Earthworm Population Density in Sugarcane Cropping System Applied with Various Quality of Organic Matter

Earthworms population in the soil are greatly impacted by agricultural management, yet little is known about how the quality and quantity of organic matter addition interact in sugarcane cropping system to earthworm population. This study describes the effect of various organic matter and application rates on earthworms in sugarcane cropping system. Earthworms were collected in April, July and December from 48 experimental plots under five kinds of organic matter application : (1) cattle manure, (2) filter cake of sugar mill, (3) sugarcane trash, (4) mixture of cattle manure+filter cake, and (5) mixture of cattle manure+sugarcane trash. There were three application rates of the organic matter (5, 10, and 15 ton ha-1). The treatments were arranged in factorial block randomize design with three replications and one treatment as a control (no organic input). Earthworms were collected using monolith sampling methods and hand-sorted from each plot, and measured its density (D) (indiv.m-2), biomass (B) (g m-2) and B/D ratio (g/indiv.). All the plots receiving organic matter input had higher earthworm density, biomass, and B/D ratio than the control. The highest earthworm population density was found in the plot receiving application of sugarcane trash (78 indiv.m-2) and the mixture of cattle manure+sugarcane trash (84 indiv.m-2). The increase in application rates of organic matter could increase the earthworm density and biomass. Earthworm population density also appeared to be strongly influenced by the quality of organic matter, such as the C-organic, N, C/N ratio, lignin, polyphenols, and cellulose content. Earthworm preferred low quality organic matter. It was caused by the higher energy of low quality organic matter than high quality organic matter. Our findings suggest that the input of low quality organic matter with application rate as 10 ton ha-1 is important for maintaining earthworm population and soil health in sugarcane land

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 > 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

Agroforestry Interactions in Rainfed Agriculture: Can Hedgerow Intercropping Systems Sustain Crop Yield on an Ultisol in Lampung (Indonesia)?

The productivity of rainfed agriculture land developed on Ultisols is limited by physical and chemical constraints. These problems can be solved and consistently high yields obtained only by the development of comprehensive manage-ment systems. In the 1980s, hedgerow inter-cropping was promoted initially for improving soil fertility and sustainability of crop production on nutrient-depleted soils. However the previous enthusiasm for hedgerow intercropping is unsupported by scientific evidence and its labour demand too high. The question remains, is there a window of opportunity where the biophysical principle of hedgerow intercropping is sound? Research to compare the long-term performance of crops and trees in hedgerow intercropping and monocluture cropping is needed. This research has been conducted at long-term field experiment station at the BMSF-Project, Lampung, Indone-sia. The experiment site had non-nitrogen-fixing peltophorum (PP), nitrogen-fixing gliricidia (GG) and alternate peltophorum and gliricidia (PG) hedgerow intercropping and maize / groundnut monoculture (C) treatments. We concluded that the net interactions related to soil fertility and competition for growth resources in peltophroum were positive for crop yield in PP and PG but negative for GG. Even so, the PP and PG sys-tems resulted in similar yields as monocropping; however, hedgerow intercropping considerably improved soil fertility attributes

Study of Arthropod Communities in a Virginia Tobacco Agro-Ecosystem

The cultivation of tobacco is one of users of agro-chemical substances such as insecticides, herbi-cides, defoliants, and fertilizers among other food crops and plants with high economical value. The use of these chemicals may bring negative effects regarding the richness and abundance of arthropods. The study of arthropod community in the Virginia tobacco ecosystem was carried out in Central Lombok, West Nusa Tenggara Province, during the 2010 plantation year. It was aimed at finding the composition, structure, and dynamic of the arthropod diversity around the tobacco field. Samples were obtained by using trapping techniques (pitfall traps, yellow-pan traps, and sweep net). The number of arthropods found in Virginia tobacco field are 69, consisting of 65 species of insects (belonging to 46 families and 8 orders) and 4 species of spiders (belonging to 4 families). The majority of insects found was Hymenoptera, dominated by bees. Based on the ecological functions, the major group of arthro-pods documented was phytophagous (20 species), mostly Coleoptera and Orthoptera. Yet, the number of predators was relatively more abundant than that of the phytophagous. The number of kinds of ar-thropods commonly interacting around the field fluctuated during the growing period, while in the cultivation period the number decreased. The diversity of the species (H) and the ratio of abundance of the natural enemies and phytophagous in the field was high