The Classification of Farming Systems in Alluvial Soil Area of the Mekong Delta

Transcription

1 The Classification of Farming Systems in Alluvial Soil Area of the Mekong Delta Ryuichi Yamada 1, Vo Quang Minh 2, Nguyen Quang Tuyen 3, Le Canh Dung 3 and Vo Van Tuan 3 1: Japan International Research Center for Agricultural Sciences Tsukuba, Ibaraki Japan 2: Department of Soil Science & Land Management, College of Agriculture Cantho University, Cantho, Vietnam 3: Mekong Delta Farming Systems Research and Development Institute Cantho University, Cantho, Vietnam Abstract We classified farming systems in the Mekong Delta by considering irrigation conditions, soil conditions, and flooding conditions. As the results of that, we made clear each characteristics of farming systems in each area. Among these, the zones with the most favorable conditions for agricultural diversification are Irrigated-Alluvial Soil-D<30cm and Irrigated-Alluvial Soil-30cm< D<60cm zone. In these areas, 2 rice crop, 3 rice crop, and fruits production are popular. We selected one village which belong to this zone as the target area where diversification has been developed. We classified farming systems and clarified main types of farming systems there. We considered crop combination and by-products exchange in classification. In term of crop combination, we identified that in farm level there are various kind of diversified farm and that rice-livestock-fruits tree is main combination followed by rice-fruits tree-upland crop. Especially, in case of the farm of which main component is livestock, there are many farms who adopt integrated farming systems. Livestock component, especially pig component plays much more important role as the core component of integrated farming systems. Introduction In the Mekong Delta, as diversification has become developed, integrated farming systems have developed so far. Our project deals with diversification and integrated farming systems. But, it cannot always be seen everywhere in the Mekong Delta. Mekong Delta has various areas with different natural conditions. Therefore, we need to make clear main type of farming systems in each representative area classified by the natural conditions. Based on this result, we will select the target area of our project. After that, it is necessary 1

2 for us to clarify target farming systems in the target area. For this purpose, we will classify farming systems in our research site selected. Methods Classification of the farming systems in the Mekong Delta will be implemented from the viewpoint of natural conditions such as irrigation conditions, flooding conditions, and soil conditions. Inundation depth, which is the indicator of flooding conditions, is divided into 3 categories as follows; 1D (flooding depth)<30cm, 2 30<D<60cm, 3D>60cm. Soil conditions can be basically divided into 3 categories such as alluvial soil, acid sulphate soil, and saline soil. In the target area (village) which is selected based on the above classification in whole Mekong Delta, we interviewed 170 farm household which occupy around 10 % of total farm household in 4 hamlets of this village. We used the questionnaire which consist of basic items such as labor, land, amount of production of each crop. We considered crop combination and by-products exchange in classification so that we can classify farming systems from diversification point of view as well as from integration point of view. Results and Discussions 1) Classification of farming systems in the Mekong Delta It is said that the land use and water use in the Mekong Delta are affected by the factors such as irrigation and drainage, salinity, flooding, and acidity (Puckridge; 1995). For example, the possibility of utilizing fresh water in the dry season is basically affected by irrigation conditions. Actually, there are many areas where the cropping pattern has been changed from 1 floating rice to 2 rice cropping. The possibility of choosing rice variety, growing fruits tree, and raising fish and prawn is affected by flooding depth. And the kinds of crop grown and the yield are affected by the acidity or salinity. In this paper, main indicators for classification are derived from irrigation conditions, flooding conditions, and soil conditions. Inundation depth, which is the indicator of flooding conditions, is divided into 3 categories as follows; 1D<30cm, 230<D<60cm, 3D>60cm. Soil conditions can be basically divided into also 3 categories such as alluvial soil, acid sulphate soil, and saline soil By using GIS method with the above indicators, the 18 zones can be obtained (2 3 3 ). After that, main type of farming systems will be identified in each zone. The results are shown in table1. According to this table, Irrigated-Acid Sulphate Soil-D>60cm zone occupy most in the Mekong Delta. Around half of this zone is the 2 rice crop area. The provinces which occupy a lot here are Long An, Dong Thap, An Giang. Most of the areas are located upstream of Mekong River. Secondly, Rainfed-Acid Sulphate Soil-30cm<D<60cm zone occupy a lot. In this zone, 1rice crop is main land use system, followed by Fallow Land, Fruits Land, and Cultivated 2

3 Land of Shrimp. Main province is Kien Giang, Ca Mau, Bac Lieu, which is located in coastal area. Thirdly, Irrigated-Alluvial soil-d>60cm area occupies 12.7%. In this zone, 2 rice cropping system occupies 60% in acreage. Main province is An Giang, Dong Thap, and Can Tho. These provinces are located in the middle reaches and upper reaches of the Mekong River. Fourthly, Rainfed-Acid Sulphate Soil-D>60cm area occupies 10.5%. In this zone, 1 rice cropping area occupies a lot, followed by Fallow Land, Cultivated Land of Shrimp. More than half of this zone belongs to Ca Mau province. The above 4 zone occupy more than half of the total area of the Mekong Delta. The zones with the most favorable conditions are Irrigated-Alluvial Soil-D<30cm and Irrigated-Alluvial Soil-30cm< D<60cm zone. In these areas, 2 rice crop, 3 rice crop, and fruits production are popular. Main provinces are located in middle reaches and down reaches of the Mekong River. These zones have the highest possibilities for agricultural diversification. Moreover, the relation between each ecosystem can be understood in this table. Firstly, most of alluvial soil area is irrigated area. That means flooding depth is crucial factor in alluvial soil area. Secondly, most of saline soil area is rainfed area. Thirdly, acid sulphate soil area includes both irrigated area and rainfed area. But, in most of the area, flooding depth is more than 30 cm. So, in acid sulphate soil area, both flooding depth (more than 30cm) and irrigation conditions should be taken into consideration. Next, table 2 shows irrigation conditions, flooding conditions, and soil conditions by each land use systems. In this table, it is possible to compare 12 rice crops and 3 rice crops, 22 rice crops and 2 rice crops-upland crop 31rice crop and traditional rice crop-shrimp/crab. It can help us to consider the requisite for diversification and for intensive agriculture. From such a point of view, main land use systems is compared as follows; Firstly, there are crucial difference in flooding depth between 2 rice crops and 3 rice crops. In more than 60% of 2 rice crops zone, flooding depth is more than 60cm. On the other hand, in 83% of 3 rice crops zone, flooding depth is less than 60cm. Besides, in 3 rice crops zone, alluvial soil area occupies 20% more than that in 2 rice crops zone. Secondly, there are much difference in soil conditions between 2 rice crops zone and 2 rice crops-upland crop zone. In 2 rice crops zone, alluvial soil area occupies 54.6%. On the other hand, in 2 rice crops- upland crop area, alluvial soil area occupies 91.5%. Moreover, it is noted that all the 2 rice crops-upland crop zone belong to irrigated area. Like this, irrigation and alluvial soil are important conditions for farmers to adopt 2 rice crops-upland crop system. Thirdly, in 1 rice crop zone, there is much more acid sulphate soil area, on the other hand, in traditional rice crop-shrimp/crab zone, there is much more saline soil area. Besides, flooding depth is relatively lower in traditional rice crop-shrimp/crab zone. 2) The outline of the agricultural production in target area As the above mentioned, among each zone classified, the zones which have the highest possibilities for agricultural diversification are Irrigated-Alluvial Soil-D<30cm and Irrigated-Alluvial Soil-30cm < D<60cm zone. Therefore, we selected representative area inside these zones. We selected Tan Phu Thanh Village as the representative area. This village is located in the middle of the Mekong River, and 3

4 belongs to Chau Thanh district, Cantho Province. In this village, we selected 4 main hamlets which have different conditions of location. Phu Loi hamlet is located along the road (rout 1), Tan Thanh Tay hamlet is located along the river. On the other hand, Thanh My Be hamlet, Long An hamlet are relatively far from the 4

5 Table1 Land Use Systems in Different Natural Conditions in the Mekong Delta Ra nk Irrigation Soil Type Flooding Conditions Area (%) 1 Land Use Systems (%) Irrigated Acid D> Rice(DX-HT)(49.0) 1 Rice (21.1) Fallow Land (13.0) Fruits (8.3) 2 Rainfed Acid 30<D< Rice (28.0) Fallow Land (16.2) Fruits (12.3) Culti- Shrimp (12.0) 3 Irrigated Alluvial D> Rice(DX-HT)(60.1) Fruits (12.7) Fallow Land (7.4) Tr-Rice-Upland(6.7) 4 Rainfed Acid D> Rice (35.3) Fallow Land (13.5) Cult-Shrimp (8.8) Fruits (8.4) 5 Rainfed Saline 30<D< Rice (50.5) 2 Rice(HT-M) (17.0) Fruits (15.8) Culti- Shrimp (5.3) 6 Irrigated Alluvial 30<D< Rice(DX-HT)(41.7) Fruits (22.9) 3 Rice (18.6) 2 Rice(HT-M) (9.5) 7 Irrigated Alluvial D< Fruits (23.1) 2 Rice(HT-M) (18.6) 3 Rice (18.5) 2 Rice(DX-HT)(16.3) 8 Rainfed Saline D< Rice (35.2) Fruits (16.6) 2 Rice(HT-M) (14.5) Tr-Rice-Shrimp (8.2) 9 Irrigated Acid 30<D< Rice(DX-HT)(42.0) Fruits (15.8) Melaleuca (9.4) 1 Rice (6.7) Rainfed Saline D> Rice (33.3) Cult-Shrimp (10.7) Shrimp-Forest(10.3) Mangrove (10.3) Rainfed Acid D< Rice (32.1) Fallow Land (23.6) Fruits (11.2) Culti- Shrimp (5.1) Rainfed Alluvial 30<D< Rice (22.7) 2 Rice(HT-M) (19.3) Tr-Rice-Upland(18.7) 2 Rice(DX-HT)(14.1) Rainfed Alluvial D< Rice(HT-M)(26.7) 1 Rice (16.8) Fallow Land (15.1) Fruits (11.4) Note: 1) Above soil types are as follows; Acid : Acid Sulphate Soil, Alluvial : Alluvial Soil, Saline : Saline Soil 2) Above D means inundation depth. 3) Above land use systems are as follows; Culti- Shrimp : Cultivated Land of Shrimp, Fruits : Household- Fruit Land, Tr-Rice-Upland : Traditional Rice-Upland Crop, Tr-Rice-Shrimp : Traditional Rice Crop-Shrimp/Crab, H-Upland : Household-Upland Crop 4) Above figures in the parenthesis are the ratio of areas of each land use systems to total areas of each natural conditions. 5) Above DX-HT means Winter-Spring, Summer-Autumn. HT-M means Summer-Autumn, Wet season. 6) We neglected the eco-systems which occupy less than 1% in acreage. 5

6 Table 2 Natural Conditions in Different Land Use Systems in the Mekong Delta Land Use Area (ha) Irrigated Areas (%) Flooding Depth (%) Soil Type (%) Rank <30 cm 30-60cm >60 cm Alluvial Saline Acid 1 2 Rice Crops (DX-HT) 883,551 (23.1) Rice Crop 845,604 (22.1) Household-Fruits Land 520,289 (13.6) Rice Crops (HT-M) 318,901 ( 8.3) Fallow Land-Shrub 312,976 ( 8.2) Cultivated Land of Shrimp 165,057 ( 4.3) Rice Crops 149,780 ( 3.9) Melaleuca 94,941 ( 2.5) Traditional Rice-Upland Crop 80,545 ( 2.1) Household-Coconut Land 72,222 ( 1.9) Pineapple Land 68,696 ( 1.8) Traditional Rice Crop-Shrimp/Crab 62,233 ( 1.6) Shrimp Land-Forest 53,077 ( 1.4) Mangrove Forest 45,928 ( 1.2) Sugarcane Land 37,947 ( 1.0) Household-Upland Crop 34,764 ( 0.9) Upland Crop 25,608 ( 0.7) Rice Crops(DX-HT)-Upland Crop 18,508 ( 0.5) Muddy Land 15,619 ( 0.4) Salt Pan 11,653 ( 0.3) New Reclamated Land 11,898 ( 0.3) Note: 1) Above figures in the parenthesis are the ratio of areas of each land use systems to total areas. 2) Above figures in each natural condition are the ratio of areas with each natural condition to total areas of each land use systems. 6

7 road and the river. Among these hamlets, we interviewed 170 farm household which occupy around 10 % of total farm household. In Tan Phu Thanh village, there are various crops that are grown. Among these, more than 90% farmers grow fruits tree. 68% farmers sell fruits. The average acreage of the garden is 35a. 76% farmers grow rice, and around 57% farmers sell rice. The average acreage of paddy field is 45a, which is very small scale. 72% farmers have livestock. 51% farmers raise pigs. 48% farmers sell pig. It means that most of the pigraising farm households sell pigs. But, average numbers of pigs is 4.6 head, which is very few. 67% farmers raise fish. But, only 21% farmers sell it. That means fish is mainly grown for self-consumption. As we can see, crop diversification has developed. At the same time, there are mainly small-scale farm households, but most of crops and animals are grown for sales except fish (Yamada, et al. 1999) 3) The type of farming systems in target area In Tan Phu Thanh village, most of the farmers combined more than two components. But, there are various types. Here, we try to define the types of farming systems by the following standard which is used by Ministry of Agriculture, Forestry, and Fisheries in Japan. The standard is decided by the ratio of sales values of one crop for that of all crops. In case that the ratio is less than 60%, we call it diversified-farm. In case that the ratio is more than 60%, less than 80%, we call it semi-diversified farm. And, in case that the ratio is more than 80%, we call it specialized farm. In considering the kind of main crop together with this definition, we can get main type of farming. In Phu Loi hamlet, the farm household of which main component is livestock occupy more than half. In Tan Thanh Tay hamlet, the main type of farming system are semi-diversified farm of which main component is fruits tree or livestock, and fruits tree specialized farm. In Thanh My B, the main type of farming systems are upland crop specialized farm, and diversified farm of which main component is fruits tree. In Long An, the main type of farming systems are diversified farm of which main component is rice, and rice specialized farm. Next, we show the type of farming systems and total values for sales of each component in table3. According to this table, the following can be pointed out. Firstly, there are relatively many farms of which main component is rice or livestock. Looking at ratio of the values for sale, in every type of farming systems, that of fish is very small. Secondly, in diversified farm of which main component is rice or livestock, main type of combination is fruits tree-livestock-rice. In diversified farm of which main component is fruits tree or upland crop, main type of combination is fruits tree-rice-upland crop. In semi-diversified farm of which main component is livestock, it is mainly combined with rice. In semi-diversified farm of which main component is rice, it is mainly combined with fruits tree. And, in semi-diversified farm of which main component is fruits tree, it is mainly combined with livestock. Thirdly, when looking at total values for sales by each type of farming systems, that of specialized farm is relatively small, except livestock specialized farm. The average size of the main crop in these specialized farms is not bigger than that of other types. These facts indicate that enlarging the size of paddy field/ garden involves a lot of difficulties. 7

8 Table3 The Type of Farming Systems and Total Value for Sale The Type of Numbers Amount of Total Value for Sale (Rate) Farming Systems of Farm Fruits Fish Livestock Rice Upland crop Total / Main Component (%) (%) (%) (%) (%) (VND) Diversified Farm Rice ,148,000 Livestock ,883,000 Fruits tree ,434,000 Upland crop ,491,000 Semi-Diversified Farm Livestock ,953,000 Rice ,473,000 Fruits tree ,432,000 Specialized Farm Rice ,149,000 Upland crop ,230,000 Livestock ,986,000 Fruits tree ,649,000 In table 4 we show the integrated farming systems by the type of farming systems based on the diversification standard. According to this table, the following can be pointed out. In the farm of which main component is rice or livestock, there are more farmers who adopt integrated farming systems. Especially, in case of the farm of which main component is livestock, there are many farms who adopt integrated farming systems. In case of the farm of which main component is rice, there are some farmers whose integrated systems don t contain rice component. On the other hand, in case of the farm of which main component is livestock, there are only 1 farmers whose integrated system don t contain livestock component. Based on these facts, we can say that livestock, especially pig play much more important role in integrated farming systems. Table 4 The Type of Farming Systems and Integration Type of Total Integrated No Farming Systems Farming Systems / Main Component (%) Systems Diversified Farm Rice 19 (100) 13 (68.4) 6 (31.6) Livestock 17 (100) 14 (82.4) 3 (17.6) Fruits tree 15 (100) 7 (46.7) 8 (53.3) Upland crop 9 (100) 3 (33.3) 6 (66.7) Semi-Diversified Farm Livestock 21 (100) 18 (85.7) 3 (14.3) Rice 10 (100) 5 (50.0) 5 (50.0) Fruits tree 8 (100) 4 (50.0) 4 (50.0) Specialized Farm Rice 17 (100) 3 (17.6) 14 (82.4) Upland crop 16 (100) 3 (18.8) 13 (81.3) Livestock 11 (100) 8 (72.7) 2 (18.2) Fruits tree 10 (100) 2 (20.0) 8 (80.0) Note: 1)The above figures are the numbers of farm household. 2)The figures of the above parenthesis are the rate of the numbers of farm household 8

9 Conclusion We have so far identified main type of farming systems in each representative zone and have described main characteristics of the farming systems in the Mekong Delta. Among these zones, the zones with the most favorable conditions are Irrigated-Alluvial Soil-D<30cm and Irrigated-Alluvial Soil-30cm< D<60cm zone. In these areas, 2 rice crop, 3 rice crop, and fruits production are popular. These zones have the highest possibilities for agricultural diversification. We selected representative area among these zones. In this target area, we have identified the main types of farming systems based on two kinds of standard such as diversification (crop combination) and integration (by-products exchange). The main points are summarized as follows; Firstly, under the limitation of land, average size of management is small as a whole, where diversification has well developed. On the other hands, specialization with enlargement of land involves difficulties. In farm level, there are various kind of diversified farm. Among that, rice-livestock-fruits tree is main combination followed by rice-fruits tree-upland crop. Secondly, there are many farmers who adopt integrated farming systems. Especially, in case of the farm of which main component is livestock, there are many farms who adopt integrated farming systems. Livestock component, especially pig component plays much more important role as the core component of integrated farming systems. Literature Cited Donald W. Puckridge, Bui Chi Buu, Nguyen Van Luat, 1995: Agriculture and Agriculture Reaesrch in the Mekong Delta, Cuulong Delta Rice Research Institute. Yamada R, Tuyen NQ The actual situation and the technical and management problems of VAC systems in the Mekong Delta of Vietnam. Japanese Journal of Farm Management 37(2):

10 PHAÂN LOAÏI HEÄ THOÁNG CANH TAÙC ÔÛ VUØNG ÑAÁT PHUØ SA ÑOÀNG BAÈNG SOÂNG CÖÛU LONG Tóm tắt Chuùng toâi phaân loaïi heä thoáng canh taùc ôû ñoàng baèng Soâng Cöûu Long theo caùch xem xeùt caùc ñieàu kieän töôùi tieâu, ñieàu kieän veà ñaát vaø ñieàu kieän ngaäp luõ. Keát quaû laø chuùng toâi ñaõ laøm roõ moãi ñaëc tính cuûa heä thoáng canh taùc ôû töøng vuøng. Trong soá naøy, nhöõng vuøng coù ñieàu kieän thuaän lôïi ñeå ña daïng hoùa trong noâng nghieäp laø vuøng Ñaát phuø sa coù töôùi vôùi ñoä saâu ngaäp döôùi 30 cm vaø Ñaát phuø sa coù töôùi vôùi ñoä saâu ngaäp trong khoaûng 30 cm vaø 60 cm. ÔÛ nhöõng vuøng naøy, saûn xuaát 2 vuï luùa, 3 vuï luùa vaø traùi caây laø phoå bieán. Chuùng toâi ñaõ choïn moät xaõ thuoäc vuøng naøy laø nôi thí ñieåm ñeå phaùt trieån ña daïng hoùa. Chuùng toâi phaân loaïi heä thoáng canh taùc vaø loïc ra caùc hình thöùc canh taùc chính ôû ñoù. Chuùng toâi caân nhaéc veà söï keát hôïp caây troàng vaø trao ñoåi saûn phaåm phuï trong phaân loaïi. Veà maët keát hôïp caây troàng, chuùng toâi nhaän thaáy raèng ôû möùc ñoä noâng hoä coù raát nhieàu loaïi noâng hoä khaùc nhau vaø moâ hình luùa-vaät nuoâi vaø traùi caây laø söï keát hôïp chính, tieáp theo laø moâ hình luùa-traùi caây vaø hoa maøu. Ñaëc bieät, trong tröôøng hôïp nhöõng noâng hoä laáy chaên nuoâi laøm chính thì coù nhieàu hoä aùp duïng caùc heä thoáng canh taùc toång hôïp. Heä thoáng chaên nuoâi, ñaëc bieät laø hôïp phaàn nuoâi heo thì ñoùng vai troø quan troïng nhö laø hôïp phaàn coát loõi cuûa caùc heä thoáng canh taùc toång hôïp. 10