Agronomy Journal Grow Your Career With ASA
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Published in Agron J 99:80-87 (2007)
DOI: 10.2134/agronj2006.0118
© 2007 American Society of Agronomy
677 S. Segoe Rd., Madison, WI 53711 USA
This Article
Right arrow Abstract Freely available
Right arrow Figures Only
Right arrow Full Text (PDF) Free
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (2)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Singer, J. W.
Right arrow Articles by Meek, D. W.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Singer, J. W.
Right arrow Articles by Meek, D. W.
Agricola
Right arrow Articles by Singer, J. W.
Right arrow Articles by Meek, D. W.
Related Collections
Right arrow Intercropping Systems
Right arrow Dryland Cropping Systems

Integrated Agricultural Systems

Tillage and Compost Effects on Corn Growth, Nutrient Accumulation, and Grain Yield

Jeremy W. Singer*, Sally D. Logsdon and David W. Meek

USDA-ARS, National Soil Tilth Lab., Ames, IA 50011

* Corresponding author (singer{at}nstl.gov)

Received for publication April 13, 2006.

   ABSTRACT
TOP
 NOTES
 ABSTRACT
INTRODUCTION
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 CONCLUSIONS
 REFERENCES
 
Applying organic amendments to cropland affects corn (Zea mays L.) response to tillage systems differently. Identifying causes of the tillage by amendment interaction could match amendment inputs to responsive tillage systems. The objectives of this research were to determine if shoot dry matter (DM), nutrient uptake, and soil water use could explain the tillage by compost interaction for corn–grain yield. A corn–soybean [Glycine max (L.) Merr.]–wheat (Triticum aestivum L.)/clover (Trifolium spp.) rotation, in all phases, with or without compost amendment, was initiated in 1998 in plots that had been managed with moldboard plow (MP), chisel plow (CT), or no-tillage (NT) since 1988. Compost amendment increased corn whole-plant P and K uptake 19 and 21%, averaged across 2 yr. No-tillage increased whole-plant P uptake 1 yr compared to MP and CT (113 vs. 65 kg ha–1) and increased grain P concentration (3.1 vs. 1.5 g kg–1). Compost provided no benefit (2 yr) or a negative effect (1 yr, 22%) to corn yield in MP. Compost provided no benefit to corn yield in CT. Corn growing in NT derived no benefit (2 yr) or a positive (1 yr, 9%) effect on grain yield from compost amendment. The tillage and compost responses observed in this study cannot be explained by plant N, soil water use, leaf gas exchange, or DM partitioning. Grain yield from soil managed using NT may respond to compost amendment, but reasons for this response remain unclear.

Abbreviations: CER, carbon dioxide exchange rates • CERmax, maximum carbon dioxide exchange rates • CT, chisel tillage • DAP, days after planting • DAPmax, maximum days after planting • DM, dry matter • gs, stomatal conductance • gmax, maximum stomatal conductance • HI, harvest index • LSNT, late-spring soil nitrate test • MP, moldboard plow • NT, no-tillage • PAR, photosynthetically active radiation • RT, ridge tillage


   INTRODUCTION
TOP
 NOTES
 ABSTRACT
 INTRODUCTION
MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 CONCLUSIONS
 REFERENCES
 
CORN YIELD response to tillage and organic amendment often exhibits interactions (Mataruka et al., 1993; Eghball and Power, 1999; Singer et al., 2004). Explanations for this response are not always conclusive. Mataruka et al. (1993) in New York reported similar maize DM yields in 1 yr and 14% lower DM yield in another year using moldboard plow with dairy cattle (Bos taurus) manure and supplemental fertilizer compared to ridge tillage (RT) with manure and supplemental fertilizer. They concluded that lower N uptake by the moldboard plow treatment with manure and supplemental fertilizer may have been associated with denitrification losses from the manure.

Eghball and Power (1999) in Nebraska reported similar dryland corn grain yield in NT and conventional tillage (disking and cultivation) with beef feedlot compost in 3 of 4 yr in their continuous corn study. In the 4th year, NT yielded less than conventional tillage with compost application. Averaged across year, the compost treatment in conventional tillage yielded 8% less than the fertilizer treatment but 20% less in NT. Compost application rates were similar in both tillage systems, and were selected to provide 151 kg N ha–1. First-year N availability from compost was approximately 20% and was similar across tillage (Eghball and Power, 1999). They concluded that beef cattle feedlot compost can be effectively utilized in NT corn production systems when the correct N availability factor is selected.

Singer et al. (2004) in Iowa reported tillage by compost interactions in 2 of 4 yr comparing MP, CT, and NT treatments with or without swine (Sos scrofa L.) compost. Corn yield in NT with compost was 11% greater than without compost and similar in MP with or without compost in the last 2 yr of the study. Chisel tillage with compost yielded 6% greater than without compost in the 3rd year and yielded similarly in the 4th year. They concluded that the tillage by compost interaction was probably not related to soil N because clover was frost-seeded during the wheat phase of the rotation in all plots and basal stalk nitrate data generally did not indicate plant deficiency or explain yield responses.

Corn response to tillage and organic amendment has been associated with soil N dynamics most often, but responses are probably more complex. Ginting et al. (1998) compared moldboard plow and RT in continuous corn with and without beef manure and reported no tillage by manure interactions for P concentration and P uptake in grain. Most of the tillage and organic amendment experiments have been conducted in continuous corn or have had short histories of organic amendment, and only compared two tillage extremes. Compost amendment adds organic matter and nutrients. The organic matter additions may increase water-holding capacity, which may improve the soil water status during periods of deficit rainfall. Hudson (1994) reported that available water capacity of soil more than doubles as organic matter content increases from 5 to 30 g kg–1. After four compost applications, Singer et al. (2004) reported organic matter concentrations of 65 g kg–1 with compost compared to 56 g kg–1 without compost amendment.

Because compost amendment increases soil organic matter, soil–plant water status was hypothesized to affect the tillage by compost response. Furthermore, because compost amendment occurs on the soil surface in NT and is incorporated in MP and CT, soil–plant nutrient status was hypothesized as a component of the tillage by compost interaction that has been reported. The objectives of this research were to determine if shoot DM, nutrient uptake, and soil water use could explain the tillage by compost interaction for corn grain yield.


   MATERIALS AND METHODS
TOP
 NOTES
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
RESULTS AND DISCUSSION
 CONCLUSIONS
 REFERENCES
 
Field research was conducted at the Iowa State University Agronomy and Agricultural Engineering Research Farm near Boone, IA (42°01' N, 93°45' W, 341 m above sea level), from 2003 to 2005 on Canisteo silty clay loam (fine-loamy, mixed, superactive, calcareous, mesic Typic Endoaquolls) and Clarion loam (fine-loamy, mixed, superactive, mesic Typic Hapludolls) soils. The experimental site had been in continuous corn production since 1987, with tillage main plots consisting of MP, CT, and NT since 1988. In 1997 the entire site was planted to soybean. In 1998, a corn–soybean–wheat/clover rotation was initiated with all phases represented each year in each tillage system. Additional information about the management practices from 1998 through 2002 can be obtained in Singer et al. (2004).

The experimental design was a randomized complete block in a split-plot treatment arrangement with four replicates. Tillage main plots, 22.8 m wide by 26.1 m long, were fall MP, fall CT, and NT. Moldboard plow depth was approximately 20 cm. Chisel plow depth was approximately 25 cm using twisted shanks. Spring secondary tillage operations included an early spring disking and a preplant field cultivation in MP and CT systems. A NT planter was used with Sukup row cleaners (Sukup Manufacturing Co., Sheffield, IA) to plant all plots. ‘Pioneer Brand 35P12’ corn was planted on 23 Apr. 2003 and 2004, and Dekalb Brand ‘DKC59-08’ was planted on 15 Apr. 2005 at a seeding rate of 81510 seeds ha–1. Rotary hoeing and interrow cultivation were performed as needed each year in all tillage systems. Metalachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide] was applied at a rate of 2.24 kg a.i. ha–1 in 75.8 L water ha–1 for corn weed control. Subplots, 7.6 m (10 rows with a 0.76-m row spacing) wide by 13.1 m long, consisted of the fall application of compost or no-compost. Bedded swine manure compost was used in the fall of 2002 and 2003 and beef cattle compost was used in the fall of 2004.

The compost application rate during the first crop rotation cycle (1998–2000) was set at 8000 kg C ha–1 per application, reduced to 4000 kg C ha–1 during the second cycle (2001–2003), and changed to a P removal basis commencing in 2004. Compost was applied after corn and wheat/clover in 2002 and 2003 and only after wheat/clover in 2004. The P removal rate was based on the P removal by corn, soybean, and wheat during the 3-yr rotation (35, 22, and 16 kg P ha–1, respectively). Compost rates were 15.7, 15.2, and 13.2 Mg dry matter (DM) ha–1 in 2002, 2003, and 2004. Compost was applied using a manure spreader in the fall of 2002 and 2003 and by hand in 2004. The fall MP and CT operations were conducted within 3 d after compost application.

In 2002, compost application added 172, 49, and 207 kg ha–1 of N, P, and K; 241, 137, and 236 kg ha–1 of N, P, and K in 2003; and 220, 75, and 219 kg ha–1 of N, P, and K in 2004. Compost total C and N were determined after acidification with 0.5 M HCl (1:2 sample/solution ratio), air drying, grinding, and dry combustion in a Carlo-Erba NA1500 NCS elemental analyzer (Haake Buchler Instruments, Paterson, NJ) as described by Cambardella et al. (2003). Compost samples from 2004 were acidified with 0.44 M tartaric acid instead of HCl. Total P and K were determined on dried, ground samples (0.85-mm screen) after digestion with 10 mL deionized (DI) water, 5 mL HNO3, and 1 mL HCl. Potassium was analyzed using atomic absorption in emission mode, while P was determined colorimetrically using ascorbic acid/ammonium molybdate.

Late spring soil NO3–N (LSNT) concentrations were used to determine sidedress N application rates in compost and no-compost plots. Eight soil cores from the surface 30 cm were collected from each subplot and a composite sample was processed (Blackmer et al., 1989). In 2003, 112, 157, and 163 kg N ha–1 was applied to no-compost plots in MP, CT, and NT while 168 and 146 kg N ha–1 were applied to all no-compost plots in 2004 and 2005. Compost plots received 101 kg N ha–1 in 2003 and 2004 and 67 kg N ha–1 in 2005. All sidedress N was 32% UAN applied using a point-injector applicator. Eight soil cores to a depth of 18 cm were collected in the spring of 2003 in each subplot to monitor changes in P and K concentrations. Potassium was surface applied to all no-compost plots in April of 2004 at a rate of 101 kg ha–1 based on soil test results.

Carbon dioxide exchange rate (CER) and stomatal conductance (gs) were measured in 2003 and 2004 using a portable open path infrared gas analyzer (IRGA; LI-6400, LI-COR, Lincoln, NE) using the most recent fully expanded leaf until silking, and then the leaf above the terminal ear was used for the remainder of the measurement period. The adaxial surface of three leaves approximately equidistant from the main stem to the leaf tip in each subplot were measured on each sampling date between 1000 and 1300 h. The instrument was set at a flow rate of 500 mol s–1, leaf boundary-layer conductance of 2.84 mol m–2 s–1, and ambient CO2 concentration of 400 µmol mol–1. Photosynthetically active radiation (PAR) exceeded 1200 µmol m–2 s–1 during all measurements. In 2003 and 2004, 21, and 16 measurements were made starting 54 and 61 d after planting (DAP) and ending 128 and 133 DAP.

One stainless steel neutron probe access tube was installed in each subplot in the row to a 2.5-m depth, although water contents deeper than 1.5 m were not used for this study because of high water tables. The access tubes were 50-mm diam. and installed with a hydraulic auger. Bentonite was filled in around the top 0.2 m to prevent water flow down the side of the tube. Neutron probe measurements were usually made once a week during the growing season. Soil water content was determined every 20 cm starting at 30 cm. A volumetric soil sampler was used to measure gravimetric soil water to 30 cm, and then subdivided every 10 cm. When the access tubes were installed in 2004, the extracted soil was saved for determining gravimetric water content at each depth the neutron probe was read. Because the access tubes were installed over a few weeks, a range of water contents enabled calibration of the neutron probe. The calibration for all sites and depths was

Formula 1[1]
where {theta} is water content, and ratio is neutron probe count divided by background count.

Shoot DM was collected in 2003 and 2004 from a 0.76-m2 area in each subplot when growth stage was approximately V6 (Hanway, 1963), V12, RS, R3, and R6. Grain was separated from the shoot material at the R6 sampling date and oven-dried to determine kernel number, kernel weight, and harvest index (HI). All shoot material was dried in a forced-air oven at 70°C until a constant weight was achieved. Grain from the harvest sample and all other dried shoot material was ground to pass through a 1-mm screen and analyzed for total N, P, and K. Total N was measured using flash combustion and a thermal conductivity detector on a gas chromatograph (GC) column. Total P and K were analyzed using an inductively coupled plasma-optical emission spectrometer (ICP–OES) after microwave digestion with 10 mL HNO3 and dilution to 100 mL using DI water. Whole plant N, P, and K uptake were calculated for each growth period as the product of whole plant N, P, and K concentration and whole plant DM.

Twelve stalk segments from 15 to 35 cm above the soil surface were collected at grain harvest, dried at 60°C for 5 d, ground to pass a 0.85-mm screen, and analyzed for NO3–N by leaching 0.25 g of the ground sample with 50 mL of 2 M KCl solution, creating a 200-fold dilution. Nitrate-N concentration in the leachate was determined using a Lachat autoanalyzer (Lachat Instruments, Milwaukee, WI; Method 12-107-04-1-B). Three interior rows were harvested with a plot combine for grain yield and adjusted to a moisture content of 155 g kg–1. Harvest plant density counts were determined by counting all the plants in 7.6 m of six rows. Daily rainfall and air temperature were recorded at a weather station about 1.5 km from the experimental site and presented by month for each growing season (Table 1).


View this table:
[in this window]
[in a new window]

  		Table 1. Monthly 2003, 2004, and 2005 growing season rainfall and air temperature near Ames, IA, and the 30-yr mean (1975–2004) for NWS COOP site Ames 8SW.

 
Preliminary analysis and diagnostics revealed considerable spatial variability in most variables. Variance stabilizing transformations were considered for each variable using multiple tests including Box-Cox transformations and symmetry plots. Fixed effect analysis of variance with a terrain covariate (mean spatial elevation or slope) were performed on each variable. Routine and spatial residual diagnostics were examined to see if the error assumptions were reasonably met. Least squares means (with probability of differences) were estimated for each factor and their interactions. For the CER and gs time response data, the season maximum and day of occurrence were estimated using methodology guided by the work of Davidian and Giltinan (1995 and 2003). Response curves for each plot and each variable were developed and the properties were derived from analysis of each curve. Analysis of variance methods were employed to estimate each property. Each response variable for each year displayed a unique response requiring unique curve form. In some cases trigonometric series were used, while in others skewed nonlinear curves worked the best. Results were considered significant if P values were <0.1.


   RESULTS AND DISCUSSION
TOP
 NOTES
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
CONCLUSIONS
 REFERENCES
 
Late-Spring Soil Nitrate Test
Separate models were run for each year because rainfall amount and timing affected plant response differently (Table 1). May rainfall in 2004, which was 96 mm higher than the 30-yr mean, probably had the greatest effect on LSNT values. The below-average air temperatures in May and June of 2003 probably also lowered LSNT values (Table 2). In 2003, a tillage by amendment interaction was detected for LSNT. No-tillage had similar LSNT across amendment (7.1 mg kg–1), while MP with compost was higher than no-compost (12.0 vs. 9.5 mg kg–1) and CT with compost was lower than without (7.8 vs. 10.7 mg kg–1). Only compost amendment in 2004 and 2005 influenced LSNT.


View this table:
[in this window]
[in a new window]

  		Table 2. Least squares means for late spring soil NO3–N in tillage and amendment treatments near Ames, IA, from 2003 to 2005.

 
These LSNT results are different than those reported by Singer et al. (2004), who observed a more pronounced tillage effect on LSNT in their 4-yr study. Singer et al. (2004) used a C-based compost application rate of 8000 kg C ha–1 during the first 3 yr of their study and 4000 kg C ha–1 in the 4th year. Those rates applied an average of 641 (1998–2000) and 310 (2001) kg N ha–1. The compost rate used during this study period was 4000 kg C ha–1 during the first 2 yr (average of 15.5 Mg ha–1) then switched to a P-based rate that applied 13.2 Mg ha–1 during the 3rd year. These rates applied 172, 241, and 220 kg N ha–1. Compost amendment increased LSNT values during the study period, except in NT and CT in 2003. Tillage effects were not observed during 2004 and 2005. Singer et al. (2004) reported tillage effects on LSNT from the same study during 3 of 4 yr. The inconsistent LSNT response may be attributed to the lower compost rate during this study period, variable clover density and subsequent N contribution before the corn phase, and spring temperature and precipitation, which would affect N release from clover residues. Bakhsh et al. (2000) reported that LSNT-based N rates were 179 and 156 kg N ha–1 for NT and CT treatments, averaged across 6 yr. In this study, the addition of frost-seeded clover to plots with and without compost may have masked tillage effects on the LSNT.

Soil Water
Averaged across dates in 2003, neither tillage nor amendment effects were observed for soil water content (data not presented). In 2004 averaged across dates, compost amendment increased depth of soil water (8.43 > 7.72 cm) compared to the no-compost treatment from the 0.0 to 0.3 m depth and for the 0.0- to 1.3-m depth (44.7 > 43.6 cm). Tillage effects were not detected in this study. More pronounced soil water effects were not detected because the landscape effects were greater than the treatment effects. Elevation and slope at the experimental site were included as covariates in most of the statistical analysis and reflect their importance in this landscape, even in these small plots. Singer and Cox (1998) reported similar soil water depletion in the 0.0- to 0.3-m soil depth between MP and CT in a corn–soybean–wheat/red clover rotation in a dry year and more rapid soil water depletion in MP than CT in a year with normal precipitation. Many of the differences in soil water depletion that Singer and Cox (1998) reported occurred within a 7- to 10-d period during linear growth in corn. The ability to detect differences in soil water depletion using neutron probes may require more intensive measurement collection.

Carbon Dioxide Exchange and Stomatal Conductance
A tillage by amendment interaction was detected for maximum carbon dioxide exchange rates (CERmax) and maximum stomatal conductance (gmax) in 2003 (Table 3). Moldboard plow had similar CERmax with or without compost (52.1 µmol m–2 s–1), while CERmax was higher in CT without compost than with compost (53.6 vs. 51.8 µmol m–2 s–1), and higher in NT with compost than without (53.7 vs. 51.7 µmol m–2 s–1). The maximum gs was similar in NT with or without compost (0.60 mol m–2 s–1) and higher in no-compost than compost treatments in both MP (0.64 vs. 0.57 mol m–2 s–1) and CT (0.66 vs. 0.60 mol m–2 s–1). Averaged across tillage, the no-compost treatment delayed the days after planting to reach maximum CER and gs in 2003. In 2004, averaged across amendment, NT reached the maximum CER 5 d later than CT. Averaged across tillage, no-compost had a higher maximum g, but also required three additional days to reach the maximum than the compost treatment. Cox et al. (1990) measured CER in MP, NT, and RT and reported that MP had higher CER than NT or RT on 11 of 16 measurement dates from 34 to 65 d after emergence during a dry period in the 1988 growing season and similar CER among tillage systems for the remainder of the growing season.


View this table:
[in this window]
[in a new window]

  		Table 3. Least squares means for the maximum carbon dioxide exchange rates (CERmax) and stomatal conductance (gmax) and days after planting (DAPmax) to reach the maximum value in 2003 and 2004 for tillage and amendment treatments near Ames, IA.

 
Whole-Plant Dry Matter and Nutrient Uptake
Dry matter accumulation was affected more by tillage and amendment treatment in 2003 than 2004 (Fig. 1 ), presumably because of the differences in timing and total rainfall. In 2003 averaged across amendment, MP and CT had greater DM accumulation at 47 DAP than NT (184 vs. 69 kg ha–1). At 103 DAP, a tillage by amendment interaction was detected because MP had similar DM in compost and no-compost treatments, while CT and NT had 13% and 18% less DM in no-compost compared to compost treatments. The MP and NT DM response at this sampling date was similar to the CERmax interaction, but not consistent with the CT CER response. At 128 DAP, the interaction was not significant (P value = 0.138). Averaged across amendment, MP and CT had greater DM accumulation than NT (27056 vs. 21257 kg ha–1) and the compost treatment had greater DM than the no-compost treatment (26769 vs. 23478 kg ha–1; Fig. 1).


Figure 1
View larger version (20K):
[in this window]
[in a new window]

  		Fig. 1. Shoot DM and N uptake in MP, CT, and NT at different measurement dates after corn planting in compost amended and nonamended soil in 2003 and 2004 near Ames, IA. Capital T and A indicate statistical significance for tillage and amendment treatments and interactions (T x A) at P values < 0.1.

 
Treatment responses between 128 and 169 DAP illustrated the effect of extreme soil water deficits on corn growth. August rainfall was only 25 mm in 2003. The linear DM accumulation that occurred from 75 to 128 DAP was not sustainable under limited soil water. Consequently, DM accumulation plateaued or declined from 128 to 169 DAP. Moldboard plow, averaged across amendment, exhibited the greatest decline in whole-plant DM between 128 and 169 DAP probably because larger plants in these treatments required more water for maintenance growth. Until 128 DAP, compost amendment increased shoot DM at three of the four measurement periods. At 169 DAP averaged across amendment, CT had greater DM (24 607 kg ha–1) than MP and NT (20 659 kg ha–1) and the no-compost treatment, averaged across tillage, had greater DM than the compost treatment (22 908 vs. 21 043 kg ha–1). In 2004, there was no tillage effect detected at any sampling date and compost had greater DM than no-compost at two of the five measurement dates, but no difference was found for final DM accumulation.

Nitrogen uptake, averaged across amendment, was greater in MP and CT (8 kg ha–1) than NT (3 kg ha–1) at 47 DAP in 2003 (Fig. 1). A tillage by amendment interaction was observed at 128 DAP in 2003 because N uptake was similar in NT with or without compost (177 kg ha–1) and 30 and 17% greater in MP and CT with compost than without. Final N uptake in 2003 was similar for tillage and compost treatments. Early season DM and N uptake patterns among treatments in 2003 was not indicative of final uptake, which is consistent with Eghball and Power (1999), who stated that early plant growth may not be a good indicator of yield or N uptake in dry years. Only the no-compost treatment exhibited increasing N uptake over time. The MP, CT, and compost treatments reached maximum N uptake at the 128 DAP sampling date. The NT treatment exhibited declining N uptake from the 103 to 128 DAP sampling interval, but increased N uptake from 128 to 169 DAP. In 2004, compost amendment increased N uptake at 63 and 116 DAP, but no differences were observed at the final sampling among tillage systems or amendment treatment.

Compost amendment increased P uptake at each sampling point in 2003 and 2004 (Fig. 2 ). Final P uptake was similar across tillage systems in 2003, but compost-amended plots removed 76 compared to 59 kg P ha–1 in the no-compost treatment. In 2004 averaged across amendment, NT removed 113 kg P ha–1 compared with 65 kg P ha–1 in MP and CT. Compost-amended plots removed 88 compared to 74 kg P ha–1 in the no-compost treatment. Potassium uptake response to amendment treatment was similar in 2003 to the P response. Moldboard plow and CT had greater K uptake than NT at 47 DAP, but similar K uptake among tillage system was measured at the final sampling date. Final K uptake was 332 and 260 kg ha–1 for compost and no-compost treatments, averaged across tillage. Compost amendment increased K uptake at each sampling date in 2004. A tillage by amendment interaction was detected at 80 DAP and tillage main effect at 95 DAP, but final K uptake was not affected by tillage. Compost amendment increased final K uptake 20% compared to no-compost amendment.


Figure 2
View larger version (19K):
[in this window]
[in a new window]

  		Fig. 2. Phosphorus and K uptake in MP, CT, and NT at different measurement dates after corn planting in compost amended and nonamended soil in 2003 and 2004 near Ames, IA. Capital T and A indicate statistical significance for tillage and amendment treatments and interactions (T x A) at P values < 0.1.

 
Grain Yield, Yield Components, and Grain Nutrient Uptake
A tillage by amendment interaction was detected for grain yield in 2003 (Table 4). Moldboard plow with compost yielded 22% less than MP without compost, while CT and NT yielded the same with and without compost. Yield in no-compost treatments ranked MP > CT > NT, and in compost treatments CT = MP > NT. No differences were detected for kernel mass, but kernel number was 20% greater in CT than MP and NT, averaged across amendment, and 10% greater in the no-compost compared to compost treatment, averaged across tillage. Differences in kernel number were probably related to soil water deficits during early reproductive growth that affected kernel development (Claassen and Shaw, 1970). Only 59 mm of rainfall was recorded in 2003 between July 11 and August 31. The higher kernel number in CT and in the no-compost treatment also increased HI. No differences among tillage or amendment treatment were detected in 2003 for N, P, or K grain concentration. No-tillage did not provide an advantage over MP or CT under deficit rainfall postsilking in 2003, regardless of compost treatment.


View this table:
[in this window]
[in a new window]

  		Table 4. Least squares means for grain yield (GY), harvest plant density (HPD), grain mass (GM), grain number (GN), harvest index (HI); and grain N, P, and K concentration in 2003 for tillage and amendment treatments near Ames, IA.

 
A tillage by amendment interaction was detected for grain yield in 2004 (Table 5). Moldboard plow and CT with compost yielded the same as the no-compost treatment, while NT with compost yielded 9% higher than the no-compost treatment (14.7 vs. 13.3 Mg ha–1). Kernel mass was similar in MP and NT with or without compost and 7% higher in CT without compost than with compost. Harvest index was higher in NT than MP and CT, but similar in amendment treatment. Nitrogen concentration was higher in NT compared to CT, but similar in amendment treatment. Phosphorus concentration was greater in NT than either MP or CT and also greater in compost compared to the no-compost treatment. Ginting et al. (1998) reported greater corn grain P uptake in manure compared with no-manure treatments in MP and reduced tillage systems, but they did not detect a tillage main effect or tillage by manure interaction. No differences were detected for K concentration among tillage systems, but compost amendment increased K concentration compared to the no-compost amendment.


View this table:
[in this window]
[in a new window]

  		Table 5. Least squares means for grain yield (GY), harvest plant density (HPD), grain mass (GM), grain number (GN), harvest index (HI), and grain N, P, and K concentration in 2004 for tillage and amendment treatments near Ames, IA.

 
Grain yield in 2005 exhibited tillage main effects (P value = 0.095) but no amendment effect (P value = 0.794) or tillage by amendment interaction (P value = 0.619). Moldboard plow yielded similarly to CT (14.8 vs. 12.7 Mg ha–1; P value = 0.110) and greater than NT (12.2 Mg ha–1, P value = 0.042). Chisel plow and NT yielded similarly (P value = 0.657). Starting in the 2003 growing season, after each compost subplot had received three compost applications, N inputs were lowered to reflect the N credit from compost. Consequently, in 2003 compost plots received 10, 35, and 38% less fertilizer N in MP, CT, and NT than the no-compost treatment and 40 and 54% less fertilizer N in 2004 and 2005, averaged across tillage, in compost than no-compost treatments. Although no amendment effect was detected in 2005, corn growing on compost-amended soil maintained yield with 54% less fertilizer N. Basal stalk nitrate results from 2004 and 2005 indicate plant N was optimal (Binford et al., 1992) and that compost amendment increased stalk nitrate concentration in 2005 (Table 6). Stalk nitrate was not detectable in 2003 (data not presented), most likely because of the dry August that limited soil N uptake and increased plant N remobilization.


View this table:
[in this window]
[in a new window]

  		Table 6. Least squares means for basal stalk NO3–N in tillage and amendment treatments near Ames, IA, in 2004 and 2005.

 
Compost amendment of soil from bedded swine manure or beef cattle manure sources provides N, P, and K inputs for crop production and adds C. Corn growing in compost-amended soil may increase growth rates under favorable early to midseason growing conditions, but this can have a detrimental effect on late-season growth, depending on tillage, if deficit rainfall occurs. Corn growing on compost-amended soil also exhibits luxury consumption of P and K. A mechanistic understanding of the causes of the tillage by compost response observed in this and other studies will require more intensive measurements to detect ephemeral differences in soil water use, soil physical and chemical properties, and corn growth.


   CONCLUSIONS
TOP
 NOTES
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 CONCLUSIONS
REFERENCES
 
Corn plants growing in compost-amended soil accumulated more P and K than plants growing in nonamended soils, but the greater uptake was not associated with increased grain yield. Compost provided either no benefit or a negative effect to corn yield in MP. Compost provided no benefit to corn yield in CT. Corn growing in NT derived no benefit or a positive effect on grain yield from compost amendment. The tillage and compost responses observed in this study could not be explained by plant N, soil water use, leaf gas exchange, or DM partitioning. Sequential compost application can reduce inorganic N inputs for corn production, but must be balanced with P removal to avoid excessive soil P accumulation.


   ACKNOWLEDGMENTS
 
The authors thank Keith Kohler for managing the field site and data collection.


   NOTES
TOP
 NOTES
ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 CONCLUSIONS
 REFERENCES
 
Mention of trade names or commercial products is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the USDA.


   REFERENCES
TOP
 NOTES
 ABSTRACT
 INTRODUCTION
 MATERIALS AND METHODS
 RESULTS AND DISCUSSION
 CONCLUSIONS
 REFERENCES
 




This article has been cited by other articles:


Home page
 Agron. J.Home page
T. J. Butler, K. J. Han, J. P. Muir, D. C. Weindorf, and L. Lastly
Dairy Manure Compost Effects on Corn Silage Production and Soil Properties
Agron. J., October 21, 2008; 100(6): 1541 - 1545.
[Abstract] [Full Text] [PDF]

Home page
 Agron. J.Home page
P. B. McDonald, J. W. Singer, and M. H. Wiedenhoeft
Self-Seeded Cereal Cover Crop Effects on Interspecific Competition with Corn
Agron. J., February 29, 2008; 100(2): 440 - 446.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Figures Only
Right arrow Full Text (PDF) Free
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (2)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Singer, J. W.
Right arrow Articles by Meek, D. W.
Right arrow Search for Related Content
PubMed
Right arrow Articles by Singer, J. W.
Right arrow Articles by Meek, D. W.
Agricola
Right arrow Articles by Singer, J. W.
Right arrow Articles by Meek, D. W.
Related Collections
Right arrow Intercropping Systems
Right arrow Dryland Cropping Systems

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