Pete Nowak

Aspects of Precision Agriculture

Precision agriculture is the application of technologies and principles to manage spatial and temporal variability associated with all aspects of agricultural production for the purpose of improving crop performance and environmental quality. Success in precision agriculture is related to how well it can be applied to assess, manage, and evaluate the space-time continuum in crop production. This theme is used here to assess the current and potential capabilities of precision agriculture. Precision agriculture is technology enabled. It is through the integration of specific technologies that the potential is created to assess and manage variability at levels of detail never before obtainable and, when done correctly, at levels of quality never before achieved. The agronomic feasibility of precision agriculture has been intuitive, depending largely on the application of traditional management recommendations at finer scales, although new approaches are appearing. The agronomic success of precision agriculture has been limited and inconsistent although quite convincing in some cases, such as N management in sugar beet (Beta vulgaris L.). Our analysis suggests prospects for current precision management increase as the degree of spatial dependence increases, but the degree of difficulty in achieving precision management increases with temporal variance. Thus, management parameters with high spatial dependence and low temporal variance (e.g., liming, P, and K) will be more easily managed precisely than those with large temporal variance (e.g., mobile insects). The potential for economic, environmental, and social benefits of precision agriculture is complex and largely unrealized because the space-time continuum of crop production has not been adequately addressed.

Disproportionality as a Framework for Linking Social and Biophysical Systems

ABSTRACT Interdisciplinary research is capable of investigating questions that no single or independent collection of disciplines can address. This interdisciplinary approach was used to investigate why nonpoint source pollution to a lake had not changed even though the often cited social drivers of this situation had changed significantly. The concept of disproportionality was adapted to examine social and biophysical interactions at different spatial and temporal scales to address this situation. Rather than using social and biophysical variable as contextual or additive relative to each other, we examined their interactive or multiplicative effects at coarse and fine spatial and temporal scales. Limited occurrence of inappropriate behaviors in vulnerable biophysical settings resulted in disproportionate environmental impacts. The concept of disproportionality implies that the environmental meaning placed on any social behavior requires accounting for where and when it occurs in a biophysical setting, and that a few outliers can determine system performance and outcomes.

Landscape Planning for Agricultural Nonpoint Source Pollution Reduction I: A Geographical Allocation Framework

Agricultural nonpoint source pollution remains a persistent environmental problem, despite the large amount of money that has been spent on its abatement. At local scales, agricultural best management practices (BMPs) have been shown to be effective at reducing nutrient and sediment inputs to surface waters. However, these effects have rarely been found to act in concert to produce measurable, broad-scale improvements in water quality. We investigated potential causes for this failure through an effort to develop recommendations for the use of riparian buffers in addressing nonpoint source pollution in Wisconsin. We used frequency distributions of phosphorus pollution at two spatial scales (watershed and field), along with typical stream phosphorus (P) concentration variability, to simulate benefit/cost curves for four approaches to geographically allocating conservation effort. The approaches differ in two ways: (1) whether effort is aggregated within certain watersheds or distributed without regard to watershed boundaries (dispersed), and (2) whether effort is targeted toward the most highly P-polluting fields or is distributed randomly with regard to field-scale P pollution levels. In realistic implementation scenarios, the aggregated and targeted approach most efficiently improves water quality. For example, with effort on only 10% of a model landscape, 26% of the total P load is retained and 25% of watersheds significantly improve. Our results indicate that agricultural conservation can be more efficient if it accounts for the uneven spatial distribution of potential pollution sources and the cumulative aspects of environmental benefits.

People, place, behavior, and context: A research agenda for expanding our understanding of what motivates farmers' conservation behaviors

Social scientists have explored why farmers engage in conservation activities for a number of decades, yet there is still a large degree of unexplained variation and a lack of understanding about the factors that contribute to, or inhibit, farmer conservation. Our goal with this article is to outline an agenda for future social science research exploring conservation behaviors in agricultural systems. We believe that greater reflection on what avenues need further exploration will lead to improved scientific understanding and ultimately greater uptake in conservation by farmers. Environmentally relevant farmer behaviors, often conceptualized as best management practices (BMPs) or conservation practices, are complex and context specific, making the adoption or use of these practices difficult to measure or predict. Additionally, farmers are a highly diverse group with differing resource endowments and exposures to risk; production needs, tenure arrangements, and ownership goals; environmental motives; personalities; proclivities for engaging in government conservation programs; and social networks. Subsequently, as indicated by earlier reviews of this literature, there are few variables that consistently explain adoption decisions. In addition to high variability in determinants of behavior, physical and temporal variation in the characteristics of the practices themselves complicate research efforts. Farm and farmer-level factors are not…

Thinking about a future conservation agenda

We do indeed stand on the shoulders of conservation giants. Whether that is H.H. Bennett, Rachel Carlson, or Aldo Leopold among others, they have shaped our conservation agenda. Yet, I am sure these conservation pioneers would agree that we should not worship them, but try to emulate their conservation contributions in our own way at a scale commensurate with our positions. Acting like a conservationist should trump honoring a conservationist. Simply following in their footsteps down the same path does little for conservation as the challenges of today are very different than the challenges of yesteryear. We live in a world where science and technology has advanced such that the source, cause, and potential remedy to degradation from agriculture can be specified with a high a degree of precision across spatial and temporal scales. However, while the agency names and program acronyms have changed across time, the fundamental premises behind our conservation policy have remained static—we still believe the farmer needs to be educated, assisted, and compensated for engaging in conservation. At a time in our history when the majority of farmers did not have an eighth grade education, as was the case in the 1930s, these premises may have…

Agriculture and change: the promises and pitfalls of precision

Abstract Site specific management (SSM) (precision agriculture) holds both promises and pitfalls. Ignoring the pitfalls while only focusing on the promises can distort research activities and limit positive impacts for end users. Particular attention is given to how SSM differs from other modem production technologies that attempt to suppress or nullify ecological variation rather than respond to it. It is argued that the “homogenizing”; mind‐set associated with other production technologies is distorting the analytical rigor applied to developing and promoting SSM systems. A true SSM system should allow the producer to respond to ecological variation in a rational and pro‐active fashion. Other promises of SSM are associated with emerging information markets, using SSM to develop risk reduction management strategies, biotechnology, and environmental protection.

SEDIMENT AND PHOSPHORUS DELIVERY FROM ALFALFA SWARDS

Alfalfa fields comprise a significant proportion of land managed by animal feeding operations in the upper Midwest, yet studies of sediment and phosphorus (P) delivery from these systems are sparse. Sediment and P delivery from two alfalfa swards (<0.04 ha) were monitored during 11 natural runoff events (2003-2004) in south-central Wisconsin. Total solids (TS) and P loads were standardized by rainfall erosivity (EI30) after verifying that linear relationships existed between these parameters for the data collected in this study. Standardized TS and particulate P (PP) loads generally exhibited increases during secondary storms (successive storms following an initial storm in a series). These increases were observed regardless of the rainfall erosivity of secondary storms. Such increases were attributed to progressive degradation of the soil conditions, which were detected by the variable representing “erosivity-standardized” TS load (K. ). Results from one series of four events beginning 1 d following manure application were examined using exploratory data analysis and yielded three primary observations. Firstly, increase in the fine-sediment fraction (<2 .m) as this series progressed suggested that broadcast manure application did not significantly protect the soil surface. Lack of protection from manuring was attributed to minimal contact time, or incubation period, between manure and soil, exacerbated by the early onset of runoff immediately following manure placement. Secondly, runoff initially transported primarily dissolved P forms, but the dissolved reactive P (DRP) fraction of total P (TP) declined throughout the series. Finally, a decreasing ratio of volatile to total solids, accompanied by an increasing fraction of fine particles, suggested that manure-derived particulates were exhausted from the surface by the first few events following manure application. Other findings included: (1) significantly greater DRP concentrations during late season runoff (November); and (2) declines in DRP and total dissolved P (TDP) concentration with increased TS delivery. By conducting research using natural runoff, this study strengthened and confirmed results of sediment and P delivery patterns observed in studies undertaken at smaller scales.

Convenience Sample of On-Farm Research Cooperators Representative of Wisconsin Farmers

Abstract Researchers interested in describing or understanding agroecological systems have many reasons to consider on-farm research. Yet, despite the inherent realism and pedagogical value of on-farm studies, recruiting cooperators can be difficult and this difficulty can result in so-called “convenience samples” containing a potentially large and unknown bias. There is often no formal justification for claiming that on-farm research results can be extrapolated to farms beyond those participating in the study. In some sufficiently well-understood research areas, models may be able to correct for potential bias; however, no theoretical argument is as persuasive as a direct comparison between a randomized and a convenience sample. In a 30-cooperator on-farm study investigating weed community dynamics across the state of Wisconsin, we distributed a written survey probing farmer weed management behaviors and attitudes. The survey contained 59 questions that overlapped a large, randomized survey of farmer corn pest management behavior. We compared 187 respondents from the larger survey with the 18 respondents from our on-farm study. For dichotomous response questions, we found no difference in response rate for 80% of the questions (α  =  0.2, β > 0.5). Differences between the two groups were logically connected to the selection criteria used to recruit cooperators in the on-farm study. Similarly, comparisons of nondichotomous response questions did not differ for 80% of the questions (α  =  0.05, β > 0.9). Exploratory multivariate analyses failed to reveal differences that might have been hidden from the marginal analyses. We argue that our findings support the notion that the convenience samples often associated with on-farm research may be representative of the more general class of farms, despite lack of bias protection provided by truly randomized designs.

The subversive conservationist

Subversion is the process of attempting to change existing political structures or other forms of authority used to maintain the status quo. Subversive activities are those that work to overturn, or significantly alter, traditional ways of thinking about critical issues. How is it, you ask, that I can use subversive and conservationist in the same title? What does subversive have to do with being a conservationist? Let me answer those questions by posing another simple question: As you look at the larger conservation community today, who speaks for soil and water resources? This simple question is rarely asked. However, when it is asked, the answer, more times than not, supports the need for subversion. Listen and see if you hear what I hear when asking this question. I hear the modern equivalent of the Tower of Babel—many agency voices representing a multitude of programs, all based on the implicit assumption that more programs and more money means more conservation. Propagating agency jargon and acronyms and implementing accountability measures surrounding these efforts has become the focus of the many professional program managers who populate these agencies. Their dogma is simple: The more money they spend under various labels and titles, the…

BARRIERS TO ADOPTION OF ANIMAL WASTE MANAGEMENT STRATEGIES

Reducing air and water pollution from livestock operations that are not regulated as concentratedanimal feeding operations (CAFOs) will require voluntary adoption of new practices and technologies.However, adoption of the manure management strategies and innovations suggested by scientistshas been disappointing. Increasing voluntary adoption of animal waste management strategieswill require improved understanding of the economic and social barriers and constraints that currentlylimit adoption. Before an innovation can be adopted, it must be invented and modified. Induced innovation theorysays that innovations are developed that economize on relatively scarce factors of production.The fact that pollution is not costly to the farmer means that technologies that reduce pollution areless likely to be developed in the free market. Therefore, well-designed regulations and policies canfacilitate the development of abatement technologies. For innovations that have been developed, a number of barriers to adoption exist. A review of theadoption and diffusion literatures in economics and sociology shows that perceived characteristicsof the innovation, characteristics related to the individual farm and farmer, as well as the social systemare important. Uncertainty regarding potential costs and benefits of manure management systemswill limit adoption and is accentuated by the complexity involved with animal and crop productionsystems. Increased information availability and trialing of innovations reduces uncertainty. Profitability, or lack thereof, is an important barrier to adoption of improved manure managementpractices. If storage structures and application equipment are required, credit constraints maybe an issue. In addition, the opportunity cost of time is an important factor with respect to both laborand management requirements. Transportation costs are a very important issue and will becomemore critical with phosphorous-based regulations. Compatibility with the goals of the farmer aswell as the current farming system is an important barrier to adoption of improved manure managementstrategies. Institutional constraints may also exist. Systems solutions, involving interdisciplinaryresearch, are required. Given the variability in farms, farmers, and location-related factors,different barriers will be most limiting and one-size-fits-all technologies and policies will not beappropriate. Methodological approaches and institutional incentives for systems research need to be designed.Technologies and policies that address the current barriers to adoption of manure managementstrategies need to be developed in a systems context. For example, production systems that result ina valuable product, which may involve multiple farm units, are needed.