Euphytica (2009) 169:141–150 DOI 10.1007/s10681-009-9908-5
RE V IEW
Do diVerent production environments justify separate maize breeding programs? M. J. Carena · J. Yang · J. C. CaVarel · M. Mergoum · A. R. Hallauer
Received: 21 July 2008 / Accepted: 24 February 2009 / Published online: 20 March 2009 © Springer Science+Business Media B.V. 2009
Abstract DiVerent production environments are being adopted by farmers. Therefore, allocation of resources to breeding research that targets diVerent production environments should be continuously assessed. Agronomists should conduct extensive hybrid £ production environment interaction research before recommending breeders to conduct separate breeding programs for each production environment. The lack of interactions between genotypes and production environments (e.g., tillage) would not justify conducting separate breeding programs and duplicating breeding resources. On the other hand, separate breeding programs would be necessary if cultivar rankings diVer. The purpose of this paper is to review the available literature on experiments designed to test genotype £ tillage interactions (GT) in maize (Zea mays L.). No-till system (NT) and conventional till system (CT) were utilized as examples of diVerent production environments. The majority of experiments reviewed showed that there is no need to develop cultivars speciWc to NT because the cultivars that were developed under CT systems performed relatively the same under NT. The magnitude of GT interactions found was very small to expect better cultivars from breeding under NT. Additional research is needed to conWrm these conclusions, especially when M. J. Carena (&) · J. Yang · J. C. CaVarel · M. Mergoum North Dakota State University, Fargo, ND, USA e-mail:
[email protected] A. R. Hallauer Iowa State University, Ames, IA, USA
applied to other production environments (e.g., development of cultivars under organic conditions). Scientists should evaluate genotype by tillage interactions before investing additional resources in breeding for those speciWc target environments. Top yielding genotypes seem be consistent across years, locations, inputs; and most of the present evidence suggests that breeding for speciWc till systems is not necessary. Keywords Breeding · Hybrid £ tillage interactions · Maize · Production
Introduction Interest and demand on sustainable, organic, and lowinput agricultural production has been increasing for decades nationally. There are signiWcant environmental issues, cost (e.g., breeding for varieties with low nitrogen needs) and their impact on the diet and health of consumers (e.g., amino acid content for animals and humans). It also raises the demand of crop varieties for such production environments, including notillage system which is a component of organic and low-input agriculture. Breeding eVorts to select maize inbred lines under diVerent tillage and/or other production environments cause signiWcant increases in resources, which can be justiWed only if the cultivars that are currently developed or under development are not adapted to alternative production environments. As a Wrst step, researchers have to be able to answer
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Table 1 Summary of 12 genotype £ tillage (GT) studies for grain yield in maize including number of locations (L), years (Y), and genotypes (G); tillage treatments, soil types, use of common
plant population (population), N fertilization rate (N) between no-tillage and conventional tillage, and genotype by tillage interaction (GT)
Study
L
Y G
Tillage treatments
Soil typesa
Population N
GT
Brakke et al. (1983)
3
1 169
NT and CTb
Argiustoll, Haplustoll
No
No
**
Wall and Stobbe (1983)
1
2 8
NT and CT
NAc
Yes
NA
**
NA
NA
Yes NS
Funnermark and Hallauer (1985) 2
1 30
CST and CT
Hallauer and Colvin (1985)
1
5 14
CT, STTd, CST, NT Hapludoll
Yes
NA
Karlen and Sojka (1985)
1
2 5
CSTe and NT
Paleudult
NA
Yes NS
Anderson (1986)
4
3 6 (12)f
NT and CT
Hapludult, Hapludalf
Yes
Yes NSi
Newhouse and Crosbie (1986)
2
2 60
NT and CT
Haplaquoll, Hapludoll NA
Yes NS
Carter and Barnett (1987)
4
2 15
NT and CT
Argiudoll, Hapludalf
Yes
NA
Kaspar et al. (1987)
1
2 4
CT, CST, NT
Haplaquoll
Yes
Yes NS
Newhouse and Crosbie (1987)
2 (3) 2 100 + 100 NT and CT
Haplaquoll, Hapludoll Yes
Yes ** + NS
Hersterman et al. (1988)
2
Ochraqualf, Hapludalf Yes
Yes NS
Hapludalf
Yes NS
Duiker et al. (2006)
1
2 15 (18) 3 5
NT and CT g
NT, CT, ST , DT
h
Yes
NS
**
** Statistically signiWcant a Great groups b Conventional tillage c Data not available d Conservation tillage (strip tillage) e Conservation tillage (disk plow) f Depending on the environment g Conservation tillage (shallow in-row) h Conservation tillage (deep in-row) i GT was signiWcant in one location
whether it is necessary to allocate resources of a breeding program to accommodate the new practice. Multi-environment trials comparing the ranking of cultivars and their interactions with current and alternative production environments are essential before adopting such production practices. Maize growers in the US largely adopted minimum till systems in the early 1980s. As a consequence of the change in tillage systems, several genotype £ tillage interaction (GT) studies were published on maize during that decade (Table 1). Those studies were conducted across diVerent genotypes and soil conditions in diVerent regions of North America. The results, however, were not always in agreement. Testing, therefore, is needed especially under production environments where data are rarely available (e.g., organic conditions) but adoption has been signiWcant. On the other hand, data for tillage systems might be compelling enough to state that speciWc breeding programs are not necessary. We tried to analyze these two perspectives since breeding programs often change their selection
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environments over time to reXect the dominant farmer management practices. The challenge is always based on resources available. In addition, breeding accuracy might be diVerent across production environments, making selection more challenging under certain conditions and trade-oVs should be considered as well. The goal of this review is to determine whether development and evaluation of maize cultivars for diVerent tillage systems is needed to select the top yielding genotypes under diVerent production environments.
No-tillage system versus conventional tillage system Tillage systems have a long history and play a signiWcant role in agricultural production in the US. The main purposes of tillage are loosening soil thus facilitating deeper penetration of crop roots, mixing organic matters (OM) and nutrients evenly, and mechanically keeping soil from weeds. However, studies
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proved that increased tillage intensities can reduce soil organic carbon and nitrogen in the topsoil, and increase soil CO2 emission. In contrast to intensive tillage which is often referred to as conventional tillage system (CT), conservation tillage practices, such as no-tillage (NT), strip-tillage, mulch-tillage, and ridge-tillage that leave a minimum of 30% of crop residue on the soil surface, are eVective in improving soil organic matter and soil quality (Agele et al. 2005; Al-Kaisi and Yin 2005; Al-Kaisi et al. 2005; Franzluebbers and Stuedemann 2008; Govaerts et al. 2006; Hooker et al. 2005; Iowa State University 2005). Additionally, NT system has particular economic advantage because of its lower labor and fuel needs (Filipovic et al. 2004; Konutic et al. 1998; Yalcin and Cakir 2006). Surveys have shown that conservation practices including NT were used on 18, 24, and 31% of the US cropland in 1973, 1982, and 1983, respectively (Lessiter 1983; CTIC 1983). In recent years, this percentage has increased to 38% (CTIC 2005). According to Anderson (1986), the increase in NT is because it reduces inputs and soil erosion on slopes. Therefore, even though farmers might want to see performance data reXecting their current practices, the development of cultivars might still be done under CT. Under NT system the residue left on the ground aids water inWltration, reduces the impact of raindrops on the soil, and buVers temperature changes (Sullivan 2004). No-tillage system minimizes the OM loss by reducing its oxidation rate compared with CT, balancing microorganism activity, and decreasing the decomposition of root biomass and below ground OM (Iowa State University 2005). However, microorganisms and OM are in larger quantities on the surface of NT soils (Doran 1980). Under NT also, because of the plant residue left on the soil surface, the soils tend to be cooler, more compact, and wetter which are even more challenging for northern regions with colder temperatures. These conditions cause higher N immobilization (Youngquist 1983), lower herbicide activity, higher weed and insect populations, and higher disease pressure when compared with CT (Kuhlman and SteVey 1982; Nyvall 1982; Tripplet 1985). These major alterations in the crop growing environment under NT have generated questions about the relative maize hybrid performance under CT versus NT (Carter and Barnett 1987) and, consequently, if hybrid breeding should be conducted under diVerent production
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environments. The statistical presence for genotype £ environment interactions (GE) is an indication for a breeding program to develop either widely adapted genotypes or to breed for a speciWc environment. A large GE indicates a potential for separate cultivar development for each environment (Brakke et al. 1983). The same principle applies to GT interactions. Presence of GT suggests the need for conducting separate breeding programs under diVerent tillage systems. This implies the need for additional breeding nurseries under new environments. Currently, the majority of maize breeding programs develop inbred lines under CT. Research and extension personnel also conduct state hybrid maize performance trials under CT even though there are an increased number of farmers growing maize under NT conditions. Therefore, research addressing interactions between genotypes and management systems should be conducted before a decision on cultivar development can be made.
Evaluation under NT and CT systems and genotype by tillage interaction Soil and crop Bulk density, penetration resistance, and soil temperature are usually investigated in studies comparing diVerent tillage systems because these parameters reXect the conditions for plant emergence and early growth. The bulk density mainly depends on the mineral make up of soil and the degree of compaction. Many studies showed higher bulk density in the topsoil of NT compared with CT on diVerent soil type (Chassot et al. 2001; Dam et al. 2005; Duiker et al. 2006; Fabrizzi et al. 2005; Laszlo and Gyuricza 2004; Monneveux et al. 2006), however, the results from Franzluebbers et al. (1995) showed that bulk density was reduced shortly after tillage, but increased to levels observed under NT during both wet and cold intervals in the fallow period and during the growing season in all crops tested (Franzluebbers et al. 1995). Duiker et al. (2006) suggested that the rate of reconsolidation may depend on soil physical structural and texture, rainfall, and post-tillage traYc intensity. They also investigated penetration resistance and soil temperature under NT and CT systems on silt loam in Pennsylvania. The results showed that the penetration
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resistance was signiWcantly higher in the soil surface of NT than in the CT system, which agree with other studies conducted in silt loam and loam soils in the Swiss midlands (Chassot et al. 2001), loamy sand soil in South Carolina (Busscher and Sojka 1987; Busscher et al. 1986), sandy loam in Atlantic Canada, Hungary, Australia, and Argentina (Carter et al. 2002; Fabrizzi et al. 2005; Laszlo and Gyuricza 2004; Ratonyi et al. 2005). The results of Duiker et al. (2006) also showed a decreased average surface soil temperature in NT compared with CT which primarily resulted from diVerences in maximum temperature instead of minimum temperature. This has been observed by other researchers as well (Beyaert et al. 2002; Chassot et al. 2001; Fabrizzi et al. 2005; Halvorson et al. 2006; Hayhoe et al. 1996). Because soil parameters such as bulk density, penetration resistance, and soil temperature change from CT to NT systems, theoretically plant emergence and early growth are sequentially aVected under these two tillage systems. Later emergence under NT compared with CT has often been reported (Beyaert et al. 2002; Dam et al. 2005; Duiker et al. 2006; Khajanji et al. 2002). However, Duiker et al. (2006) reported that the emergence of hybrids tested was aVected more by hybrid than by tillage, and there was no correlation between emergence and yield. Even if later emergence was observed under NT in most cases, the percentage of emergence was generally higher in wet soil conditions regardless tillage methods (Bayhan et al. 2006; Yalcin and Cakir 2006). Dam et al. (2005) suggested that cooler soil temperatures and higher soil moisture in NT might be the main reason to cause poor emergence, however, these seedbed conditions are heavily inXuenced by climatic conditions, as well as crop residual cover. Additionally, studies showed that neither late emergence nor late maturity resulted in a reduced plant count (Burgess et al. 1996; Hayhoe et al. 1996). Delayed emergence under NT might be compensated by faster growth afterward (Duiker et al. 2006; GriYth et al. 1998). Chassot et al. (2001) investigated the impacts of tillage intensity, NT versus CT, on the morphology, vertical and horizontal distribution of maize root mass. Their results showed that the root length density was greater and the mean root diameter smaller in CT than in NT, while the vertical and horizontal distribution of roots did not diVer between CT and NT. Other studies also indicated that the maize roots are thicker under NT than under CT
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system (Holanda et al. 1998; Pereira de Mello Ivo and Mielniczuk 1999). The diVerences in maize root growth between tillage systems persist until anthesis (Qin et al. 2006). Other traits such as plant height, grain and silage yield have been investigated under NT and CT systems to answer if diVerent tillage systems have signiWcant eVects to maize production. Bayhan et al. (2006) reported that tillage methods signiWcantly aVect the average of plant height (F20 = 2.36), stem diameter (F20 = 3.05), and silage maize yield (F20 = 44.7). In their study, yield under NT was higher than that under CT due to higher percentage of emergence under NT, since Weld was irrigated after planting resulting in higher water content in NT plot which promoted higher percentage of emergence. SigniWcant tillage method eVects on plant height and grain yield have been reported by other researchers and it was found that maize yield was decreased under NT more than under the CT system (GriYth et al. 1998; Jug et al. 2007; Ratonyi et al. 2005; Yalcin and Cakir 2006; Zougmore et al. 2006). However, some studies reported diVerent results. Beyaert et al. (2002) compared productivity under zone tillage, NT, and CT systems in a coarse-textured soil in Canada. They found that the eVect of tillage system on plant height and grain yield was not signiWcant across three years. Bermudez and Mallarino (2004) studied maize response to starter fertilizer and tillage in Iowa by conducting seven replicated strip trials. Their results showed that tillage increased grain yield, dry weight and early nutrient uptake of maize in only three of seven Welds; tillage for maize in Iowa resulted in infrequent and small grain yield responses. These inconsistent results suggested that maize production diVerences between NT and CT depend on diverse factors such as soil type, climatic eVects, crop residual cover, rotation, and previous Weld tillage management, rather than tillage method itself. It is, therefore, wise to investigate genotype £ tillage interactions to address the question whether there is a need to allocate resource for particular tillage system. In addition, hybrid genetics seems to be the major factor. Genotype by tillage interaction The lack of GT interactions seems to justify breeding under CT. Although researchers reported evidence of signiWcant GT (Brakke et al. 1983; Wall and Stobbe 1983; Carter and Barnett 1987), the majority of the
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available studies reported non-signiWcant GT (Funnermark and Hallauer 1985; Hallauer and Colvin 1985; Karlen and Sojka 1985; Anderson 1986; Newhouse and Crosbie 1986; Kaspar et al. 1987; Hersterman et al. 1988; Duiker et al. 2006). Brakke et al. (1983) evaluated 169 maize genotypes in an experiment arranged in a partially balanced lattice design evaluated across three Nebraska locations (Alliance, ScottbluVs, and Sidney) in 1980. They utilized two contrasting tillage systems: (1) CT with 60,000 plant ha¡1, a 115 kg ha¡1 N fertilization, and irrigation; (2) NT with 25,000 plant ha¡1, a 60 kg ha¡1 N fertilization, and no irrigation. The genotypes were highly diverse, including genetically diverse and narrow crosses with a cold tolerant population. Two of the three locations had one tillage treatment; therefore, the eVects of tillage system and location were confounded. The authors concluded that all the sources of variation were signiWcant, including GT (i.e., the genotypes yielded relatively diVerent under NT compared to CT including a rank diVerence). However, because they utilized diVerent plant populations, N fertilization rates, and water regimens between CT and NT, their estimation of GT could be inXated by genotype £ N, genotype £ water regimen, or genotype £ plant population interactions. Wall and Stobbe (1983) studied the GT of eight maize hybrids under CT and NT in one experiment arranged in a split-plot design with two planting densities at one location in Manitoba, Canada, during 1980 and 1981. They reported signiWcant GT for grain weight per ear for 1981 (1980 was not signiWcant). However, the authors planted the experiment on a soil that did not have any NT history before the trial. Therefore, the only diVerence between the two treatments was the plant residue on the soil surface, causing diVerent water inWltration regimes and variable soil temperatures. This is a main diVerence in NT compared with CT, but often there are more diVerences between soils under CT compared to those under NT that were not present in this study (e.g., increases in OM content, stratiWcation of nutrients, increase in soil percent of porosity, and in microbiology activity). Funnermark and Hallauer (1985) conducted experiments including 21 maize hybrids (12 classiWed as cold tolerant) arranged in a randomized complete block design (RCBD) at Algona and Conrad, IA, during 1980. They utilized two tillage systems, CT and
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conservation tillage, this latter deWned as one pass of a tandem disk plow over maize stalks. They found signiWcant diVerences among hybrids for grain yield. However, comparisons between hybrids classiWed as cold tolerant or not cold tolerant were not signiWcant. The authors did not Wnd any diVerence in hybrid performance between the two tillage systems (i.e., GT was not signiWcant). Hallauer and Colvin (1985) studied GT in one IA location across 5 years (from 1979 to 1983) for four tillage methods: CT (fall plow), strip till, spring disk, and NT. Fall plow was representative of the widely used method for maize production in the US Maize Belt. The other three methods were recommended for maize as alternative conservation tillage methods. Strip till included one pass of a strip-tiller that caused a strip of soil disturbance of 0.25 m wide in which the seeds were placed. They planted 14 maize hybrids in one experiment with split-plot arrangement, with tillage as the whole plot, and hybrid as the subplot. The whole plot remained unchanged in space over the 5-year period, randomly assigning the hybrids each year. The results from the combined analyses across years showed signiWcant diVerences among tillage methods for grain yield, but the GT was not signiWcant. The extensive testing of this particular study across years made their conclusions very reliable. The relative performance of the hybrids was similar regardless the tillage method utilized. In addition, Hallauer and Sears (unpublished data) studied the diVerent responses of genotypes to tillage systems in a maize-soybean rotation. Fourteen single-cross hybrids were evaluated at one location under the same four tillage treatments, and experimental design utilized by Hallauer and Colvin (1985). The experiment was laid out over a soybean crop the year before (1984). The soil was under NT (or CT) for at least 7 years. Even though the conditions under each treatment could be considered as “true” NT and CT, they did not Wnd signiWcant GT in either single environments or in the combined analysis across all 4 years of data (Table 2). Karlen and Sojka (1985) included two tillage treatments, conventional (disked) and conservation (nondisked). They evaluated Wve maize hybrids in an experiment with split-plot arrangement in two South Carolina environments. Tillage was the whole plot and hybrid the subplot. They observed delayed plant emergence and lower plant populations under
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Table 2 Analysis of variance for grain yield of 14 single-cross corn hybrids evaluated in experiments conducted in a corn-soybean rotation in the state of IA (Hallauer and Sears, unpublished) Source of variation
DF
Mean squares Combined
1991
Replicates
3
30,107**
5,341**
Tillage (T)
3
3,853
599**
Error A
9
1,157
271
Hybrids (H)
13
1,702**
432**
H£T
39
192
86
Error B
156
203
125
Years (Y)
3
4,858
NA
Error C
9
2,917
NA NA
T£Y
9
710
Error D
27
418
NA
H£Y
39
430**
NA
H£T£Y
117
165
NA
Error E
468
175
NA
Total
896
NA
NA
NA not applicable ** Statistically signiWcant
conservation tillage compared with CT. There were signiWcant diVerences among hybrids for grain yield, but those diVerences were not consistent among years. The GT for grain yield was not signiWcant, which the authors speculated may have been caused by the thinning to a common plant population between the two methods. Anderson (1986) evaluated six commercial maize hybrids in a split-plot experiment (tillage as whole plots and hybrid as subplots) in three locations in Maryland (Queenstown, Beltsville, and Sharpsburg) during 1982. The Welds had been under NT production for 1 year or more in all locations. The GT for grain yield was non signiWcant, except at the Beltsville location. The lack of signiWcant GT for grain yield indicated that these commercial hybrids would yield similarly under either tillage method. Newhouse and Crosbie (1986) grew 60 commercial maize hybrids under CT and NT systems, at two IA locations during 2 years. Tillage was the main plot and the subplots were incomplete blocks of 20 hybrids. The hybrids were nested within blocks as sub-subplots. Traits measured in the study included emergence percentage, plant height, grain moisture at harvest, stalk lodging, and grain yield. None of the
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traits had signiWcant GT. According to the authors, the lack of signiWcant GT could be due to the selection for stress tolerant hybrids, the elimination of potentially adapted hybrids to NT hybrids during selection under CT, or an actual lack of GT for maize. Newhouse and Crosbie (1987) also grew S1 lines from genetically broad-based populations [BS22(R) C1 and BS13(SCT)C6] under both CT and NT systems. Experiments were grown at two IA locations (Ames and Nashua) in 1981, and at three IA locations (Ames, Nashua, and Kanawha) in 1982. GT was not signiWcant for BS22(R)C1 S1 lines for grain yield. However, GT was signiWcant among BS13(SCT)C6 S1 lines. Twenty lines of each improved population were selected under both NT and CT on the basis of high grain yield across all environments. Ten of the 20 selected lines (under CT) derived from BS22(R)C1 were also selected under NT. In addition, 12 of the 20 BS13(SCT)C6 S1 lines selected were common under both CT and NT. The results from this study suggest that selection can be performed under either CT or NT, without having the necessity to add resources to a breeding program. Carter and Barnett (1987) evaluated 15 maize hybrids under CT and NT monoculture systems at Janesville, Arlington, Sparta, and River Falls, WI, in 1984 and 1985. At Janesville and Arlington, the Welds had been under CT before 1984. At River Falls and Sparta, the Welds had been under NT production for 1 year. Tillage represented the whole plots and hybrid the subplots in a split-plot experiment arrangement. Results showed non-signiWcant GT for emergence percentage, vegetative dry weight, plant height, and stalk lodging. However, authors found signiWcant GT for grain moisture at harvest and grain yield. Although GT was signiWcant for grain yield, the highest ranked hybrids under CT were also the highest ones under NT. Moreover, the combined analyses across years and locations showed that hybrids ranked in the top Wve under CT had also the top Wve yields under NT. Utilizing means across environments, Kendall’s concordance test between the rankings of the genotypes under NT compared with CT showed a value of 0.80 (signiWcant at = 0.01). Therefore, even though Carter and Barnett (1987) found signiWcant GT, the relative rankings of the genotypes were not signiWcantly diVerent according to Kendall’s test. Kaspar et al. (1987) evaluated four maize hybrids (developed by Pioneer Hi-Bred International Inc.)
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under three tillage systems (full moldboard plow with spring disk, spring disk, and NT) at one IA environment (Ames) in 1981. Hybrids were evaluated in an experiment arranged in a RCBD with split-plot arrangement (tillage represented whole plots and hybrid the subplots). The soil was under CT until the year previous to the trial. Maize plants grew slower under NT compared with the other systems, similar to the research reported by Karlen and Sojka (1985). GT, however, was non-signiWcant for plant height, grain moisture at harvest, and grain yield. Hestermann et al. (1988) set up experiments at two Michigan locations in 1985 and 1986. The locations were: Lansing (poorly drained soils), and Hickory Maizeers (well drained). Eighteen (Lansing) and 15 (Hickory Maizeers) maize hybrids were planted using CT and NT systems. The experimental design was a RCBD with a split-plot arrangement at Lansing and a split-split-plot arrangement at Hickory Maizeers. At Lansing, whole plots were tillage systems and hybrid cultivars were the subplots. At Hickory Maizeers, whole plot was the irrigation treatment; tillage was the subplot, and hybrid the sub-subplot. There was no signiWcant GT in this experiment for maize grain or silage yield. Duiker et al. (2006) evaluated a GT experiment at Landisville, Pennsylvania across three years. The experimental Weld was under CT until the previous year to the experiment. Five genotypes were used from the Dekalb (Monsanto) maize breeding program. Three of them were commercialized for NT and two for CT. However, no mention on the development process of these hybrids was made. The experimental design was a RCBD with split-plot arrangement in which tillage was the whole plot and hybrid the subplot. The tillage treatments were: (1) NT; (2) shallow in-row, where they cultivated only 15 cm deep and 15 cm wide where the seeds were placed; (3) deep in-row, similar to the previous one but cultivated 40 cm deep; and (4) CT which include plowing plus disking. GT was not signiWcant for emergence percentage, plant height, and grain yield. The hybrids that were commercialized for NT did not have higher percent of emergence under NT compared with CT.
Discussion and conclusions As reviewed, studies indicated NT system intends to increase bulk density and penetration resistance of
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topsoil, decrease soil surface temperature, which consequently aVect maize emergence and root development. Yet the tillage method eVect on maize yield is not clear. Duiker et al. (2006) concluded that higher bulk density and penetration resistance under NT than other tillage systems do not have eVects on maize growth and yield. Delayed emergence might be compensated by later faster growth, which is supported by studies conducted by Bermudez and Mallarino (2004). They found that maize growth rates were similar among NT and CT in the early part of the growing season but were higher for NT during late vegetative and early reproductive growth. The thicker root development of maize under NT might promote nutrition and water uptakes thus ensure plant growth and grain Wlling at the normal level relative to CT. Although poor emergence rate can be highly correlated with grain yield, the seedbed conditions, which are the main contributors to emergence rate, are highly inXuenced by climatic conditions and residual cover (Dam et al. 2005). All the information implies that the diVerence of maize yield between NT and CT might result from a combination of soil temperature, rotation system, residual cover, and climatic conditions while not only due to tillage systems. As a result, maize hybrid responses for diVerent tillage systems are small. The objective of this paper was to determine whether development and evaluation of maize cultivars for diVerent tillage systems is needed. Based on the data available it seems scientists do not need to spend additional resources to conduct separate maize breeding programs. These results will probably apply to other crops. An unbiased evaluation of the studies gathered in this review showed mostly non-signiWcant GT for grain yield, as well as for agronomic traits. These studies represent the evaluation of 540 maize genotypes across 23 locations and 27 years (Table 1). As a consequence of this extensive testing breeding, selection, and evaluation of lines and hybrids under NT practices may be unnecessary. Also, growers could select hybrids for NT using the results from performance trials conducted under CT and based on hybrids developed under CT. The focus of this review was to evaluate the need for separation of breeding schemes (i.e., breed for speciWc tillage systems). From this summary, we can conclude that the lack of GT justiWes the current approach of developing maize inbred lines and
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hybrids under CT as well as the evaluation of maize genotypes under CT only. However, this may only apply to GT interactions. Currently, few reports are available for interactions between genotypes and alternative production environments, e.g., organic versus conventional farming systems. Maize breeding lines were evaluated under organic and conventional production systems (Lorenzana and Bernardo 2007). They conducted the study in Minnesota using testcrosses of a group of B73 £ Mo17 recombinant inbred lines. They concluded that it might be unnecessary to have a separate organic maize breeding program. Interestingly, the study conducted by Burger et al. (2008) suggested the opposite conclusion. Their research was conducted in Germany between 2004 and 2006 and the testcross performance of elite Xint and dent inbred lines were evaluated under both organic and conventional conditions. They concluded that a strong genotype £ farming system interaction exists and it is better to develop varieties speciWc for organic farming. Moreover, a study on lentil varieties under these two alternative environments (Vlachostergios and Roupakias 2008) suggested that a genotype £ farming system interaction exists with varieties which have speciWc adaptation but not for varieties with broad adaptation. In any case more research is needed to assess interactions between genotypes and alternative production environments. Even though interactions between genotypes and other production environments are not well studied, our review suggested that current eVorts focused on cultivar development under NT could be avoided. We have learned that diVerent locations are desirable to sample diVerent soil types (well vs. poorly drained), diVerent years to sample diVerent temperature and precipitation conditions, and common cultural practices are needed to measure certain interactions without the bias usually caused by other interactions (e.g., genotype £ plant population, genotype £ N, genotype £ water regimen). The current evidence suggests that breeding for speciWc tillage systems is not necessary. Experiments with extensive testing will be essential to determine if breeding programs need to be targeted for alternative production environments in cultivar development. We encourage scientists to evaluate extensive genotype £ production environment interactions before developing and testing cultivars under alternative production environments (e.g., organic production) to make accurate and most eYcient decisions.
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This review serves as precedent for research needed and re-direction for funding avoiding unnecessary waste of energy, time, and resources.
References Agele SO, Ewulo BS, Oyewusi IK (2005) EVects of some soil management systems on soil physical properties, microbial biomass and nutrient distribution under rainfed maize production in a humid rainforest AlWsol. Nutr Cycl Agroecosyst 72:121–134. doi:10.1007/s10705-004-7306-x Al-Kaisi MM, Yin X (2005) Tillage and crop residue eVects on soil carbon and carbon dioxide emission in maize-soybean rotations. J Environ Qual 34:437–445 Al-Kaisi MM, Yin X, Licht MA (2005) Soil carbon and nitrogen changes as aVected by tillage system and crop biomass in a maize-soybean rotation. Appl Soil Ecol 30:174–191. doi:10.1016/j.apsoil.2005.02.014 Anderson EL (1986) No-till eVects on yield and plant density of maize hybrids. Agron J 78:323–326 Bayhan Y, Kayisoglu B, Gonulol E, Yalcin H, Sungur N (2006) Possibilities of direct drilling and reduced tillage in second crop silage maize. Soil Tillage Res 88:1–7. doi:10.1016/ j.still.2005.04.012 Bermudez M, Mallarino AP (2004) Maize response to starter fertilizer and tillage across and within Welds having no-till management histories. Agron J 96:776–785 Beyaert RP, Schott JW, White PH (2002) Tillage eVects on maize production in a coarse-textured soil in southern Ontario. Agron J 94:767–774 Brakke JP, Francis CA, Nelson LA, Gardner CO (1983) Genotype by cropping system interactions in maize grown in a short-season environment. Crop Sci 23:868–870 Burger H, Schloen M, Schmidt W, Geiger HH (2008) Quantitative genetic studies on breeding maize for adaptation to organic farming. Euphytica 163:501–510. doi:10.1007/ s10681-008-9723-4 Burgess MS, Mehuys GR, Madramootoo CA (1996) Tilage and crop residue eVects on maize production in Quebec. Agron J 88:792–797 Busscher WJ, Sojka RE (1987) Enhancement of subsoiling eVect on soil strength by conservation tillage. Trans ASAE 30:888–892 Busscher WJ, Sojka RE, Doty CW (1986) Residual eVects of tillage on Coastal plain soil strength. Soil Sci 141:144–148. doi:10.1097/00010694-198602000-00007 Carter PR, Barnett KH (1987) Corn-hybrid performance under conventional and no-tillage systems after thinning. Agron J 79:919–926 Carter MR, Sanderson JB, Ivany JA, White RP (2002) InXuence of rotation and tillage on forage maize productivity, weed species, and soil quality of a Wne sandy loam in the coolhumid climate of Atlantic Canada. Soil Tillage Res 67:85– 98. doi:10.1016/S0167-1987(02)00043-0 Chassot A, Stamp P, Richner W (2001) Root distribution and morphology of maize seedlings as aVected by tillage and fertilizer placement. Plant Soil 231:123–135. doi:10.1023/ A:1010335229111
Euphytica (2009) 169:141–150 CTIC (1983) 1982 Survey of conservation tillage practices. Conservation Technology Information Center, West Lafayette, IN CTIC (2005) 2004 National crop residue management survey. Conservation Technology Information Center, West Lafayette, IN Dam RF, Mehdi BB, Burgess MSE, Madramootoo CA, Mehuys GR, Callum IR (2005) Soil bulk density and crop yield under eleven consecutive years of maize with diVerent tillage and residue practices in a sandy loam soil in central Canada. Soil Tillage Res 84:41–53. doi:10.1016/j.still.2004.08.006 Doran JW (1980) Soil microbial and biochemical changes associated with reduced tillage. Soil Sci Soc Am J 44:765–771 Duiker SW, Haldeman JF Jr, Johnson DH (2006) Tillage £ maize hybrid interactions. Agron J 98:436–442. doi:10.2134/ agronj2005.0063 Fabrizzi KP, Garcia FO, Costa JL, Picone LI (2005) Soil water dynamics, physical properties and maize and wheat responses to minimum and no-tillage systems in the southern Pampas of Argentina. Soil Tillage Res 81:57–69. doi:10.1016/j.still. 2004.05.001 Filipovic D, Konutic S, Gospodaric Z (2004) InXuence of diVerent soil tillage systems on fuel consumption, labour requirement and yield in maize and winter wheat production. Agric Sci Prof Rev 10:17–23 Franzluebbers AJ, Stuedemann JA (2008) Early response of soil organic fractions to tillage and integrated crop-livestock production. Soil Sci Soc Am J 72:613–625. doi:10.2136/ sssaj2007.0121 Franzluebbers AJ, Hons FM, Zuberer DA (1995) Tillage and crop eVects on seasonal dynamics of soil CO2 evolution, water content, temperature, and bulk density. Appl Soil Ecol 2:95–109. doi:10.1016/0929-1393(94)00044-8 Funnermark WL, Hallauer AR (1985) Cold tolerance in corn hybrids as aVected by tillage systems and planting dates. Proc Iowa Acad Sci 92:58–62 Govaerts B, Mezzalama M, Sayre K-D, Crossa J, Nicol J-M, Deckers J (2006) Long-term consequences of tillage, residue management, and crop rotation on maize/wheat root rot and nematode populations in subtropical highlands. Appl Soil Ecol 32:305–315. doi:10.1016/j.apsoil.2005.07.010 GriYth DR, Kladivko EJ, Mannering JV, West TD, Parsons SD (1998) Long-term tillage and rotation eVects on maize growth and yield on high and low organic matter, poorly drained soils. Agron J 80:599–605 Hallauer AR, Colvin TS (1985) Corn hybrids response to four methods of tillage. Agron J 77:547–550 Halvorson A-D, Mosier A-R, Reule C-A, Bausch W-C (2006) Nitrogen and tillage eVects on irrigated continuous maize yields. Agron J 98:63–71. doi:10.2134/agronj2005.0174 Hayhoe HN, Dwyer LM, Stewart DW, White RP, Culley JLB (1996) Tillage, hybrid and thermal factors in maize establishment in cool soils. Soil Tillage Res 40:39–54. doi:10.1016/ S0167-1987(96)01045-8 Hersterman OB, Pierce FJ, Rossman EC (1988) Performance of commercial corn hybrids under conventional and no-tillage systems. J Prod Agric 1:202–206 Holanda FSR, Mengel DB, Paula MB, Carvaho JG, Bertoni JC (1998) InXuence of crop rotations and tillage systems on phosphorus and potassium stratiWcation and root distribution in the soil proWle. Commun Soil Sci Plant Anal 29:2383–2394. doi:10.1080/00103629809370118
149 Hooker B-A, Morris T-F, Peters R, Cardon Z-G (2005) Longterm eVects of tillage and maize stalk return on soil carbon dynamics. Soil Sci Soc Am J 69:188–196 Iowa State University (2005) Resources conservation practices: tillage management and soil organic matter [Online]. Iowa State University Extension Service, Ames. Available at: http://www.extension.iastate.edu/Publications/PM1901I.pdf (Accessed Feb 2007) Jug D, Stipesevic B, Jug I, Samota D, Vukadinovic V (2007) InXuence of diVerent soil tillage systems on yield of maize. Cereal Res Commun 35:557–560. doi:10.1556/CRC.35.2007.2.98 Karlen DL, Sojka RE (1985) Hybrid and irrigation eVects on conservation tillage corn in The Coastal Plain. Agron J 77:561–567 Kaspar TC, Crosbie TM, Cruse RM, Erbach DC, Timmons DR, Potter KN (1987) Growth and productivity of four corn hybrids as aVected by tillage. Agron J 79:477–481 Khajanji S-N, Gautam R-C, Patel J-R (2002) EVect of tillage and weed control methods on growth and yield of maize. J Maharashtra Agric Univ 27:277–279 Konutic S, Filipovic D, Gospodaric Z (1998) InXuence of diVerent soil tillage systems on yield, energy and labour requirement in spring barley production. Poljoprivreda 4:67–75 Kuhlman DE, SteVey KL (1982) Insect control in no-till corn. Proc Annu Corn Sorghum Res Conf 37:118–147 Laszlo P, Gyuricza C (2004) EVect of the ridge tillage system on some selected soil physical properties in a maize monoculture. Acta Agron Hung 52:211–220. doi:10.1556/AAgr.52. 2004.3.1 Lessiter F (1983) 1982–1983 No till farmer acreage survey. No-till Farmer, BrookWeld, WI, pp 8–9 Lorenzana RE, Bernardo R (2007) Genetic correlation between corn performance in organic and conventional production systems. North Central Regional Corn Breeding Research Meeting, St. Charles, pp 21–22. http://corn2.agron.iastate. edu/NCR167/Abstracts/2007/NCCC167%20abstract%20 Lorenzana.pdf. Cited 02 February 2009 Monneveux P, Quillerou E, Sanchez C, Lopez-Cesati J (2006) EVect of zero tillage and residues conservation on continuous maize cropping in a subtropical environment (Mexico). Plant Soil 279:95–105. doi:10.1007/s11104-0050436-3 Newhouse KE, Crosbie TM (1986) Interactions of maize hybrids with tillage systems. Agron J 78:951–954 Newhouse KE, Crosbie TM (1987) Genotype by tillage interactions of S1 lines from two maize synthetics. Crop Sci 27: 440–445 Nyvall RF (1982) Disease control. In: Cruse RM, Horton R (eds) Tillage and the soil environment. Iowa Cooperative Extension Service Bull. CE-1755 Pereira de Mello Ivo WM, Mielniczuk J (1999) InXuence of soil structure on the distribution and morphology of maize roots under three tillage methods. Rev Bras Cienc Do Solo 23:135–143 Qin R, Stamp P, Richner W (2006) Impact of tillage on maize rooting in a Cambisol and Luvisol in Switzerland. Soil Tillage Res 85:50–61. doi:10.1016/j.still.2004.12.003 Ratonyi T, Huzsvai L, Nagy J, Megyes A (2005) Evaluation of soil tillage systems in maize production. Acta Agron Hung 53:53–57. doi:10.1556/AAgr.53.2005.1.7
123
150 Sullivan P (2004) Sustainable soil management: soil systems guide. ATTRA National Sustainable Agriculture Information Service. National Center for Appropriate Technology (NCAT) Tripplet GB Jr (1985) Principles of weed control for reducedtillage corn production. In: Wiese AF (ed) Weed control in limited-tillage systems. Weed Science Society of America, Champaign, IL Vlachostergios DN, Roupakias DG (2008) Response to conventional and organic environment of thirty-six lentil (Lens culinaris Medik.) varieties. Euphytica 163:449–457. doi:10.1007/s10681-008-9712-7 Wall DA, Stobbe EH (1983) The response of eight corn (Zea mays L.) hybrids to zero tillage in Manitoba. Can J Plant Sci 63:753–757
123
Euphytica (2009) 169:141–150 Yalcin H, Cakir E (2006) Tillage eVects and energy eYciencies of subsoiling and direct seeding in light soil on yield of second crop maize for silage in Western Turkey. Soil Tillage Res 90:250–255. doi:10.1016/j.still.2005.10.003 Youngquist WC (1983) Maize breeding for the Nebraska panhandle inXuence of tillage system and location on genotype testing and selection. MS Thesis. University of Nebraska Zougmore R, Nagumo F, Hosikawa A (2006) Nutrient uptakes and maize productivity as aVected by tillage system and cover crops in a subtropical climate at Ishigaki, Okinawa, Japan. Soil Sci Plant Nutr 52:509–518. doi:10.1111/ j.1747-0765.2006.00067.x
