An exploration of the various methods for improving rangelands and principles of sound grazing management options in Zimbabwe

1. RANGELAND MANAGEMENT AND
IMPROVEMENT TECHNIQUES IN
ZIMBABWE
(NZIRA DZEKUVANDUDZA
NEKUCHENGETEDZA MAFURO
MUZIMBABWE)
Eddington Gororo
20 March 2013
Grasslands Research Institute, Marondera

2. Outline (Zvatichakurukura)
2
1. Introduction (Nhanganyaya)
 The need for rangeland improvement
 Zvikonzero zvekuvandudza mafuro
2. Range improvement (kuvandudza mafuro)
 Rangeland improvement methods
 Nzira dzekuvandudza mafuro
3. Rangeland management (Kushandisa
mafuro)
 Rangeland management techniques
 Kushandisa mafuro kwakanaka
4. Conclusion (Saka tiri kutii?)

3. Need for rangeland improvement
Sei tichifanira kufunga nezvemafuro edu?
3
 Deterioration evidenced by:
1. Changes in grass species composition –
invader/increaser species (Sporobolus, Aristida)
2. Proliferation of undesirable/invasive plants
e.g., forbs
3. Bush encroachment and tree recruitment – we
have to arrest plant succession at the grass
stage
4. Soil erosion
5. Accumulation of top hamper and moribund
material
 Ultimately low animal productivity (growth

4. Changes in species composition
Huswa huri kushanduka mumafuro
4

5. Undesirable & invasive plants
Miti nehuswa hwusingadyiwe nemombe
5

6. Bush encroachment and tree recruitment
Miti iri kuwanda kupfuura huswa
6

7. Accumulation of top hamper
Huswa hauchanyotsomera marara awanda
7

8. Grass tufts die out (become moribund)
Zvidzitsi zveuswa zviri kufa
8

9. Rangeland Improvement
9
Kuvandudza mafuro
 Kuvandudza kuita sei?
= improving range (natural veld) condition and
productivity or facilitate more efficient utilization of
the range.
 Tinovandidzirei mafuro? (Reasons)
 increased forage yields and quality
goho remafuro rinokwirira
 higher stocking rates
tinochengeta mombe dzakawanda pahekita
 Increased animal productivity and daily
performance (better milk yields, higher conception
rates, faster growth rates)

10. Reasons for rangeland
Improvement
10
Tinovandidzirei mafuro?
 Sustainable future
Mafuro anoramba achiita zvakanaka
mune ramangwana
 Soil erosion control (ivhu harichaende
nemvura kana mhepo)
 Reduction of undesirable plants (miti
isinei neufuro haizokuri)
 Reduction of fire hazards (moto yesango
inoita mishoma)

11. Nzira Dzekuvandudza Mafuro
11
1. Rangeland fertilization (kuisa fetiraiza
mumafuro)
2. Control of undesirable plants (kubvisa miti
nehufuro husingadiwe)
3. Range rehabilitation (kugadzirisa
zvakakanganisika)
4. Reinforcement (kuwedzera humwe huswa)
5. Replacement with sown pastures (kuisa
mafuro matsva)
6. Improved grazing management

12. Kuisa fetiraiza mumafuro
12
 Types: Ammonium Nitrate (AN), single supers
 How– every 4 years (kamwe chete mumakore
mana)
 Benefits/Zvakanakira kuisa fetiraiza
 increased forage yields and quality (goho
rinokwirira)
 higher stocking rates (tinochengeta mombe
dzakawanda)
 Increased animal productivity
 Reduction of undesirable plants

13. Kuisa fetiraiza mumafuro
13
 Disadvantages/Matambudziko
 Poor response to fertiliser application (mutsauko
wacho mudiki mumafuro atagara tiinawo)
 Rangelands areas have limited land use
capability - water-logged vlei soils; shallow
soils, steep slopes, rockiness, etc. (nzvimbo
dzine mafuro hadzirimike uye dzinonetsa kuisa
fetiraiza)
 High cost (fetiraiza inodhura)
 Shortages (fatiraiza yacho haiwanikwi)
 Generally not economic on native pasture in
Zimbabwe
 Not recommended (nzira iyi hatiikurudzire)

14. Control of undesirable plants
Kubvisa miti nehufuro
14
husingadiwe
 These are plants that are:
 Notreadily eaten by animals
 Less productive or reduce veld productivity
 Reduce amount of utilisable herbage
 Conflict with veld management
 Undesirable plants:
 Invaderand invasive species
 Poisonous species
 E.g.,
Lantana camara, Dichapetalum
cymosum, Urginea sanguinea, Solanum incanum
(nhundurwa), etc.
 Bushes and trees

15. Control of undesirable plants
Kubvisa miti nehufuro
15
husingadiwe

16. Control of undesirable plants
Kubvisa miti nehufuro
16
husingadiwe
 Bushes and trees
 Removal by stumping, ring barking, or by
mechanical means like bulldozers, brush-cutters
and motorized saws.
 chemicals (arboricides eg picloran, bromacil etc)
 use of prescribed hot fires
 Bushes and other undesirable plants
 practicinggood veld management
 Prescribed hot burns (fire).

17. Range rehabilitation
17
(kugadzirisa zvakakanganisika)
 Degraded and eroded areas
 Methods of rehabilitation
 Thatching and brush laying
 Pitting
 Stone lines
 Planting grass lines- e.g., vetiver grass (Vetiveria
zizanoides), elephant grass (Pennisetum
purpurem) and paspalum (Paspalum notatum).
 Often a combination of techniques is needed for
most effective and rapid rehabilitation.
 Rehabilitation is an attractive option on a small-
scale but almost not feasible on a large scale.

18. Rangeland Reinforcement
(kuwedzera humwe huswa mumafuro aripo)
18
 Veld reinforcement entails the sowing of
improved grass and legume species into
native pasture
 This is the most feasible means by which
rangeland productivity can be raised above
natural levels in this country.
 Most effective when legume content is >30%
in veld
 Legumes planted into the top-land veld and
grasses into vleis.

19. Reinforcement with legumes
19
 Fix nitrogen (80-100kg N/ha)
 Come away earlier in the season
 Legumes have higher feeding value in late
summer and winter (extend grazing season)
 Results in Zimbabwe:
 Grazing capacity increased by up to 20%
 Production increased by over 50%
 At Grasslands, steers on improved veld gained
40kg/year more than those on unimproved
veld

20. Natural veld with silverleaf
20

21. Reinforcement with improved grasses
21
 In vleis/wetter areas we find that often
improved grasses are more suitable than
legumes.
 The following improved grass species are
suitable for veld reinforcement in vleis in
Zimbabwe:
 Acroceras macrum (Nile grass)
 Brachiaria arrecta (tanner grass)
 Paspalum urvillei (vasey grass)
 Panicum repens (torpedo grass)
 Paspalum dilatatum (dallis grass)

22. Rangeland reinforcement
22
 High rainfall areas – Desmodium spp (heavier
soils) Stylosanthes spp (lighter soils)
 Low rainfall areas – siratro, cassia and Archer
 The benefits of rangeland improvement
include:
 greaterrange productivity
 increased forage quantity and quality
 improved animal performance and
 reduced winter protein supplementation.
 Reduced fattening costs due to higher induction
masses
 This strategy for veld improvement is highly

23. Replacement with sown pastures
(kuisa mafuro matsva)
23
 Native grassland is ploughed out and
completely replaced with highly productive
pasture grasses
 Dryland temporary pastures – short term
leys, they form part of the cropping system.
 rotation with tobacco for rootknot nematode
tolerance - Katambora Rhodes grass (Chloris
gayana)
 Also: forage sorghum, millets, velvet
bean, lablab, etc.
 Need little fertilisation as they rely on residual

24. Replacement with sown pastures
(kuisa mafuro matsva)
24
 Permanent dryland pastures – star
grass, kikuyu, napier grass, etc.
 species should respond well to nitrogen
fertilisation and withstand severe
defoliation/grazing pressure.
 Irrigated pastures
 veryexpensive form of production
 mostly used for finishing cattle and for dairying.
 Ryegrass, Lucerne (alfalfa) and clovers are the
most suitable species for irrigated pastures.

25. KUCHENGETEDZA MAFURO
(Sound range and grazing management
25
principles)
 Principles to be discussed
1. Stocking rates
2. Period of stay
3. Resting
4. Top hamper removal
5. Grazing systems
6. Use of fire (Prescribed burning)

26. Stocking rates
26
 Stocking rate is the number of hectares allocated
by the farmer for each livestock unit (i.e., a beast
weighing 500kg)
 It is the most important factor affecting productivity
and stability of the veld.
 Correct stocking rates are important for the
perpetuation of the range (condition and
productivity), well-being of the livestock and the
economic stability of livestock operation.
 Overstocking results in overgrazing.
 Under grazing leads to a build-up of top
hamper, reduction of forage value and productivity
and animal production.

27. Recommended stocking rates
27
Natura Rainfall Stockin
l (mm) g Rate
Region (ha/LU)
NR I >1,000 3.5
NR II >800 3.5
NR III 500-950 5.5
NR IV 400 8.0
NR V <400 12

28. Potential grazing capacity of grassveld types described by
Rattray (1957) when in good condition (Gammon 1983)
28
Veld Description Grazing capacity
type (ha/LU)
1 Montane grassveld 2-3
2a Hyperrhenia grassveld 2.5-3.5
2b Hyperrhrnia-other species 4-5
veld
3 Heteropogon-other species 5-6
veld
4 Eragrostis-other species 7.5-10
veld
5 Aristida-other species veld 10-16
6 Cenchrus-other species veld 7.5-10

29. Grazing period
29
 Depends on:
 veld condition
 season
 stocking density
 veld type
 Frequent close grazing will reduce grass vigour
 Too long a grazing period will lead to more
frequent defoliation of the more desirable species
 Too short a grazing period will lead to too light
defoliation of certain species and accumulation of
top hamper

30. Grazing period
30
 The rule of thumb in high rainfall areas
(>700mm) in mid-summer is that the maximum
grazing period in days should be no longer
than 60 divided by the number of paddocks
per herd.
 In early summer grazing period should be half
that of mid-summer and in winter can be
longer because the grass is dormant

31. Rest period
31
 A period of no graze after defoliation or
grazing
 The objectives of rest are many and
varied as is their timing and duration
 Rests Based on the requirements of the
animals
• For herbage accumulation (optimum
intake)
• To provide for herbage accumulation
for conservation (hay, foggage, silage)

32. Rest period
32
 Rests based on the requirements of the
plants
• improve forage quality, species
composition, plant density and vigour
• seed production
• seedling establishment
• vegetative growth of the plant
• promote rapid growth phase of the plant
 Rests for management purposes
• To accumulate sufficient fuel for a prescribed
late winter burn

33. Recommendations for grazing cycles in mid-
summer
33
Veld type Grazing Rest period
period
Sweet veld 3 weeks 35-45 days
Sour veld 6 weeks >60 days

34. Removal of top hamper
34
 The accumulation of old grass in a tuft reduces
the vigour of the sward by shading out basal
buds and hinders grazing
 Control of top hamper accumulation
 Correct stocking rates, grazing and rest periods
 fencing off areas of similar vegetation type for a
more uniform utilisation of the veld
 Trampling by cattle
 Cool fire just before the flush of grass in spring

35. Grazing systems
35
Set Stocking Deferred grazing
 All livestock are managed  Also called rotational
as a single herd and kept resting
in a single paddock  e.g., split season system
(whole farm) for the entire
 grazing is subdivided into
grazing period
one enclosure more than
 SR should be 20% less the number of herds. The
than normal grazing extra paddock is afforded
capacity a full rest for a season or
 Only SR is variable full year
Continuous Grazing
(set stocking) Grazed Grazed Rested

36. Grazing systems
36
Rotational resting and
grazing
Rotational  It incorporates both
grazing rotational grazing and
rotational resting (deferred
grazing) simultaneously

37. Prescribed burning
37

38. Prescribed burning
38
 Fire is both inevitable and necessary for
maintaining the structure and functioning of
mesic savanna rangelands.
 Used for:
 removal of surplus vegetation (moribund material
or top hamper)
 prevention of accidental fires
 suppression of tree recruitment and thus control
bush encroachment

39. Prescribed burning
39
Effects of a fire depend on:
 fire intensity
 Hot – control tree recruitment
 Cool – top hamper removal
 frequency of burning
 4 years or longer
 Season
 Early summer burns – top hamper removal
 Late dry season burns - to control encroaching plants
 type of fire
 ground fires, surface fires and crown fires
 Head fire, backfire

40. Communal area grazing
40
 Tragedy of the commons
 Controlled grazing schemes
 Improving crop residue quality, collection and
utilisation
 Incorporation of fodder and forage production
in cropping systems
 leypastures on fallow land, contours and
waterways
 fodder banks of multi-purpose legume trees
 Forage conservation (hay, silage)

41. NDATENDA
41