Low External Input Sustainable Agriculture (LEISA) - PowerPoint PPT Presentation

1 / 34
About This Presentation
Title:

Low External Input Sustainable Agriculture (LEISA)

Description:

Low External Input Sustainable Agriculture (LEISA) approaches to soil fertility management Optimise soil conditions for plant growth Principles timely availability of ... – PowerPoint PPT presentation

Number of Views:4927
Avg rating:3.0/5.0
Slides: 35
Provided by: PaulD107
Category:

less

Transcript and Presenter's Notes

Title: Low External Input Sustainable Agriculture (LEISA)


1
Low External Input Sustainable Agriculture
(LEISA) approaches to soil fertility management
  • Optimise soil conditions for plant growth
  • Principles
  • timely availability of water, air, nutrients
  • good soil structure
  • appropriate soil temperatures
  • minimise toxicity and / or practices which lead
    to toxicity

2
Optimising nutrient availability cycling
Principles
3
  • Limit nutrient losses by
  • recycling of organic waste
  • reduce leaching (e.g. by using bedding straw
  • for cattle to conserve urine)
  • reduce runoff soil erosion
  • reduce burning of stubble
  • use slow-releasing fertilisers such as rock
  • phosphate
  • nutrient pumping by deep rooted spp.
  • limit nutrient export by producing crops with
  • relatively high economic value compared to
  • nutrient content (fruits, nuts, herbs)

4
  • Capture / manage nutrients by
  • utilising legumes / N-fixing bacteria or
    blue-green algae
  • encourage capture of (water and air-borne)
    sediments
  • from outside flowing over farm
  • make maximum use of livestock manure
  • use green manures

5
  • Supplement nutrients by
  • use of OM from off farm (e.g. agro-industrial
    waste)
  • purchased fodder and/or concentrates

Use complementary systems e.g. .........
6
(No Transcript)
7
(No Transcript)
8
  • Manure handling improvement
  • Improve quantity / quality by
  • adjusting animal numbers / species
  • improved feeds (more concentrates, more
    legumes,
  • urea treatment of residues)
  • minimise distances between collection
    application
  • points (but N.B. effect of collection on
    non-arable land
  • fertility)
  • use chicken manure (sheds)
  • bat droppings ?

9
  • Composting
  • improves quality of organic fertiliser
  • heaps or pits (latter better in hot climates
  • - less oxidation)
  • in situ applications

10
(No Transcript)
11
(No Transcript)
12
  • constraints
  • availability of materials
  • transport
  • labour
  • water
  • cultural taboos
  • oxidation (mainly where there is a hot dry
    season
  • reduced by decreasing tillage intensity)

13
  • Green manures
  • improve OM and N
  • other elements translocated to top-soil
  • cover crops such as yam bean (Pachyrrhizus
    erosus)
  • Mucuna utilis suppress weeds such as Imperata
    spp.
  • which may proliferate as a result of
    shortening or
  • eliminating fallows

14
  • Forms include
  • improved fallow (whole year or dry season
  • pre-planting crop (in rice in India)
  • alley cropping (prunings used as a mulch or
    incorporated)
  • single trees in field
  • (legumes such as Erythina poeppigiana cut for
    mulch)
  • relay fallows (plant dry season green manure
    fallow
  • before harvesting main crop, e.g. Tephrosia
    vogelii,
  • Sesbania rostrata, Mucuna pruriens
  • live mulches - food crops sown into cover crops
    such
  • as Centrosema pubescns, Pueraria
    phaseoloides,
  • Arachis prostrata after strips removed by
    herbicides or
  • hand to reduce tillage operations
  • azolla and blue-green algae

15
Some green manure exotic species for improving
soil fertility include see table in handout
16
Criteria for selection of plants for improved
fallow
17
(No Transcript)
18
  • Problems include
  • shortage of land
  • seasonal migration (India)

Can you think of others ...
19
  • Use of mineral fertilisers
  • apply in low to moderate amounts in combination
    with
  • organic fertilisers
  • increase efficiency by control of weeds, crop
    pests,
  • diseases, soil erosion, leaching, rotations
    (shallow then
  • deep rooted crops), attention to timing (e.g.
    split
  • applications for N), applying fertiliser below
    surface
  • near roots
  • use mild fertilisers for preference (e.g.
    "Thomas slag",
  • thermo-phosphate, bone-meal)
  • CAN better than urea better than AS
  • mineralisation of rock phosphate accelerated by
  • acidification (e.g. by adding to compost)

20
  • Vermiculture
  • manure earthworms ? less manure (30
    reduction)
  • vermicompost more earthworms
  • surface application
  • mass of earthworms produced 5 of manure
    weight
  • reduces environmental contaminants in solution
  • pH becomes more neutral

21
  • Examples of indigenous sources of nutrients
  • termite mounds for sorghum / cowpea in Sudan
    Congo
  • ant refuse for fertilising crops in Mexico
  • Faidherbia albida / sorghum millet systems in
    Senegal
  • mulch / shade / recycled nutrients
  • use of weeds as green manure and mulch in
    Tanzania

22
  • Managing flows of solar radiation, water, air
  • Principles
  • Improve micro-climates by
  • crops of different heights
  • shade, wind protection
  • Improve soil moisture by
  • improving soil structure OM
  • tillage
  • mulches
  • Reduce erosion by
  • vegetative measures
  • physical measures

23
Mulches Zero tillage Wind breaks Water
harvesting Tied ridging Strip
cropping Permeable contour-line barriers Small
ponds
24
Integrated farm systems Bio-intensive gardening
(example) - double dug beds
25
(No Transcript)
26
  • double dig raised beds 30 to 60 cm
  • keep covered with crops or mulch
  • liquid manure (40 kg of weeds dung in 200
  • litre drum left for 3 weeks mix liquid 13
    with water,
  • apply every 10 days)
  • many spp. of veg. fruits

27
(No Transcript)
28
(No Transcript)
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32
Crop - livestock - fish-farming
33
(No Transcript)
34
  • Farmer involvement
  • indigenous knowledge investigations / databases
  • / self-awareness
  • encouraging farmer to farmer spread / training
  • farmer experimentation
  • participatory technology development (PTD)
  • exposure visits
Write a Comment
User Comments (0)
About PowerShow.com