Ha Of Lowlands Research Articles

Resource-use efficiency and environmental sustainability in the village tank cascade systems in the dry zone of Sri Lanka: An assessment using a bio-economic model

IntroductionVillage tank cascade systems (VTCSs) were built in ancient Sri Lanka as autonomous and climate-resilient agro-ecological systems. This study examines crop choices, farming profitability, and environmental sustainability under alternative rainfall regimes and market interventions in the Mahakanumulla VTCS of the Anuradhapura district.MethodA bio-economic model was developed to represent farming activities in the VTCS for the 2018-19 Maha and 2019 Yala cultivation seasons with data gathered from secondary sources and a key informant survey. The objective function of the model was the maximization of profits from farming. Resource limits were set for four types of land (highlands and lowlands in the Maha and Yala seasons), two types of labor (hired and family), and twelve-monthly water constraints. Six different models were developed for the six sub-divisions of the VTCS, considering the water-management hierarchy of the system. The models were simulated under alternative rainfall regimes and market interventions. The optimal crop mixes, farm profits, and shadow prices of resources associated with the baseline scenarios were compared with those of the counterfactual scenarios.Results and discussionThis analysis clearly illustrated that water and labor are the key determinants of the system. Also, when 922 ha of lowlands and 205 ha of uplands were allocated per annum for crop cultivation under normal environmental conditions, the annual profitability of the VTCS was LKR 111 million. During drought periods, a sharp reduction in profits was observed in the Maha season. Year-round drought caused a 77% profit reduction compared to the baseline. The Maha drought alone caused a reduction of 47%. The introduction of a buy-back arrangement for chili and maize helped farmers to increase profits by 185 and 28%, respectively, under normal climate scenarios, turning to 954 and 5% during extreme drought scenarios, compared to the baseline. The least nitrate leaching and soil losses occurred in green chili cultivation. The introduction of market-based solutions is recommended to address extreme climate events experienced by the rural communities dependent on the VTCSs in Sri Lanka.

Fondements Géographiques De La Valorisation Agricole Des Bas-Fonds Au Sud Du Bassin Versant De l’Oti (Bénin)

In the south of Oti catchment in Benin, the agricultural development of the lowlands for rice and vegetable cultivation, guarantees a large part of food resources. It also serves as an important source of financial income to agricultural households. This paper focuses on understanding the geographical foundations of this kind of agricultural production in the study area. Surveys of 207 farm households and the statistical processing of climatic, demographic, agricultural and socio-economic data have made it possible to highlight the natural and human factors of farm occupation and the use of these lowland agro-ecosystems. The results obtained revealed that the population of the south of Oti catchment has almost doubly increased between 1992 and 2013. It will increase four times in 2050 by creating the need to have excess food. In addition to this situation, climatic parameters fluctuation, plateau land qualitative tiredness, and major constraints of traditional agriculture were added. Henceforth, these are factors, in addition to the richness of the lowlands and water availability for a long period, which have helped in motivating the population of farmers. About 2000 ha of lowlands were reclaimed by irrigation schemes between 1982 and 2015 in this area. This was possible with the help of technical structures and agricultural development organizations.

Nutrients accumulation in drainage channel sediments

The drainage channel network in Vojvodina, northern part of the Republic of Serbia, in total length of around 20,000km, transfers excessive (under)ground waters from around 2.15 million ha of lowlands. Channels are mostly in direct connection with the surrounding arable agricultural land and are exposed to different run-off, leaching and/or wind erosion processes. Close to urban areas, some channel sections serve as recipients of unrefined sewage and industrial waste waters. Water flows and velocities, as well as the transportable capacity of fluvial materials (sediments) are relatively low. This, in combination with other natural and anthropogenic impacts, contributes to sediment generation in the drainage channel network. Based on around 100 sediment samples from 46 channels, concentrations of primary nutrients (N, P and K) were elaborated in this study. Detected concentrations of macronutrients in the channel sediments (e.g. N 1–1.2%, P 100–265 and K 100–380mg 100g-1) exceeded their content in surrounding arable land by a few fold. Also, significantly higher nutrient concentrations (in average by 50%) were detected in downstream (vs. upstream) channel sections. An excessive presence of observed elements in channel sediments, due to interactive processes between water and sediment material, can adversely influence the water quality and life conditions for channel biota and caused other negative environmental impacts such as eutrophication. These results clearly confirm that the processes of nutrient accumulation in channel sediments are greater than those in the surrounding, mostly intensively arable land areas. The erosion of unprotected agricultural areas and sediment transport as the most important pollution pathways from the drainage basin to channel network may be essential factors responsible for detected condition of nutrient accumulation.

Land Suitability for Developing Soybean Crops in Bumi Nabung and Rumbia Districts, Central Lampung

Bumi Nabung district consists of 6 villages with a total area of 7,810 ha which are divided into 251 ha of rain fed rice lands, 4,908 ha of dry land, 1,317 ha of lowland, 1,158 ha of yards and 176 ha of others. Rumbia district consists of 14 villages which has a total area of 22,696 ha of land consisting of 2,728 ha of yards, 17,358 ha of dry land, 326 rainfed paddy field, 839 ha of swamp land, 1,470 ha of lowland and 4,232 ha of others. Bumi Nabung and Rumbia districts have a low soil fertility potential that is reflected by the lowof soil pH, CEC, total N, available P, and high level of exchangeable Al and Al saturation. The results assessment based on the physical and chemical characteristics showed that Bumi Nabung district have 5 villages on suitable class S-2 (North Bumi Nabung, East Bumi Nabung, Bumi Nabung Ilir, South Bumi Nabung, and Sri Kencono) and one village New Bumi Nabung has less suitable class S-3. In the Rumbia District, there were 14 villages belonged to suitable class (S-2), namely Reno Basuki, Rekso Binangun, Teluk Dalam Ilir, Rukti Basuki, Restu Baru, Restu Buana, Bina Karya Buana, Bina Karya Putra, Bina Karya Jaya, Bina Karya Utama, Bina Karya Sakti, Joharan, Rantau Jaya Ilir and Rantau Jaya Baru. Bumi Nabung and Rumbia districts have the potential fertility and land suitability for extensification and development of soybean crops. The main technology components to support this program are the use of ameliorant (dolomite and zeolite), the application of organic fertilizers (manure and compost) and inorganic fertilizers (NPK).Keywords: Acid soil, central Lampung, land suitability, soil fertility, soybeans

Proposed complex utilization of water resources in the Prut River basin

The realization of the proposed water-resources development scheme for the multi-purpose utilization of water and land resources in the Prut River basin would make possible the following: a) flood control, which would prevent the frequent flooding of 250,000 ha of lowland. This would make it possible to include the area in a program of intensive agricultural utilization, and would also prevent flooding and erosion of existing settlements and other objectives of the economy. b) The proposed multi-purpose storage reservoirs would permit regulating the river flow for water supply, irrigation and power generation. The total capacity of the run-of-river and pumped-storage plants in the basin is planned at 640,000 kW (if necessary it could be increased by increasing the capacity of the pumped-storage plants) with a total energy generation of 1047 million kWh/yr in a region with a big deficit in peak capacity. c) To achieve in the limits of the USSR territory land improvement on a 147,000 ha area and to improve agricultural utilization of the land on a 57,000 ha area. d) To reduce soil erosion, to protect agricultural facilities, and to increase land productivity. e) The storage reservoirs would create favorable conditions for recreation and sports facilities.