Dissertation abstracts to evaluate effectiveness of AF systems in vo nhai district, thai nguyen province

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INTRODUCTION

1. Rationale
Nowadays Viet Nam and other developing countries are facing to fierce
conflicts of which to satify the need of food for moutainous people and
environment conservation for sustainable development. Agro-forestry (AF) is
the best way to solve the conflict, contribute to food security and sustainable
natural resource management.
Vo Nhai is a district in moutainous region of Thai Nguyen, it has diverse
topography that is advantageous for AF . However the current situation of AF in
the district is still sparse, which leads to low economic and environmental effect

In order to support local farmers to define solutions for the development of
AF towards sustainable resources management, we carried out the project:
“To evaluate effectiveness of AF systems in Vo Nhai district, Thai Nguyen
province”
2. Puposes, objectives
* Purposes
To evaluate effect of typical AF systems in order to develop sustainable
cultivated systems for improving living standard of local farmers in the district
and in the mountainous and highland.
* Objectives
- Evaluating current situation of AF and define effects of representative
systems in Vo Nhai, Thai Nguyen.
- Proposing solutions to enhance effects of local AF systems in order to
contribute to sustainable land use.
3. Object of study

- AF systems which are being managed by local farmers in the district.
4. Signification and new points of the thesis
*Scientific significations
- Results of the project supplemented foundation for economic development
planning of the Vo Nhai distict and Northern highland of Viet Nam as well.


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- To enrich the knowledge on land use systems of AF for sustainable
highland rural and agricultural development.
* Practical significations
The solutions which the project proposed will be applied into pratice for
AF development in the manner of high economic efficiency, sustainable land use
and enhancing living standard of the farmers in Vo Nhai and highland as well.
* New points of the thesis
- The project is a complete and systematical research on AF in a district.
- Quantitative analysis of economic, social and environmental effect of 6
AF systems in 3 ecological regions of Vo Nhai, which were not mentioned in
previous researchs.
- Proposing AF systems which are appropriate with conditions of the
research area.
5. The layouts of the thesis
Besides the introduction and conclusion, the thesis consists of 3 chapters, total
110 pages, 32 tables, 8 pictures and 132 domestic and foreign reference
materials.
Chapter 1: Oveview of research issues.
1.1. Studies of AF in the World
1.1.1. History of studies of AF in the world
In history of AF development, King (1987) claimed that in medieval time in

Europe, people cleared forests, burned tree branches and cultivated crops to make
use of nutrition of forest soil. Although this sort of cultivation was not
widespread and long-lasting, in Finland and Germany, this type of farming
existed until the 1920s. After shifting cultivation methods, the advent of Taungya
method in the tropical regions was regarded as a forecast for the development of
AF. According to Blandford (1858), the origin of this method is from the dialect
of Myanmar: Taung means cultivation, ya is the same as hills. Taungya is the
cultivation method on hilly land. After that, Taungya system was put into use
very early in India and spread across Asia, Africa and Latin America.
Aggro-forestry is a scientific field which was recommended in the 1960s
by King (1969). For many years, a lot of different definitions have been
developed. The below definition of AF which have been growing until now.
Nowadays AF is defined as a system of resources management based on
ecological characteristics. It is effective due to the coordination of perennial


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plants into farms to diversify and strengthen the production, increasing social
utilities, economic profits and environmental efficiency in various levels of farms
(ICRAF, 1997).
Therfore, Agroforesty is the method of cultivation on sloping lands to take
advantage of soil, limit the deterioration of natural resources and environment,
contributing to the sustainable use of land.
1.1.2. Classification of AF systems in the World
The criteria for classifying AF systems are based on: Structure, Function,
Economic - Social correlation, Management, and Ecologial impact of the system.
AF researchers all over the world have divided AF systems into some main
types:
The agro-sylviculture: including trees, shrubs and herb (Agricultural crops,

industrial crops and timber).
The forest-livestock: Trees, pasture and grazing.
The agro-sylviculture-livestock: Crops,trees combined with cattles.
The special Agro-forestry: Apiculture with trees, fruit trees, aquaculture in
mangrove areas…
From these main AF systems, different types of Agroforesty are formed (
Nair,1985; MacDicken and Cs, 1990).
1.2. Study on AF in Viet Nam
1.2.1. History of AF study in Viet Nam
The study of AF in Viet Nam has just begun since the 1960s. According to
Nguyen Trong Ha (1966), the first reseaches on AF belonged to Nguyen Ngoc Binh,
Nguyen Qui Khai, Cao Van Minh, Nguyen Xuan Quat, Bui Nganh in 1964 worked on
anti-erosion experiments in Cau Hai- Phu Tho. Ton Gia Huyen, Bui Quang Toan
(1965) carried out experiments and constructed anti-erosion model in the hamlet of
the Northern State-owned farm which brought back positive results.
Thai Phien, Nguyen Tu Siem (1986) summarized the research results in 5
years (1980 - 1985) of the state program on “Application of scientific and
technical progress in the work of reclamation and anti-erosion for new
reclamation land” has generalized measures of protection and improvement of
feralit soil, reclamation and restoration of sloping areas of the country. Many
models of soil protection with the plant structure was implemented and applied.


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The authors Tran Ngoc Ngoan, Nguyen Huu Hong, Dang Van Minh (1999)
concluded that AF is a term used to refer to the land use systems, in which the plant
(crops, trees ) and animal, are combined with forest trees in spatial or rotation with
the interaction of both ecology and economics.
1.2.2. Classification of AF systems in Vietnam

In Vietnam, on the basis of results of researchs on AF authors Hoang Hoe,
Nguyen Dinh Huong, Nguyen Ngoc Binh classified AF systems into eight main
types so called "farming systems", the subunits of farming systems are called the
"method" or "model" farm.

According to the classification above, the AF systems in Viet Nam is divided
into eight farming systems: Agro-sylvicuture, agro-sylvicuture–livestock, forestry-
livestock, multi-pupose timber, forestry-fishery, agro-sylvicuture-fisheries,
apiculture-timber, agro-sylvicuture-fishery-animals. (Pham Duc Tuan et al, 1992).
The farming systems is divided into 27 different types of cultivation depending on
ecological zones. The last one is household AF "model"

Chapter 2: Research tasks and methodoloy


2.1. Research tasks
1. Descriptions of the natural and socio-economic characteristics in study area.
2. AF development status in the study area.
3. Assessing effectiveness: economic, environmental, social of the typical AF
systems.
4. Improvement measures, testing and proposed solutions to develop the AF in
the research area and the similar areas.

2.2. Research methods
Applied research methods by majors:
(1) Inherited selectively (documents in conjunction with consultation)
(2) RRA (Rapid rural appraisal) and PRA (Participatory rural appraisal)-
(3) Field Investigation and field survey
(4) Experimental layout

(5) Data processing with the support of the specified software.


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Chapter 3: Results and discussion
3.1. Natural and socio- economic features in Vo Nhai district 3.1.1. Natural
features
Vo Nhai is a district located in the mountains northeast of Thai Nguyen, 37
km far from Thai Nguyen city on the road Thai Nguyen - Lang Son.
Geographical location and topography: the East boder is Bac Son district
(Lang Son); West boder is Dong Hy and Phu Luong districts (Thai Nguyen), the
South bordering on Dong Hy and Yen The district ( Bac Giang), The northern
border is Na Ri district ( Bac Kan). Vo Nhai martial elevation a.s.l from 100 -
800m, generally topography of the district is sloping and is divided by two
mountain ranges: The Ngan Son and Bac Son, which cause great difficulties for
the construction of infrastructure, especially for development of agriculture and
forestry.
Climate: The district has full nature of tropical monsoon climate of northern
Vietnam, with 2 distinct seasons: dry and rainy.
The structure of land use
Table 3.1. The structure of land use of districts in 2007
Land use types Area (ha) Rate (%) No
Natural land area 84.510,41 100,00
I Land for

Agriculture
61.719,41

73,12

1.1 Crop land 6.325,0

7,48

+ Annual crops 5.364,0


- Rice paddy- field 3.152,0


- Upland
and
industrial crops
2.072


- Vegetables 140,0


+ perennial crops 812,0


- Tea 255,0


- Fruit trees 557,0


+ Lakes and ponds 149

1.2 Forest land 55.469,41

65,64

II None-Agricultural
land
932,0

1,10

2.1 Specialized land 492,0

0,58

2.2 Residential land 440,0

0,52

III Unused land 21.784,0

25,78


Thus the district’s land potentials are huge. Natural land area is 84,510.41
hectares. In the group of agricultural land, there is 55,469.41 ha of forest land


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accounting for 65.64%, crop land is only 6.325,0 ha at the rate of 7.48%. Land in the
district are mostly sloping, with the degree from 15 to 45
0
. Types of soil: Yellow-
brown feralit soil developed on mother gravel rocks and limestone; sloping
converging soil; sediment deposition soil Those also shows that economic
development on hills by AF cultivation is the direction towards promoting potentials
of the district.
Production situation of agriculture - forestry
According to statistics of the District Agriculture Office (2006), among
10.406,5 ha of agricultural crop land, the area of food crops account for a large
percentage of 73,4% (7.633,5 ha). Mayor crop area is rice paddy 4.442,0 ha. The
corn area is second after rice and then cassava. Area of industrial crops (tea,
tobacco, sugarcane, peanuts, soybeans, green beans…) is small (up 20.3%). Fruit
trees for only 5,30% of the area.
* Irrigation: With the financial support of the state Vo Nhai has built 11
reservoirs, 50 solid dams, 12 pumping stations, 132km of canals, but these still
not provide adequate irrigating water in dry seasons. .
* Electricity: Vo Nhai now has 35KV and 10KV electrically wired systems
running along Highway 1B and from Dinh Ca town to Trang Xa commune.
Demographic characteristics, ethnic, labor
District population is 62,612 people with 13,676 households in which main
labors are 35,596 people (accounting for 56.85% of the district population). The
population density is 74 people/km2, composed of nine ethnic groups. Where:
Kinh is of the highest proportion (37%), Tay (22%), Nung (20%), Dao (13%).
The rest are other ethnic groups (Dept of Agri& Rural Devp of Vo Nhai, 2006).
Based on topographical and ecological conditions, Vo Nhai is divided into
three regions with the following characteristics:
Region 1 (KVI): including the communes located along the national

highway No. 1B. The region has relatively flat terrain, mainly low hills, and
convenient traffic conditions. Residents are mainly the Tay, Nung and Kinh
group, whose main income is from the rice production. Local people’s cultivating
experience is outstandingly higher than other regions of the district. In this region
we selected two representatives communes: La Hien and Lau Thuong.
Region 2 (KV2): Including the northern communes of the district. The
topography of this area is mainly limestone alternating with valleys and low
mountains. Residents are mostly the Tay and Dao, Hmong living on agriculture,


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the region’s transportation is very poor. In this region, we investigated two
communes: Cuc Duong and Vu Chan
Region 3 (KV 3): The southern communes of the district, the topography of
this region are mainly hilly steep slopes. The residents in this region is mainly
Kinh, Tay, Nung, in addition to some other ethnic groups such as Dao, Cao Lan.
In this area we investigated four communes: Lien Minh, Trang Xa, Dan Tien and
Binh Long
In brief: In terms of the characteristics of the natural conditions of the district
as above, generally speaking, it is relatively favorable conditions for the
development of agricultural and forestry production in general and AF in
particular.
3.2 Current situation of AF in the study area
Classification of AF systems based on structure.
Table 3.2. Classification of the surveyed AF systems
Unit:Model, rate ratio%

Reg. 1 Reg. 2 Reg. 3
Sum of 3

Reg(s)
N
o

SYS
LH LT

CĐ

VC

LM TX DT BL

Total

%
1 RVACRg 5

4

5

6

7

4

5

5

41

12,43

2 RVAC 5

7

10

11

5

7

6

6

57

17,70

3 VAC 9

10

6

7

10

8

8

11

69

21,43

4 RChe Rg 11

10

4

2

8

9

6

7

57

17,70

5 RRg 3

4

9

8

5

7

6

5

47

1,60

6 RVCRg 4

5

9

7

6

7

7

6

51

15,84


Total

37

40

43

41

41

42

38

40

322

100,00

Note: Communes symbolized by region:
LH: La Hiên ; LT: Lâu Thượng; CĐ: Cúc Đường; VC: Vũ Chấn; LM: Liên
Minh; TX: Tràng Xá; DT: Dân Tiến; BL: Bình Long
Systems symbolized:
VACRg (garden, pond,, stables, rice field); RVAC (forest, garden, pond,
stables); VAC (garden, pond, stables), RChèRg (forest, tea, rice field); RRg
(forest, rice field); RVCRg (fores, garden, stables, rice field)
In the table 3.2, it can be seen that there are different AF systems in Vo
Nhai district, however, only 6 systems are being commonly applied: VACRg,
RVAC, VAC, RChèRg, RVCRg. Most of these consist of forest.


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Below are some typical system models in Vo Nhai district.
Figure: 3.1

Figure:3.2 Figure: 3.3









Figure: 3.4 Figure: 3.5

Note: Figure 3.1: Sys Forest- Garden- Barn- Rice field; Figure 3.2: Sys Shade
trees for tea; Figure 3.3: Sys Forest- Tea- Orchard coordinated in the model of
SALT; Figure 3.4: Sys coordinated in the manner of Taungya; Figure 3.5: Sys
Forest- Tea- Field.
3.3. Efficiency of AF systems.
3.3.1. Economical efficiency
Economic efficiency of surveyed systems by income per ha in a year.
To compare economic efficiency between systems, we based on the criteria
of income (million VND- mVND) per ha in a year (/ha/year). The results show
that: Of 322 surveyed AF models in entire Vo Nhai district, the majority at 166
ones (51,56%) has income on the range of more than 4 to 8 mVND 84 models


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occupying 21.57% output the income/ha/year fewer than 2 to 4 mVND. The
number of models whose income/ha/year ranges from 8 to more than 10 mVND is
72 ( 22.36%). Thus at the time of investigation, the economic efficiency of AF
systems in Vo Nhai district is not still commsurate with potential.
Economic effectiveness (E.e) of systems calculated on production formulas.
* The E.e of the system RVACRg by formulas.
Some common cultivation formulas:
The formula 1: (Natural forest, litchee, longan, fish, pig, rice); The formula
2: (Eucalyptus, fruit trees, fish, cow, rice, tobacco); The formula 3:
(Manglietia glauca, custard apple, fish, cow, rice, tobacco); The formula 4:
(Acacia, pine apple, fish, chicken, rice, food crpops).
The calculated results indicates that: The highest income/ha/year of 8,862
mVND is seen in the 3
rd
formula. In contrast, the 1

st
one makes up the lowest at
7,069 mVND.
* The E.e of the system RVAC by formulas.
Some common cultivation formulas:
The formula 1: (Eucalyptus, pine-apple, food crops,fish, cow); The formula
2: (Natural forest, fruit trees, food crops, fish, duck or chicken); The formula
3: (Acacia, litchee, longan, fish, pig); The formula 4: (Manglietia, custard-
apple, fish, goat, food crops).
After calculating E.e, we can summarize the total income in the system RVAC
as follows: The 4
th
formula had the greatest income at 13,39 mVND/ha/year.
Meanwhile, the lowest income at 8,682 mVND/ha/year is seen in the 3
rd

formuala
* The E.e of the system VAC by formulas.
Some typical cultivation formulas:
The formula 1: (Fruit trees, food crops, fish, duck, chicken); The formula
2: (Litchee, longan, fish, pig); The formula 3: (Custard-apple, food crops,
grass, fish, goat); The formula 4: (Pine-apple, food crops, grass, fish, cow).
According to the calculations of E.e from the formulas of the system VAC,
the total income is as follows: The highest total income at 14,910 mVND/ha/year
is seen in the 3rd formula. Whereas the 2nd formula outputs the lowest income at
10,710 mVND/ha/year. In this formula, because of the devaluation of litchees
and longans, pigs yield less E.e.
* The formularily E.e of the system RChèRg.

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Some cultivation formulas of the system RChèRg
The formula 1: (Natural forest, tea, rice, corn); The formula 2: (Accacia,
tea, rice); The formula 3: ( Bamboo, tea, rice); The formula 4: (Manglietia,
tea, rice, tobacco)
The calculating results of E.e of the system RChèRg formulas shows the total
income in all of the above formulas as follows: The highest total income at
15,390 mVND/ha/year is seen in the 4
th
formula. Meanwhile, the 1
st
one releases
the lowest income at 12,107 mVND/ha/year. This is the system of the highest
income formularily compared to other systems in the entire area. Because the
main income is from tea, but this system is more costly and labour-consuming
than others for tea management so that they is taken over only by households
with adequate capital and labour.
*The formularily E.e of the system RRg.
Some common cultivation formulas:
The formula 1: (Manglietia, rice, corn); The formula 2: (Natural forest,
rice, tobacco); The formula 3: (Accacia, rice); The formula 4: (Eucalyptus,
bamboo, rice, tobacco).
The calculating results of E.e of the system RRg shows the total income in
all of the above formulas as follows: The highest total income at 6,525
mVND/ha/year is seen in the 4
th
formula. Meanwhile, the 3
rd
one releases the

lowest income at 3,434 mVND/ha/year. This is the system of the lowest income
compared to other systems in the region. Because the income from forest trees,
rice and corn is always low.
* The formularily E.e of the system RVCRg.
Some common cultivation formulas:
The formula 1: (Natural forest, litchi, longan, pig, rice ); The formula 2:
(Accacia, fruit trees, duck, rice, corn); The formula 3: (Natural forest,
manglietia, custard apple, goat, rice); The formula 4: (Bamboo, pine apple,
chicken, rice, corn ).
After doing some calculations on E.e of production formulas, we realize that:
The highest total income at 9,780 mVND/ha/year is seen in the 3
rd
formula.
Following is the 4
th
one with relatively high total income at 8,726
mVND/ha/year. Meanwhile, the 1
st
one releases the lowest income at 6,874
mVND/ha/year. This system generates comparatively high income when


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compared to others in the district because of multicomponent income, including
animal husbandry. However, the initial investment capital is rather considerable.
Summary on the average E.e of production formulas by each AF system
In order for the average E.e of those systems to be asily recognized, we form
this following table 3.3:
Table 3.3: Summary on the average E.e of production formulas by each

system (per ha in a year)

Criteria Syst
RVAC
Rg
RVAC

VAC
RChè
Rg
RRg
RVC
Rg
1. Production value (Pv)

Unit
Pv/ ha 1000đ 10.659 13.968 16.259 18.393 6.399 11.26
Pv / Pc time 3,40 3,69 4,22 3,42 3,26 3,23
Pv /day of labor 1000đ 33,74 37,94 43,37 38,88 28,07 38,01
2.Production cost (Pc)
Total Pc/ha 1000đ 3.122 3.781 3.884 5.385 1.962 3.477
Variable cost/ha 1000đ 2.525 2.920 3.185 4.502 1.495 2.906
Fixed cost/ ha 1000đ 597 860 699 884 467 776
3.Gross income
Total income / ha 1000đ 7.884 11.297 13.074 13.892 4.882 8.560
Total income/ Pc time 2,48 2,99 3,39 2,58 2,47 2,45
Total income/ day of labor 1000đ 25,80 29,94 38,00 29,37 21,47 31,12
4. Pure income (Pi)
Pi /ha 1000đ 7.530 10.855 12.375 13.008 4.437 7.784
Pi / Pc time 2,36 2,69 3,14 2,42 2.23 2,38

Pi / day of labor 1000đ 23,79 27,63 36,16 27,48 19,38 25,90
5.Labors in total day 314 368 338 472 222 299
The summarized results in the table 3.3 reveals the remarkable difference
of the average E.e of systems.
The system of the greatest E.e is RcheRg. The system VAC ranks the next,
which is alsmost the same as the 1
st
one. Following is the systems RVAC,
RVCRg and. The system RRg bottoms the list with the lowest total income, as in
this system, there are only two components, including forest and rice or corn and
food crops.
In short, the E.e depends greatly on plants and livestock. However, we must
take particular conditions into account when applying those systems into AF
production.
The E.e of some systems with crops and trees in AF system


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Table 3.4. Comparison of the E.e of some monocultural and intercrop crops
in the AF system (Unit: 1000 VND/ha/year)

Total cost Total income Profit
Crops
AF
Mono-
culture

AF
Mono-

culture

AF
Mono-
culture

Profit
compare
Up (+)
Down (-)
Reg. 1







2-crop Corn 9.090

9.090

16.800

16.120

7.810

7110

+ 700

Spring corn 4.545

4.545

9.474

9.128

4.929

4.583

+ 346

Sugar cane 7.700

7.700

11.035

11.290

3.335

3.590

- 255

Cassava 4.252

4.252

7.792

7.680

3.540

3.428

+ 112

Soybeans 7.075

7.075

15.095

14.685

8.020

7.610

+ 410

Tea 8.102

8.102

21.132

18.944

13.030

10.842

+ 2.188

Reg. 2







Two-crop
Corn
9.090

9.090

16.640

16.050

7.550

6.960

+ 590

Spring corn 4.545

4.545

9.278

8.957

4.733

4.407

+ 326

Sugar cane 7.700

7.700

11.038

11.350

3.338

3.650

- 312

Cassava 4.252

4.252

7.721

7.650

3.419

3.398

+ 21

Soybeans 7.075

7.075

14.750

14.426

7.675

7.351

+ 324

Tea 8.102

8.102

18.500

17.128

10.398

9.026

+ 1.372

Reg. 3







2-crop Corn 9.090

9.090

16.290

15.820

7.200

6.730

+ 470

Spring corn 4.545

4.545

9.082

8.792

4.537

4.247

+ 290

Sugar cane 7.700

7.700

10.836

11.186

3.136

3.486

- 350

Cassava 4.252

4.252

7.430

7.380

3.178

3.128

+ 50

Soybeans 7.075

7.075

14.472

14.344

7.397

7.269

+ 128

Tea 8.102

8.102

17.600

16.620

9.498

8.518

+ 980


From the table 3.4, it can be seen that most of Agricultural crops in AF
system in the 3 regions output greater E.e than in Monoculture system.
Obviously, agroforesrtry not only makes use of soil but it also reinforces the
productivity of agricultuaral crops. Because in the reality, the ability of forest
trees in the AF sys to assist the crops development and limit soil erosion has a
direct effect on the productivity of agricultuaral crops.


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Table 3.5. Growth of trees in intercrop AF and Monoculture

Planting method
AF Monoculture
Re
g
Species of trees, Tree
age
Heigh
t
(m)
D1.3
(cm)
Height

(m)
D1.3
(cm)
Compare
in height
Up (+)
Down (-)
Compare
in D1.3
Up (+)
Down (-)
1
Acasia age 5 (1) 10,52 14,60
10,57 14,22
+ 0,05 + 0,38
Acasia age 5 (2) 10,61 14,69 + 0,04 + 0,47

Acasia age 5 (3) 10,66 14,84 + 0,09 + 0,62
Eucaliptus age 3 (1) 6,80 6,28
6,70 6,14
+ 0,10 + 0,24
Eucaliptus age 3 (2) 6,81 6,45 + 0,11 + 0,31
Eucaliptus age 3 (3) 6,86 6,66 + 0,16 + 0,52
2
Acasia age 5 (1) 10,48 14,38
10,45 14,21
+ 0,03 + 0,17
Acasia age 5 (2) 10,51 14,64 + 0,06 + 0,43

Acasia age 5 (3) 10,57 14,78 + 0,12 + 0,57
Eucaliptus age 3 (1) 6,77 6,25
6,65 5,97
+ 0,12 + 0,28
Eucaliptus age 3 (2) 6,81 6,42 + 0,16 + 0,45
Eucaliptus age 3 (3) 6,89 6,64 + 0,24 0,67
3
Acasia age 5 (1) 10,42 14,32
10,39 14,18
+ 0,03 + 0,14
Acasia age 5 (2) 10,44 14,56 + 0,05 + 0,38

Acasia age 5 (3) 10,50 14,69 + 0,11 + 0,51
Eucaliptus age 3 (1) 6,73 6,13
6,62 5,91
+ 0,10 + 0,22
Eucaliptus age 3 (2) 6,74 6,30 + 0,12 + 0,39
Eucaliptus age 3 (3) 6,82 6,52 + 0,20 + 0,61

Notes: Forest trees’ density is 250 – 300/ha. (1): Tea intercrop; (2): Corn
intercrop; (3): Soybean intercrop. Monocultuara: Acasia and Eucaliptus with the
density of 1.660/ha. D1.3:Diameter at chest height level
The results in table 3.5 indicates that forest trees intercropped in AF systems
in all the 3 regions have faster growth than monocultural ones. However, height
development rises unremarkably, while there is an obvious increase in the
development of D1.3. The trees combinated with soybeans had the highest
growth. According to the analysis of ours and the farmers, because of intercrop
the trees utilize the fertilizers supplied for crops. On the other hand, litter and
remnant of crops after harvest which makes the soil softer and more organic
matter than that in monoculture soil. This clearly reflects the interactive
relationship among components in the AF system.
3.3.2. Environmental effectiveness (En.e) evaluation of AF and Crop
systems.
The roles of trees in decreasing soil erosion of AF and crop systems.


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The ultimate difficulty of cultivating in sloping land which affects is the high
degree of slope, therefore, trees and crops systems affect on the level of soil
erosion.
The results in the table 3.6 show that the crop systems had influence on the
ability to limit soil erosion on difrent degree of slope, especially at the degree of
more than 30
0
. Trees such as Acasia, Eucalyptus, Litchee in the stage of closing
capony are much more capable of restricting soil erosion than anual crops.
Table 3.6. Amount of eroded soil by degrees of slope of crop systems. (Unit:
Ton/ha/year)

Amount of eroded soil in different degrees of
slope

Crop system
10 -15

>15-20 >20- 25 >25-30 >30
Tea mixed with Tephrosia 16,42 19,24 22,78 26,41 31,52
One-crop Corn
89,44
104,32 116,29 155,27
207,36
Two-crop Corn 42,34 56,11 62,27 77,83 82,76
Closed-capony Eucaliptus 11,98 14,37 17,24 26,31 29,87
Closed-capony Acasia
6,17
6,92 7,27 8,97
10,75
Closed-capony Litchee 12,15 15,81 19,81 27,63 34,45
AF
(*)
6,08 7,12 8,37 9,21 9,89
Note:
(*)
Acasia, Manglietia glauca, Bat Do Bamboo , Longan, Corn, Bean
For clear realization about the impact of crop components in limiting soil
erosion when cultivated on sloping land, we carry out the correlation analysis
between the amount of eroded soil by degrees of slope and crop components.
Table 3.7 Regression correlation between slope and soil erosion
(tons/ha/year) in the crop systems ( Y=ax+b)

Trees Correlation function
regression
Coefficient of
correlation
Tea
Y = 0,7474x + 6,4575 0,9941
One-crop Corn
Y = 5,7385x + 5,4805 0,95529
Two-crop Corn
Y = 2,0512x + 18,11 0,98814
Closed-capony Eucaliptus
Y = 0,9544x - 1,52 0,9723
Closed-capony Acacia
Y = 0,2242x + 2,9715 0,9630
Closed-capony Litchee
Y = 1,1284x – 3,419 0,9869
AF
(*)

Y = 0,1942x + 3,7645 0,9939
Note: Slope (X), amount of soil erosion (Y)


15

From the table 3.7 results, it can be seen that the regression
orrelation equation between the amount of eroded soil in the slope and the plant
components is very closely correlated. Correlation coefficient (r) is always > 0.95. This
demonstrates that the plant components is crucial to the sustainability of the soil.
Table 3.8. Amount of soil erosion in AF system compared to pure farming

system (ton/ ha).
Amount of eroded soil in rainy months System kinds
and tree
components
4 5 6 7 8 9 10
Total

1: (RRg) 1,11 1,34 1,44 2,23 3,12 2,97 2,01

14,22
2:(RVC) 0,52 0,73 0,78 0,80 1,27 1,11 0,75

5,96
3: (RChèRg) 0,84 1,51 0,87 0,93 2,12 1,92 1,31

9,50
4: (R V) 0,72 1,21 1,05 0,74 1,64 1,52 1,10

7,98
5.Pure farming 2,67 4,56 4,12 2,89 6,45 5,68 1,27

27,64
Note: Components in the system:1- Manglietia glauca, Acacia,Corn, Rice.; 2-
Acacia, Litchee, Persimmon, Tea, Tephrosia, Elephant grass, Vegetable, goat; 3-
Acacia, Canarium, Tea, Vegetable, water Rice,; 4- Acacia, Chukrasia,
Eucalyptus, Bamboo, Corn, Peanut, Taro, Bean; 5- Corn, Bean, vegetable.
Of all above systems, the 2nd sys is the most capable of limiting soil erosion,
which is followed by the 4th one. Ranking next are the 3rd and the 1st system,
coming at the last is the 5
th

(the non-tree farming system).
Paticipatory evaluation of En.e of AF and non-tree Farming systems.
Environmental efficiency is also assessed through understanding, awareness,
and experience in the manufacturing process of the local people.


16

Table 3.9. Local people’s evaluation of environmental efficiency of AF
systems and the role of Agricultural crops in AF system
Unit: Points
Criteria


System
Erosion
limit
Soil fertility
improvement
Water
retaining
Total
points
Rank
AF
R-VAC-Rg 8 6 8 22 I
RVAC 8 5 5 18 III
VAC 5 5 4 14 VI
Rche Rg 7 5 5 17 IV
RRg 7 4 5 16 V

RVCRg 8 6 6 20 II
Agri. crops
Litchee- longan 6 5 6 17 I
Custard-apple 4 4 4 12 IV
Pine-apple 6 2 5 13 III
Tea 5 5 4 14 II
2-crop Corn 3 3 2 9 VII
1-crop Corn 2 2 2 6 IX
Sugar Cane 4 3 3 10 VI
Cassava 3 1 4 8 VIII
Soybean 3 5 3 11 V
The statistics of the table 3.9 demonstrates that the two systems of highest
total points are RVACRg and RVCRg. According to the local people, those
systems are both able to protect the environment, which are followed by RVAC,
RcheRg systems. The lowest points are seen in the system of RVAC, RcheRg. As
for agricultuaral crop systems, the system of the greatest ability to protect soil
and water is Litchee-longan, ranking the next are systems of Tea, Pineapple,
Custard apple. Cassava and One-crop corn bottom the list. This indicates that
villagers have a discernible roles of trees in erosion limit and water retaining.
3.3.3. Social impacts of AF systems.
Job generation for labourers in the household
The most obvious social effect that AF system brings people is to create
jobs for workers in the household. Through the actual investigation, the
efficiency of job resolution for labourers of the system is quite great. The number


17

of turns of labourers per hectare per year in each system shows that: The system
RChèRg tops the list at 475, RVAC with 370, VAC with 340, RVACRg with

310, RVCRg with 300. Coming the last is the system RRg. The above result
reveals that AF application has comprehensively made use of available labour
in the households, especially multi-component systems which require a great deal
of labor, help local people decrease their leisure time and limit social evils.
Promoting cultural development, improving standard of living,
strengthening community relation and enhancing cultivation level
It is obvious that although AF systems have been built in the recent years,
they have considerably contributed to the innovation of the rural areas. A few
years ago, many poor families could only afforf for their children to finish
secondary school, but now they can send their children to Universities, build
house, and are classified into well-off households. The level of cultivation is
improved, creating a change in thinking and way of doing business among local
people, contributing to deterring life of deprivation and backwardness, gradually
raising the villagers’ standard of living and repelling social evils.
AF increases goods development, helping control market prices.
In the villagers’ opinion and through the reality of the market, most of AF
produts are likely to become exchanged goods such as Rice, Beans, Corns,
Litchis, Longans, Mangos, Custard-apples, Pineapples, Bananas… Foods like
Fish, Chicken, Pork, Beef… because it is very essential to every family.
Particularly, tea and tobacco have become valuable commodities for export.
3.3.4. Evaluation of the sustainability of AF systems
Participatory evaluation of the sustainability Agroforesrty systems
To assess the sustainability of local AF systems , the dissertation, with the
cooperatoion of system owners and households of good agriculture and forestry
business, has standardized 11 important criteria (on a sclale of 10) for
comprehensive assessment, which are displayed in the following table:


18

Table 3.10. Participatory Evaluation of the sustainability AF systems
Unit: Points
System
Criteria
RVAC
Rg
RVAC
RVCRg

RChè
Rg
VAC RRg
Easy for application 6 7 8 8 9 10
Suitable with the local
conditions
8 8 9 8 7 9
Little investment 8 7 8 7 6 10
Soil improvement, water
retaining
10 9 9 8 5 8
Saleable produces 9 8 9 8 6 6
Economic efficiency 8 8 7 9 9 5
Risk 10 8 9 7 5 6
Long-term income 9 8 10 9 6 7
Interaction among
components
10 9 9 8 7 4
Labour exploitation 9 9 9 10 8 6
Sustainability of AF
compared to pure

farming
10 8 9 8 5 7
Total points 96 89 97 90 73 78
By descending the table results, we can see the following sequence:
RVCRg, RVACRg, RChèRg, RVAC, RRg and the last is VAC. Therefore, the
more points each system has, the more beneficial it is for sustainable
development of AF .
Evaluation of the sustainability of AF systems through soil productive
capacity.
Soil productive capacity is measured the most accurately through crop yield
between the current year and the year before. For more comfirmation of the
sustainability of AF systems, we interviewed groups of households and carry out
an opinion poll among 322 system owners in the district.
The data in the table 3.11 shows that most opinions (74,5 – 96,7%) are in
favour of the fact that the AF method outputs the same yields of crop and
livestock. Of which, RVACRg and RVCRg systems are evaluated at the highest
rate of increase (from 12.8 – 21.7%), since according to what local people
analyzed from annual actual productivity gain as well as the cultivation process,
they found that physical properities of the soil are much more improved such as


19

porosity and moisture…. The system assessed with the greatest decrease rate is
VAC, from 11.4% to 21,6%, because trees grown in this system is mainly annual
agricultural crops mixed with fruit trees, erosion happens more frequently,
leading to the noticeable fall in the crop yields of some households.
Table 3.11. Evaluation of soil productive capacity in AF systems over
the period of 3 years (2006 – 2008)
Year

Opi-
nion
rate(%)
Reg. 1 Reg. 2


Reg. 3

System
+ 0 - + 0 - + 0 -
RVACRg
21,7 75,5 2,8 17,9 81,4 4,7 18,2 76,2 3,6
RVAC
7,2 84,5 8,3 3,6 86,6 9,8 5,2 87,4 7,4
RVCRg
15,7 79,1 5,2 18,7 74,4 6,9 12,8 82,5 4,7
RChèRg
3,8 89,7 6,5 2,7 84,9 12,4 3,2 88,9 7,9
VAC
1,2 77,2 21,6 0,5 80,7 18,8 0,8 87,8 11,4
RRg
2,2 95,4 2,4 0,7 97,4 1,9 1,8 96,7 1,5
Note: (+) Up ; (-) Down ; (0) None change
3.4. Measures for impovement, testing and solutions to the development of
AF in Vo Nhai
3.4.1. Main advantages and disadvantages in the development of AF systems
in the locality.
Advantages of each ecological regions in the district
Region 1: Less steep land, abundant source of labour, high standard of intensive

farming. Most of cultivated area is in water initiative. Convenient transportation,
strength of tea tree, tobacco, corn, rice and pig, chicken raising.
Region 2: Abundant source of labour, comparatively high standard of education.
Much farmland, large hills, relatively convenient transportation. Strengths focus
on Fruit, Sugar cane, Corn, Cassava, Rice, Tea and the husbandry of pigs,
chickens, goats, buffaloes, cows.
Region 3: Abundant source of labour, large hills. Strengths are Corn,
Soybean, Cassava, and Fruit and cattle development: Goat, Buffalo, Cow.
Main disadvantages of ecological regions and of each system in the district.


20

Region 1: Small area of hilly land, mostly farmland, agricultural service is
not well developed, shortage of capital and disease prevention techniques, lack of
irrigating water.
Region 2: Erosion of hilly land, limited intensive farming techniques,
shortage of capital and prevention techniques for diseases, drought, sub-standard
infrastructure.
Region 3: Strong erosion of hilly land, shortage of capital, limited intensive
farming techniques, drought in dry seasons, sub-standard economic conditions
and infrastructure.
The majority of households are involved in: capital shortage, sloping land
leading to strong erosion, limited techniques for cultivation on sloping land and
husbandry; low yields of some crops ans livestock; no knowledge of suitable
selection of seedlings for each system; unstable market. Especially, cattle and
poultry diseases. Above are the main constraints hindering the development of
Agroforesty systems.
3.4.2. Some solutions to the development of AF system in Vo Nhai district.
Selection of trees, crops, livestock for AF systems.

After making a summary of opinions, we found that the generality of people
chose trees chiefly Manglietia glauca and Acacia. Such trees as: Luong bamboo,
Eucalyptus, Styrax, Canarium, Bat Do Bamboo were less chosen. Fruit species
like Longan, Persimmon, Custard apple, Pineapple which were in the majority,
were also planted in the system. Oranges, Mangoes, Litchees, were less selected,
due to their unstable consuming market, too cheap prices, difficulty in preserving
products, easy damage on transportation. Anual crops like Rice, Corn, Soybean,
Taro, Cassava,… especially Tea which fits well into Southern communes were
selected as well.
In terms of livestock, species like Pig, Chicken, Duck, were chosen as main
livestock, Buffalo, Cow, Goat were the next to be selected. As for Buffalo, Cow,
besides the cash they bring plough power and muck to local people. However
they are big animals which cosume a great deal of food, require large initial
capital, high risk, therefore it is impossible to raise many at once. Moreover,
pasture-lands are not large enough.


21

Participatory selection of techniques to improve AF systems.
Local people based on potentials and current conditions of the system to
choose 5 common methods: Planting elephant grass (Pennisetum purpureum) in
bands; Intercropping Tephrosia into bands of Tea or Fruits; Implementing Bat
Do Bamboo, Implementing Taro; Improving farm system. With the desire to
apply more suitable technical measures to enhance economic efficiency as well
as land sustainability. Testing results indicates that improving methods are all
economically efficient and erosion-limiting.
Applications of some improving measures into AF system: System 1 (RVAC)
with the improving method: In the area of hillside, The sour Orange Trees were
replaced by Bat Do Bamboos, which led to an increase of 2,110 mVND/ha/year

in income.
In the 2
nd
system (RChèRg), we experimented 2 improving methods at the
same time: (i) The 1
st
measure: Planting a band of double rows of Tephrosia
along a band of 4 tea rows in the hillside. The remains from the pruning of
Tephrosia was discarded for Tea roots. (ii) The 2
nd
measure: Implementing Taro
into the system. Ater the improvement of system, the gap between income and
cost per hectare per year went up by 3,210 mVND/ha/year owing to the
supplemented income from increased productivity of Tea, and the sale of fragrant
Taro.
In regards of the 3
rd
system (VAC), the improving method is: Planting
elephant grass around pond banks, in the wide band alternating fruit trees in the
hillsides and around foothills to feed goats and grass carps. There was an
increase of 4,220 mVND/ha/year in income.
At the same time, the above 3 AF systems also investigated the capability
of protecting soil before and after the application of those reforming measures. It
was concluded that there was a considerable decrease in the amount of eroded
soil (tons/ha/year), in particular, the 1
st
system (RVCRg) with 2,09, the 2
nd

system (RChèRg) with 1,64, the 3

rd
one (VAC) with 2,60.
In a nutshell, all the 3 systems which applied different technical improving
methods have reached the target of increasing economic efficiency and


22

restricting soil erosion. So they are recommended for the local people to apply in
household models, contributing to land sustainability and efficiency in the future.
Selection of measures to limit soil erosion.
To overcome the problem of soil erosion which often occurs in rainy
seasons, farmers chose such measures as: creating terraces, rock embankment,
planting tree bands, digging trenches and other measures.
Particular solutions to each ecological region.
Solutions for the 1
st
region: Planting new corn varieties (CV1, VN1) which is
highly productive and drought tolerant. Focus on developing plants of strength
like: new varieties of Tea LDP1. One-crop tobacco land. Constructing such
systems as RVACRg; RChèRg, VACRg, VAC.
Solution for the 2
nd
region: Planting new corn varieties (CV1, VN1) which
is highly productive and drought tolerant. Focus on developing plants of strength
like: new varieties of Tea LDP1,Sugar cane, highly productive Soybean like
DT84, DT99. Constructing such systems as RVACRg; RChèRg, RVCRg, RVC.
Raising livestock like Buffaloes, Cows, Goats because of large hilly land.
Solution for the 3
rd

region: Planting new corn varieties (CV1, VN1) which
is highly productive and drought tolerant, expanding the area of elephant grass to
feed cattle and limit soil erosion. Constructing such systems as RRg, RVCRg;
RCRg, RVC due to sloping land. Raising cattle and Goats.
Solutions to each system.
Improving AF systems in the near future, concentrating on developing
varieties of high economic values, especially fruit trees like: Longan, Xuan Dinh
Persimmon, Custard-apple. Improving economic efficiency by adding species of
high economic values and ecological environment protection like: Bat Do
Bamboo, Dien Truc bamboo, Acacia, Manglietia glauca… to be tailored to
specific conditions for each selected system.


23

CONCLUSIONS AND RECOMMENDATIONS
1. Conclusion
1.1. Natural, socio-economic conditions of research area.
Generally, natural and socio-economic conditions in Vo Nhai are
comparatively favorable for the development of AF production. Three ecological
regions are formed with their own characteristics.
1. 2. AF development status in the research area.
Of 322 investigated AF systems in the entire district, there are 6 popular
systems: VACRg, RVAC, VAC, RChèRg, RRg, RVCRg.
Each region has quite different proportions of systems. In the 1
st
region,
RChèRg system accounts for the highest rate of 27,27%, the next is VAC with
24,68%, which is followed by 3 systems RVAC, RVACRg, RVCRg. The system
RRg is at the bottom of 9.09%. In the 2

nd
region RVAC system makes up
25,00%, systems: RRg and RVCRg are in the following positions with 20.24 and
19.05% respectively, the very next are VAC, RVACRg. The lowest proportion is
RChèRg with 7.14%. In the 3
rd
region VAC occupies the largest (22,98%),
RChèRg and RVCRg with 18.63 and 16.15%, then to RVAC system (14.91%),
RRg (14.29%), RVACRg (13.04%).
1.3. Effectiveness of AF systems
Average economic efficiency of AF systems in the order of income
(mVND/ha/year): The highest is RChèRg at 13,892, next are VAC and RVAC at
13,074 and 11,297 respectively. After that, the 2 systems RVCRg and RVACRg
with the total income stopping at 8,560 and 7,884. Ranking the last is the system
of RRg, with the smallest income of 4,482.
1.3.2. Environmental effectiveness
Environmental effectiveness of the systems mentions the ability to limit soil
erosion : Non-tree systems has the amount of eroded soil (tons/ha/year) at 27,64;
RRg at 14.22; RChèRg at 9.50; RV at 7.98; RVC at 5.96.
1.3.3. Social impacts
Job generation for households in the system, with 230 – 475 turns of
labour/ha/year.
1.3.4. The sustainability of AF systems
RVCRg system is the most sustainable, which is followed by 2 systems
RChèRg and RVAC, then it is RRg system. Coming at the last is VAC system
which is least sustainable.
1.4. Testing measures and some common solutions to the development of AF
in Vo Nhai
1.4.1. Research and testing measures.
* Selection of crops and livestock.

With regards to forest trees: The 3 areas chose chiefly Manglietia glauca and
Acacia. Such trees as: Luong bamboo, Eucalyptus, Styrax, Canarium, Bat Do
Bamboo were less chosen. Fruit species: Longan, Persimmon, Custard apple,
Pineapple are selected in the majority in all regions as well, and in the 3
rd
region


24

alone, Custard-apple was more chosen than in the 1
st
and 2
nd
region. Oranges,
Mangoes, Litchees, were less selected. Tea which was the staple crop in the 1
st

and 2
nd
region was planted into the systems. In terms of livestock Pig, Chicken,
Duck, were chosen as main livestock in all 3 areas, Buffalo, Cow, Goat were the
next. Particularly in the 2
nd
and 3
rd
area, owing to large hilly lands, Buffalo and
Cow were more chosen.
* Improving and testing measures.
The system of RVAC: After the reformation, the economic efficiency

increased by 2,1 mVND, the amount of eroded soil decreased by 2,09
tons/ha/year. The system of RChèRg: After the improvement, the income went
up by 3,21 mVND, the amount of eroded soil fell by 2,09. The system of VAC:
After being reformed, the income rose by 4,22 mVND, the amount of eroded soil
declined by 2,60.
1.4.2 Solutions to the development of AF in Vo Nhai district.
Solutions for each ecological region.
Solutions for the 1
st
region: Planting new corn varieties CV1, VN1. Focus on
developing Tea LDP1. Constructing such systems as RVACRg; RChèRg,
VACRg, VAC. Growing livestock like: Pigs, Chickens, Duck.
+ Solution for the 2
nd
region: Planting new corn varieties CV1, VN1.
Planting hedgrow, alternating Bat Do Bamboo, elephant grass to feed cattle and
limit soil erosion. Focus on developing plants of hilly lands: Tea LDP1, Sugar
cane, Soybean like DT84, DT99. Constructing such systems as RVACRg;
RChèRg, RVCRg, RVC. Raising livestock like Buffaloes, Cows, Goats.
+ Solution for the 3
rd
region: Planting new corn varieties CV1, VN1.
Planting hedgrow alternating Bat Do Bamboo, expanding elephant grass to feed
cattle and limit soil erosion. Constructing such systems as RRg, RVCRg; RCRg,
RVC due to sloping land. Raising cattle and Goats.
Solutions for each system.
Improving such systems as RVACRg; RChèRg, RVCRg, RVC developing
varieties of high economic values, especially fruit trees like: Longan, Xuan Dinh
Persimmon, Custard-apple. Enhancing economic efficiency of forest component
by forest enrichment with Bat Do, Dien Truc bamboo, Acacia, Manglietia …, In

RRg system supplement Acacia, Manglietia glauca, conserve natural forests, do
intensive farming with agriculture crops. As for VAC system, it is necessary to
train techniques of diseases prevention for animal, planting perennial fruits such
as: Longan, Litchees, Persimmon… to protect soil.
2. Recommendations
More study time required to comprehensively keep tracks of changes in
ecological environment and fluctuations in economic efficiency of components
in the AF system in order to put forward more practicable solutions.
In regards of the evaluation of economic efficiency, there needs to be
researches on economic efficiency standards reliant on initial investing capital
when constructing models.



25


MINISTRY OF EDUCATION AND TRAINING
THAI NGUYEN UNIVERSITY






ĐAM VAN VINH

TO EVALUATE EFFECT OF AGROFORESTRY
SYSTEMS IN VO NHAI DISTRICT
THAI NGUYEN PROVINCE


Major: Crop science
Code: 62.62.01.01








Summary of Agronomy Ph.D thesis










Thai Nguyen - 2011