Herbicides with soil-residual activity have the potential for carryover into subsequent crops, resulting in injury to sensitive crops and limiting productivity if severe. The increased use of soil-residual herbicides in the United States for management of troublesome weeds in corn- and soybean-cropping systems has potential to result in more cases of carryover. Soil management practices have different effects on the soil environment, potentially influencing herbicide degradation and likelihood of carryover. Field experiments were conducted at three sites in 2019 and 2020 to determine the effects of corn (clopyralid and mesotrione) and soybean (fomesafen and imazethapyr) herbicides applied in the fall at reduced rates (25% and 50% of labeled rates) and three soil management practices (tillage, no-tillage, and a fall-established cereal rye cover crop) on subsequent growth and productivity of the cereal rye cover crop and the soybean and corn crops, respectively. Most response variables (cereal rye biomass and crop canopy cover at cover crop termination in the spring, early-season crop stand and herbicide injury ratings, and crop yield) were not affected by herbicide carryover. Corn yield was lower when soil was managed with a cereal rye cover crop compared with tillage at all three sites, while yield was lower for no-till compared with tillage at two sites. Soybean yield was lower when managed with a cereal rye cover crop compared with tillage and no-till at one site. Findings from this research indicate a low carryover risk for these herbicides across site-years when label rotational restrictions are followed and environmental conditions favorable for herbicide degradation exist, regardless of soil management practice on silt loam or silty clay loam soil types in the U.S. Midwest region.

This study evaluates the effects of vegetative soil conservation practices (afforestation and/or bamboo planting) on farm profit and its components, revenue and variable cost. Since farmers self-select themselves as adopters of conservation measures, there could be a problem of selection bias in evaluating their soil conservation practices. We address the selection bias by using propensity score matching. We also check if there exists spatial spillover in adoption of vegetative conservation measures and how it affects matching. We use primary survey data from the Darjeeling district of the Eastern Himalayan region for the year 2013. Our results suggest strong spatial correlation. We find that the propensity score estimated from the spatial model provides better matches than the non-spatial model. While the results show that vegetative soil conservation can lead to significant gains in revenue, it also increases costs so that no significant gains in profit accrue to farmers.

Interseeding provides flexibility in cover crop establishment, but most cover crop species are not well-adapted to the duration of low-intensity light beneath the cash crop canopy. Field pennycress (Thlaspi arvense L.) has physiological seed dormancy traits and its emergence pattern may be better synchronized with cash crop senescence. The objective of this study was to demonstrate proof-of-concept for using pennycress as an interseeded cover crop. A 2-year field experiment was conducted where cereal rye (Secale cereale L.), mustard (Guillenia flavescens L.) or pennycress were interseeded into edamame [Glycine max (L.) Merr.] 1 month after planting. Rye and mustard emerged within 6 days, whereas pennycress emergence was delayed up to 56 days after interseeding. Pennycress provided 37–57% soil cover in fall and produced 0.4–2.5 Mg ha−1 biomass the following spring. Preliminary results demonstrate the utility of pennycress as an interseeded cover crop and the potential value of seed dormancy traits in interseeding systems.

Soil conservation on the Loess Plateau is important not only for local residents but also for reducing sediment downstream in the Yellow River. In this paper, we report a decrease in soil erosion from 2000 to 2010 as a result of the ‘Grain for Green' (GFG) Project. By using the Revised Universal Soil Loss Equation and data on land cover, climate and sediment yield, we found that soil erosion decreased from 6579.55tkm–2yr–1 in 2000 to 1986.66tkm–2yr–1 in 2010. During this period, there was a major land cover change from farmland to grassland in response to the GFG. The area of low vegetation coverage with severe erosion decreased dramatically, whereas the area of high vegetation coverage with slight erosion increased. Our study demonstrates that the reduction in soil erosion on the Loess Plateau contributed to the decrease in the sediment concentration in the Yellow River.

This research aimed to illicit nonfarming absentee landowners’ and producers’ preferences for the benefits and characteristics derived from conservation practices during adoption decisions using maximum difference scaling, also called the best-worst method. Both groups are found to rank and value the attributes and reasons for adoption of conservation practices differently at the 95% significance level. This difference between the two groups reinforced the importance of land tenure in decision making. This indicated the need for new extension educational efforts, research efforts, and economic incentives to reduce negative externalities that could be ameliorated from adoption of soil and water conservation practices.

The dynamics of buried weed seeds in ridge-tilled corn (Zea mays L.) and soybeans [Glycine max (L.) Merr.] were studied in Minnesota. Soils subjected to continuous corn production harbored at least twice as many buried weed seeds as soils under corn/soybean rotations. Truncation of ridges at the time of crop sowing removed 31 to 37% of the buried weed seeds from ridges of continuous corn, and 80 to 100% of those from ridges of the corn/soybean rotations. From 14 to 36% of weed seeds originally in ridges were lost through germination either on the ridge or in the furrow. Ridging soil at layby stimulated germination of numerous weed seeds. The resulting population of small weeds eventually produced up to 1000 seeds/m2 in continuous corn but only about 100 seeds/m2 in corn/soybean rotations, thoroughly replenishing the soil seed reserve in both cropping systems. After 7 to 8 yr of good to excellent weed control with herbicides, crop yield losses in the absence of herbicides were 10 to 27% in continuous corn, and 0% for corn and 6 to 10% for soybeans in corn/soybean rotations.

Field experiments were conducted to determine the effects of various densities of four fall-seeded small grain mulches and diphenamid (N,N-dimethyl-α-phenyl benzeneacetamide) on weed control, yield, and quality in no-till flue-cured tobacco (Nicotiana tabacum L. ‘McNair 944’). A greenhouse study investigated the effects of non-soil-incorporated mulch from the same small grains plus alfalfa (Medicago sativa L.) on various growth parameters of tobacco (‘Speight G-70’). None of the mulches used in the greenhouse study adversely affected growth of the tobacco. Mulch from rye (Secale cereale L. ‘Abruzzi’) killed about 2 weeks before transplanting plus diphenamid provided better annual broadleaf weed control (85%) than wheat (Triticum aestivum L. ‘McNair’), barley (Hordeum vulgare L. ‘Keowee’), and no mulch. Oat (Avena sativa L. ‘Brooks’) mulch resulted in 80% broadleaf weed control. There were no differences in annual grass control (which was short lived) among mulches but control was lower in the no-mulch treatment. Rye mulch resulted in a 22% increase in the control of broadleaf weeds compared to no-mulch. Yield of the no-till tobacco did not differ among mulches and averaged 82% of that conventionally grown. The quality was not affected. The rye mulch did not affect the yield or quality of tobacco when compared to a nonmulch, noncultivated treatment. The 18% decrease in the no-till yield was apparently the result of the lack of tillage and increased weed interference and was not due to adverse effects from the rye.

Over the past few decades, farmers have increasingly integrated cover crops into their cropping systems. Cover-crop benefits can help a farmer to achieve sustainability or reduce negative environmental externalities, such as soil erosion or chemical runoff. However, the impact on farm economics will likely be the strongest incentive to adopt cover crops. These impacts can include farm profits, cash crop yields or both. This paper provides a review of cover-crop adoption, production, risk and policy considerations from an economic perspective. These dimensions are examined through a review of cover-crop literature. This review was written to provide an overview of cover crops and their impacts on the farm business and the environment, especially with regard to economic considerations. Through increasing knowledge about cover crops, the intent here is to inform producers contemplating adoption and policy makers seeking to encourage adoption.

Potato, dry bean, and sugar beet production have increased markedly in recent years on irrigated cropland in Alberta, Canada. Concerns exist about declining soil quality and increased soil erosion when these low-residue crops are grown in sequence in short-duration rotations. A 12-yr rotation study was conducted to determine the merits of adopting various conservation practices (reduced tillage, cover crops, composted manure) and longer-duration rotations to develop a more sustainable production system for these row crops. This article reports on weed density and weed seedbank data collected in the study. Weed densities recorded prior to applying postemergence herbicides indicated that conservation compared with conventional management treatments had greater weed densities in 30 to 45% of the cases in 3-, 4-, and 5-yr rotations. In contrast, a 6-yr conservation rotation that included 2 yr of timothy forage resulted in similar or lower weed densities than rotations with conventional management practices. Residual weed densities recorded 4 wk after applying postemergence herbicides were only greater in conservation than conventional rotations in 2 of 12 yr, regardless of rotation length. Weed seedbank densities at the conclusion of the 12-yr study were similar for 3- to 6-yr rotations under either conservation or conventional management. These findings indicate that implementing a suite of conservation practices poses little risk of increased weed populations in the long term. This knowledge will facilitate grower adoption of more sustainable agronomic practices for irrigated row crops in this region.

This paper presents the methodology, assumptions, and data used to generate regional and national environmental benefit estimates of the USDA's Conservation Reserve Program (CRP). It's assumed that, without the program, production and conservation practices on CRP lands would be the same as those used on surrounding lands. When range and forest lands are (are not) included as land-use options, 54 (71) percent of the CRP land would be in crop production—which is consistent with past analyses. Soil erosion would be 222 to 248 million tons per year—about 11 percent—higher than the current level. Benefits are estimated by applying environmental benefit models, estimated in previous analyses, to the CRP's estimated effect on erosion and wildlife habitat. Nationally, the CRP is estimated to provide $1.3 billion in annual benefits, which represents 75 to 80 percent of the program's cost. In seven of the 10 USDA Farm Production Regions, the CRP's environmental benefits exceed costs. Thus, reallocating acreage to these regions could increase net program benefits. However, because many benefits could not be estimated, one cannot conclude that regional and national benefits do not exceed costs.

Conservation initiatives in the 1985 Farm Bill affected farmers' decisions regarding soil conservation. A farmer survey was conducted and a multi-period mixed-integer programming model was developed to determine an optimal farm plan with choices of crop-tillage combinations and land retirement Results indicate that farmers' incentives to reduce soil loss in the Sand Mountain region in Alabama are not substantially affected by provisions of the 1985 Farm Bill. The bid price for the Conservation Reserve Program will have to be considerably higher than 1988 levels to provide an incentive to remove land from production.

This study developed an intertemporal profit function to determine optimal conservation adoption strategies under alternative scenarios with respect to crop prices, relative yields, discount rates, and other assumptions. Special emphasis was placed on determining from the analysis when the switchover from conventional to soil-conserving practices should take place. Technological change was incorporated by allowing crop yields to vary over time. Our analysis thus provides a new, more precise measurement of the cumulative net benefit differential. The optimal period for switchover from conventional to soil-conserving practices was found to vary depending on the assumptions made about corn prices and discount rates. Empirical results were based on an erosion damage function (EDF) for Western Kentucky corn production.

A conceptual optimal control theory model which considers farm level decision making with respect to soil management is developed. A simplified version of the theoretical model is applied to the Piedmont area of Virginia. The model includes the productivity impacts of both soil erosion and technological progress. Both the theoretical model and its empirical application are improvements over previous efforts. Results suggest that farmers in the study area can achieve substantial reductions in soil erosion by adopting alternative farming practices.

This paper analyzes the effects of uncertain soil loss in farm planning models. A disaggregated approach was used because of an interest in examining the impact of probabilistic soil loss constraints on farm level decisionmaking. A stochastic programming model was used to consider different levels of probability of soil loss. Traditional methods of analysis are shown to consistently overestimate net returns.

Evaluations of the factors influencing the adoption of agricultural and natural resource management technologies among small farmers in developing countries have been mostly limited to qualitative discussions or simple descriptive statistics resulting in superficial and inconclusive findings. This study introduces the use of Poisson Count Regressions as a statistically appropriate procedure to analyze certain common types of adoption data. It uses them to assess the impact of key socio-economic, bio-physical, and institutional factors on the adoption of integrated pest management, agroforestry, and soil conservation technologies among small farmers in three Central American countries: Costa Rica, Panama, and El Salvador.

Using data from a survey of farm operators in two Virginia counties, the authors analyze farmers' soil conservation decisions. Results indicate that financial factors, including income and debt, are the most important influences on the sample farmers' use of conservation practices. Additional factors such as perception of erosion, education level, off-farm employment, and tenancy also influence conservation expenditures. Factors influencing conservation tillage acreage differ from those influencing expenditures for other conservation practices. In particular, age and race of the operator and on-farm erosion potential are significantly related to the use of conservation tillage but not other practices. These results are discussed in terms of their implications for conservation programs.

Wind erosion is a serious environmental problem in the inland Pacific Northwest, US. In addition to onfarm damage to soil and crop quality, it causes off-farm damage, including human respiratory illness, traffic accidents and diminished recreational values. Three key practices for effectively controlling wind erosion in eastern Washington are reduced tillage, continuous spring cropping and vegetative wind strips. Although these are effective in controlling wind erosion, their adoption by farmers in the region has been slow. Technology adoption theory has been classified into three paradigms: income, utility and innovation-adoption. This study on adoption of wind erosion control practices draws from all three paradigms. However, unlike most past research, this study distinguishes between single-practice adopters and multiple-practice adopters, and compares single-practice adopters with zero-practice adopters. Data were obtained from a random sample survey of 266 farmers in six semi-arid counties in a region of east-central Washington State prone to wind erosion. Statistical results revealed: (1) that adopters of multiple conservation practices contrast more sharply with non-adopters than do adopters of a single conservation practice; and (2) adopters of a single practice differ more from zero-practice adopters than they do from all other farmers (including adopters of other practices). More specifically, this study recognizes heterogeneity among ‘adopters’ in erosion control, and suggests that there may be some hierarchy among adopters in strength of innovation. It also supports earlier findings-by sociologists that early adopters have more financial resources or larger farms and that education may aid adoption. Adopters were more aware of an erosion control educational program. Multiple-practice adopters are a distinct identifiable group, who may play a key role as innovators who can influence neighbors to adopt effective conservation practices. These individuals also possess unique information on the comparative cost, yields and technical challenges of alternative conservation practices that could be used on farms with similar soil and climatic conditions. Knowledge of the attributes associated with innovative multiple-practice adopters may permit soil conservation policymakers and field staff to target educational programs more accurately during the early stages of technology dissemination. Conservation-practice dissemination strategies may benefit by including innovative farmers in leadership roles in the initial stage of conservation education programs.

The effects of contour live barriers of vetiver and pennisetum on soil erosion were studied on four small farms in south central Honduras. Paired plots were installed and soil erosion measured by changes in the soil surface level of transects 0.3 and 6.0 m up the slope from the barrier. After three years, transects 0.3 m above the barriers significantly retained eroded soil compared with control transects. Soil accumulation by barriers ranged from 2.6 to 11.2 cm, and natural terrace formation (the difference between the barrier and corresponding control transect) ranged from 5.2 to 13.8 cm. No difference was detected between barrier and control for the transects 6.0 m above the barrier. Deposition in front of the barriers and reduction in surface rilling were apparent to farmers. Erosion from up slope on the barrier plots and from both transects in the control sections was not obvious. Direct measurement and farmer observation of sediment deposition by live barriers will help evaluate farmer-identified species for future use. The deposition helps farmers become aware of sheet erosion before the effects of soil degradation on crop yields become grossly apparent and soil fertility restoration becomes too costly for small-scale farmers.