Full Text]
- SAS Institute. 2000. SAS/STAT User's Guide, Version 8. SAS Institute, Cary, NC.
- Varsa, E.C., and S.A. Ebelhar. 2000. Effect of potassium rate and placement on soil test variability across tillage systems. Commun. Soil Sci. Plant Anal. 31:2155–2161.
- Vasilas, B.L., R.W. Esgar, W.M. Walker, R.H. Beck, and M.J. Mainz. 1988. Soybean response to potassium fertility under four tillage systems. Agron. J. 80:5–8.[Abstract/Free Full Text]
- Voss, R.D., J.E. Sawyer, A.P. Mallarino, and R. Killorn. 1999. General guide for crop nutrient recommendation in Iowa. Publ. Pm-1688 (Rev.). Iowa State Univ. Ext., Ames.
- Waddell, J.T., and R.R. Weil. 1996. Water distribution in soil under ridge-till and no-till corn. Soil Sci. Soc. Am. J. 60:230–237.[Abstract/Free Full Text]
- Walker, W.M., and G.A. Raines. 1988. Effect of corn cultivar, phosphorus and potassium on yield and chemical composition. J. Plant Nutr. 11:1715–1726.
- Webb, J.R., A.P. Mallarino, and A.M. Blackmer. 1992. Effects of residual and annually applied phosphorus on soil test values and yields of corn and soybean. J. Prod. Agric. 5:148–152.
This article has been cited by other articles:
|
|
|
|
 
A. P. Mallarino and R. Borges
Phosphorus and Potassium Distribution in Soil Following Long-Term Deep-Band Fertilization in Different Tillage Systems
Soil Sci. Soc. Am. J.,
February 27, 2006;
70(2):
702 - 707.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. R. Dodd and A. P. Mallarino
Soil-Test Phosphorus and Crop Grain Yield Responses to Long-Term Phosphorus Fertilization for Corn-Soybean Rotations
Soil Sci. Soc. Am. J.,
June 2, 2005;
69(4):
1118 - 1128.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. U. Haq and A. P. Mallarino
Response of Soybean Grain Oil and Protein Concentrations to Foliar and Soil Fertilization
Agron. J.,
May 13, 2005;
97(3):
910 - 918.
[Abstract]
[Full Text]
[PDF]
|
|
|
TOP
ABSTRACT
INTRODUCTION
