Dissertation abstracts: To evaluate effectiveness of AF systems in Vo Nhai district, Thai Nguyen province

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Purposes to evaluate effectiveness of AF systems in Vo Nhai district, Thai Nguyen provinceto 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.

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Nội dung Text: Dissertation abstracts: To evaluate effectiveness of AF systems in Vo Nhai district, Thai Nguyen province

1 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.
2 - 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
3 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.
4 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.
5 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 No Land use types Area (ha) Rate (%) Natural land area 84.510,41 100,00 I Land for 61.719,41 73,12 Agriculture 1.1 Crop land 6.325,0 7,48 + Annual crops 5.364,0 - Rice paddy- field 3.152,0 - Upland and 2.072 industrial crops - 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 932,0 1,10 land 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
6 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 450. 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,
7 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% Sum of 3 N Reg. 1 Reg. 2 Reg. 3 SYS Reg(s) o LHLT C 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 Thư ng; C : Cúc ư ng; VC: Vũ Ch n; LM: Liên Minh; TX: Tràng Xá; DT: Dân Ti n; 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.
8 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
9 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 3rd formula. In contrast, the 1st 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 4th 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 3rd 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.
10 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 4th formula. Meanwhile, the 1st 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 4th formula. Meanwhile, the 3rd 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 3rd formula. Following is the 4th one with relatively high total income at 8,726 mVND/ha/year. Meanwhile, the 1st one releases the lowest income at 6,874 mVND/ha/year. This system generates comparatively high income when
11 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) RVAC RChè RVC Criteria Syst RVAC VAC RRg Rg Rg Rg 1. Production value (Pv) Unit Pv/ ha 1000 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 1000 33,74 37,94 43,37 38,88 28,07 38,01 2.Production cost (Pc) Total Pc/ha 1000 3.122 3.781 3.884 5.385 1.962 3.477 Variable cost/ha 1000 2.525 2.920 3.185 4.502 1.495 2.906 Fixed cost/ ha 1000 597 860 699 884 467 776 3.Gross income Total income / ha 1000 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 1000 25,80 29,94 38,00 29,37 21,47 31,12 4. Pure income (Pi) Pi /ha 1000 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 1000 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 1st 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
12 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 Profit compare Crops Mono- Mono- Mono- AF AF AF Up (+) culture culture culture 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 9.090 9.090 16.640 16.050 7.550 6.960 + 590 Corn 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.
13 Table 3.5. Growth of trees in intercrop AF and Monoculture Planting method Compare Compare Re Species of trees, Tree AF Monoculture in height in D1.3 g age Heigh Up (+) Up (+) D1.3 Height D1.3 Down (-) Down (-) t (cm) (m) (cm) (m) 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.
14 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 300. 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 Coefficient of regression 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). System kinds Amount of eroded soil in rainy months and tree Total 4 5 6 7 8 9 10 components 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 5th (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 Erosion Soil fertility Water Total Rank limit improvement retaining points System 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 RVAC RChè Criteria RVAC RVCRg VAC RRg Rg Rg Easy for application 6 7 8 8 9 10 Suitable with the local 8 8 9 8 7 9 conditions Little investment 8 7 8 7 6 10 Soil improvement, water 10 9 9 8 5 8 retaining 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 10 9 9 8 7 4 components Labour exploitation 9 9 9 10 8 6 Sustainability of AF 10 8 9 8 5 7 compared to pure farming 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- Reg. 1 Reg. 2 Reg. 3 nion rate(%) 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.