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Agroecology, Food Security, and Sustainable Plant Production - Coggle…

- - - - Definition
        It's based on three pillars:
        
        No or reduced tillage
        
        Permanent soil cover
        
        Crop diversification
      - Advantages
        
        Improved soil structure
        
        Promotes soil life
        
        Reduced energy use
        
        Erosion protection
        
        Soil protection
        
        Less time investment?
      - Disadvantages
        
        Weed management increases
        
        Pest control increases
        
        Reduced warming of soil in spring
        
        Reduced air permability of soil
        
        More compacted soil?
      - Scientific findings
        
        Particularly promising in dry climates
        
        Practically no difference with conventional farming in regards to yield (winterwheat and barley)
        
        Soil biology is improved under no or reduced tillage
        
        Less erosion risk with increasing soil cover
    - - Definition
        Agriculture that incorperates cultivation of trees to that of arable crops and/or animals.
      - Advantages
        
        Higher carbon storage
        
        Reduced nitrate leeching
        
        Reduced erosion risk
        
        Higher pollination services and biodiversity
      - Disatvantages
        
        Lower biomass production
        
        Lower groundwater recharge
    - - Defenition
        No synthetic compounds are used. It relies on internal cycles, soil fertility, and sustainablity, which it achieves through crop rotation, and mixed farming.
      - Advantages
        
        Promotes biodiversity
        
        Better soil quality
        
        Yields depend on fertilisation level and crop species (maize in CH similar to conventional)
      - Disatvanteges
        
        Yields are lower than in conventional
        
        Yield reliability and stability is worse
    - - Defenition
        It's NOT a practice in itself, rather a combination of sustainable agriculture techniques, and is therefore used as a broader term. It's general aims are:
        
        Keep the soil covered
        
        Minimise soil disturbances
        
        Preserve living roots year round
        
        Limit or eliminate use of synthetic compounds
        
        Increase species diversity
        
        Integrate livestock
        
        Recycling farm waste
  - - - Definition
        Is a land use form where some parts of the land intesively managed, and other parts are set aside for nature protection and biodiversity.
- - - - Crop rotations
      - Agroforestry
      - Crop diversity types
        
        Monocropping
        One single species year after year without rotation.
        
        Intercropping
        Cultivation of two or more species per year on the same field. There is row, strip, mixed, and relay intercropping.
        
        Diverse species mixture
        Practice of mixing several species randomly in one field. Used for cover cropping and forage lay blends.
      - Crop types
        
        Cover crops
        Grown between periods of main crop production to protect the soil and improve its productivity, health, and quality.
        Green manure: Adds fixed nitrogen to the soil and improves fertility.
        Catch crop: Catches soil nutrients and decreases nutrient leeching.
        
        Forage lay
        Planted for feeding grazing animals.
        
        Cash crops
        Grown to provide additional revenue.
  - - - Mechanisms
        Targets bacterial machines or macromolecular synthesis
        
        Disrupt cell wall synthesis
        
        Inhibit Protein synthesis
        
        Inhibit RNA synthesis
        
        Inhibit DNA replication
      - Properties
        
        Bacteriocidal (kills them) vs bacteriostatic (prevents reproduction)
        
        Broad-spectrum vs narrow-spectrum
    - - Mechanisms
        Bacteria have developed several strategies:
        
        Restrict access
        
        Pump out antibiotics
        
        Alteration of target
        
        Destroying the drug
      - Horizontal gene transfer
        Some surviving bacteria can transfer the antibiotic resisting genes through:
        
        Transduction (with bacteriophage, a virus)
        
        Conjugation (direct transfer)
        
        Transformation (after death)
    - - Reasons for use
        
        Treating disease
        
        Preventing disease
        
        Promoting growth
      - Exposure and risk
        Animals are given antibiotics, which kills bacteria, while resistent bacteria survives and reproduces. The resistant bacteria spreads to animal products (or produce through contaminated water or soil). Humans can get sick with resistant infections through exposure to contaminated food or environment.
        
        Threats to the soil ecosystem
        Antibiotics alter soil microbial communities that play a role in the ecosystem multifunctionality.
        
        Solutions
        
        Education
        
        Consumption of less meat
        
        Vaccination of animals
        
        Limitation of intesive practices
  - - - Origin of crops
        Crop plants have been strongly modyfied by human selection. Hunter-gatheres began domesticating food plants independently in over 20 different regions. Often, changes in gene expression were domesticated. So, domestication and breeding rely on selection of desired characteristics, which can lead to a loss of genetic diversity.
      - Introducing genetic variation
        
        Classical breeding
        Crossing a cultivar with the wild plant, or crossing different variants.
        
        Mutation breeding
        Seeds are exposed to radiation, chemicals, or enzymes.
        
        Gene technology
        A multitude of genes is introduced in some way, e.g. particle bombardment or through another organism.
        
        Genome editing
        A single gene is introduced by directly inserting it, e.g. with CRISPR Cas9, and is precise. After editing mostly only the desired change is present.
      - Breeding targets
        
        Disease resistance
        
        Tolerance to abiotic stresses
        
        Higher yields with less input
        
        Consumer traits (quality)
        
        Complex traits (breeding)
      - Genetic uniformity
        Uniformity in terms of flowering time and seed maturity is needed for industrial production. It can be achieved through inbreds, vegetative propagation, and F1 hybrids.
        
        Inbreeding
        Crossing related plants
        
        Vegetative propagation
        Plants reproduction from roots, stems, or leaves.
        
        F1 Hybrids
        First filial offspring of two distinct parent varieties
        
        Generating hybrid seeds
        Requires crossing of parents by:
        
        Hand
        
        Cytoplastic male sterility system (3-line hybrids)
        
        Conditional male sterility system (2-line hybrids)
        
        Apomixis (1-line hybrids)
        
        CMS
        A condition where pollen is made sterile, so that only fertile airborne pollen is used to pollinate
        
        Apomixis
        Is asexual reproduction. Apomitic offspring are genetically identical, and are used to fix complex genotypes. Sexual progeny are used for the creation of new variations.
      - Genetically modyfied crops
        Can contribute to alleviate effects of climate change, reduce the use of nutrients, pesticides and/or chemicals, reduce the use of machines (less energy), and improve the nutritional value of food.
    - - Plant diseases
        Pests and pathogens affects major crops worldwide, and outbreaks are increasing in frequency due to global trade, global warming, and resistances.
      - Genetic engineering
        
        Gene silencing
        Regulation of gene expression in a cell to prevent the expression of a certain gene. This can be done through transgenesis; the induction of a foreign gene into an organism.
        -> Host- or spray-induced gene silencing
        
        Genome editing of susceptibility gene
        Inducing a mutation that is resistant to a pathogen into the plant. The susceptible gene is the one that is edited through:
        
        Naturally occuring
        
        Chemically-induced
        
        RNAi-induced
        
        TALEN-induced
        
        CRISPR-induced
        
        Transfer and pyramiding of resistance genes
        
        PRRs
        Pattern recognition receptors
        Those are proteins that recognise pathogens and damages to the cells, and are crucial for a immunitary response. PRRs could be transfered between plant families to confer new microbial recognition specificity and so increase disease resistance. -> EFR -> Bacterial wilt, Fire blight, (Bacteria)
        
        NLRs
        Nucleotide-binding oligomerisation domain-like receptors
        Are intercellular sensors of pathogen- or damage-associated molecular patterns and are types of PRRs. -> Rpi genes, Pm4 -> Late blight disease, Powdery mildew, (Fungi)
        
        Atypical R genes
        The resistant allele evolved after wheat domestication, while in rice and sorghum the allele is still susceptible. The protein sequence is similar to an ABC-transporter, but the mechanism is unknown -> Lr34 -> Leaf rust, Stripe rust, (Fungi)
        
        Pyramiding
        Creating resistence by stacking resistance genes from the cultivar (e.g. wheat) and its wild relatives.
        
        Microbioms
        Plants live in assosiations with microbes, in all the parts of the plant. This microbes play a crucial role in disease resistance and could be used for this purpose, e.g. through application of such communities.
      - Modern breeding techniques
        Such as mutagenesis, transgenesis, genome assisted breeding, and genome editing, can help, together with biocontrol approaches, solving the crop loss through pathogen problem. In addition it can help reduce input in intensive systems. For durable disease resistance combined mode-of-actions are required.
  - - - GRUD/PRIF
        Grundlagen der Düngung landwirtschaftlicher Kulturen in der Schweiz.
        Principles of agricultural crop fertilisation in Switzerland.
        -> Fertilisation norms, practical recommendations
      - 4R nutrient stewardship principle
        
        Right rate
        Ensure right amount of essential nutrients for optimal yield and quality.
        
        Adjust fertiliser norm based on predictions (prognostic)
        
        Measure soil and plants and adjust rate (diagnostic)
        
        Right source
        Choose plant available nutrient forms that provide a balanced supply of all essential nutrients.
        
        Organic fertiliser (Animal manure and slurry)
        
        Chemical fertiliser (Mineral), target specific and known amounts and properties
        
        Right time
        Application timinig of nutrients by considering interaction of crop uptake, soil supply, effects to environment, and field operation logistics.
        
        Number of applications
        
        Crop rotations and cover crops affect timing
        
        Washing out of nutrients
        
        Hygenic and mechanical reasons make it difficult
        
        Right place
        Placing the nutrients in a way that minimises nutrient losses, and that takes advantage of root-soil dynamics, considering nutrient movement and spatial variability in the field.
        
        Optimal placement is related to roots and uptake over time
        
        Optimal distribution is related to in field differences (sensor based adjustments can be made)
      - Defenition of a good practice
        
        Ensure nutrient supply to plants (needs)
        
        Optimise nutrient ratio (soil supply)
        
        Improve soil properties and mantain soil health through sustainable management
        
        Economic optimum
        
        Effects to environment
        -> Management needs to be site and situation specific
    - - Nutrients
        Essential nutrients:
        Those nutrients (17) are needed to complete the life cycle.
        Beneficial nutrients:
        May improve tolerance to stress factors, and supports symbiosis or mutualism.
      - Law of the minimum
        The nutrient that is most limiting affect the yield most.
        Sprengel & Liebig
      - Law of diminishing yield
        With increasing input of a nutrient, yield stagnates to a maxium.
        Mitscherlich
      - Concentration
        Nutrient concentration in plant affects health and growth. At first there is deficiency (with negative symptoms), then sufficiency, then there is a surplus where it is toxic for the plant
    - - Suisse-Bilanz
        The farms balance themselves, using the Suisse-Bilanz to figure out how much fertiliser they should add. Ii is based on avarage values and oversimplifications. The calculation is basically nutrient availability minus the potential losses. Suisse-Bilanz considers that soil contain less available nutrients then they really do.
        Needs revision.
- - - - Top down
        Collect data on prices and quantities, sum up and subtract cost, and calculate sector income.
      - Bottom up
        Collect data from randomly sampled farms, and calculate average farm income.
        
        Stratification of swiss agriculture
        Stratify in farm type, region, and size. Select farms from strata with high variability. Contact farms via call centre and submit data to swiss FADN (Farm accountancy data network) website.