Advances in irrigation management in greenhouse cultivation

The advantages of greenhouse include the ability to secure better conditions than outdoor environment for crop growth and development, increased off-season production and autonomy from external weather conditions. This chapter provides an up-to-date critical overview of scientific advances in irrigation management for greenhouse vegetables and ornamentals. The chapter presents a technical design of a typical greenhouse irrigation system, before covering water balance and crop evapotranspiration techniques as well as the use of high-tech moisture sensors for irrigation scheduling. In the context of enhancing the water use efficiency of greenhouse crops, the chapter also discusses innovative management practices such as biostimulants and grafting. Finally, the chapter concludes by looking ahead to future prospects and research breakthroughs

Agribusiness supply chain risk management: A review of quantitative decision models

Supply chain risk management is a large and growing field of research. However, within this field, mathematical models for agricultural products have received relatively little attention. This is somewhat surprising as risk management is even more important for agricultural supply chains due to challenges associated with seasonality, supply spikes, long supply lead-times, and perishability. This paper carries out a thorough review of the relatively limited literature on quantitative risk management models for agricultural supply chains. Specifically, we identify robustness and resilience as two key techniques for managing risk. Since these terms are not used consistently in the literature, we propose clear definitions and metrics for these terms; we then use these definitions to classify the agricultural supply chain risk management literature. Implications are given for both practice and future research on agricultural supply chain risk management

A Systematisation of Methods for Heat Integration of Solar ThermalEnergy in Production Processes: A Review

The widespread use of fossil fuels and their limitation leads to find other sources of energy. Solar thermal energy is a possible solution. There are many projects that use renewable energy. Solar thermal energy can be easily used for heating. However, there are problems in the efficiency of solar collectors, the loss of heat, the consistency of heat supply, temperature and weather conditions, the biggest problem being the heat storage. In this paper is provided an overview of the methodologies for thermal integration of solar heating systems implemented in various projects and research. Solar heating systems have different designs and can generate heat in different temperature ranges. The main emphasis in this comprehensive overview is the systematisation of the various methodologies used in the integration of solar heat in production. In principle, solar heating systems are directly connected to the production systems. Furthermore, a few methodologies like Pinch technology, mathematical modelling and cogeneration are included

Waste Not, Want Not: Using Source-Separated Urine to Cultivate Maize in the Southern Highlands, Tanzania

In Sub-Saharan African countries, soil fertility is low due to unsustainable agricultural practices and little to no access to chemical fertilizer. Poor yields have resulted in many of these countries struggling to produce enough food to feed their growing populations. Human urine has been used as an effective, low-cost alternative to chemical fertilizers in greenhouse and plot trials on a variety of vegetables, but its effects on elemental grain composition in cereal crops are largely unknown. Here we tested whether diluted human urine applied as a fertilizer can increase maize crop growth, yield and nutritional content on small family-owned plots. In Hagafilo village, in the Southern Highlands of Tanzania, participating farmers maintained family plots (n=8) within which half of the plot received urine fertilizer and water, while the other half received water only. The experiment ran for one growing season. We found that urine fertilizer significantly increased growth (above and below ground dry biomass, stem length) and yield (cob length, number of total and developed cobs) metrics. We also found that shoot/root ratio was greater in the control treatment, suggesting that the fertilized plants invested a greater proportion of resources into roots relative to shoots; this could have implications for soil health as extended root systems can minimize soil erosion and have longer term benefits on soil fertility. In contrast, urine fertilizer did not significantly alter maize kernel nutrients. An increase in grain nitrogen is usually observed with increases in fertilizer supplied. This study supports the use of human urine fertilizer as a way to increase food security

Automatic Romaine Heart Harvester

The Romaine Robotics Senior Design Team developed a romaine lettuce heart trimming system in partnership with a Salinas farm to address a growing labor shortage in the agricultural industry that is resulting in crops rotting in the field before they could be harvested. An automated trimmer can alleviate the most time consuming step in the cut-trim-bag harvesting process, increasing the yields of robotic cutters or the speed of existing laborer teams. Leveraging the Partner Farm’s existing trimmer architecture, which consists of a laborer loading lettuce into sprungloaded grippers that are rotated through vision and cutting systems by an indexer, the team redesigned geometry to improve the loading, gripping, and ejection stages of the system. Physical testing, hand calculations, and FEA were performed to understand acceptable grip strengths and cup design, and several wooden mockups were built to explore a new actuating linkage design for the indexer. The team manufactured, assembled, and performed verification testing on a full-size metal motorized prototype that can be incorporated with the Partner Farm’s existing cutting and vision systems. The prototype met all of the established requirements, and the farm has implemented the redesign onto their trimmer. Future work would include designing and implementing vision and cutting systems for the team’s metal prototype

Exploring the potential for adopting alternative materials to reduce marine plastic litter

The ocean has become a repository for an increasing quantity of plastics and microplastics. This has been matched, in recent years, by growing awareness of the social, economic and environmental impacts that this phenomenon is causing. There is widespread recognition that urgent action is required to reduce the leakage of plastics to the ocean, but that there is no simple solution. It is clear that the traditional linear production, use and disposal model for conventional plastics is not sustainable and results in unacceptable harm. This requires the development and implementation of more closed-loop, or circular, production models. But there is scope for assessing whether there are alternative solutions that minimise the use of conventional plastics for applications in which they are not essential. The purpose of this study was to assess the potential of replacing conventional plastics with alternative materials in certain applications, as part of a wider strategy of reducing marine plastic litter and microplastics. The target audience is governments and businesses. This may appear a daunting task, given the ubiquity of plastics in our daily lives, described in Chapter 2, so it seemed sensible to identify certain categories of plastics that may prove more amenable to reduction or replacement. Following an assessment of the most common items reported in field surveys (Chapter 3) it was decided to focus part of the study on 'single-use' plastic waste from single-use packaging and consumer products intended for short-term use, such as food and drink containers, given the preponderance of these categories in surveys of ocean plastics, especially in shoreline debris. Another common feature of microplastics identifed in surveys of biota, sediments and seawater is the abundance of micro-fbres. Micro-fibres on shorelines, especially near urban centres, consist mostly of textile fibres and this provided a second focus for the study