Association of arbuscular mycorrhizal fungi (AMF) with plant roots is often stated as critical to the successful establishment and diversification of terrestial plants. Information on AMF associations with Lycopodiaceae, ancient lineages of terrestrial plants, contributes to the understanding of terrestrial colonization of plants. While diversity of AMF and other fungal endophytes of some agricultural plants in Indonesia is extensively studied, terresterial Lycopodiaceae are not well documented. In this study, colonization status of AMF and root endophytic fungi (REF) in sporophytes of terresterial Lycopodiaceae (Huperzia selago, H. serrata and Lycopodium clavatum) inhabiting Mt. Pangrango at different altitudes were investigated on the basis of root microscopic observations and culture-dependent methods, respectively. As results, AMF colonization was observed in H. selago collected from near summit (NS, 2998 m asl) and H. serrata collected from Kandang Badak (KB, 2440 m asl) and Cibereum Water Fall (CF, 1728 m asl), but not in L. clavatum from Mount Pangrango Summit (PS, 3019 m asl). These results indicate that the colonization rate of AMF is affected by differences in altitude. REF isolates consisting of seven genera including Cadophora, Cladophialophora, Cryptosporiopsis, Leohumicola, Leptodontidium, Phialocephala, Pseudoclathrosphaerina (putatively similar to Meliniomyces), and ecologically uncertain Helotiales were obtained. These isolates contained putative dark septate endophytes (DSE) and ericoid mycorrhiza and were more diverse around sub-alpine areas (NS, KB and PS sites) than in motane areas (CF site). The presence of these REF may be affected by a complex and mixed plant vegetation in the transition zone between the montane and sub-alpine areas.
Land use optimization for agriculture is an attempt to increase the utilization of land resources by matching agricultural land with the most productive crop to both expand the plantable area and maximize productivity. The expansion of the cultivated area is actively occurring in the eastern Indonesian, region of East Seram, Maluku Province. One of the prospective commodity crop planned for the region is sugarcane (Saccharum spp.). The method used for evaluating land for determining optimal land use is land suitability analysis, a combination of multi-criteria decision making and GIS mapping. We used multi-criteria decision making to identify the optimal area for sugarcane plantations and sugar industries, using criteria to identify land suitable for sugarcane growing in three suitability classes, very suitable, suitable and unsuitable, subject to achieving economic viability for a sugar mill. Mill viability was based on the ability of the planted area to support at least a minimum number of cane milling days per years (150/y), and a daily production target of ≥8,000 tonnes cane crushed per day (TCD). In East Seram district our analysis of a selected 206,235 ha are identified 34,894 ha in suitability classes highly suitable, moderately suitable and marginally suitable. The identified optimal area was estimated to be capable of producing 2,119,424 tonnes of sugarcane per year, yielding a mill productivity of 14,129 TCD over the crushing season, thus indicating strong economic viability for a single mill but possibly not for two mills.
Inadequate management of nitrogen and water stress are the main factors underlying poor growth and yield in maize (Zea mays L.). To evaluate the effects of nitrogen and water stress on the growth and physiology of maize plants, two field experiments were conducted at the National Corn and Sorghum Research Center, Thailand, during 2010-2011 and 2012 under short pre-anthesis drought and prolonged flowering-stage drought, respectively. A split-plot design with factorial randomized complete block arrangement was used for the experiment, with two water regimes (well-watered and water-stressed) forming the main plots and two maize hybrids (Pioneer 30B80 and Suwan 4452) and three nitrogen levels (0, 160 [optimal] and 320 [supra-optimal] kg N ha−1) forming the subplots. We found that supra-optimal nitrogen (urea) temporarily changed the soil pH significantly. Optimal nitrogen and well-watered conditions enhanced the net assimilation rate at the vegetative stage (NARv), ovule number per primary ear (ONpe), leaf area duration in the reproductive period (LADr), specific leaf weight at anthesis (SLWa), current assimilate transfer to kernels (CATK), chlorophyll content at anthesis (Chla), nitrogen use efficiency, biomass yield, and kernel yield per plant (KYP). In contrast, supra-optimal and zero nitrogen and water stress had detrimental effects on these parameters, except Chla. Prolonged flowering-stage drought was found to be more detrimental than short pre-anthesis drought regarding plant performance. Greater root-to-shoot ratio, LADr, Chla, nitrogen use efficiency, NARv, and ONpe were recorded as traits of nitrogen and water-stress tolerance in Pioneer 30B80. The optimal nitrogen level improved drought resistance, especially under short pre-anthesis drought. The correlations between KYP and LADr, Chla, NARv, ONpe, and CATK were positive and highly significant, and NARv, ONpe, and CATK had significant and positive direct effects on KYP under both short pre-anthesis and prolonged flowering-stage drought.
Climate change could have significant impacts in the Philippines on large sections of the population who are poor and vulnerable, especially those who live in areas prone to coastal storms, drought and sea level rise. The sectors mostly affected by climate change are agriculture and food security because of the risk of low productivity due to increasing temperature, drought, and increasing frequency and intensity of rainfall that brings about floods and landslides. Located in the northernmost tip of the country, the Batanes group of islands lies on the country’s typhoon belt. Because of vulnerability and isolation from the rest of the archipelago, the Ivatans have developed self-sufficient, organic and climate-resilient crop production systems. This paper presents the indigenous crop production systems that have made the Ivatans food self-sufficient despite vulnerability of their agroecosystem. A typical Ivatan farmer owns 3-7 parcels of land. Each parcel has an average size of 300-500 m2. Farmers practice a rootcrop-based multiple cropping system with specific spatial arrangements of corn (Zea mays), gabi (Colocasia esculenta), yam (Dioscorea alata) and tugui (Dioscorea esculenta), using corn stover, hardwood trees or a local reed called viyawu (Miscanthus sp.) as trellis. Banana (Musa sp.) and assorted vegetables are planted around the parcels. One to two parcels are planted per season and the rest are left to fallow and used as grazing areas for cattle. The same crops are planted on the other parcels in the next season and the first two parcels utilized will again be planted only after 3-5 years. This unique fallow system maintains soil fertility without the use of chemical fertilizers. They also practice an indigenous storage system that involves hanging of their harvest such as corn, rice, garlic and onion bulbs, even meat and fish, above the firewood-fed cooking area. For generations, the Ivatan farmers’ indigenous agricultural production systems have ensured a food security at the household level.
Biodiesel is a renewable fuel that is produced from oils derived from plants, animals, or microbes. It is nontoxic and biodegradable. Various methods such as transesterification, blending, cracking, microemulsification, and pyrolysis have been developed to convert oils from biological sources into biodiesel that is comparable to diesel fuel. Transesterification, by a number of consecutive reversible reactions, is the most common method: triglycerides are converted stepwise to diglycerides, monoglycerides, and finally glycerol, with the liberation of fatty acid methyl ester defined as biodiesel at each step. Generally, an alcohol and a catalyst are needed for transesterification of triglycerides. Microalgae are microscopic (2-200 μm), autotrophic organisms that can grow by photosynthesis. Most are eukaryotes, but the prokaryotic cyanobacteria are often included. Some microalgae contain more than 70% (w/w, dry basis) lipids. Microalgae grow extremely rapidly under optimal conditions and can grow 100 times faster than terrestrial plants. The oil yield from microalgae containing 30% oil content is 58700 L ha-1 year-1, which is much higher than that from other crops (e.g., 636 L ha-1 year-1 for soybean and 5366 L ha-1 year-1 for oil palm). Importantly, microalgal cultivation need not encroach on arable land suitable for food production. Currently, there are several areas of research on transesterification of microalgal oil. The conversion efficiency of biodiesel production via transesterification depends on microalgal characteristics, amount and type of alcohol used, catalyst, operating temperature, and reaction time. This study reviews the technologies that generate biodiesel from microalgae by transesterification. The relative performances of alkaline, acidic, and enzymatic catalysts are evaluated. New techniques used in biodiesel production, e.g., methods using microwaves and supercritical solutions, are discussed.