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Effectiveness of Residue and Tillage Management on Runoff Pollutant Reduction from Agricultural Areas
Laxmi R. Prasad1,*, Anita M. Thompson1,**, Francisco J. Arriaga2, Lydia Koropeckyj-Cox3, Yongping Yuan4
Published in Journal of the ASABE 66(6): 1341-1354 (doi: 10.13031/ja.15518). 2023 American Society of Agricultural and Biological Engineers.
1Biological Systems Engineering, University of Wisconsin, Madison, Wisconsin, USA.
2Department of Soil Science, University of Wisconsin, Madison, Wisconsin, USA.
3Arcadis, Raleigh, North Carolina, USA.
4Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, North Carolina, USA.
Correspondence: *lprasad@wisc.edu, **amthompson2@wisc.edu
Submitted for review on 31 December 2022 as manuscript number NRES 15518; approved for publication as a Review Article and as part of the Agricultural Conservation Practice Effectiveness Collection by Community Editor Dr. Ruth Book of the Natural Resources & Environmental Systems Community of ASABE on 22 June 2023.
Mention of company or trade names is for description only and does not imply endorsement by the USDA. The USDA is an equal opportunity provider and employer.
Highlights
Abstract. Reduced tillage management conservation practices (No-till and Reduced-till) are widely adopted in agriculture; however, understanding their overall effectiveness for water quality protection is challenging. A meta-analysis was conducted to understand and quantify the effectiveness of residue and tillage management on runoff, sediment, and nutrient losses from agricultural fields. Annual runoff and the associated sediment, and nutrient (nitrogen and phosphorus) loads were compiled from 60 peer reviewed research articles published across the United States and Canada. A total of 1575 site-years of data were categorized into tillage (<30% surface cover), no-tillage (<30% surface cover), tillage with residue (>30% surface cover), no-tillage with residue (>30% surface cover), and pasture management. No-tillage, no-tillage-residue, and tillage-residue managements were evaluated for their effectiveness in reducing runoff, nutrients, and sediment loads compared to tillage. Synthesized and surveyed corn yield data were used to evaluate the economic cost effectiveness of no-tillage-residue management with respect to tillage. Across the site years (1968-2019) studied, median runoff depth for no-tillage and no-tillage-residue were 84% and 70% greater than tillage and tillage-residue management, respectively. No-tillage-residue management had up to 86% less sediment losses than tillage systems, on average, for both >30% and <30% surface cover. No-tillage-residue management was most effective, with a positive performance effectiveness of 65% to 90% in controlling sediments, particulate, and total nutrient losses in runoff compared to tillage. Cost effectiveness analysis revealed the benefits of no-tillage-residue management in reducing nutrient loads and increasing net-farm revenue by avoiding tillage operational costs. Except for dissolved phosphorus, no-tillage-residue management cost effectiveness for sediments and nutrient loads ranged from negative $6 to negative $102 per every Mg or kg of load reduction, indicating it had both economic and environmental benefits compared to tillage management. Overall, these results indicate that over the long-term, no-tillage and tillage, combined with greater than 30% residue cover, can effectively reduce sediment and nutrient losses. This work highlights the importance of crop residues on the soil surface to reduce runoff losses, even in no-tillage systems.
This article is part of a collection that provides a formance and cost-effectiveness of selected agricultural conservation practices (ACPs) on nutrient and sediment reduction.
Natural Resource Conservation Service (NRCS) practice standards, "Residue and Tillage Management, No-Till" (USDA-NRCS, 2017f) and "Residue and Tillage Management, Reduced Till" (USDA-NRCS, 2017g), are ACPs that "limit soil disturbance to manage the amount, orientation, and distribution of crop and plant residue on the soil surface year-round" (USDA-NRCS, 2017f). "Tillage" in this context is defined as the mechanical manipulation of soil for the purpose of crop production, whereas "No-Till" refers to a method where no type of tillage is applied during any part of the year or growing season. "Reduced Till" refers to a reduced frequency of tillage or a less disruptive tillage method compared to conventional tillage practices. Conventional tillage is defined as complete soil surface disturbance (in one tillage pass or multiple) using plows, discs, or harrows, and leaves minimum or no-residue on the surface. Residue and tillage management (RTM) practices are also commonly applied with other ACPs, such as Conservation Crop Rotation (USDA-NRCS, 2017a), Nutrient Management (USDA-NRCS, 2017d), Pest Management (USDA-NRCS, 2017e), Grassed Waterway (USDA-NRCS, 2017c), and Irrigation Water Management (USDA-NRCS, 2017b).
Residue and tillage management have long existed to combat sediment and nutrient losses from agricultural fields (Montgomery, 2007). Recent research also focuses on RTM effects on global biogeochemical cycles, especially gas emissions and carbon sequestration (Zhang et al., 2019; Mirzaei et al., 2022). Numerous studies have well-documented changes in soil characteristics (e.g., porosity and structure) and processes (infiltration and runoff) due to the implementation of RTM (Karlen et al., 1994; Tiessen et al., 2010). Studies have observed that no-tillage and reduced-tillage maintain or improve soil structure, infiltration rates, and biological activities compared to conventional tillage (Arshad et al., 1999; Cavalieri et al., 2009; Li et al., 2020; Qi et al., 2021). The higher infiltration rates in turn reduce surface runoff, sediment, and nutrient losses (Montgomery, 2007; Maetens et al., 2012). Additionally, crop residues on the surface protect soil from raindrop impact, decreasing surface sealing and crust formation (Sharpley and Smith, 1991; Blanco-Canqui and Lal, 2009). Several studies have also quantified the effects of no-tillage and reduced-tillage, to increase soil organic matter and microbial productivity as soil microorganisms decompose the organic material left on the soil surface (Busari et al., 2015). In fact, any tillage system that leaves at least 30% of the soil surface covered with crop residue after planting can improve soil health by increasing or maintaining organic matter (Maetens et al., 2012).
While the global soil and water conservation benefits of reduced-tillage and no-tillage practices are widely recognized, some recent studies have also identified increased runoff and dissolved nutrient losses from these practices when compared to conventional tillage (Baumhardt et al., 2017; Darynto et al., 2017a,b). These results were generally attributed to compaction and nutrient stratification, making the RTM benefits debatable for water quality protection (Carretta et al., 2021). In claypan regions and frozen soils, no-tillage was found to produce significantly higher runoff associated nutrient losses than tillage systems (Blanco-Cauanqui et al., 2002; Prasad et al., 2022). The other negative impacts, especially of no-tillage, are challenges for weed control and intensified herbicide use, increasing herbicide loss in surface runoff (Cessna et al., 2013). The longevity of the practices should also be considered, as it has been estimated that it takes about five to seven years (transition period from conventional tillage) for no-tillage and reduced-tillage systems to develop the soil characteristics fully and benefit soil and water conservation (Hobbs et al., 2008; Carretta et al., 2021). A recent review indicated that occasional tillage every five to ten years in no-tillage systems can reduce compaction and nutrient stratification and aid in negating the negative impacts of reduced-tillage and no-till for water quality protection (Blanco-Canqui and Wortmann, 2020).
The studies discussed above have added substantial knowledge on the effects of RTM for soil and water conservation. However, the conflicting results observed among studies can, at least in part, be attributed to dynamic site-specific weather and soil conditions, as well as differences in study designs. In addition, most of the information on RTM effectiveness in reducing water pollutants from agricultural fields is available at seasonal scales, with most studies having focused on the growing season runoff and not considering other critical times of the year. The synthesis of RTM effects on annual runoff, sediment, and nutrient losses is lacking. For example, a specific RTM practice that may be effective during the growing season may not be as effective during the non-growing season. Therefore, improving the systematic understanding of RTM at an annual scale might provide guidance for adapting management practices to mitigate overall nutrient pollution. The specific objectives of this study were to: (1) synthesize peer-reviewed literature information available at an annual scale on the impact of residue and tillage management on surface water quality; (2) compare the effect of crop residue and tillage management on surface water quality parameters with a meta-analysis approach; and (3) estimate the performance and cost effectiveness of reduced tillage practices with respect to conventional tillage for runoff associated pollutant reduction. The information gained from this meta-analysis can then be used to help inform the selection of RTM practices for water quality improvement.
Materials and Methods
Literature Search
A search of peer-reviewed literature was performed between April and September 2020 to gather data from relevant research articles that reported on the effects of residue and tillage management on water quality, either as a primary or secondary treatment. Primary treatment indicates that the article's main focus was on investigating tillage and/or residue management. Secondary treatment refers to articles in which the focus was not on tillage and/or residue management, but either tillage and/or residue management were evaluated. For example, Bormann et al. (2012) evaluated the runoff measurement scale effect on phosphorus losses by collecting runoff from agricultural fields of varying sizes (0.0001 – 12 ha) that had undergone different RTM practices. While their primary focus was not on RTM, the study provided information related to the RTM effect on water quality. For the literature search, keywords "tillage," "no-tillage," "residue cover," "conservation tillage,” "runoff,” and "water quality" were used on the Web of Science platform. The collected articles published between 1968 and 2019 were segregated based upon the geographical region (North America vs. non-North America/international) and timescale of data collection (seasonal vs. annual). For the purposes of this meta-analysis and its applicability, only field studies conducted within the United States (US) and Canada were included in the database. Next, articles were screened, and studies with only seasonal scope (i.e., not year-round), rainfall simulation, and modeling data were excluded. Therefore, the literature considered for this work included annual scale data pertaining to precipitation, surface runoff and associated sediment, nitrogen (N), and phosphorus (P) losses. Subsurface N and P losses were not collected from the literature and were not part of this analysis. To avoid extraction errors, which could lead to additional uncertainty in the dataset, no software or other methods were used to extract information from figures. Information presented in tables and text was manually extracted from the selected articles and used for analysis. The references of the articles considered in this meta-analysis are listed in supplementary information.
Data Collection
Using the criteria described above (literature search), 60 research articles published between 1968 and 2019 were identified that had the necessary information required for this meta-analysis. The extracted runoff and nutrient loss data were further categorized into five management categories (four residue and tillage management practices and one pasture management) for analysis. For studies that did not present residue cover information, categorization into residue or no-residue was based on the number of crops grown at the site during the 12 months annual period. For example, if a site has corn-silage during summer and fall and is immediately followed by Rye cover for winter and spring, it is categorized as residue because the soil is covered by crop for most of the year. For the same site, with only the summer crop (corn-silage), and winter fallow, it is categorized as no-residue. The main focus of this article is on RTM in crop lands; however, pasture management is included to provide a comparison between crop and grasslands. These management categories were specifically selected to help determine the impact of soil disturbance and residue cover somewhat individually. The five categories used are summarized in table 1, and the definition of each category pertains to one-year management.
Data Analysis
The geographical distribution of the data was mapped, and the number of site-years for each management category were calculated. Precipitation, runoff, sediment, and nutrient loss data of each management category were analyzed and compared using descriptive statistics. Box-and-whisker plots were plotted to summarize the variability and distribution of data for the five management categories. The nutrient loss data were grouped into dissolved, particulate, and total forms (table 2) to evaluate the management effect on specific nutrient losses. Runoff loss as a percentage of precipitation was computed to attempt to normalize the effects of differences in precipitation amounts on runoff losses. The runoff loss as a percentage of precipitation is not intended to fully normalize geographic effects, including climate and soil type.
| Table 1. Residue and tillage management categories used to extract data from published literature. | |||
| Category | Definition | ||
| Tillage (T) | Any form of soil disturbance operation comprising moldboard, chisel, disk, subsoiler, vertical, and reduced tillage leaving <30% of surface cover. | ||
| No-tillage (NT) | No soil disturbance following harvest of previous crop, with the only soil disturbance happening during seedling/planting stage with < 30% of surface cover. This category also applies for cropping systems that leave little crop residues after harvest, such as corn (Zea mays L.) silage production. | ||
| Tillage- residue (T-R) | Any form of tillage operation listed in T but with >30% of surface cover. Fields with a summer- winter crop rotation system were considered a form of residue management because the standing crop covers the soil for most of the year. | ||
| No-tillage- residue (NT-R) | As defined under NT, no soil disturbance other than during seeding operations with >30% of residue cover and any summer-winter crop rotation system. | ||
| Pasture (PA) | Any rangeland, improved pasture, and hay land, all of which may or may not be used for animal feeding. | ||
Table 2. Criteria used to group different nutrient forms in runoff. | |||
| Nutrient Form | Nitrogen (N) | Phosphorus (P) | |
| Dissolved[a] | Nitrate Nitrate + Nitrite Ammonium Nitrate + Ammonium | Dissolved Reactive Phosphorus Soluble Reactive Phosphorus Water extractable Phosphorus | |
| Particulate | Sediment Bound N (PN) | Sediment Bound P (PP) | |
| Total | Dissolved N + Particulate N (TN) | Dissolved P + Particulate P (TP) | |
[a]All four dissolved forms of N and three dissolved forms of P were lumped to dissolved N (DN) and dissolved P (DP) | |||
Performance Effectiveness
Performance effectiveness is commonly calculated using percent mass load and/or concentration reduction compared to a baseline (Smith et al., 2019). In this study, tillage (T) management (<30% residue) was considered a baseline practice, and the performance effectiveness of other management practices was evaluated. For example, the performance effectiveness of no-tillage (NT) regarding nutrient load was computed by subtracting the nutrient load of NT from that of the control (T), dividing by the load of the control (T) (eq. 1), and then expressing it as a percentage. The A negative percent effectiveness value would indicate that NT increased nutrient loads (less effective), whereas a positive value would indicate that NT decreased nutrient loads (more effective). The performance effectiveness of different management combinations was analyzed using descriptive statistics and compared using box-and-whisker plots.
(1)
where
x represents runoff volume or depth, sediment load, or the nutrient load of interest within each management category.
Cost Effectiveness Analysis
The cost-effectiveness (CE) analysis was generally used to evaluate the relative costs associated with the implementation of ACPs to the benefits gained (e.g., pollutant reductions) (Koropeckyj-Cox et al., 2021; Liu et al., 2021). However, when it comes to RTM, particularly the implementation of NT and NT-R, can result in cost savings compared to conventional systems. The CE methodology used to assess RTM is adapted from the incremental cost effectiveness ratio used for medical interventions (Neumann et al., 2016). Single Cost-effectiveness ($ kg-1) was estimated by calculating the difference in net revenue ($ ha-1) between the treatment of interest and the baseline, then dividing by the difference in their respective sediment or nutrient loads (kg ha-1). For example, considering NT-R management as treatment and T as baseline, CE of NT-R with respect to T was determined by subtracting the net revenue of T from the net revenue of NT-R and dividing by the sediment or nutrient load difference between NT-R and T (eq. 2). The numerator in equation 2 represents the difference in net revenue between treatment and baseline. The denominator in equation 2 represents the difference in nutrient loads between treatment and baseline. A “positive” numerator indicates the treatment has higher revenue than the baseline. A “negative” numerator indicates the treatment has less revenue than the baseline. A “positive” denominator indicates treatment losses are higher than baseline. A “negative” denominator indicates treatment losses are lower than baseline. A CE value indicates the combination of two outcomes (performance effectiveness and economic benefits) and may help guide decisions of implementing management practices that have both environmental and economic benefits. If CE falls in quadrant A of figure 1, the treatment is both effective in reducing sediment or nutrient loads and has higher net revenue than the baseline. Conversely, if CE falls in quadrant C, the treatment does not reduce sediment or nutrient loads and has lower revenue than the baseline. If CE falls in quadrant B, the treatment has higher net revenue but is ineffective in reducing sediment or nutrient loads. For quadrant D, the treatment is effective in reducing sediment and nutrient losses but has lower revenue than the baseline.
 |
| Figure 1. A cost-effectiveness plane divided into four quadrants (A, B, C, and D). Y-axis represents numerator and X-axis represents denominator of equation 2. |
Most of the no-tillage studies evaluated in this study practiced >30% residue cover. Therefore, only the CE of NT-R management with respect to T (baseline) for continuous corn (Zea mays [L.]) is presented as an example. The other managements (NT, T-R, and PA) were not evaluated for CE. The net revenue of NT-R and T for continuous corn production was calculated by subtracting production costs (tillage, seed, planting, N-fertilizer, pesticide, harvesting, and labor) from crop revenue (crop yield times market price of the crop). Only summer crop production costs and revenue were considered in these calculations. Except for tillage operational costs for T management, the other production costs were similar for NT-R and T (table S14). The majority of studies reviewed as part of this meta-analysis did not report crop yield information. While tillage type affects corn yield depending upon site specific weather and soil characteristics (DeFelice et al., 2006; Liu et al., 2021), crop revenue of NT-R and T managements was calculated by assuming both practices had similar yields. An extensive literature review study supports our assumption that the national average (United States) of corn yield between no-tillage and conventional tillage systems is negligible (DeFelice et al., 2006). The mean sediment and nutrient loads for NT-R and T were obtained for the corn cropping system (table S16) from the data collected from research articles as part of this meta-analysis. Only data from studies (n=5) that evaluated both NT-R and T on the same site and year were used. Production costs and corn pricing were fixed, and no adjustments were made to historical pricing although the data were from different years. Relevant values for production costs, corn price, corn yield, and other inputs were obtained from the USDA National Agricultural Statistics Service (NASS), the Iowa State University Cooperative Extension, the University of California Cooperative Extension, and other university extension service publications. Except for the cost of corn seed, which was from NASS Quick Stats 2014, all other costs were from surveys conducted between 2016 to 2019. The CE analysis did not account for tax benefit programs, government subsidies, or projected inflation. Details of costs and CE calculations are summarized in the supplemental information.
(2)
where
x represents sediment or nutrient loss of interest.
Results and Discussion
Data Overview
A total of 60 peer-reviewed research articles spanning 20 states in the conterminous US and four provinces in Canada were identified that reported annual data on precipitation, runoff, as well as sediment and nutrient losses, comprising a total of 1575 site-years (fig. 2). The sediment and nutrient loss data from these studies included annual loads (mass per area) and concentrations (mass per volume). The loads and concentrations were measured through various methods, mainly based on the collection and chemical analysis of water samples from experimental plots, edge of fields, and watersheds. Experimental unit size ranged between 0.0009 and 103 ha, with 64% of the total site-years coming from sites of <1 ha, 33% from sites between 1 and 30 ha, and 3% from sites larger than 30 ha. Most of the data came from studies conducted in the southern and midwestern states of the US. In the Midwest, Ohio alone accounted for 14% of total site-years. In the southern US, Texas and Oklahoma contributed to 10% and 16% of total site-years, respectively. Except for California, no data were found for states in the West and Pacific Northwest. Four provinces in Canada (British Columbia, Manitoba, New Brunswick, and Ontario) contributed 7% of the total site-years.
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| Figure 2. Distribution of data collected from peer-reviewed articles on annual runoff losses across the US and Canada. |
Tillage (T; 616 site years) and pasture (PA; 521 site years) managements accounted for 72% of site-years, with the remaining 28% distributed among NT (73 site years), T-R (225 site years), and NT-R (140 site years). No-tillage had the fewest site years of data, and it appeared that NT management was practiced either with residue cover (>30%) or with summer-winter crop rotations (increasing ground surface cover throughout the year), making it challenging to obtain data for strictly no-tillage systems (without residue cover). In the 521 site-years of PA data, Texas and Oklahoma contributed 47% of the site-years, and 47% of the site-years were evenly distributed among states in the Midwest and Southeast. The remaining 6% of PA data were contributed by California and Canada (Ontario).
Given the variation among study sites (i.e., soils, climate, topography, etc.), values, percentage differences, effectiveness, and estimated cost benefits reported here represent the range of effects that may be encountered with different management scenarios. Therefore, the reported estimates should not be used to forecast outcomes of management choices for any particular field. Rather, the analysis may be considered a general indication of the possible range of outcomes.
Runoff Losses
Depending on volumes and flow rates, surface runoff on agricultural landscapes can lead to erosion and the transport of sediments and plant-beneficial nutrients out of fields. Nutrient-rich runoff entering water bodies contributes to eutrophication and degradation of water quality. Runoff losses evaluated among five management practices were not normally distributed and varied considerably within and among the practices. The median runoff was highest in NT management (155.5 with a range of 21.9 to 407.0 mm) and lowest in PA management (41.0 with a range of 4.0 to 202.0 mm). While runoff for NT and NT-R were similar, the median runoff for T-R was 6% higher than that of T (fig. 3). Aggregated across all studies, residue cover in no-tillage did not affect the annual median runoff, while both tillage managements (i.e., T and T-R) were better at reducing runoff volumes than both NT and NT-R.
The amount and timing of runoff can vary greatly because of differences in precipitation amount and intensity between locations. Since precipitation varies geographically and temporally due to climate differences, comparing the aggregated surface runoff alone can be misleading for understanding the effects of RTM. To address this, the percentage of precipitation loss as runoff was computed for the five management categories (fig. 4). No-tillage residue management (18%) had the highest, and PA (6%) had the lowest runoff losses adjusted for precipitation. The NT (17%) and NT-R (18%) had greater percent precipitation losses compared to T (12%) and T-R (11%), respectively. For aggregated data of T and T-R managements, residue cover did not affect the percentage of precipitation loss as runoff; that is, tillage with <30% surface residue and tillage with >30% residue categories had similar precipitation losses. However, for studies that compared T and T-R on the same site and year (n=13; data not shown), median precipitation loss as runoff of T-R was 28% less than T. The PA studies reported in this meta-analysis had ~73% less median runoff than no-tillage’s (NT and NT-R). Where both systems (PA and no-tillage) had minimal or reduced soil disturbance from tillage, regardless of soil type and climate, more runoff was reported for no-tillage than PA management (Menzel et al., 1978; Berg et al., 1988). Several field studies have reported no soil disturbance or animal trampling depending on the stocking intensity of compact soil in PA systems (Drury et al., 1993; Daniel et al., 2002; Barreto et al., 2022). Results from this meta-analysis suggest that compaction in PA management had less effect on runoff than compaction in no-till cropping systems due to machine traffic and no-soil disturbance.
The surface runoff results obtained in this meta-analysis contrast with the general notion that no-tillage practices result in less runoff compared to conventional tillage methods (Maetens et al., 2012; Carretta et al., 2021). Depending on climate and site-specific conditions, no-tillage systems can produce greater runoff than tillage systems. For example, in a long-term study (27 years) conducted in Bushland, TX, annual runoff from no-tillage fields was greater than that from stubble mulch tillage in a wheat-sorghum-fallow rotation and was significantly higher during the fallow period (Baumhardt et al., 2017). Similarly, in a five-year study, greater runoff was reported from no-tillage watersheds than those with conventional tillage, irrespective of the cropping systems (Richardson and King, 1995). For frozen or partially frozen soil conditions, during winters in the midwestern US and Canada, no-tillage was found to produce significantly higher runoff than chisel tillage (Prasad et al., 2022). No-tillage in Claypan soils that restrict water flow in subsurface layers (due to higher bulk density and lower saturated hydraulic conductivity than soil immediately above and below it) was also found to produce significantly higher runoff than conventional tillage (Ghidey and Alberts, 1998; Blanco-Canqui et al., 2002). Although long-term no-tillage management improves soil pore structure and aggregate stability, eventually increasing the soil infiltration capacity and reducing runoff (Schreiber and Cullum, 1998), some studies have reported that soil consolidation in no-tillage can reduce infiltration (Jones et al., 1985) and the smooth/even surface can accelerate runoff (Drury et al., 1993), resulting in greater runoff volumes relative to tillage (Angle et al., 1984). In tilled fields, the disturbance of the topsoil creates a roughened surface with depressions and channels. Depending upon the soil antecedent moisture, rainfall intensity, and duration, this rough surface can impede runoff flow by holding the water in place and increasing the infiltration opportunity time (Angle et al., 1984).
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| Figure 3. Annual surface runoff losses for different residue and tillage management practice categories. T-tillage, NT-no-tillage, T-R – tillage with residue, NT-R- no-tillage with residue, PA- pasture; "n" indicates the sample size or number of data points in the box plot. |
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| Figure 4. Percent of precipitation lost as surface runoff for each management practice category. T-tillage, NT-no-tillage, T-R – tillage with residue, NT-R- no-tillage with residue, PA- pasture; "n" indicates the sample size or number of data points in the box plot. |
Some researchers have reported that residue cover can control runoff flow and reduce runoff volumes in most cases by increasing infiltration rates, irrespective of tillage management (Kenimer et al., 1987; Mostaghimi et al., 1992). The effect of residue in reducing runoff depends upon the percentage of ground area covered with residue (Balco-Canqui and Lal, 2009). While a higher percentage of residue cover seems to have greater benefit in runoff reduction, higher residue cover can reduce evaporation rates, increase soil water, and eventually increase runoff (Blanco-Canqui and Lal, 2009; Baumhardt et al., 2017). The timing of residue cover could also impact runoff in addition to the amount and percentage of ground cover. In a 12-year study conducted in the Claypan region of Missouri, regardless of conventional, chisel, or no-tillage, 52% to 80% of annual runoff in corn and soybean occurred during the period between harvest and the next primary tillage or seedbed preparation (Ghidey and Alberts, 1998). Although all tillage systems had >30% residue cover throughout the year, ground cover during harvest to the next primary tillage or seedbed preparation was less than during the rest of the year (Ghidey and Alberts, 1998). Further, it was also observed that residue cover had no effect on reducing runoff in no-tillage systems in rainfall simulation studies (Lindstrom et al., 1984). In other words, it appeared that the soil properties that developed from no-tillage restricted infiltration and overpowered the beneficial effects of residue cover (Gupta and Allmaras, 1987; Ess et al., 1998). Findings from this meta-analysis agree with those that reported an increase in the runoff with no-tillage.
Sediment Losses
Not all studies reviewed as part of this meta-analysis presented sediment loss information. Compared to the reporting of runoff and nutrients, annual sediment loss was the least reported. Only three studies were found that reported annual sediment losses for NT. The remaining four management categories (T, TR, NT-R, and PA) have 24, 10, 13, and 13 studies that reported sediment losses, respectively. Median sediment loads varied greatly among the management practices (fig. 5). Pasture management had the lowest median sediment loss (0.1 with a range of 0 to 2.8 Mg ha-1), while T (3.8 with a range of 0.1 to 22.2 Mg ha-1) had the highest. The NT-R management median sediment loss (0.5 Mg ha-1) was less than NT (3.6 Mg ha-1); however, this value was from only three studies. The T and T-R (3.4 Mg ha-1) sediment losses were greater than NT-R, on average.
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| Figure 5. Annual sediment losses for different residue and tillage management practice categories. T-tillage, NT-no-tillage, T-R – tillage with residue, NT-R- no-tillage with residue, PA- pasture; "n" indicates the sample size or number of data points in the box plot. |
Irrespective of the scale (i.e., plot, field, and watershed) of the studies (those included in this meta-analysis and others), tillage was reported to produce higher sediment losses than no-tillage in most cases. Although seasonal and rainfall simulation data were not included in this work, this effect of tillage on sediment losses was especially evident in seasonal and rainfall simulation studies.(e.g., Lindstrom et al., 1998; Grandy et al., 2006). Greater sediment losses have been observed under conventional tillage as a result of major storm events occurring during early seedbed preparation and after crop harvest when the soil cover was minimal (Angle et al., 1984; Wittmuss and Swanson, 1964; Langdale et al., 1985). According to Angle et al. (1984), one or two rainfall events were responsible for 78% of annual sediment losses under conventional tillage. Though no-tillage had significantly lower sediment loss than conventional tillage, 99% of the no-tillage annual losses occurred during one storm event (Angle et al., 1984).
While any form of tillage creates soil disturbance and may increase the threat of sediment loss, in many cases, greater sediment losses could be a direct effect of precipitation intensity, runoff volume, and soil condition rather than tillage itself. Jeong et al. (2011) reported that large runoff events (>500 m3 ha-1) generated several magnitudes more total suspended solids than small runoff events and that residue cover did not have any impact on reducing sediment losses for large runoff events. The decision of which RTM practices to implement for controlling sediment losses needs to be made based upon management effectiveness across different seasons (time periods of year) and site-specific characteristics. Implementing management practices that can reduce sediments across diverse temporal conditions may be of greater benefit than just targeting critical periods because these critical periods may keep shifting with expected changes in precipitation patterns for North America (Easterling et al., 2017).
Nitrogen (N) Losses
In comparison to the four tillage management categories, PA had lower N losses irrespective of the form (i.e., dissolved, particulate, and total N). Median DN losses were highest in NT (3.3 kg ha-1), while PN and TN losses were greater with T (5.9 and 13.9 kg ha-1, respectively). Overall, residue and tillage systems with >30% surface cover (T-R and NT-R) controlled most runoff constituents better than tillage system with <30% residue cover (T and NT).
Dissolved Nitrogen (DN)
No-tillage had greater median losses of DN (3.3 with a range 0.5 to 6.0 kg ha-1), and PA had the least (0.6 with a range 0 to 2.7 kg ha-1) compared to other RTM categories. The T management had a greater variation in DN loss than the other four categories, with losses of up to 43 kg ha-1 reported (fig. 6). The DN loads, especially for NO3-, were reported to be higher in NT systems (NT and NT-R) than T. The observed greater losses for NT are due to a lack of soil disturbance impacts on the partitioning of runoff and percolation due to poor drainage characteristics (in clay-rich soils), surface sealing, and N stratification in the upper soil layers (0-15 cm) (Daryanto et al., 2017a; Blanco-Canqui and Wortman, 2020). The majority of studies in this meta-analysis found that NT systems contributed higher DN losses than tillage systems; however, it is unlikely that no-tillage systems always produce higher DN loads than tillage. Since nutrient load depends upon runoff volumes and concentrations (Randall and Mulla, 2001), some studies reported no difference in NO3- and NH4+ loads between no-tillage and tillage systems but found that concentrations were significantly higher in no-tillage (Gal et al., 2007; Daryanto et al., 2017a). Also, it is not likely that the benefits of tillage in reducing runoff volumes will always result in reduced DN losses, as studies have observed significantly higher DN losses in tillage systems than no-tillage (Sharpley and Smith, 1994; Drury et al., 2014). These contradicting results might be due to site-specific characteristics, including physical (e.g., rainfall variability, soil texture) and management factors (e.g., crop species, fertilizer type). However, despite these contrasting results, this meta-analysis found that tillage systems having >30% surface cover (T-R and NT-R) reduced DN losses by 39% and 21%, respectively, compared to tillage systems with <30% surface cover (T and NT).
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| Figure 6. Annual dissolved nitrogen losses for different residue and tillage management practice categories. T-tillage, NT-no-tillage, T-R – tillage with residue, NT-R- no-tillage with residue, PA- pasture; "n" indicates the sample size or number of data points in the box plot. |
Particulate Nitrogen (PN)
Particulate N losses followed a similar trend to sediment losses (fig. 7). Pasture management produced the lowest PN losses compared to the other management categories. The PN losses of NT-R were comparable to those of PA, which implies that plant surface residue cover can protect the soil from losing sediments and associated nutrients via runoff (Mostaghimi et al., 1988; Kenimer et al., 1987; Soileau et al., 1994; Torbert et al., 1999).
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| Figure 7. Annual particulate nitrogen losses for different residue and tillage management practice categories. T-tillage, NT-no-tillage, T-R – tillage with residue, NT-R- no-tillage with residue, PA- pasture; "n" indicates the sample size or number of data points in the box plot. |
Total Nitrogen (TN)
The median TN losses were highest in T (13.9 with a range of 1.0 to 47.1 kg ha-1) and lowest in PA (1.0 with a range of 0.1 to 8.6 kg ha-1; fig. 8). In contrast to DN and PN, the TN losses had greater differences among the five management categories. Also, TN loss data were consistent over different regions and periods. Compared to T, in most of the studies included in this analysis, NT was effective in reducing TN loads. The load reductions were more evident for southern US states, where soils minimally or never undergo freeze-thaw cycles. While studies from the Midwest also reported positive effects of NT in reducing TN losses compared to T, some studies observed that NT produced more TN losses, especially during the non-growing season and when soils were frozen. Similar to DN and PN losses, this meta-analysis showed systems with >30% surface cover had 54% and 48% lower TN losses, respectively on average, compared to the same systems with <30% surface cover. These results were similar to the findings of other studies, where residue cover reduced TN losses irrespective of the tillage system, which was attributed to lower sediment losses (Schuman et al., 1973; McDowell and McGregor, 1984; Soileau et al., 1994; Blanco-Canqui and Lal, 2009).
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| Figure 8. Annual total nitrogen losses for different residue and tillage management practice categories. T-tillage, NT-no-tillage, T-R – tillage with residue, NT-R- no-tillage with residue, PA- pasture; "n" indicates the sample size or number of data points in the box plot. |
Phosphorus (P) losses
In comparison to the four tillage management categories, PA had lower P losses irrespective of the form (i.e., dissolved, particulate, and total P). The median DP (1.1 kg ha-1 with a range of 0.1 to 2.0 kg ha-1) losses were highest in NT, while PP and TP losses were highest in T (1.4 with a range of 0.1 to 6.9 kg ha-1 and 1.9 with a range of 0.1 to 9.3 kg ha-1. Although PP loss from NT (1.8 kg ha-1) was higher than T it was only from one study (fig. 10). Given that median DP losses were highest in NT, it is counterintuitive for the highest TP losses to be in T. This may be partially explained by the variability in TP data (fig. 11) and the smaller sample size of NT (n=6) than T (n=80). Similar to N losses, tillage systems with >30% surface cover (T-R and NT-R) were better at limiting P loss compared to the systems with <30% surface cover (T and NT).
Dissolved Phosphorus (DP)
Dissolved P losses differed more among the five management categories than PP or TP (fig. 9). The magnitude of losses greatly varied within each category. The median DP losses were highest in NT (1.1 with a range of 0.1 to 2.0 kg ha-1) and lowest in T-R (0.1 with a range of 0 to 0.5 kg ha-1) and PA (0.1 with a range of 0 to 1.6 kg ha-1) managements. Compared to T, NT and NT-R had 266% and 67% higher median DP losses, respectively. Tillage systems with >30% surface cover (T-R and NT-R) had 67% and 54% less median DP losses than tillage systems with <30% surface cover (T and NT), respectively.
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| Figure 9. Annual dissolved phosphorus losses for different residue and tillage management practice categories. T-tillage, NT-no-tillage, T-R – tillage with residue, NT-R- no-tillage with residue, PA- pasture; "n" indicates the sample size or number of data points in the box plot. |
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| Figure 10. Annual particulate phosphorus losses for different residue and tillage management practice categories. T-tillage, NT-no-tillage, T-R – tillage with residue, NT-R- no-tillage with residue, PA- pasture; "n" indicates the sample size or number of data points in the box plot. |
The higher DP losses in NT systems can be attributed to insufficient sediments to sorb solution P and leaching P from the crop and weed decaying tissue (McDowell and McGregor, 1980; Soileau et al., 1984; Langdale et al., 1985; Sharpley and Smith, 1994; Schreiber and Cullum, 1998; Tiessen et al., 2010). Also, lower soil disturbance in no-tillage systems can increase surface soil P saturation, increasing the phosphate supplying capacity of sediments and DP losses (McDowell and McGregor, 1980; Tiessen et al., 2010). Reduced DP losses in tillage systems are likely due to disturbance of the soil, which reduces P saturation at or near the surface and incorporates plant and weed residues. While several studies have documented positive effects of NT in reducing DP loads, other studies report negative and/or no effect compared to tillage systems. These mixed results stem from differences in management (other than tillage and residue), climate, and site characteristics. This meta-analysis found that tillage systems were better at limiting DP losses over no-tillage systems, regardless of field size, region of study, and management practices.
Particulate Phosphorus (PP)
Particulate P was the least reported nutrient form compared to others. Of the 60 articles reviewed for this meta-analysis, only eight reported nutrient losses from NT, and only one of those eight reported PP. Particulate P loss was reported for each of the other four management categories, but in fewer studies than other nutrient forms. Median PP losses varied greatly among the residue and tillage management categories (fig. 10). Tillage (1.4 with a range of 0.1 to 6.9 kg ha-1) had the highest PP losses, while PA (0.1 with a range of 0 to 0.8 kg ha-1) had the lowest. In comparison to T, T-R and NT-R had 70% and 78% less median PP losses, respectively. The reduced losses in T-R and NT-R managements are likely due to >30% surface cover, which dissipates rainfall impact energy, and traps sediments, restricting their losses from the field, and subsequently reducing PP (Langdale et al., 1985; Richardson and King, 1995; Tiessen et al., 2010). Similar to PN, most of the studies in this meta-analysis correlated PP loss to sediments. Greater sediment losses will likely result in greater PP losses.
Total Phosphorus (TP)
Total P losses followed a similar trend to that of TN (fig. 11). The median TP losses were highest in T (1.9 with a range of 0.1 to 9.3 kg ha-1) and lowest in PA (0.2 with a range of 0 to 1.6 kg ha-1). In contrast, TP losses from NT (1.7 with a range of 0.4 to 1.9 kg ha-1) were similar to T. Tillage systems with >30% surface cover (T-R and NT-R) had, on average, 47% and 29% less TP losses than tillage systems with <30% surface cover (T and NT), respectively. Similar to TN, most studies attributed the reduction in TP losses to the physical benefits of > 30% surface cover (Schuman et al., 1973; McDowell and McGregor, 1984; Soileau et al., 1994; Blanco-Canqui and Lal, 2009).
Performance Effectiveness
This section compares the effectiveness of NT, NT-R, and T-R management practices with respect to T. Most studies considered in this meta-analysis did not directly compare PA with T management. Due to this data constraint, the management effectiveness of PA with respect to T was not computed. However, PA had 40%-99% less losses than other RTM categories, irrespective of the variable of interest (runoff, sediments, and nutrient losses).
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| Figure 11. Annual total phosphorus losses for different residue and tillage management practice categories. T-tillage, NT-no-tillage, T-R – tillage with residue, NT-R- no-tillage with residue, PA- pasture; "n" indicates the sample size or number of data points in the box plot. |
The impact of NT in reducing runoff was neutral, with median effectiveness close to zero (0.8%) (fig. 12). In the 13 (n) comparisons made from six different studies, NT reduced runoff in seven, increased in five, and had a neutral effect in one. Despite the limited information (n = 2 to 4), NT was effective in reducing sediments (95%), TN (73%), PP (83%), and TP (75%) losses. However, NT negatively impacted DN and DP losses with -20% and -284% effectiveness, respectively. These results were similar to NT-conservation effectiveness reported by Smith et al., 2019.
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| Figure 12. Performance Effectiveness of NT with respect to T for Runoff (R), Sediments (S), Dissolved N (DN), Particulate N (PN), Total N (TN), Dissolved P (DP), Particulate P (PP), and total P (TP). Solid black line represents 0% effectiveness; "n" indicates the number for comparisons represented by the box plot. |
Except for DP, NT-R had a positive effect in reducing runoff and its associated constituents (fig. 13). Unlike NT, NT-R management reduced runoff with a median effectiveness of 10%. Similar to NT, NT-R largely reduced sediments (91%), PN (86%), TN (70%), PP (89%), and TP (65%) losses. For dissolved nutrient losses, NT-R median effectiveness was positive for DN (53%), and negative for DP (-67%). Leaving >30% surface cover after tillage appeared to reduce runoff and its associated losses in T-R relative to T (fig. 14). Despite the limited information, T-R was effective in reducing runoff (24%), sediment (76%), DN (10%), TN (16%), and TP (42%) losses.
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| Figure 13. Performance Effectiveness of NT-R with respect to T for Runoff (R), Sediments (S), Dissolved N (DN), Particulate N (PN), Total N (TN), Dissolved P (DP), Particulate P (PP), and total P (TP). Solid black line represents 0% effectiveness; "n" indicates the number for comparisons represented by the box plot. |
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| Figure 14. Performance effectiveness of T-R with respect to T for Runoff (R), Sediments (S), Dissolved N (DN), Particulate N (PN), Total N (TN), Dissolved P (DP), Particulate P (PP), and total P (TP). Solid black line represents 0% effectiveness; "n" indicates the number for comparisons represented by the box plot. |
Cost Effectiveness
Cost effectiveness results showed NT-R was beneficial compared to T for both higher net revenue and reduction in sediment and most nutrient loads. The estimated net revenue difference between NT-R and T was positive (~$47 ha-1; table 3), indicating NT-R has higher revenue than T. Other cost analysis/surveys conducted across the midwestern US similarly found higher net-return in corn no-tillage systems than conventional tillage (Bowman et al., 2020). Except for DP, differences in sediment and nutrient loads were all negative, resulting in CE values of NT-R ranging from negative $6 to negative $102 per Mg or kg of load reduction (table 3).
All these CE values fall in quadrant A of figure 1 indicating NT-R reduced nutrient loads and also achieved higher net-revenue by avoiding tillage operational costs. For DP, CE was ~$250 kg-1 (table 3), and it falls in quadrant B of figure 1, indicating although NT-R achieved higher net returns it contributed to higher DP losses than T. Overall, switching from T to NT-R management reduces sediment and most nutrient losses and increases farm revenues by avoiding tillage costs.
According to the Iowa and Wisconsin Farm Custom Rate Surveys (2019 to 2022), regardless of tillage method (chisel, disking, moldboard, vertical, and strip), mean tillage costs ranged from $34 to $61 ha-1. While these costs will vary seasonally and regionally, any type of tillage management that avoids or reduces tillage costs has the potential to benefit net farm revenue. However, converting from tillage to a no-tillage system might involve initial machinery (no-till planters or attachments that support existing planters in no-till fields) costs, which might nullify or exceed the savings from not performing tillage in the initial years of conversion (Krause and Black, 1995). In no-tillage fields, weed management and herbicide resistance over time might also increase management costs. Further, increased weed resistance in no-tillage may impact crop yields and reduce revenue. A long-term study (29 years) conducted to assess no-tillage sustainability in Michigan found that for their study site, initial costs were recovered between 10 and 29 years after its implementation (Cusser et al., 2020). Future work that accounts for the initial cost of converting tillage to no-tillage and weed management costs would further help to produce a better estimate of CE for RTM.
| Table 3. Net-revenue, nutrient load difference, and cost effectiveness of no-tillage residue (NT-R) management with respect to tillage (T) management in US dollars per unit nutrient loss reduction. | ||||
| Difference in net revenue[b] ($ ha -1) | Difference in nutrient or sediment load[c] (Mg ha-1 or kg ha-1) | Cost effectiveness ($ Mg -1 or $ kg -1) | Cost effectiveness quadrant in figure 1[d] | |
| Sediment[a] | 46.8 | -7.80 | -6.00 | A |
| DN | -1.97 | -23.8 | A | |
| PN | -12.0 | -3.90 | A | |
| TN | -4.75 | -9.90 | A | |
| DP | 0.19 | 249 | B | |
| PP | -4.90 | -9.60 | A | |
| TP | -0.46 | -102 | A | |
[a] Sediment units for nutrient load difference and cost effectiveness are Mg ha-1 and $ Mg-1 , respectively. [b]Difference in net-revenue is numerator in equation 2. [c]Difference in sediment or nutrient load is denominator in equation 2. [d] Indicates in which quadrant the cost effectiveness value falls in figure 1 based on its difference in net revenue (numerator in eq. 2) and difference in nutrient loads (denominator in eq. 2). | ||||
Implementation of most conservation management practices for water quality protection involves cost, which may impact farm revenues. The CE methodology presented in this manuscript has the potential to be applied for management systems other than RTM. Assessing conservation practices, considering both their environmental benefits and impact on farm revenues, could help establish robust recommendations for conservation practices.
Summary and Recommendations for Future Work
Through meta-analysis, we quantified RTM effectiveness on runoff, sediment, and nutrient loss reduction from agricultural systems in the US and Canada. Across the 1575 site-years and five management categories (T, T-R, NT, NT-R, and PA) studied, NT was the least reported management, while T was the most reported. Regardless of the variable of interest (runoff, sediments, and nutrient losses), PA management had the lowest losses compared to all other RTM categories. The impact of RTM on runoff, sediment, and nutrient losses varied with site-specific characteristics. However, in general, tillage systems with >30% surface cover (T-R and NT-R) were superior to tillage systems with <30% residue cover (T and NT) in controlling most runoff constituents. Tillage and T-R managements reduced dissolved nutrients but not sediments and particulate nutrients compared to NT and NT-R, respectively. The performance effectiveness of NT, NT-R, and T-R managements revealed they were effective in decreasing sediments, particulate, and total nutrient losses from agricultural catchments relative to T. Overall, PA management was found to be most effective in regulating surface runoff volumes, sediment, and associated nutrient losses than other RTMs evaluated in this study. Within the tillage managements (NT, NT-R, and T-R), NT-R was most effective, with largely positive performance effectiveness (65% to 90%) compared to T in controlling sediments, particulate, and total nutrient losses in runoff.
The cost effectiveness analysis assessed the combined environmental benefits and economic returns of NT-R with respect to T. No-tillage residue management was estimated to increase net farm revenue by avoiding tillage operational costs and also decrease pollutant loadings except for DP, with a cost effectiveness of approximately negative $6 for every Mg of sediment, and negative $24, $10, and $102 for every kg of DN, TN, and TP, respectively, compared to T.
In light of these findings, it is advised to choose RTM practices based upon site-specific water pollutants of concern. Tillage and T-R managements have the potential to decrease runoff and dissolved nutrient losses. However, these practices may need to be balanced with practices that help decrease the risk of soil erosion and its associated nutrients. While long-term NT and NT-R managements have the potential to reduce sediments and associated nutrients, reducing runoff and dissolved nutrient losses may require occasional tillage (once every 5-10 years) to avoid surface sealing, compaction, and nutrient stratification.
Residue and tillage management will continue to be vital agricultural management practices; therefore, understanding their combined effectiveness on an annual scale through long-term monitoring across multiple sites and years would help establish robust recommendations. With predicted changes in precipitation patterns and intensities and added uncertainty with those predictions across North America and globally, the recommendations must focus on management practices that can prevent sediment and nutrient losses in different weather conditions or seasons. Finally, residue and tillage management practices affect water and nutrient volume (in runoff and percolation), their transportation pathways, and nutrient-carrying capacities by affecting soil physicochemical properties. Management that reduce runoff losses might increase percolation, nutrient stratification, and volatile losses. Similarly, managements that reduce percolation losses might increase runoff losses. Therefore, RTM should be integrated with other practices (not limited to nutrient management, cover crops, etc.) to effectively prevent sediment and nutrient transport from agricultural landscapes for future water quality protection.
Supplemental Material
The supplemental information mentioned in this article is available for download from the ASABE Figshare repository at: https://doi.org/10.13031/23690898
Acknowledgments
This work was funded by the USDA National Institute of Food and Agriculture (NIFA), Hatch Act (Project # WIS01939). Funding for L. Koropeckyj-Cox was supported in part by an appointment to the Research Participation Program at the U.S. Environmental Protection Agency (USEPA) Office of Research and Development (ORD), administered by the Oak Ridge Institute for Science and Education (ORISE), through an interagency agreement between the USEPA and the U.S. Department of Energy (USDOE). Although this manuscript has been reviewed and approved for publication by the USEPA, the views expressed in this manuscript are those of the authors and do not necessarily represent the views or policies of the Agency or ORISE. The authors would like to thank Dr. Brent Johnson, Dr. David Smith from the USEPA, the journal editors, and the anonymous reviewers for their technical review and valuable comments and suggestions, which helped improve the manuscript.
References
Angle, J. S., Mc Clung, G., Mc Intosh, M. S., Thomas, P. M., & Wolf, D. C. (1984). Nutrient losses in runoff from conventional and no-till corn watersheds. J. Environ. Qual., 13(3), 431-435. https://doi.org/10.2134/jeq1984.00472425001300030021x
Arshad, M. A., Franzluebbers, A. J., & Azooz, R. H. (1999). Components of surface soil structure under conventional and no-tillage in northwestern Canada. Soil Tillage Res., 53(1), 41-47. https://doi.org/10.1016/S0167-1987(99)00075-6
Barreto, P., Ernst, O., Pérez Bidegain, M., & Perdomo, C. (2022). Effects of grazing, rotation, and tillage on surface runoff in a heavy textured Uruguayan soil. Soil Sci. Soc. Am. J., 86(4), 1096-1112. https://doi.org/10.1002/saj2.20427
Baumhardt, R. L., Schwartz, R. C., Jones, O. R., Scanlon, B. R., Reedy, R. C., & Marek, G. W. (2017). Long-term conventional and no-tillage effects on field hydrology and yields of a dryland crop rotation. Soil Sci. Soc. Am. J., 81(1), 200-209. https://doi.org/10.2136/sssaj2016.08.0255
Berg, W. A., Smith, S. J., & Coleman, G. A. (1988). Management effects on runoff, soil, and nutrient losses from highly erodible soils in the Southern Plains. J. Soil Water Conserv., 43(5), 407-410. Retrieved from https://www.jswconline.org/content/jswc/43/5/407.full.pdf
Blanco-Canqui, H., & Lal, R. (2009). Crop residue removal impacts on soil productivity and environmental quality. Crit. Rev. Plant Sci., 28(3), 139-163. https://doi.org/10.1080/07352680902776507
Blanco-Canqui, H., & Wortmann, C. S. (2020). Does occasional tillage undo the ecosystem services gained with no-till? A review. Soil Tillage Res., 198, 104534. https://doi.org/10.1016/j.still.2019.104534
Blanco-Canqui, H., Gantzer, C. J., Anderson, S. H., Alberts, E. E., & Ghidey, F. (2002). Saturated hydraulic conductivity and its impact on simulated runoff for claypan soils. Soil Sci. Soc. Am. J., 66(5), 1596-1602. https://doi.org/10.2136/sssaj2002.1596
Bormann, N. L., Baxter, C. A., Andraski, T. W., Good, L. W., & Bundy, L. G. (2012). Scale-of-measurement effects on phosphorus in runoff from cropland. J. Soil Water Conserv., 67(2), 122-133. https://doi.org/10.2489/jswc.67.2.122
Bowman, M., Verville, T., & Cornell, J. (2020). Conservation’s impact on the farm bottom line. Retrieved from https://www.soilhealthpartnership.org/farmfinance/achieving-profitability-with-on-farm-conservation/
Busari, M. A., Kukal, S. S., Kaur, A., Bhatt, R., & Dulazi, A. A. (2015). Conservation tillage impacts on soil, crop and the environment. Int. Soil Water Conserv. Res., 3(2), 119-129. https://doi.org/10.1016/j.iswcr.2015.05.002
Carretta, L., Tarolli, P., Cardinali, A., Nasta, P., Romano, N., & Masin, R. (2021). Evaluation of runoff and soil erosion under conventional tillage and no-till management: A case study in northeast Italy. CATENA, 197, 104972. https://doi.org/10.1016/j.catena.2020.104972
Cavalieri, K. M., da Silva, A. P., Tormena, C. A., Leão, T. P., Dexter, A. R., & Håkansson, I. (2009). Long-term effects of no-tillage on dynamic soil physical properties in a Rhodic Ferrasol in Paraná, Brazil. Soil Tillage Res., 103(1), 158-164. https://doi.org/10.1016/j.still.2008.10.014
Cessna, A. J., McConkey, B. G., & Elliott, J. A. (2013). Herbicide transport in surface runoff from conventional and zero-tillage fields. J. Environ. Qual., 42(3), 782-793. https://doi.org/10.2134/jeq2012.0304
Cusser, S., Bahlai, C., Swinton, S. M., Robertson, G. P., & Haddad, N. M. (2020). Long-term research avoids spurious and misleading trends in sustainability attributes of no-till. Global Change Biol., 26(6), 3715-3725. https://doi.org/10.1111/gcb.15080
Daniel, J. A., Potter, K., Altom, W., Aljoe, H., & Stevens, R. (2002). Long-term grazing density impacts on soil compaction. Trans. ASAE, 45(6), 1911. https://doi.org/10.13031/2013.11442
Daryanto, S., Wang, L., & Jacinthe, P. A. (2017b). Meta-analysis of phosphorus loss from no-till soils. J. Environ. Qual., 46(5), 1028-1037. https://doi.org/10.2134/jeq2017.03.0121
Daryanto, S., Wang, L., & Jacinthe, P.-A. (2017a). Impacts of no-tillage management on nitrate loss from corn, soybean and wheat cultivation: A meta-analysis. Sci. Rep., 7(1), 12117. https://doi.org/10.1038/s41598-017-12383-7
DeFelice, M. S., Carter, P. R., & Mitchell, S. B. (2006). Influence of tillage on corn and soybean yield in the United States and Canada. Crop Manag., 5(1), 1-17. https://doi.org/10.1094/CM-2006-0626-01-RS
Drury, C. F., McKenney, D. J., Findlay, W. I., & Gaynor, J. D. (1993). Influence of tillage on nitrate loss in surface runoff and tile drainage. Soil Sci. Soc. Am. J., 57(3), 797-802. https://doi.org/10.2136/sssaj1993.03615995005700030028x
Drury, C. F., Tan, C. S., Welacky, T. W., Reynolds, W. D., Zhang, T. Q., Oloya, T. O.,... Gaynor, J. D. (2014). Reducing nitrate loss in tile drainage water with cover crops and water-table management systems. J. Environ. Qual., 43(2), 587-598. https://doi.org/10.2134/jeq2012.0495
Easterling, D. R., Kunkel, K. E., Arnold, J. R., Knutson, T., LeGrande, A. N., Leung, L. R.,... Wehner, M. F. (2017). 2017: Precipitation change in the United States. In D. J. Wuebbles, D. W. Fahey, K. A. Hibbard, D. J. Dokken, B. C. Stewart, & T. K. Maycock (Eds.), Climate science special report: Fourth national climate assessment (Vol. I, pp. 207-230). US Global Change Research Program. https://doi.org/10.7930/J0H993CC
Ess, D. R., Vaughan, D. H., & Perumpral, J. V. (1998). Crop residue and root effects on soil compaction. Trans. ASAE, 41(5), 1271-1275. https://doi.org/10.13031/2013.17294
Gál, A., Vyn, T. J., Michéli, E., Kladivko, E. J., & McFee, W. W. (2007). Soil carbon and nitrogen accumulation with long-term no-till versus moldboard plowing overestimated with tilled-zone sampling depths. Soil Tillage Res., 96(1), 42-51. https://doi.org/10.1016/j.still.2007.02.007
Ghidey, F., & Alberts, E. E. (1998). Runoff and soil losses as affected by corn and soybean tillage systems. J. Soil Water Conserv., 53(1), 64-70. Retrieved from https://www.jswconline.org/content/jswc/53/1/64.full.pdf
Grandy, A. S., Robertson, G. P., & Thelen, K. D. (2006). Do productivity and environmental trade-offs justify periodically cultivating no-till cropping systems? Agron. J., 98(6), 1377-1383. https://doi.org/10.2134/agronj2006.0137
Gupta, S. C., & Allmaras, R. R. (1987). Models to assess the susceptibility of soils to excessive compaction. In B. A. Stewart (Ed.), Advances in soil science (Vol. 6, pp. 65-100). New York: Springer. https://doi.org/10.1007/978-1-4612-4682-4_2
Hobbs, P. R., Sayre, K., & Gupta, R. (2008). The role of conservation agriculture in sustainable agriculture. Philos. Trans. R. Soc. B: Biol. Sci., 363(1491), 543-555. https://doi.org/10.1098/rstb.2007.2169
Jeong, C. Y., Weindorf, D. C., DeRamus, A., & Goodeaux, L. L. (2011). Surface and subsurface phosphorus losses from sugarcane fields with different management practices. Water Air Soil Pollut., 217(1), 649-661. https://doi.org/10.1007/s11270-010-0617-4
Jones, O. R., Eck, H. V., Smith, S. J., Coleman, G. A., & Hauser, V. L. (1985). Runoff, soil, and nutrient losses from rangeland and dry-farmed cropland in the southern High Plains. J. Soil Water Conserv., 40(1), 161-164. Retrieved from https://www.jswconline.org/content/jswc/40/1/161.full.pdf
Karlen, D. L., Wollenhaupt, N. C., Erbach, D. C., Berry, E. C., Swan, J. B., Eash, N. S., & Jordahl, J. L. (1994). Crop residue effects on soil quality following 10-years of no-till corn. Soil Tillage Res., 31(2), 149-167. https://doi.org/10.1016/0167-1987(94)90077-9
Kenimer, L., Mostaghimi, S., Young, R. W., Dillaha, T. A., & Shanholtz, V. O. (1987). Effects of residue cover on pesticide losses from conventional and no-tillage systems. Trans. ASAE, 30(4), 953-959. https://doi.org/10.13031/2013.30505
Koropeckyj-Cox, L., Christianson, R. D., & Yuan, Y. (2021). Effectiveness of conservation crop rotation for water pollutant reduction from agricultural areas. Trans. ASABE, 64(2), 691-704. https://doi.org/10.13031/trans.14017
Krause, M. A., & Black, J. R. (1995). Optimal adoption strategies for no-till technology in Michigan. Rev. Agric. Econ., 17(3), 299-310. https://doi.org/10.2307/1349575
Langdale, G. W., Leonard, R. A., & Thomas, A. W. (1985). Conservation practice effects on phosphorus losses from Southern Piedmont watersheds. J. Soil Water Conserv., 40(1), 157-161. Retrieved from https://www.jswconline.org/content/jswc/40/1/157.full.pdf
Lindstrom, M. J., T. E. Schumacher, N. P. Cogo, and M. L. Blecha. "Tillage effects on water runoff and soil erosion after sod." Journal of Soil and Water Conservation 53, no. 1 (1998): 59-63.
Lindstrom, M. J., Voorhees, W. B., & Onstad, C. A. (1984). Tillage system and residue cover effects on infiltration in northwestern Corn Belt soils. Journal of Soil and Water Conservation, 39(1), 64-68.
Li, Y., Song, D., Liang, S., Dang, P., Qin, X., Liao, Y., & Siddique, K. H. (2020). Effect of no-tillage on soil bacterial and fungal community diversity: A meta-analysis. Soil Tillage Res., 204, 104721. https://doi.org/10.1016/j.still.2020.104721
Liu, Z., Cao, S., Sun, Z., Wang, H., Qu, S., Lei, N.,... Dong, Q. (2021). Tillage effects on soil properties and crop yield after land reclamation. Sci. Rep., 11(1), 4611. https://doi.org/10.1038/s41598-021-84191-z
Maetens, W., Poesen, J., & Vanmaercke, M. (2012). How effective are soil conservation techniques in reducing plot runoff and soil loss in Europe and the Mediterranean? Earth Sci. Rev., 115(1), 21-36. https://doi.org/10.1016/j.earscirev.2012.08.003
McDowell, L. L., & McGregor, K. C. (1980). Nitrogen and phosphorus losses in runoff from no-till soybeans. Trans. ASAE, 23(3), 643-648. https://doi.org/10.13031/2013.34638
McDowell, L. L., & McGregor, K. C. (1984). Plant nutrient losses in runoff from conservation tillage corn. Soil Tillage Res., 4(1), 79-91. https://doi.org/10.1016/0167-1987(84)90018-7
Menzel, R. G., Rhoades, E. D., Olness, A. E., & Smith, S. J. (1978). Variability of annual nutrient and sediment discharges in runoff from Oklahoma cropland and rangeland. J. Environ. Qual., 7(3), 401-406. https://doi.org/10.2134/jeq1978.00472425000700030022x
Mirzaei, M., Gorji Anari, M., Taghizadeh-Toosi, A., Zaman, M., Saronjic, N., Mohammed, S.,... Caballero-Calvo, A. (2022). Soil nitrous oxide emissions following crop residues management in corn-wheat rotation under conventional and no-tillage systems. Air Soil Water Res., 15. https://doi.org/10.1177/11786221221128789
Montgomery, D. R. (2007). Soil erosion and agricultural sustainability. Proc. Natl. Acad. Sci., 104(33), 13268-13272. https://doi.org/10.1073/pnas.0611508104
Mostaghimi, S., Dillaha, T. A., & Shanholtz, V. O. (1988). Influence of tillage systems and residue levels on runoff, sediment, and phosphorus losses. Trans. ASAE, 31(1), 128-132. https://doi.org/10.13031/2013.30677
Mostaghimi, S., Younos, T. M., & Tim, U. S. (1992). Crop residue effects on nitrogen yield in water and sediment runoff from two tillage systems. Agric. Ecosyst. Environ., 39(3), 187-196. https://doi.org/10.1016/0167-8809(92)90053-E
Neumann, P. J., Ganiats, T. G., Russell, L. B., Sanders, G. D., & Siegel, J. E. (2016). Cost-effectiveness in health and medicine (2nd ed.). New York: Oxford University Press. https://doi.org/10.1093/acprof:oso/9780190492939.001.0001
Prasad, L. R., Thompson, A. M., Arriaga, F. J., & Vadas, P. A. (2022). Tillage and manure effects on runoff nitrogen and phosphorus losses from frozen soils. J. Environ. Qual., 51(5), 978-989. https://doi.org/10.1002/jeq2.20396
Qi, J.-Y., Han, S.-W., Lin, B.-J., Xiao, X.-P., Jensen, J. L., Munkholm, L. J., & Zhang, H.-L. (2022). Improved soil structural stability under no-tillage is related to increased soil carbon in rice paddies: Evidence from literature review and field experiment. Environ. Technol. Innov., 26, 102248. https://doi.org/10.1016/j.eti.2021.102248
Randall, G. W., & Mulla, D. J. (2001). Nitrate nitrogen in surface waters as influenced by climatic conditions and agricultural practices. J. Environ. Qual., 30(2), 337-344. https://doi.org/10.2134/jeq2001.302337x
Richardson, C. W., & King, K. W. (1995). Erosion and nutrient losses from zero tillage on a clay soil. J. Agric. Eng. Res., 61(2), 81-86. https://doi.org/10.1006/jaer.1995.1034
Schreiber, J. D., & Cullum, R. F. (1998). Tillage effects on surface and groundwater quality in loessial upland soybean watersheds. Trans. ASAE, 41(3), 607-614. https://doi.org/10.13031/2013.17228
Schuman, G. E., Burwell, R. E., Piest, R. F., & Spomer, R. G. (1973). Nitrogen losses in surface runoff from agricultural watersheds on Missouri Valley loess. J. Environ. Qual., 2(2), 299-302. https://doi.org/10.2134/jeq1973.00472425000200020030x
Sharpley, A. N., & Smith, S. J. (1991). Effects of cover crops on surface water quality. In W. L. Hargrove (Ed.), Cover crops for clean water (pp. 41-49).
Sharpley, A. N., & Smith, S. J. (1994). Wheat tillage and water quality in the Southern plains. Soil Tillage Res., 30(1), 33-48. https://doi.org/10.1016/0167-1987(94)90149-X
Smith, D. R., White, M., McLellan, E. L., Pampell, R., & Harmel, R. D. (2019). Using the Conservation Practice Effectiveness (CoPE) Database to assess adoption tradeoffs. J. Soil Water Conserv., 74(6), 554-559. https://doi.org/10.2489/jswc.74.6.554
Soileau, J. M., Touchton, J. T., Hajek, B. F., & Yoo, K. H. (1994). Sediment, nitrogen, and phosphorus runoff with conventional-and conservation-tillage cotton in a small watershed. J. Soil Water Conserv., 49(1), 82-89. Retrieved from https://www.jswconline.org/content/jswc/49/1/82.full.pdf
Tiessen, K. H., Elliott, J. A., Yarotski, J., Lobb, D. A., Flaten, D. N., & Glozier, N. E. (2010). Conventional and conservation tillage: Influence on seasonal runoff, sediment, and nutrient losses in the Canadian prairies. J. Environ. Qual., 39(3), 964-980. https://doi.org/10.2134/jeq2009.0219
Torbert, H. A., Potter, K. N., Hoffman, D. W., Gerik, T. J., & Richardson, C. W. (1999). Surface residue and soil moisture affect fertilizer loss in simulated runoff on a heavy clay soil. Agron. J., 91(4), 606-612. https://doi.org/10.2134/agronj1999.914606x
USDA-NRCS. (2017a). Conservation Crop Rotation, Code 328. Washington, DC: USDA Natural Resources Conservation Service.
USDA-NRCS. (2017b). Irrigation Water Management, Code 449. Washington, DC: USDA Natural Resources Conservation Service.
USDA-NRCS. (2017c). National Handbook of Conservation Practices. Retrieved from https://directives.sc.egov.usda.gov/viewerFS.aspx?hid=22299
USDA-NRCS. (2017d). Nutrient Management, Code 590. Washington, DC: USDA Natural Resources Conservation Service.
USDA-NRCS. (2017e). Pest Management, Code 595. Washington, DC: USDA Natural Resources Conservation Service.
USDA-NRCS. (2017f). Residue and Tillage Management, No-Till, Code 329. Washington, DC: USDA Natural Resources Conservation Service.
USDA-NRCS. (2017g). Residue and Tillage Management, Reduced Till, Code 345. Washington, DC: USDA Natural Resources Conservation Service.
Wittmuss, H. D., & Swanson, N. P. (1964). Till-planted corn reduces soil losses. Agric. Eng., 45(5), 256-257.
Zhang, P.-p., Xu, S.-z., Zhang, G.-j., Pu, X.-z., Wang, J., & Zhang, W. (2019). Carbon cycle in response to residue management and fertilizer application in a cotton field in arid Northwest China. J. Integr. Agric., 18(5), 1103-1119. https://doi.org/10.1016/S2095-3119(18)62075-1