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Cimanggu Wetan, Indonesia

McLeod M.K.,Tamworth Agricultural Institute | Slavich P.G.,Tamworth Agricultural Institute | Irhas Y.,Assessment Institute for Agricultural Technology | Moore N.,Tamworth Agricultural Institute | And 5 more authors.
Agricultural Water Management

The 2004 Indian Ocean tsunami inundated about 37,500 ha of coastal farmland in Aceh, and crops planted after the tsunami were severely affected by soil salinity. This paper describes the changes of soil salinity over time on tsunami affected farms and the implications for resuming crop production after natural disasters. Soil salinity and salt leaching processes were assessed across the tsunami affected region by measuring soil apparent electrical conductivity (ECa) using an electromagnetic induction soil conductivity instrument (EM38) combined with limited soil analysis. The ECa was measured 5 times between August 2005 and December 2007 in both the vertical (EMv) and horizontal (EMh) dipole orientations at 23 sites across Aceh. The level of salinity and direction of salt movement were assessed by comparing changes in mean profile ECa and relative changes in EMv and EMh. Eight months after the tsunami the average soil salinity in the 0-1.2 m soil depth varied from ECe 22.6 to 1.6 dS m-1 across sites in the affected region and three years after the tsunami it varied from 13.0 to 1.4 dS m-1. Soil salinity tended to be higher in rice paddy areas that trapped saline tsunami sediments and held seawater for longer periods. Leaching of salts occurred slowly by both vertical displacement and horizontal movement in surface waters. Hence, soil salinity persisted at a level which could reduce crop production for several years after the 2004 tsunami. High soil salinity persisted three years after the tsunami even though there had been more than 3000-7000 mm of accumulated rainfall to leach salts. The slow leaching is likely to have been due to the loss of functional drainage systems and general low relief of the affected areas. Monitoring of soil salinity with EM38 assisted local agricultural extension agencies to identify sites that were too saline for crops and determine when they were suitable for cropping again. The methodology used in this study could be used after similar disasters where coastal agriculture areas become inundated by seawater from storm surges or future tsunamis. Crown Copyright © 2009. Source

Verbist B.,Geo Institute | Poesen J.,Geo Institute | van Noordwijk M.,ICRAF SEA | Widianto,Brawijaya University | And 3 more authors.

Tropical deforestation and land use change is often perceived as the major cause of soil loss by water erosion and of sediment load in rivers that has a negative impact on the functioning of hydropower storage reservoirs. The Sumberjaya area in Sumatra, Indonesia is representative for conflicts and evictions arising from this perception. The purpose of this study as part of a Negotiation Support System approach was to assess sediment yield both at plot and catchment scale and to relate it to a variety of possible clarifying factors i.e. land use, geology, soil and topography. Sediment yield at catchment scale per unit area, was found to be 3-10 times higher than soil loss measured in erosion plots. A stepwise regression showed that the dominant factors explaining sediment yield differences at catchment scale in this volcanic landscape were a particular lithology (Old Andesites) and slope angle followed by the silt fraction of the top soil. In lithologically sensitive areas soil loss at the plot scale under monoculture coffee gardens decreases over time from on average 7-11 Mg ha- 1 yr- 1 to 4-6 Mg ha- 1 yr- 1, mainly because of the development of surface litter layers as filters and top soil compaction in the areas without litter, but remains higher than under shade coffee systems or forest. The runoff coefficient under monoculture coffee remains on average significantly higher (10-15%) than under forest (4%) or under shade coffee systems (4-7%). In lithologically stable areas soil loss remained below 1.8 Mg ha- 1 yr- 1 and the runoff coefficient below 2.5% under all land use types, even bare soil plots or monoculture coffee gardens. Less than 20% of the catchment area produces almost 60% of the sediment yield. The reduction of negative off-site effects on e.g. the life time of a storage reservoir would benefit greatly from an improved assessment of the lithologies in volcanic landscapes and the consideration of potential sediment source and sink areas. In lithologically sensitive areas, a shift from sun to shade coffee systems may result in reducing surface runoff and soil loss, although water erosion at the plot scale is not the main contributor to sediment yield at the catchment scale. The quantification of land use effects on dominant erosive processes such as river bank and river bed erosion, landslides and the concentrated flow erosion on footpaths and roads can contribute to more targeted efforts and relevant incentives to reduce (or live with) sediment load of the rivers. © 2009 Elsevier B.V. All rights reserved. Source

van Noordwijk M.,World Agroforestry Center | Agus F.,Indonesian Soil Research Institute | Dewi S.,World Agroforestry Center | Purnomo H.,Bogor Agricultural University
Mitigation and Adaptation Strategies for Global Change

Land-based emissions of carbon dioxide derive from the interface of forest and agriculture. Emission estimates require harmonization across forest and non-forest data sources. Furthermore, emission reduction requires understanding of the linked causes and policy levers between agriculture and forestry. The institutional forestry traditions dominated the emergence of the discourse on Reducing Emissions from Deforestation and forest Degradation (REDD+) while more holistic perspectives on land-based emissions, including agriculture, found a home in international recognition for Nationally Appropriate Mitigation Actions (NAMAs). We tested the hypothesis that, at least for Indonesia, the NAMA framework provides opportunities to resolve issues that REDD+ alone cannot address. We reviewed progress on five major challenges identified in 2007 by the Indonesian Forest Climate Alliance: 1) scope and 'forest' definition; 2) ownership and tenurial rights; 3) multiplicity and interconnectedness of drivers; 4) peatland issues across forest and non-forest land categories; and 5) fairness and efficiency of benefit-distribution mechanisms across conservation, degradation and restoration phases of tree-cover transition. Results indicate that the two policy instruments developed in parallel with competition rather than synergy. Three of the REDD+ challenges can be resolved by treating REDD+ as a subset of the NAMA and national emission reduction plans for Indonesia. We conclude that two issues, rights and benefit distribution, remain a major challenge, and require progress on a motivational pyramid of policy and polycentric governance. National interest in retaining global palm oil exports gained priority over expectations of REDD forest rents. Genuine concerns over climate change motivate a small but influential part of the ongoing debate. © 2013 The Author(s). Source

Maswar,Indonesian Soil Research Institute | Soelaeman Y.,Indonesian Soil Research Institute

An effort to increase the yield and reduce carbon loss from maize farming practices on Ultisols largely depend on fertilizer inputs and in situ crop residual management. The experiment aimed to estimate yields, biomass production and carbon dynamics of several management fertilization on maize farming practice on Ultisols has been conducted from March to July 2013 in Tamanbogo Experimental Farm, East Lampung. The experiment was set up as a randomized complete blockdesign, consisted of 6 treatments namely: 5 t ha-1 of cattle manure, 5 t ha-1 of dried sludge manure, and its combination with 200 kg urea ha-1 + 125 kg SP36 ha-1-1 + 50 kg KCl ha-1 (50% of recommended dose of inorganic fertilizers “RDIF”) and 75% of RDIF. The experimental results revealed that application of combined organic with inorganic fertilizers increased the biomass production, carbon fixation, and grain yield significantly. More than 50% of produced biomass and fixed carbon (grain, maize cob, maize husk, stems and leaves) were removed from maize farming. The use of organic fertilizer combined with NPK fertilizer at 50% of RDIF can be applied to increase the biomass production, organic carbon fixation and maize grain yield in sustainable ways. © 2016, Agriculture Faculty Brawijaya University. All rights reserved. Source

Soelaeman Y.,Indonesian Soil Research Institute | Maswar,Indonesian Soil Research Institute

This research was aimed to evaluate the kind and amount of feed consumed by 20 heads of cattle and the amount of manure produced, to evaluate the amount of biogas, sludge and slurry produced by digester and to study the application of manure, dried sludge manure, and NPK fertilization on the growth and yield of hybrid maize of Pioneer 27 (P27). Research was conducted from 2012 to 2013 in Tamanbogo Experimental Farm. Results showed that the total weight of feed consumed in the rainy and the dry season achieved the recommendation of 10% of the body weight of cattle. The average production of manure and urine was 11.25 kg head-1 day-1 with the biogas production of 3 m3 day-1 sufficient for cooking and lighting for 5 members of family daily. The by-product of biogas production was 8 kg day-1 of sludge and 127 L day-1 of slurry. The grain yield of P27 with application of dried sludge accompanied with 50% of NPK fertilizer recommendation dose gave the highest yield of P27 (4.45 t ha-1) with a profit Rp. 3,466,000 ha-1 and B/C of 1.5. © 2014, Agriculture Faculty Brawijaya University. All rights reserved. Source

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