ABSTRACT We present a compelling rationale for defining agroecology as the ecology of food systems. Our purpose is to provide framework that will guide research, education, and action in multiple interacting facets an increasingly complex global agriculture system. To accomplish such goals, it essential build bridges connections among beyond our disciplines production agriculture, well farm gate into rural landscape community. Fields sociology, anthropology, environmental sciences, ethics,...

Corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] farmers in the upper Midwest are showing increasing interest winter cover crops. The effects of crops on soil quality this region, however, have not been investigated extensively. objective experiment was to determine a cereal rye (Secale cereale crop after more than 9 yr corn silage–soybean rotation. Four treatments were established 2001: no crop, soybean, silage, both. Soil organic matter (SOM), particulate (POM), potentially...

Abstract The transdisciplinary field of agroecology provides a platform for experiential learning based on an expanded vision research sustainable farming and food systems the application results in creating effective landscapes students. With increased recognition limitations fossil fuels, fresh water, available farmland, educators are changing focus from strategies to reach maximum yields those that feature resource use efficiency resilience production less benign climate. To help students...

Core Ideas Cover crop mixtures did not provide benefits beyond cover monocultures. crops influence soil temperature, P or K concentrations, corn yield. weed density community in subsequent corn. The use of can decrease erosion, density, and nitrate leaching while improving quality. We investigated nine crops, winter rye ( Secale cereale L.), triticale (× Triticosecale Wittm. ex A. Camus), two canola Brassica napus camelina [ Camelina sativa (L.) Crantz], spring barley Hordeum vulgare oat...

Abstract Intermediate wheatgrass [IWG, Thinopyrum intermedium (Host) Barkworth & D.R. Dewey, trade name Kernza] is a widely adapted, cool‐season forage grass, actively bred for perennial grain production. Most of IWG's net primary productivity directed to nonreproductive structures, so dual‐use strategies harvest both and represent potentially viable pathway increase its profitability. We conducted 3‐year trial at nine diverse environments across North America evaluate yields nutritive...

Abstract Forage Brassica spp. have been shown to produce adequate amounts of herbage during the cooler months fall, thus allowing extension grazing season in higher latitudes. The objective this study was determine if nutritive quality initial and regrowth influenced by planting harvest date. In 1987, 1988, 1989, three (rape [ B. oleracea L.], turnip rapa L.] hybrid L. × pekinensis L.]) were planted late May early June, June July, July August harvested each year at 64, 76, or 85 DAP. plants...

C onventional agriculture production systems in developed countries rely heavily on fossil energy, but emerging uncertainties energy supply indicate a need to better understand efficiency conventional and alternative systems. We used 6 yr of data from cropping experiment conducted Iowa compare use conventionally managed corn ( Zea mays L.)–soybean [ Glycine max (L.) Merr.] system (a 2‐yr rotation) with two low‐external input (LEI) that more diverse rotations manure, substantially lower...

Abstract Our aim is to describe open-ended case studies for learning real-life problem solving skills, and relate this approach conventional, closed-ended decision studies. Teaching methods are cases in agroecology, an alternative traditional strategies that lead students through prepared materials structured discussions determine outcome already known the instructor. method promotes a culture of curiosity. Multiple evaluation criteria show how strategy provides with practice researching,...

Animal performance on brassica diets often does not reflect laboratory estimates of the nutritive value herbage. Hay supplementation pastures should increase diet DM and fiber intake dilute anti-quality factors. The optimal hay:brassica ratio needed to achieve desirable animal performance, however, has been established. Effects changing feed water intake, apparent digestibility diets, thyroid status, anemia were examined in five Dorset-cross wether spring lambs (initial BW 32.8 ± 3.2 kg)....

Abstract The response of a long‐term, mixed‐species hayfield in Maine, USA, to commercial fertilizers and liquid dairy manure was evaluated over 6‐year period, including the effects on yield, nutrient concentration cycling, forage species composition soil levels. Nutrient treatments included an unamended control, N fertilizer, NPK fertilizer (LDM). application rates plant‐available N, P, K were constant across treatments. Application nutrients any form increased generally by 2–4 t dry matter...

Perpetuating cereal cover crops through self‐seeding may increase adoption by reducing risk and cost. Winter rye ( Secale cereale L.), wheat Triticum aestivum triticale (× Triticosecale Wittmack) were used to develop crop systems in a soybean [ Glycine max (L.) Merr.]–corn Zea mays L.) rotation. Cereal planted varying row spacing configurations managed chemically mechanically achieve different levels of resource utilization time space. The objective this study was quantify interspecific...

Abstract Cow–calf operations in grass-based agricultural systems Marion County, Iowa, are multifunctional their provision of agronomic, ecological, economic and social uses. Since 1992, however, pastureland cow–calf have decreased because urban encroachment, leading to a speculative loss some beneficial functions. The goal this interdisciplinary project, conducted from 2003 2005, was employ farming research evaluation platform investigate grassland multifunctionality at farm, field community...

Abstract Nitrate toxicosis is more prevalent when ruminants consume forages high in NO 3 and low readily fermentable carbohydrates. Environmental conditions vary with season may differentially affect herbage N total nonstructural carbohydrate (TNC) composition. Experiments were conducted to determine the concentrations partitioning of −N, (TN), TNC, inorganic summerand autumn‐grown brassicas CT. Kale ( Brassica oleracea var. acephala DC.), rape B. napus L.), turnip rapa tyfon [ L. ✕...

The inherent variability of pasturelands makes it difficult to sample soils and accurately characterize a pasture. Indirect methods such as soil electroconductivity (EC) can be used rapidly, noninvasively, inexpensively quantify variability. objective this study was determine if rapidly collected, georeferenced information could propose an accurate, multistage sampling scheme for five variables in central Iowa Results from suggest that the use noninvasively collected EC topographic data...

Tall fescue (Festuca arundinacea Schreb.) is a cool-season grass with physiological and morphological traits suitable for stockpiled grazing. The effect of late summer nitrogen (N) application was measured yield quality responses using four N rates (0, 25, 50, 100 lb/acre) three autumn harvest dates. Averaged across date, linear increases dry matter (DM) occurred in 1999 2000. In 1999, = 1747 + 15 × rate (R 2 0.92, RMSE 235) 2000, 672 19 0.96, 202). Year by date year interactions were...

Abstract The multifunctional agronomic, ecological, economic and social uses of grass-based agricultural systems in peri-urban Marion County, Iowa, were the subject investigation from 2003 to 2005. Following a sociocultural analysis that identified diverse motivations cow–calf operators, an on-farm, agroecological experiment was established with member study group. objective investigate feasibility establishing prairie pasture response operator's interest certified organic, warm-season plant...

Abstract Brassica crops have potential use as a forage during summer, fall, and early winter months. The influence of planting date harvest on the initial regrowth herbage yields for three species: rape ( B. napus L., ‘Winfred’ in 1987 ‘Emerald’ 1988 1989), turnip rapa ‘Purple Top’), hybrid × pekinensis ‘Tyfon’) were investigated. species planted late May to June, June July, July August 1987, 1988, 1989. Herbage before grazing taken 64, 76, or 85 d after planting. remaining was allowed...

How can student outcomes assessment (SOA) be incorporated into one's courses and teaching? The purposes of this article are to explore a process enacted in the Department Agronomy at Iowa State University using SOA to: (i) develop clearer understanding what students should learn course, (ii) determine how course or fit within curriculum, (iii) improve teaching practices ultimately students’ learning. An assignment from required agronomy curriculum provides an illustration instructor use...

Core Ideas Do agricultural travel courses have an impact on the student-travelers' careers, and do employer employee perceive any benefits? We surveyed 335 students who had participated in Iowa State ag-led international ag study course between 1964 1990. Overall survey showed strong impacts favorable attitudes decades after participation course. University College of Agriculture Life Sciences (CALS) has offered since 1963. Students traveled to Europe, Eastern or Asia roughly a bi-annual...

In recent years, interest has increased in finding nongrass cover crop species that could be planted after soybean [ Glycine max (L.) Merr.] and before corn ( Zea mays L.) central Iowa rotations. this study, we investigated the use of winter canola Brassica napus as an alternative for Iowa, characterize effect fall seeding date on its growth survival. a field experiment, cultivar Baldur was seeded at four dates 2012 2013. Aboveground biomass (AGB) production, nitrogen (N) accumulation,...

Abstract Lupin ( Lupinus albus L.), a high protein grain legume, has the potential of being grown in Pacific Northwest as an alternative crop for pea Pisum sativa L.) and lentil Lens culinaris L.). Greenhouse studies were conducted to determine tolerance white lupin cultivar Astra preplant incorporated (PPI), preemergence (PRE), postemergence (POE) applications herbicides commercially available other legumes. All herbicide made at two rates; rate labelled pea, lentil, or soybean [ Glycine...