Aluminium tolerance of <i>Mucuna</i>:A tropical leguminous cover crop

In the humid tropics leaching of N and other nutrients to the subsoil may occur throughout the growing season. Typically, soils in this zone have a low soil pH, a high Al saturation of the cation exchange complex and low levels of Ca and P in the subsoil. Efficiency of N-use under such conditions generally is very low, due to a combination of high leaching rates and shallow root development. The ability to develop a deep root system is important in this sítuation for recovery of nutrients leached early on. ... Zie: Summar

Soil Carbon Transitions Supporting Climate Change Mitigation

Maintaining and where feasible restoring soil carbon stocks is part of all sustainable development strategies that have a chance of meeting the global commitment of the Paris Agreement to contain global warming within a 1.5oC limit. Active policies to incentivize increased soil carbon storage require under­standing of the drivers of soil carbon decline, as well as the conditions under which soil management leads to an increase. Soil carbon transitions -- shifts from decline to increase of soil carbon stocks -- have been recorded as part of agricultural intensification. Organic inputs supporting soil carbon may primarily depend on roots, rather than aboveground inputs, and thus on the choice of crops, trees, and grasses that make up an agricultural land use system

Are High Carbon Stocks in Agroforests and Forest Associated with High Plant Species Diversity?

Conserving plant diversity and retaining terrestrial carbon stocks are targets for environmental policy and appear to be generally compatible. However, detailed information on the way both respond to agroforestry management is lacking. Rubber and fruit tree agroforestry systems combine planted trees and trees that are tolerated or actively managed that derived from natural vegetation. The research aimed to evaluate plant species diversity, vegetation structure, and C stock in rubber agroforestry system (AF) and secondary forest grown in silty clay and sandy soils in Pulang Pisau Regency, Central Kalimantan province. A number of multistrata agroforestry systems was compared to the secondary (natural) forests (SNF) of the area; these included Fruit-Based Rubber Agroforestry (AFB) of about 100 years of age, Old Rubber Agroforestry (ARO) and Young Rubber Agroforestry (ARY). The highest C stock was found in AFB (415 Mg ha-1), while the average C stocks of other AF and SNF were 217 Mg ha-1. A plant diversity index (H') was only weakly correlated to aboveground C stocks. Including the farmer-managed agroforests in schemes to reduce emissions from deforestation and forest degradation is relevant, as their carbon stocks match or exceed those of remaining forests in the area

Manipulasi Cahaya Untuk Menurunkan Kelimpahan Nematoda Parasit Tumbuhan Pada Pembibitan Kopi

Light manipulation to reduce the plant parasitic nematodes abundance on coffee nursery. Plant parasitic nematode problem on monoculture coffee can be caused not only by the suitable hosts but also by the environmental changes, such as soil water content and soil temperature. A semi-field experiment was conducted in Sumberjaya, West Lampung on May-September 2007 with the aim to study the effect of shading levels and fertilizer levels of coffee nursery on plant parasitic nematodes abundance. The results showed that the shading level treatment on coffee nursery significantly affected the abundance of plant parasitic nematodes but did not affect the free-living nematode abundance. The relationship between the plant parasitic nematode abundance with the shading level is polynomial with the highest nematode abundance (500 individual/300 ml of soil) was under 40% shading level. The increase in shading level indirectly affected the increase in plant parasitic nematode abundance through the increas in of soil water content. Inorganic N, P and K fertilizer at the recommended level for coffee nursery increased the abundance of plant parasitic nematodes from 216 to 282 individual/300 ml of soil. The interaction between the shading level and fertilizer did not significantly affect the plant parasitic nematode abundance

Plant Species Diversity in Relation to Carbon Stocks at Jangkok Watershed, Lombok Island

The area around Jangkok watershed has changed, dividing it into some land use systems. This research aimed to study the effect of plant species diversity onC-stocks, and to analyse the characteristics of land use systems based on their similarity. The observations were carried out on 18 plots representing six land use systems in Jangkok watershed (Lombok Island) i.e. primary forest (PF), disturbed forest (DF), Mahogany- woodlot (MW), candlenut- agroforestry (CA), multistrata- agroforestry (MA), and simple- agroforestry (SA).The species diversity level was measured using Shannon-Weiner diversity index, whileC-stocks according to the method of RaCSA (Rapid Carbon Stock Appraisal). Results showed that forest conversion to agricultural land usesreduced the number and density of the species, average wooddensity andtree basal area. The PF represented the highest biodiversity index (3.46), while the other land uses were categorised in medium and low. Largest C-stock wasfound inPF and in(30 years old) of MWaveraged of 500 Mg ha-1, while the lowest was in SAof 68 Mg ha-1, while in other land uses was 219 Mg ha-1.The quantity of C-stock was not related tospecies diversity and its density, but closely related (pof tree (R2=0.84), basal area of all sizes tree (R2=0.86), and with the basal area of big trees (diameter &gt; 30 cm) (R2=0.71). Based on the number and species density, agroforestry system (MA and CA) resembled the characteristics of natural forest (DF and PF)./spanEN-GBspan style