Published in Agron. J. 96:1125-1130 (2004).
© American Society of Agronomy
677 S. Segoe Rd., Madison, WI 53711 USA
PRODUCTION PAPER
Evaluation of Tillage and Poultry Litter Applications on Peanut
P. J. Wiatrak*,
D. L. Wright and
J. J. Marois
Dep. of Plant Pathol., North Florida Res. and Educ. Cent., Univ. of Florida, 155 Research Rd., Quincy, FL 32351
* Corresponding author (pjwiatrak{at}mail.ifas.ufl.edu).
Received for publication October 28, 2003.
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ABSTRACT
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Detrimental levels of poultry litter (mixture of manure and bedding material) and concurrent effects of tillage need to be determined for peanut (Arachis hypogaea L.) production. Two field trials with ‘Georgia Green’ peanut were conducted in 2001 and 2002. The objective of the first study was to evaluate the influence of seven tillage treatments (chisel, conventional, disk, fall moldboard plow, moldboard plow + chiselvator, ripper bedder, and strip-till) and three poultry litter applications (0, 4.5, and 9.0 Mg ha–1) before tillage. The objective of the second study was to evaluate four application timings (0, 1, 2, and 3 wk before planting) of high poultry litter rate (13.4 Mg ha–1) on peanut. In the first experiment, the application of 4.5 and 9.0 Mg ha–1 poultry litter decreased peanut yields in disk and moldboard plow + chiselvator treatments in both years. However, no detrimental effect of poultry litter was noted with 4.5 Mg ha–1 on treatment with fall moldboard plow or strip-till. Due to tomato spotted wilt tospovirus severity, peanut yields were less with the application of 4.5 and 9.0 Mg ha–1 (1844 and 1643 kg ha–1, respectively) compared with treatment without poultry litter application (2037 kg ha–1) in 2002. In the second experiment, the least yield decrease was observed with high litter application at 1 wk before planting peanut (1059 kg ha–1) compared with control (1669 kg ha–1). These studies indicate that the detrimental effect of poultry litter may be reduced with less poultry litter (up to 4.5 Mg ha–1) applied to strip-tilled peanut.
Abbreviations: TSWV, tomato spotted wilt tospovirus
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INTRODUCTION
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POULTRY HUSBANDRY and hence litter production are increasing in the Southeast Coastal Plain (Gascho et al., 2001), and research is needed to determine if application of litter has any detrimental effects on peanut. Poultry litter applied to cropland serves as an important means of waste disposal (Parker et al., 2002) and is a relatively inexpensive source of nutrients, particularly N and P (Nyakatawa and Reddy, 2002). Pederson et al. (2002) noted that poultry litter is commonly applied to pastures and hayfields as fertilizer. The application of poultry litter to peanut is not a common practice due to inconsistent results. However, only a small percentage of the produced litter is applied to cropland due to limitations of timely availability and insufficient information on its impact on crops grown in conservation tillage (Endale et al., 2002). The unused poultry litter is stacked up for compost until it can be applied to cropland.
The application of poultry increases soil P, K, Cu, Zn, and Mn and yields of cotton (Gossypium hirsutum L.), pearl millet [Pennisetum glaucum (L.) R. Br.], wheat (Triticum aestivum L.), and canola (Brassica napus L.) (Gascho et al., 2001). Also, studies conducted by Nyakatawa and Reddy (2002) indicated a positive impact of poultry litter applications on lint yields of cotton and grain yields of corn (Zea mays L.). However, peanut yields may decrease with poultry litter application due to increased disease pressure. Gascho et al. (2001) noted that increased Rhizoctonia limb rot damage in peanut, where poultry litter was applied, may have contributed to yield decreases. Tomato spotted wilt, caused by tomato spotted wilt tospovirus (TSWV), is also a serious disease of several important crops (Marois and Wright, 2003) and has become a limiting factor to peanut production in the southeast USA (Culbreath et al., 1996). According to Olson and Funderburk (1986), tobacco thrips (Frankliniella fusca Hinds) are the most important vector in tomato spotted wilt spreading on peanut, and plants infected early in the season often develop more severe symptoms (Brown et al., 2000). Culbreath et al. (1992) noted that infestation with TSWV reduces peanut yields due to decrease in the number and weight of individual seed.
Adoption of conservation tillage has increased in the Southeast in recent years because it can substantially reduce soil erosion (Mutchler et al., 1985), increase soil organic matter, increase soil moisture, and improve soil structure, which all result in increased crop yields (Hargrove, 1990). Research of Endale et al. (2002) showed that cotton grown no-till with the application of poultry litter can produce as much as 50% more lint compared with conventionally tilled and fertilized cotton. However, some of the biggest challenges for farmers using reduced tillage are good stand establishment and maintenance of yields (Campbell et al., 2002), which can be less in reduced-tillage systems (Jordan et al., 2001; Grichar, 1998) or similar to yields in conventional tillage systems (Dowler et al., 1999). Our objectives were to evaluate the influence of tillage and poultry litter rate application and also a timing of litter application on diseases and yields of peanut.
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MATERIALS AND METHODS
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Two irrigated field trials with Georgia Green peanut were conducted in 2001 and 2002 on a Dothan sandy loam (fine, loamy siliceous, thermic Plinthic Kandiudults) at the University of Florida's North Florida Research and Education Center in Quincy, FL. Soil tests were performed at 0- to 15-cm soil depth 2 mo before planting peanut. Soil organic matter was 5 g kg–1, and pH (KCl) was 6.2. Based on Mehlich-1 extraction procedure, soil contained 29 mg kg–1 P, 134 mg kg–1 K, and 113 mg kg–1 Ca. The Mehlich-1 extraction solution, also referred to as the dilute double acid extractant (0.05 M HCl + 0.0125 M H2SO4), is intended for use in extracting element readings from weathered soils that have cation exchange capacities of less than 10 cmol kg–1 and whose soil pH is less than 7.0 (SRIEG, 1983). Poultry litter consisted of 210.5 g kg–1 C and 25.4 g kg–1 N. Total N and C in poultry litter were measured by dry combustion using CE Elantech (CE Elantech, Inc., Lakewood, NJ) CN analyzer. The experimental area, following a wheat crop for grain (1999–2000) and winter fallow (2000–2001), was broadcast-sprayed with glyphosate [N-(phosphonomethyl) glycine] at 0.78 kg a.i. ha–1 + 2,4-D (2,4-dichlorophenoxyacetic acid) at 0.78 kg a.i. ha–1 on 18 April in 2001 and glyphosate at 1.38 kg a.i. ha–1 on 18 and 26 March in 2002.
Tillage and Poultry Litter Application
Tillage systems were chosen from a variety of tillage treatments often used in the southeast USA. Tillage consisted of seven treatments (chisel, conventional, disk, fall moldboard plow, moldboard plow + chiselvator, ripper bedder, and strip-till), and poultry litter consisted of three rates (0, 4.5, and 9 Mg ha–1). Poultry litter was applied 1 wk before planting peanut, except the treatment with fall moldboard plow where litter was applied in the fall. Tillage treatments followed poultry litter application. The chisel treatment consisted of disking (15-cm soil depth), chiseling (25 cm), and leveling with the s-tine harrow. Conventional tillage included disking (15 cm), chiseling (25 cm) before planting, leveling with the s-tine harrow before planting, and the chiselvator (between peanut rows) was applied about 4 wk after planting peanut. Disk treatment consisted of disking (15 cm) and leveling with an s-tine harrow. Fall moldboard plow treatment included moldboard plowing (25 cm) and leveling with an s-tine harrow. The moldboard plowing + chiselvator treatment consisted of moldboard plowing (25 cm), leveling with the s-tine harrow before planting, and chiselvator (between peanut rows) applied about 4 wk after planting peanut. The ripper-bedder treatment included a KMC ripper bedder (35 cm) (Kelley Manufacturing Co., Tifton, GA) and leveling with the s-tine harrow. The rows in strip-till sections were ripped (20 cm deep and 15 cm wide with 0.91 m between row centers) with a Brown strip-till implement (Brown Manufacturing Co., Ozark, AL). Georgia Green peanut was planted using a Monosem pneumatic planter (ATI Inc., Lenexa, KS) at six seeds per 0.3 m of row on 24 and 9 April in 2001 and 2002, respectively. Each plot (6.0 by 5.4 m) consisted of six rows with 0.91-m row spacing.
The experimental design was a randomized complete block in a split-plot treatment arrangement with four replications. The main effects were tillage treatments, and subplots were poultry litter rates. Data were analyzed using the general linear models (SAS Inst., 1989), and means were separated using Fisher's Protected Least Significant Difference Test (P 
0.05).
Timing of High Poultry Litter Application
Poultry litter was applied at the rate of 13.4 Mg ha–1 at 3, 2, 1, 0 wk before planting peanut, except for control plots (without litter application). After each application, a disk was used to incorporate the poultry litter into the soil. Just before planting, all plots were disked again, and peanut was planted with a Monosem pneumatic planter at six seeds per 0.3 m of row on 8 May and 11 April in 2001 and 2002, respectively. Each plot (12.2 by 5.4 m) consisted of six rows with 0.91-m row spacing.
The study design was a randomized complete block with four replications. Data were analyzed using the general linear models (SAS Inst., 1989), and means were separated using Fisher's Protected Least Significant Difference Test (P 0.05).
Both studies were treated with pendimethalin [N-(1-ethylpropyl)-3,4-dimethyl-2,6-dinitrobenzenamine] at 3.7 kg a.i. ha–1 after planting followed by imazapic {2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-methyl-3-pyridinecarboxylic acid} at 70.6 g a.i. ha–1 with a nonionic surfactant at 0.25% (v/v) approximately 40 d after emergence to control weeds. The early (Cercospora arachidicolla S. Hori) and late [Cercosperidium personatum (Berk. & M.A. Curtis) Deighton] leaf spot diseases were controlled with chlorothalonil (tetrachloroisophthalonitrile) at 1.75 kg a.i. ha–1 applied every 2 wk beginning 40 d after planting.
Tomato spotted wilt tospovirus and leaf spot disease severities were determined by surveying 3 m in each of the two adjacent middle rows. For TSWV, plants were rated from 0 to 5, with 0 indicating no symptoms, 1 slight wilting, 2 slight chlorosis, 3 general chlorosis, 4 some necrosis, and 5 general necrosis or death. Leaf spot disease incidence was evaluated on a scale of 1 to 10, with 1 being no symptoms; 2, very few spots in lower canopy; 3, few spots in lower and middle canopy; 4, some spots with light defoliation; 5, spots noticeable in upper canopy with some defoliation (up to 25%); 6, spots numerous with significant defoliation (up to 50%); 7, spots numerous with heavy defoliation (up to 75%); 8, very numerous spotting of few remaining leaves with very heavy defoliation; 9, very few remaining leaves heavily spotted with near complete defoliation; and 10, dead plants.
Peanut plants, from both studies, were inverted and harvested on 13 and 3 September in 2001 and 2002, respectively, and dried to 100 g kg–1 moisture before yields were determined. Plant stand and yield data were taken from the two adjacent middle rows of each plot. Plant stand was determined by quantifying the number of emerged plants 2 wk after planting in a 3-m section in each of the two adjacent middle rows.
Weather data were collected near the test sites from a weather station located at the North Florida Research and Education Center, Quincy, FL (84°33'W, 30°36'N). The monthly air temperatures and rainfall with 20-yr average and sum, respectively, during the two growing seasons are shown in Table 1. Air temperature was similar compared with 20-yr average data. Rainfall was generally less during the 2-yr vegetation periods compared with the 20-yr average, except greater precipitation in March, June, and September of 2001 (252, 310, and 194 mm, respectively) and September of 2002 (223 mm). Irrigation of these two experiments was applied by a lateral-move irrigation system to compensate for inadequate rainfall. Peanut studies were irrigated at 12.7 mm on 2 and 8 May in 2001, 19.1 mm on 30 April and 3 May, 15.2 mm on 17 May, 12.7 mm on 3 and 19 July, and 15.2 mm on 14 August in 2002.
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Table 1. Average monthly air temperature and total rainfall at Quincy, FL, during the growing seasons of 2001 and 2002.
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RESULTS AND DISCUSSION
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Tillage and Poultry Litter Application
No tillage x litter interaction was observed for leaf spot disease, and the effect of tillage and poultry litter on disease was very small (Table 2). The difference among tillage treatments for leaf spot disease was not significant (P 0.05), except the least disease severity from fall moldboard and strip-till treatments at 134 d after planting in 2002. Yancey (2002) also observed a decrease in leaf spot diseases from using strip-till compared with conventional tillage. The leaf spot severity was reduced by litter application at 92 d after planting in 2001 and 2002, 99 d after planting in 2001, and 120, 127, and 134 d after planting in 2002. However, litter applications of 4.5 and 9.0 Mg kg–1 did not generally increase the leaf spot severity in peanut compared with treatments without litter application. Overall, poultry litter applications do not increase leaf spot severity in peanut, and strip-till may help to decrease the leaf spot disease pressure.
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Table 2. Leaf spot severity under seven tillage systems and three poultry litter application rates at Quincy, FL, in 2001 and 2002.
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Severity of TSWV was small (Table 3). Generally, TSWV disease was not affected by tillage and poultry litter application, except tillage influence on TSWV severity at 113 d after planting in 2002. The TSWV disease pressure was greatest from the conventionally planted peanut and lowest from treatments with moldboard plow + chiselvator, disk, fall moldboard, and strip-till. Baldwin and Hook (1998) also reported less TSWV in reduced-tillage systems compared with conventional tillage. Litter applications of 4.5 and 9.0 Mg ha–1 on peanut did not influence the TSWV disease. These results indicate that application of poultry litter is not expected to increase the TSWV disease and reduced tillage may help to decrease this disease in peanut.
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Table 3. Tomato spotted wilt tospovirus (TSWV) severity, plant stand, and peanut yields under seven tillage systems and three poultry litter application rates at Quincy, FL, in 2001 and 2002.
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Plant stand was affected by tillage (Table 3). Plant stands were 25, 24, and 21% less in treatments with strip-till, ripper bedder, and conventional, respectively, than moldboard plow + chiselvator in 2001. In 2002, stand count was 24 and 19% less from strip-till and ripper bedder, respectively, compared with fall moldboard plow. Campbell et al. (2002) also observed that plant stand was less in strip-till than conventional tillage. The difference between poultry litter rates on plant stand of peanut was not significant. Generally, plant stand may be reduced in strip-till compared with conventional tillage; however, plant stand decreases are not expected with the litter application.
A tillage x litter interaction was observed for peanut yields in 2001 and 2002 (Table 3). The application of 4.5 and 9.0 Mg ha–1 poultry litter decreased peanut yields in conventional tillage, disk, and moldboard plow + chiselvator treatments in 2001 and decreased yields from chisel, disk, moldboard plow + chiselvator, and ripper bedder in 2002 (Table 4). However, in both years, a positive yield response was observed with 4.5 Mg ha–1 of poultry litter with fall moldboard plow and strip-till compared with treatments with no litter application. Peanut yields, averaged across tillage systems, were less with the application of 4.5 and 9.0 Mg ha–1 (1844 and 1643 kg ha–1, respectively) compared with treatment without poultry litter application (2037 kg ha–1) in 2002 (Table 3).
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Table 4. Yields of peanut under seven tillage treatments and three poultry litter application rates at Quincy, FL, in 2001 and 2002.
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The response of peanut to different tillage and poultry litter applications may be due to significant changes in soil physical, chemical, and biological properties with litter applications as indicated by Parker et al. (2002). In Florida, at some locations, greater peanut yields were obtained from strip-till than conventional tillage (Marois and Wright, 2003) while at other locations, conventional tillage gave better results (Yancey, 2002). Gascho et al. (2001) reported that due to increased Rhizoctonia limb rot damage, litter applications of 4.5 Mg ha–1 decreased yields of peanut by 20, 18, and 4% in 1996, 1997, and 1998, respectively, compared with no litter application. Only in 1999, peanut yields were 15% greater with poultry litter than without (Gascho et al., 2001). They also observed that increased diseases with poultry litter applications of 9.0 Mg ha–1 decreased yields of peanut by 5, 22, and 7% in 1996, 1997, and 1998, respectively, compared with treatments without poultry litter. The results of our study indicate that poultry litter application may decrease peanut yields; however, using fall moldboard plow or strip-till may help to reduce this detrimental effect of litter application on peanut.
A Pearson correlation of peanut yields with the leaf spot disease was generally low, except a negative correlation at 92 d after planting in 2001 (r = –0.26) (Table 5). A negative correlation of peanut yields with the TSWV disease was observed for all observations, except at 99 and 127 d after planting peanut in 2001 and 2002, respectively (Table 5). Gascho et al. (2001) also reported that increased diseases with poultry litter applications decreased yields of peanut compared with treatments without poultry litter. Generally, leaf spot disease was effectively controlled by application of chlorothalonil, and the late leaf spot disease occurrence in the season did not reduce yields of peanut. However, the yield reductions were due to TSWV in 2001 and 2002.
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Table 5. Pearson correlation coefficient of peanut yields under tillage and poultry litter with tomato spotted wilt tospovirus (TSWV) and leaf spot severity at Quincy, FL, in 2001 and 2002.
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Timing of High Poultry Litter Applications
The timing of high poultry litter application (13.4 Mg ha–1) did not generally affect leaf spot, except disease severity at 99 and 134 d after planting in 2001 (Table 6). Greater leaf spot severity at 99 d after planting was noted from treatments with 1 and 2 wk of litter application before planting peanut compared with other treatments in 2001. The same year, high poultry litter application did not increase leaf spot severity compared with treatment without litter application. Generally, leaf spot was small and little affected by high poultry litter application on peanut.
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Table 6. Leaf spot and tomato spotted wilt tospovirus (TSWV) severity, and peanut yields under high poultry litter application timing at Quincy, FL, in 2001 and 2002.
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Tomato spotted wilt tospovirus disease was influenced by high poultry litter application at only 120 d after planting peanut in 2001 (Table 6). High poultry litter application did not increase TSWV severity in peanut compared with the treatment without litter application. No TSWV disease increase would be expected with high poultry litter application.
Peanut yields were not influenced by high poultry litter application in 2001; however, yields decreased with litter application in 2002 (Table 6). The least yield decrease was observed with high litter application at 1 wk before planting peanut (1059 kg ha–1) compared with control (1669 kg ha–1) in 2002. Gascho et al. (2001) also noted a significant yield decrease with high poultry litter application rate (13.5 Mg ha–1) in 1996, 1997, and 1998; however, the yields of peanut between the control and the 13.5 Mg ha–1 litter application were not significantly different in 1999. Yield of peanut may decrease with high litter application in some years.
According to the Pearson correlation coefficient, peanut yields were only negatively correlated with the leaf spot at 134 d after planting in 2001 (Table 7). Similar results were obtained by Gascho et al. (2001) who noted a disease increase with poultry litter applications compared with treatments without poultry litter. The TSWV disease was not correlated with peanut yields in either 2001 or 2002. Peanut yield decreases with high poultry litter may be due to leaf spot diseases in some years.
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Table 7. Pearson correlation coefficient of peanut yields under high poultry litter application timing with tomato spotted wilt tospovirus (TSWV) and leaf spot severity in 2001 and 2002.
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SUMMARY
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Our experiments investigated the influence of tillage and poultry litter rate application and also a timing of litter application on diseases and yields of peanut in 2001 and 2002. In both years, the application of 4.5 and 9.0 Mg ha–1 poultry litter decreased peanut yields in disk and moldboard plow + chiselvator treatments. However, a positive yield response was observed with 4.5 Mg ha–1 poultry litter with fall moldboard plow and strip-till compared with the treatment with no litter application. Leaf spot disease was effectively controlled by application of chlorothalonil, and the late leaf spot disease occurrence in the season did not reduce yields of peanut. The main yield reductions were due to TSWV severity. Strip-till system decreased the leaf spot and TSWV disease pressure compared with conventional tillage. Peanut plant stand may be reduced in strip-till compared with conventional tillage; however, plant stand decreases are not expected with the litter application.
Application of high poultry litter on peanut may decrease yields in some years. Leaf spot was little influenced by high poultry litter application on peanut. This study indicates that poultry litter application may decrease peanut yields in some years due to TSWV disease. However, this detrimental effect of poultry litter may be reduced with less poultry litter (up to 4.5 Mg ha–1) applied to strip-tilled peanut.
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NOTES
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This research was supported by the Florida Agricultural Experiment Station and approved for publication as Journal Series no. R-09852.
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REFERENCES
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- Baldwin, J.A., and J. Hook. 1998. Reduced tillage systems for peanut production in Georgia. Proc. Am. Peanut Res. Educ. Soc. 30:48.
- Brown, S., J. Todd, A. Culbreath, J. Baldwin, J. Beasley, and H. Pappu. 2000. Tomato spotted wilt of peanut: Identifying and avoiding high-risk situations. Bull. 1165. Univ. of Georgia Coop. Ext. Serv., Athens.
- Campbell, H.L., J.R. Weeks, A.K. Hagan, and B. Gamble. 2002. Impact of strip-till planting using various cover crops on insect pests and diseases of peanuts. p. 161–164. In E. van Santen (ed.) Proc. Annu. Southern Conserv. Tillage Conf. for Sustainable Agric., Auburn, AL. 24–26 June 2002. Spec. Rep. 1. Alabama Agric. Exp. Stn. and Auburn Univ., Auburn, AL.
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- Nyakatawa, E.Z., and K.C. Reddy. 2002. Conservation tillage and poultry litter effects on cotton and corn yields: Five year results. p. 142–147. In E. van Santen (ed.) Proc. Southern Conserv. Tillage Conf. for Sustainable Agric., Auburn, AL. 24–26 June 2002. Spec. Rep. 1. Alabama Agric. Exp. Stn. and Auburn Univ., Auburn, AL.
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- Parker, M.A., E.Z. Nyakatawa, K.C. Reddy, and D.W. Reeves. 2002. Soil carbon and nitrogen as influenced by tillage and poultry litter in North Alabama. p. 283–287. In E. van Santen (ed.) Proc. Southern Conserv. Tillage Conf. for Sustainable Agric., Auburn, AL. 24–26 June 2002. Spec. Rep. 1. Alabama Agric. Exp. Stn. and Auburn Univ., Auburn, AL.
- Pederson, G.A., G.E. Brink, and T.E. Fairbrother. 2002. Nutrient uptake in plant parts of sixteen forages fertilized with poultry litter: Nitrogen, phosphorus, potassium, copper, and zinc. Agron. J. 94:895–904.[Abstract/Free Full Text]
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- Yancey, C.H. 2002. Strip-till. The Peanut Farmer. Feb. 2002., p. 6–8.
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ABSTRACT
INTRODUCTION
