The use of forage as a cover crop is an alternative for the sustainable management of conilon coffee (Coffea canephora Pierre ex Froehner) crops. The objective of this study was to evaluate the herbage accumulation and nutritive value of forages used as cover crops and their effect on the productivity and physiology of conilon coffee plants. The inter-row management assessed were 1- Congo grass [Urochloa ruziziensis (R. Germ. & C.M. Evrard) Crins], 2- Mombaça guineagrass [Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs], 3- Marandu palisadegrass [Urochloa brizantha (Hochst. ex A.Rich.) R.D.Webster], 4- weeds, 5- weeding and herbicide application. The experiment was conducted in 2020 and 2021 using a randomized block design (split-plot) with four replications and a plot size of 24 m2. Herbage accumulation of Congo grass, Mombaça guineagrass and Marandu palisadegrass (1.12 to 3.81 t/ha) were higher than weeds (0.18 to 1.95 t/ha) in seven periods evaluated. Mombaça guineagrass had the highest average herbage accumulation (1.47 to 3.81 t/ha). The forage cover crops did not differ among themselves for dry matter concentration, crude protein and C:N ratio in three periods evaluated. The inter-rows management with cover crops did not reduce productivity, grain/fruit ratio, grain size, vegetative vigour and physiology of the coffee plants compared to the management with weeding and herbicide in 2021. In 2022, they stagnated or reduced productivity by up to 49%, with changes in plant physiology. Adjustments in the management of cover crops are needed for the development of competitive and sustainable coffee crops.

Weed invasion has become increasingly recognized as a major threat to the practice of sustainable agriculture and the maintenance of natural ecosystems around the world. Without effective and ongoing management strategies, many weed species have the aggressive capacity to alter ecosystem functions and reduce the economic potential of the land into which they have been introduced. Although traditional weed management strategies can be useful in eliminating certain weeds, these approaches can be costly, economically damaging, and laborious and can result in variable long-term success. To further add to these challenges, several weed species have now developed resistance to a range of herbicide modes of action, which, to date, have been the major mechanism of weed control. As a result, it is anticipated that the use of emerging technology will help to provide a solution for the economical and environmentally sustainable management of various weeds. Of particular interest, emerging technology in the areas of weed detection and control (chemical, mechanical, electrical, laser, and thermal) has shown promising signs of improving long-term weed management strategies. These methods can also be assisted by, or integrated alongside, other technology, such as artificial intelligence or computer vision techniques for improved efficiency. To provide an overview of this topic, this review evaluates a range of emerging technology used for the detection and control of various weeds and explores the challenges and opportunities of their application within the field.

Unproven economic returns at the farm level are a major barrier to large-scale adoption of cover crops. The objective of this study was to evaluate the short-run private net returns to producers implementing a cereal rye (Secale cereale L.) cover crop preceding the no-till corn (Zea mays L.) phase of a US Midwest corn–soybean (Glycine max [L.] Merr.) rotation in an integrated crop and cow–calf operation. We used experimental agronomic data from six location-years in Iowa to estimate private net returns to cereal rye across alternative scenarios in a partial budget framework. Net returns in the absence of grazing averaged −$123.74 ha−1 and were negative for 82.2% of the treatments, while net returns under partial grazing averaged −$15.24 ha−1 and were negative for 54.8% of the treatments. Early-broadcast cereal rye produced higher biomass and larger net cost savings in the livestock enterprise than late-drilled cereal rye, but it also resulted in higher corn yield penalties. In the no-grazing scenario, net losses for early-broadcast cereal rye were $165.97 ha−1 larger, on average, than for late-drilled cereal rye. Our findings should raise awareness about the low probability of obtaining positive annual private net returns to cereal rye in Iowa in the absence of sizable targeted financial incentives, and inform the policy discussion on the cost-effectiveness of government-sponsored conservation programs.

Silvopastoral systems (SPSs) are sustainable alternatives for pasture intensification. Management practices such as thinning are options to diminish competition for resources between pasture and trees, ensuring appropriate forage production. The objective of this study was to evaluate the productive and nutritive traits of Piatã palisadegrass (Urochloa brizantha cv. BRS Piatã) after thinning the forest component of a SPS. Forage production and nutritive value, along with microclimate variables were assessed in a SPS and in an intensive system (INT) in São Carlos-SP, Brazil, from 2016 to 2018. The INT was a full sun pasture of Piatã palisadegrass, while the SPS was established with Piatã palisadegrass shaded by eucalyptus (Eucalyptus urograndis clone GG100) spaced 15 × 2 m but thinned to 15 × 4 m before the onset of the experiment. In the SPS, measurements were made under the tree row (SPS_1), 3.75-m (SPS_2), 7.5-m (SPS_3) and 11.25-m (SPS_4) distant from the North row. Forage accumulation in the two systems were similar, whereas the pre-grazing forage mass in most of the SPS positions were smaller than that of the INT during the autumn of 2017 and summer of 2018. Crude protein (CP) content was greater in the SPS than in the INT in most positions and seasons. Forage production was favoured by the thinning of the trees mainly in the seasons close to the event, while forage CP was consistently greater in the understory pasture. Thinning of trees in SPSs can be adopted to provide forage production similar to intensive pastures with higher protein content.

Aquaponics technology has recently been offered as a good option for sustainable food systems among small-scale farmers, particularly those seeking an organic production or dealing with land quality constraints, such as urban farmers. However, there is a lack of empirical evidence for the capacity of small farmers to adopt the technology. The unique requirements of aquaponics may create technical, economic and even cultural constraints and opportunities. This paper uses empirical evidence gathered with small-scale farmers in São Carlos, State of São Paulo, Brazil, to present the capacity of adoption for the technology, including possible limiting factors and incentives for farmers. The study conducted interviews with owners of ‘agriculturas familiares’ (Portuguese for small family owned farms) within 30 km of São Carlos. The interviews revealed that there is widespread interest in the potential profitability of aquaponics systems, significant interest in environmentally friendly practices, familiarity with organic production and hydroponics and a large base of agricultural knowledge in the community that can drive adoption. However, lack of initial financing, limited human power and concerns about product placement were significant barriers to adoption. For settlement farmers (those working on land formerly abandoned) poor soil quality and water scarcity are key issues that could be alleviated by the technology. The city of Sao Carlos present program for purchasing specific types of products from these farms could be used as a model for increasing aquaponics adoption and relieving success concerns.

The agricultural-chemical industry has been offering solutions in plant protection for several decades. The primary role of Industry in weed control has mainly been to provide chemicals with increasingly attractive profiles regarding safe handling, ecological acceptance, and economical attractiveness. These objectives have been reached by significant developments, e.g. in rates, persistence, and specificity for non-target organisms. It is therefore safe to assume that in the year 2015 and beyond chemicals will continue to maintain a major role in weed control. However, as cropping systems and criteria for desirable control levels change, industry will have to change from a re-active to a pro-active participant in the development of integrated systems. Chemical solutions will be complemented by biological and agronomical methods and will be further supported by biotechnological successes in the crop area. In addition, it is anticipated that sophisticated computer models now in development will help exploit the potential of products as well as of integrated systems. Thus, fully integrated companies active in chemical, biological, and molecular-biological research and having branches in the agro-chemical as well as in the seed business will be especially suited to be driving forces in the changing world of modern weed control. The practice will ask for services much more than for single products. Industry will not only have to offer those services but at the same time assist in the education of growers to enable efficient use of the increasingly intricate methods of future weed control.

Combining existing traditions of rice and of fish in an integrated rice−fish (IRF) culture is a promising strategy for sustainably increasing land productivity and diminishing the need for external inputs in smallholder agriculture of Amazonia. This study evaluates the potential of IRF for weed control in irrigated rice production. It was conducted from August 18 to December 5, 2008 in the Maranhão lowlands in the eastern periphery of Amazonia. We compared weed communities in four 3-year-old IRF and four adjacent ‘conventional’ irrigated rice (CIR) fields at 20 and 40 days after transplanting (DAT), at the mid-vegetative stage and at the onset of flowering, which served as an indicator of potential grain yield. Rice–fish fields contained differing mixtures of herbivore and omnivore fish species totaling 4000 fish per ha or 1.7 fish per m3. Total weed density was reduced in the IRF system, particularly early in the season, the most critical stage for rice development. The integration of fish into irrigated rice cultivation affected weed species composition, with fish-weeding preferentially reducing monocotyledonous Cyperaceae, one of the more aggressive and problematic weed families in this region. Monocot weed density was negatively correlated with rice aboveground biomass at 40 DAT rice. Although floristic similarity between IRF and CIR fields was low, the impacts of IRF on weed species diversity and weed species richness were not significant. Thus, IRF was not associated with a simplification of the weed community. We conclude that fish-weeding may substitute for manual or chemical weeding in irrigated rice agriculture, an important consideration for resource-poor smallholder agriculture in environmentally sensitive riverine or delta areas of eastern Amazonia.

Human watch-keeping is necessary to prevent incidents at sea such as groundings and collisions. For many years, electronic aids to navigation have been utilised in watch-keeping but, with electronic marine systems becoming more sophisticated, the part they play in preventing collisions and groundings should become increasingly important. However, this article uses secondary data from the Safety Digest for 2008 compiled by the Marine Accident Investigation Bureau of the United Kingdom; eight case studies are used to show that electronic marine systems, whether integrated or not, are still playing a part in poor watch-keeping resulting in collisions, near misses and groundings. Primary data from fishing skippers of British based vessels have been used to confirm the findings from the secondary data that poor watch-keeping is often the cause of not keeping a proper lookout and that the watch-keeper has a too heavy reliance on the electronic aids. Brief suggestions are made as to how the electronic aids may be adapted to overcome these problems and thus to support the watch-keeper.

Integrated electronic marine systems are becoming part of the numerous screens which are to be found on ships' bridges and in wheelhouses of fishing vessels. This paper continues previous work which has focussed on perceived safety aspects of integrated electronic marine systems, in particular, a small study completed within the last two years which showed that some fishing skippers had negative perceptions of integrated electronic marine systems. This present study uses semi-structured interviews with skippers in the United Kingdom fishing fleet to show that integrated electronic marine systems can be perceived as increasing safety as well as being of good value in terms of need and cost. It is possible that such perceptions are dependent on experiencing the use of integrated electronic marine systems within off-shore trawling.

US agriculture operates in a market driven economy, although government policies can have influence on what farmers produce and how they produce it. As with other businesses, agricultural producers respond to economic incentives and disincentives, and make decisions to maximize their welfare; usually measured as net income. We examined how external economic drivers shape the type of agricultural systems that producers adopt. Specifically, we considered the influence of technological advancements, income supports embodied in farm legislation, and changes in market structure and consumer demand. Changes in technology have often favored large-scale and specialized operations. Many of the technological advancements have required large-scale production units to justify the investment. Often the technology has been commodity specific. However, there is some evidence that more diversified production units might be able to achieve economies of both scale and scope. The influence of commodity support programs has been ambiguous. As farm legislation has evolved to decouple production decisions from program benefits, the incentives to specialize in program crops (crops that receive price and/or income benefits under federal legislation, such as corn, other grains and oil seeds) have diminished. However, wealth and risk effects, albeit small, may have promoted or inhibited the adoption of a more integrated system. The ability of producers to adopt more integrated systems has been primarily influenced by their natural resource base and proximity to markets. Changes in market structure, channels and consumer demand in the past five decades have been dramatic with consolidation and specialization in both production and marketing sectors. However, the diversity of consumer demand has also created opportunities for more integrated farm operations. There is an increasing number of consumers who have become concerned about how and where their food has been produced. Markets for organic, locally produced, free range and the like are expected to grow. While price and income supports may have been biased towards specialization (as these programs were targeted to specific commodities), the reduction in risk associated with the programs has enabled producers to expand the number and diversity of their production enterprises. Furthermore, through the use of strategic alliances, cooperation among producers on a regional basis may eventually lead to greater integration and diversification than could be achieved for the individual farm operation.

Integrated electronic marine systems have been put forward as one way of reducing information overload for officers of the watch and other personnel who work on ships' bridges or in fishing wheelhouses. It may be that such systems will improve safety records which, in the case of fishing, are amongst the worst in the world. This article builds on previous work about issues for the systems designer by using a small study of fishing skippers to ascertain their perceptions of using integrated electronic systems in the wheelhouse. Semi-structured interviews were used with 11 skippers from one port who were all familiar with integrated electronic marine systems but did not use them on their vessels. The main reasons for this were a perception of unreliability of both the hardware and the software, together with concerns about data integrity and user control.

Marine accidents have many causes but a recurring theme is poor watch-keeping often caused by weak bridge management. Information overload is sometimes blamed for accidents and attempts to reduce information overload may include electronic systems which have been produced for integrating information from various electronic sources so that information is concentrated on fewer screens. This article explores some of the issues facing the designers of such systems. While acknowledgement is given to some of the technical problems, the article concentrates on those issues associated with the user of such systems, in particular, domain knowledge, screen design and user control. Available Marine Accident Investigation Reports for 2004 are used to highlight that, in that year, only one passenger vessel incident was attributed in part to poor data from electronic aids. However, it is accepted that a much wider study of such reports is needed before any firm conclusions can be drawn.

This paper addresses the problem of assigning economic weights to heritable genetic traits of dairy cows while taking all implicit natural resource values into consideration. To do so, a deterministic bio-economic model of a dairy farm enterprise driven by input probabilities of oestrous detection and conception rates that act through the calving interval is constructed. The model further accounts for biologically limiting factors of both livestock and land within a neo-classical economics framework of profit maximization. Departing from the more customary approach of obtaining gross margins to calculate levels of return in the agricultural sector, we employ a natural resource economics methodology where returns are set against an economic point of reference specified as the value of natural assets' productivity and terminal assets' resale value. Introducing the impact of farming intensity on soil fertility enables us to obtain long-run variations in natural asset values as affected by tillage intensity. Results show that economic weights are not constant over the range of changes in genetic improvements due to the non-linearity of the system induced by diminishing marginal product of inputs and finite carrying capacity of resources employed. These values, while invariant to area farmed, are however subject to variations in resource quality and therefore will reflect the sensitivity of long-term sustainability of the system to managerial decisions on intensity of operation. Results further demonstrated that achieving optimum levels of output while precluding the impact of intensity on land productivity can seriously reduce the time horizon over which sustainability can be maintained. Inclusion of the implicit costs of land use on the other hand tended to suggest optimum levels of output below those identified when only considering accounting data.

The most important source of increased crop yield in the Middle East has probably been the increase in irrigated area although it has been accompanied by other inputs such as chemical fertilizers, improved varieties, mechanization, and pesticides. Palestine, which in this paper encompasses West Bank and Gaza, has had a similar emphasis on irrigation although only 5% of West Bank agricultural land is irrigated. However, the possibility of further expanding or even maintaining present water use for fostering agricultural growth in this dry region is diminishing. There now is a growing understanding that future sustainable agriculture in the Middle East may depend on shifting emphasis to rainfed farming; in the past, this was not considered possible because of its perceived low productive potential. Recent research, however, has evaluated the status of rainfed farming in Palestine and targeted areas that need improvement. Experiments and demonstrations have shown the potential to vastly improve rainfed farming's production, economic return and status. Following up on these initial steps should be an important priority in maintaining food production in this region.

Over the past half century, American agricultural productivity has increased while the number of full time farmers and rural populations have decreased. Although most people believe we have a safe, nutritious, and affordable food supply, the high level of productivity has had negative impacts on the environment and rural communities and has increased farmers' dependence on purchased inputs. As Americans become more concerned about food safety and the environment, a new paradigm for American agriculture is emerging. This new alternative agriculture takes an ecological approach to food production. The challenge facing the land-grant university system is how to answer questions about sustainable agricultural systems, maintain productivity and respond to the needs and concerns of their broadened clientele. Whole farm case studies, focus groups, farm improvement clubs, on-farm research, field-size research trials, and whole farm comparisons are new qualitative and quantitative methods for interdisciplinary research and education. These methods integrate biological and social strategies and bring community members into the research and education process. When these groups work together, questions critical to maintaining the long-term sustainability and productivity of agricultural systems can be answered.