There is limited documented scientific information on garden production systems managed in developing countries, partly because both researchers and research administrators have, until recently, ignored them as legitimate areas of study, and because such production systems have been regarded as informal production activities, managed outside conventional market and economic channels. Yet in a developing country such as Ghana, these production systems are potentially able to contribute substantially to the food security and health needs of households. This study was aimed primarily at providing critical scientific information for understanding the complex web of production and management factors associated with garden production systems. A total of 300 survey responses, representing the Sudan savannah, Guinea savannah and moist deciduous forest agro-ecological zones of Ghana, were analyzed (27% of respondents were females and 73% were males). Several hypotheses from the field agriculture literature were tested to determine their relevance in garden production systems. Although, for the country as a whole, a variety of garden crops are cultivated, each agro-ecological zone concentrated on a set of four major crops, with the actual food crops differing across agro-ecological zones. The type of protective fencing used was not statistically associated with land tenure (i.e., own versus rented land) status of the gardener (χ2=3.285, P=0.4501). Gender responsibilities in garden production and management tended to be more equally shared in the forest agro-ecology, where garden crops are cultivated for household consumption and for generating family income. In contrast, in the two savannah zones, adult males undertook a disproportionate share of activities to produce garden crops that were primarily for marketing. Valuable information on production and management exist within the traditional garden production systems studied, and range from socio-economic, agronomic and medicinal considerations in selecting garden crops and fruit trees, to ecological monitoring systems and strategies for garden management.

Current production practices in the Red River Valley of North Dakota and Minnesota involve use of extensive tillage and/or herbicides to control weeds. Given the erosion potential, environmental concerns associated with herbicides, and herbicide-resistant weeds, alternative cropping systems that mitigate these problems need to be assessed economically. Furthermore, the role that government commodity programs play in the adoption of more ecologically friendly cropping systems needs to be determined. We evaluated 8 years of yield data (1994–2001) from field plots near Fargo, North Dakota, to compare the economics of two alternative cropping systems, reduced-input (RI) and no-till (NT), to a conventional tillage (CT) cropping system. The RI system relies on a more diverse rotation of soybean (SB), spring wheat (SW), sweet clover (SC) and rye, and uses fewer herbicide and fertilizer inputs than CT or NT. Both NT and CT systems rotate SB and SW. We found that CT returns averaged over $47 ha−1 more than NT during the study period. Because SC yield data were not available, the economic competitiveness of RI was calculated using break-even yields and returns for SC. Historical SC yields in Cass County, North Dakota were not statistically different from the break-even yields. However, when government program payments were considered, break-even returns for SC increased by about $15 and $18 ha−1 and break-even yields by 0.44 and 0.52 MT ha−1 for RI to compare with NT and CT, respectively. These results indicate that CT management offers greater economic return than either RI or NT and that government program payments impede adoption of more environmentally friendly cropping systems in the northern Great Plains.

The conversion of cropland to the production of woody biomass, or short-rotation woody crops (SRWCs), has the potential to provide an economic alternative to Midwestern farmers, while simultaneously offering an environmental dividend in the form of reduced erosion and nutrient pollution of streams. However, notwithstanding a wealth of plot-scale and anecdotal data suggestive of these benefits, there are few watershed-scale integrated analyses on which to base regional policy decisions regarding incentives to convert fields to SRWCs. This study applied a field-scale runoff, sediment and nutrient transport model (Agricultural Drainage and Pesticide Transport, ADAPT) to a simulation of 10, 20 and 30% cropland conversion to SRWCs, grown on a 5-year rotation, in a representative Minnesota River sub-watershed. While the generation of a highly precise simulation would require extensive calibration of the model, its application with parameters previously calibrated to neighboring, similar watersheds provided reasonably robust results that indicated real differences resulting from cropland conversion. At the highest conversion level, mean annual runoff was reduced by up to 9%, sediment loads by 28% and nitrogen (N) loads by 15%, although total phosphorus (P) loads increased by 2% relative to the no-SRWC scenario. However, the relative benefits of conversion at the field level were contingent on soil type, drainage status and the alternative crop. These differences provide useful insights with respect to the targeting of possible conversion incentives.

Soil biological quality can affect key soil functions that support food production and environmental quality. The objective of this study was to determine the effects of management and time on soil biological quality in contrasting dryland cropping systems at eight locations in the North American Great Plains. Alternative (ALT) cropping systems were characterized by greater cropping intensity (less fallow), more diverse crop sequences, and/or reduced tillage than conventional (CON) cropping systems. Soil biological properties were assessed at depths of 0–7.5, 7.5–15, and 15–30 cm from 1999 to 2002 up to three times per year. Compared to CON, ALT cropping systems had greater microbial biomass and potentially mineralizable N. ALT cropping systems also had greater water stable aggregates in the surface 7.5 cm, but only at four locations. Total glomalin (TG), an organic fraction produced by fungi associated with aggregate stability, differed only at one location (Mandan), where the ALT cropping system had 27% more TG than the CON cropping system. Fatty acid methyl ester (FAME) profiles were highly location dependent, but total extracted FAME tended to be higher in ALT cropping systems. Soil biological properties fluctuated over time at all locations, possibly in response to weather, apparent changes in soil condition at sampling, and the presence or absence of fallow and/or legumes in rotation. Consequently, preplant and post-harvest sampling, when weather and soil conditions are most stable, is recommended for comparison of soil biological properties among management practices. Overall, ALT cropping systems enhanced soil function through: (1) improved retention and cycling of nutrients and (2) maintenance of biodiversity and habitat, implying improved agro-ecosystem performance over time.

Soils perform a number of essential functions affecting management goals. Soil functions were assessed by measuring physical, chemical, and biological properties in a regional assessment of conventional (CON) and alternative (ALT) management practices at eight sites within the Great Plains. The results, reported in accompanying papers, provide excellent data for assessing how management practices collectively affect agronomic and environmental soil functions that benefit both farmers and society. Our objective was to use the regional data as an input for two new assessment tools to evaluate their potential and sensitivity for detecting differences (aggradation or degradation) in management systems. The soil management assessment framework (SMAF) and the agro-ecosystem performance assessment tool (AEPAT) were used to score individual soil properties at each location relative to expected conditions based on inherent soil-forming factors and to compute index values that provide an overall assessment of the agronomic and environmental impact of the CON and ALT practices. SMAF index values were positively correlated with grain yield (an agronomic function) and total organic matter (an agronomic and environmental function). They were negatively correlated with soil nitrate concentration at harvest (an indicator of environmental function). There was general agreement between the two assessment tools when used to compare management practices. Users can measure a small number of soil properties and use one of these tools to easily assess the effectiveness of soil management practices. A higher score in either tool identifies more environmentally and agronomically sustainable management. Temporal variability in measured indicators makes dynamic assessments of management practices essential. Water-filled pore space, aggregate stability, particulate organic matter, and microbial biomass were sensitive to management and should be included in studies aimed at improving soil management. Reductions in both tillage and fallow combined with crop rotation has resulted in improved soil function (e.g., nutrient cycling, organic C content, and productivity) throughout the Great Plains.

Agricultural systems produce both detrimental and beneficial effects on soil quality (SQ). We compared soil physical properties of long-term conventional (CON) and alternative (ALT) cropping systems near Akron, Colorado (CO); Brookings, South Dakota (SD); Bushland, Texas (TX); Fargo, North Dakota (ND); Mandan (ND); Mead, Nebraska (NE); Sidney, Montana (MT); and Swift Current, Saskatchewan (SK), Canada. Objectives were to quantify the changes in soil physical attributes in cropping systems and assess the potential of individual soil attributes as sensitive indicators of change in SQ. Soil samples were collected three times per year from each treatment at each site for one rotation cycle (4 years at Brookings and Mead). Water infiltration rates were measured. Soil bulk density (BD) and gravimetric water were measured at 0–7.5, 7.5–15, and 15–30 cm depth increments and water-filled pore space ratio (WFPS) was calculated. At six locations, a rotary sieve was used to separate soil (top 5 cm) into six aggregate size groups and calculate mean weight diameter (MWD) of dry aggregates. Under the CON system at Brookings, dry aggregates (>19 mm) abraded into the smallest size class (<0.4 mm) on sieving. In contrast, the large aggregates from the ALT system abraded into size classes between 2 and 6 mm. Dry aggregate size distribution (DASD) shows promise as an indicator of SQ related to susceptibility of soil to wind erosion. Aggregates from CON were least stable in water. Soil C was greater under ALT than CON for both Brookings and Mead. At other locations, MWD of aggregates under continuous crop or no tillage (ALT systems) was greater than MWD under CON. There was no crop system effect on water infiltration rates for locations having the same tillage within cropping system. Tillage resulted in increased, decreased, or unchanged near-surface BD. Because there was significant temporal variation in water infiltration, MWD, and BD, conclusions based on a single point-in-time observation should be avoided. Elevated WFPS at Fargo, Brookings, and Mead may have resulted in anaerobic soil conditions during a portion of the year. Repeated measurements of WFPS or DASD revealed important temporal characteristics of SQ that could be used to judge soil condition as affected by management.

Organic and low-input farmers often plant seed varieties that have been selected under conventional practices, traditionally including high inputs of artificial fertilizers, crop protection chemicals and/or water. In addition, these crops are often selected in environments that may or may not represent the local environment of the farmer. An evolutionary participatory breeding (EPB) method emphasizes the utilization of natural selection in combination with site-specific farmer selection in early segregating generations of a heterogeneous crop population. EPB is a combination of two specific breeding methods, evolutionary breeding and participatory plant breeding. Evolutionary breeding has been shown to increase yield, disease resistance, genetic diversity and adaptability of a crop population over time. It is based on a mass selection technique used by farmers for over 10,000 years of crop improvement. Participatory plant breeding programs originated in developing countries to meet the needs of low-input, small-scale farmers in marginal environments who were often overlooked by conventional crop breeders. The EPB method is an efficient breeding system uniquely suited to improving crop varieties for the low-input and organic farmer. The EPB method utilizes the skills and knowledge of both breeders and farmers to develop heterogeneous landrace populations, and is an effective breeding method for both traditional and modern farmers throughout the world.

In Ghana, studies on the use of organic materials to increase soil productivity have focused on crop-residue management, use of green and animal manures, and legume cover cropping. Few studies have assessed the use of human waste for agriculture, even though this is widely practiced by farmers in the northern part of the country. This study was carried out to investigate the stakeholders in the use of faecal sludge (FS) for crop production in Tamale and Bolgatanga municipalities in the guinea savanna agroecological zone of Ghana. The aim was to determine the driving factors, constraints and potentials for this practice. Field survey and focus group discussions were carried out among 90 farmers who use FS, and officials of the Municipal Sanitation Unit were interviewed. Sixty-four percent of farmers interviewed used FS as a cost-effective way to improve soil fertility and increase yields of maize and sorghum. Sludge is discharged by spreading it on the soil surface, or it is stored and dried in pits during the dry season and incorporated into the soil at the onset of the rainy season. The high temperatures of the savanna climate and this long period of drying allow sludge to be handled easily. Although this treatment is perceived to reduce the number of pathogens in dried sludge, 22% of farmers complained of itching feet and foot rot after working with FS, which is done without wearing protective foot covering. This constraint is coupled with the foul smell, transport problem and public mockery associated with the use of human waste for agriculture. In spite of these problems, there is competition for FS among farmers, due to benefits derived from its use. Further investigation is required to ascertain the causes of itching feet and foot rot, and there is a need for education on proper handling and appropriate hygiene practices when working with FS. Information regarding optimal FS application rates is also required.

Cover crops offer many benefits for farmers seeking to reduce their reliance on external inputs. These include maintaining and improving soil quality, preventing erosion and, in some cases, allelopathic weed control. Allelopathic potential has been well documented for cover crops such as cereal rye (Secale cereale L.), hairy vetch (Vicia villosa Roth) and red clover (Trifolium pratense L.). Much less is known about other potentially allelopathic cover crops, including certain brassicaceous species that are normally grown for their oilseeds, including canola and rapeseed (both Brassica napus L.) and mustards (e.g., Sinapis alba L., white and yellow mustard). Because of their potential contribution to pest management, there is increased interest in growing brassicas, both as cover crops and as seed crops harvested for oil production. In this review, we first discuss unique attributes of brassicas that make them promising options for pest management, as well as generally beneficial cover crops. Next, we review the literature from controlled settings on the effects of brassicas, brassica extracts and isolated compounds contained therein on seed germination, seedling emergence and establishment, and seedling growth—effects that, combined or taken alone, could contribute to reducing the density and vigor of weed communities in the field. Field studies examining the detrimental effects of brassicas in rotation with other crops, as well as examining the effects of brassica cover crops on weed dynamics in subsequent crops, also are reviewed. Finally, we review some important agronomic considerations about the use of brassica cover crops.

In anticipation of the Philippines being a major producer of organic bananas, this study was conducted to provide a quantitative basis for certain practices in organic farming. The nutrient supplying capacity of banana residues in combination with leguminous materials and chicken manure was investigated in composting studies. Changes in the chemical composition of ten formulations of banana residue-based compost involving leguminous plants (Sesbania rostrata, Flemingia macrophylla, Arachis hypogea) and chicken manure were analyzed periodically during a composting period of 16 weeks. Results showed that combinations of banana residues (BnR) and chicken manure or leguminous plants were highly decomposed compared to untreated BnR. The use of leguminous plants and/or chicken manure enhanced the composting process significantly compared to the effect of Bioquick. The compost piles were characterized by increases in pH, total N and total P, and decreases in total K, total carbon and C/N ratio with time. Notably, BnR+chicken manure attained a C/N ratio of 15 at 4 weeks, while the BnR+leguminous materials reached such a low C/N ratio at 8–16 weeks. An incubation study was conducted under greenhouse conditions for 24 weeks. It was designed to follow the dynamics of nitrogen (N), phosphorus (P) and potassium (K) availability in two clay soils (Antipolo and Lipa) amended with five compost formulations (BnR alone, BnR+Sesbania prunings, BnR+Flemingia prunings, BnR+peanut stover and BnR+chicken manure) and with uncomposted banana residue at an application rate of 20 Mg ha−1. Results showed that net N mineralization occurred in soils amended with BnR+chicken manure and BnR+leguminous materials, which had C/N ratios ranging from 12 to 16. Net N immobilization during the earlier period of incubation was observed in uncomposted and composted banana residues with a C/N ratio of 68 and 24, respectively. Significantly higher net P mineralization was obtained only in soils amended with BnR+chicken manure. An abrupt increase in exchangeable K was observed in all treatments 2 weeks after the incorporation of organic residues. Higher available K in pure BnR treatments (uncomposted or composted) exhibits the inherently high K content of banana residues.

Organic farmers throughout Austria were asked in 1999 if, once the first agri-environmental program (ÖPUL) ends, they intended to commit themselves to a further five-year period of organic farming. The study presented here addresses those farmers who expressed in the survey the intention to end their participation in organic farming under ÖPUL, or who were undecided at that time. The aim was to compare and analyze the intended behavior with actual behavior. The research was based on material from, and analyses of, the 1999 survey and the survey conducted in 2002. Additional information regarding the reasons for abandoning (or continuing) organic farming and the decision-making process itself was collected through a series of telephone interviews in 2004. The comparison revealed a connection between actual behavior and the intentions expressed in the 1999 survey. However, there were no clear differences in terms of the reasons given in 1999 for potentially discontinuing with organic farming between those farms that remained organic and those that reverted to conventional farming methods. There were differences between those reasons given in the 1999 survey for potentially leaving organic agriculture and the reasons that determined the actual decision, as cited in telephone interviews in 2004. In the 1999 survey, economic issues were the main reasons for potentially ceasing to farm organically. When it came to the actual decision, problems concerning organic guidelines and inspections were more prominent. The environmental attitudes and the social embedding of the farmers within organic agriculture played a decisive role on those enterprises that chose to continue farming organically. The analysis indicates that the presence of a successor is also a stabilizing factor for organic farming.

Since keeping nutrient cycles intact is one of the most important goals in organic farming, the option of recycling by-products from organic food processing by feeding them to organically raised pigs was analyzed in this study. A more specific objective was to estimate the potential of this nutrient source for reducing the protein deficiency in organic pig nutrition. Sector-specific questionnaires were sent to 321 processors of organic foods in Austria. The information provided was used to estimate the total quantity of the respective by-products available. Proximate analysis, amino acid and mineral analysis were performed for different by-products. These data were combined with the available quantities of the respective by-products, resulting in the amounts of nutrients potentially recyclable for pig nutrition. Each year 2400 t of wheat bran, 990 t of rye bran and 1300 t of residues from the separation of seed grains are already fed to different kinds of livestock. Some 510 t of stale bread are currently disposed of, but could be used as a highly nutritive feedstuff for pigs, once the problem of collection is solved. Relevant amounts of other energy-rich by-products were found: currently, about 11,000 t (2000 t on a dry matter basis) of feed-grade potatoes are composted, resulting in a waste of 27,000 GJ of metabolizable energy (ME). These potatoes could be better utilized as a dietary energy source for approximately 12,300 pigs. Additionally, about 12,900 t of whey from organically produced milk are discarded, which could be used to feed roughly 14,000 pigs. High-protein by-products are scarce. Annually, 80 t and 63 t of expellers from pumpkin seed and sunflower seed, respectively, are produced from organically grown oilseeds. Only small quantities of okara (by-product of the production of tofu from soybeans) and buttermilk are available. Only 4% and 5% of the protein and lysine requirements, respectively, of the pigs currently kept on organic farms in Austria could be covered by by-products rich in protein. Excluding feed-grade potatoes means a loss of 18% crude protein (CP), 18% lysine and 26% ME of the entire nutrient supply available from organic by-products.

A sustainable agricultural and food system is characterized by two qualities: availability of high-quality, healthy food along with the best possible preservation of natural resources. Organic farming is discussed as a solution model for the complementary achievement of both aims. Taking the region Mostviertel-Eisenwurzen (A) as a case study, the present investigation examines the regional self-reliance in food production by means of three scenarios. In the basic scenario, the current land use of the region is set against the present-day food demand of the local population. The organic scenario assumes that the farming method of the region adheres 100% to the guidelines of organic farming. The food produced is set against the current food demand, as in the basic scenario. In the third scenario–-the organic-alternative scenario–-the 100% organically produced food is set against a food demand of the local population that follows the recommendations of nutritional science, comprising more plant-based diets. The results show that in the case of the hypothetical conversion to organic farming, food production decreases in absolute numbers. Despite this reduction, the local population can be sufficiently supplied with food energy, both in the case of the average Austrian diet as well as in a diet according to the recommendations of nutritional science. The number of people that can be supplied outside the region is higher in the nutritional science diet than in the average Austrian diet, despite the lower total net export quantity. While egg, meat and milk production are up to six times the local demand, the degree of self-supply of plant products (especially fruit and vegetables) covers only two-thirds of the demand after conversion. Moreover, our calculations show how a change of consumption patterns affects the demand for imported feedstuff. The region changes from being a net importer of concentrate (76,190 t fresh mass) at the starting point to a gross exporter (39,784 t fresh mass) in the organic and the organic-alternative scenario. In summary, agricultural production according to the guidelines of organic farming and a diet following the recommendations of nutritional science seems a promising strategy for achieving a sustainable agricultural and food system.

We consider the adoption of biologically integrated agricultural practices from the perspective of farm management style. Adoption decisions for farming practices must fit into a broader farm decision-making context that incorporates economic, environmental, social, family and personal considerations, as well as use of agricultural information sources. Drawing from a study of California almond and winegrape growers, we demonstrate that management styles differ substantially among farmers, these differences affect use of information sources and adoption of biologically based practices on the farm, and such adoption does not negatively affect crop performance. We used Q-methodology, a method for eliciting qualitative data using a variant of factor analysis, to identify three distinct management styles among a purposive sample of 40 growers. The Environmental Stewards' management style places higher priority on conservation of natural resources than on getting the highest possible yields or profits. Production Maximizers, with a different style, prioritize more traditional goals of producing the highest possible yields and quality and focusing resources on the farm rather than on outside concerns. Networking Entrepreneurs, on the other hand, value learning about innovative techniques in social contexts such as informational field days, evaluate new information with a business-like attitude and enjoy off-farm interests. A two-season mail survey of farming practices and information sources demonstrated that differences in management styles affect the adoption of practices. Environmental Stewards were more likely to practice biological pest control and encourage wildlife and less likely to use the most toxic chemicals. Production Maximizers had a greater tendency to use prophylactic and broad-spectrum chemicals, while Networking Entrepreneurs preferred more innovative biological pest controls but tended to avoid time-consuming cultural practices. Production Maximizers were distinguished by less use of more social forms of communication, such as attending field days and talking with other growers. Crop health and quality indicators showed that almost all growers were managing their crops very successfully, regardless of management style or choice of practices. These results hold important implications for efforts to increase the adoption of sustainable agriculture, especially by showing that contents and methods of outreach efforts must vary to accommodate diverse farm management styles.

Can banded herbicide be eliminated in ridge-tilled soybean (Glycine max)? The effects of banded herbicide, rotary hoeing and cultivation on weed populations and soybean yield in a ridge-tillage system were tested on three farms in Iowa, USA in 1989 and 1990. In 1989, plots either had no herbicide or had herbicide banded in the row at planting in mid-May; all plots received two rotary hoeings and two cultivations. In 1990, treatments were banded herbicide with no rotary hoeing, banded herbicide with one rotary hoeing, and no herbicide with one or two rotary hoeings; all plots received two or three cultivations. In both years, over all weed species [primarily giant foxtail (Setaria faberi), Pennsylvania smartweed (Polygonum pensylvanicum) and redroot pigweed (Amaranthus retroflexus)], seedling emergence was highest in late May and early June, with few seedlings emerging after mid-June. Weed populations were highest in May and June, after which rotary hoeing and cultivation reduced weed numbers in all plots. There were no consistent differences among treatments in weed numbers in early August for the 2 years. In both years, there was no significant difference in soybean yield among treatments. Within-farm mean yields ranged from 2.26 to 3.01 Mg ha−1 among farms in 1989 and from 2.07 to 2.93 Mg ha−1 among farms in 1990. Ridge-tillage without herbicide was generally equivalent to ridge-tillage with banded herbicide, with respect to total number of weeds and number of broad-leaved weeds remaining in August after tillage, and to soybean yield.