Pemberdayaan Kelompok Tani Pattunggalengan di Kabupaten Takalar melalui inovasi budidaya bawang merah

Shallots are one of the horticultural crops cultivated by the Pattunggalengan Farmer Groups in Banggae Village, Takalar Regency, whose production is decreasing. The decline in production is influenced by application inorganic systems and use of seeds that are not superior because they come from multiplied tillers and cultivation systems that are semi-manual. The purpose of this activity’s to provide counseling and assistance on onion cultivation innovation in Pattunggalengan Farmer Groups, from selecting seeds, making planting demonstration plots, fertilizing, planting, watering and harvesting. The method used was discussion group forum and making of planting demonstration plot using Super Philip and drip irrigation. The soil pH condition demonstration plot location was 6.5, which classified optimal but was given organic fertilizer to provide macro nutrients, shallot seeds by giving mankozeb fungicide with drip irrigation watering system on each sample bed. The yield obtained with 100 kg and the number of seeds were 250 kg/100 m2. The counseling and mentoring that was carried out made the Pattunggalengan farmer know good soil cultivation, superior seeds and production resulting from the innovation of shallot cultivation

Effects of Sample Plot Size and GPS Location Errors on Aboveground Biomass Estimates from LiDAR in Tropical Dry Forests

Accurate estimates of above ground biomass (AGB) are needed for monitoring carbon in tropical forests. LiDAR data can provide precise AGB estimations because it can capture the horizontal and vertical structure of vegetation. However, the accuracy of AGB estimations from LiDAR is affected by a co-registration error between LiDAR data and field plots resulting in spatial discrepancies between LiDAR and field plot data. Here, we evaluated the impacts of plot location error and plot size on the accuracy of AGB estimations predicted from LiDAR data in two types of tropical dry forests in Yucatán, México. We sampled woody plants of three size classes in 29 nested plots (80 m2, 400 m2 and 1000 m2) in a semi-deciduous forest (Kiuic) and 28 plots in a semi-evergreen forest (FCP) and estimated AGB using local allometric equations. We calculated several LiDAR metrics from airborne data and used a Monte Carlo simulation approach to assess the influence of plot location errors (2 to 10 m) and plot size on ABG estimations from LiDAR using regression analysis. Our results showed that the precision of AGB estimations improved as plot size increased from 80 m2 to 1000 m2 (R2 = 0.33 to 0.75 and 0.23 to 0.67 for Kiuic and FCP respectively). We also found that increasing GPS location errors resulted in higher AGB estimation errors, especially in the smallest sample plots. In contrast, the largest plots showed consistently lower estimation errors that varied little with plot location error. We conclude that larger plots are less affected by co-registration error and vegetation conditions, highlighting the importance of selecting an appropriate plot size for field forest inventories used for estimating biomass.

Local Spatial Heterogeneity of Holocene Carbon Accumulation throughout the Peat Profile of an Ombrotrophic Northern Minnesota Bog

ABSTRACTWe evaluated the spatial heterogeneity of historical carbon accumulation rates in a forested, ombrotrophic bog in Minnesota to aid understanding of responses to an ongoing decade-long warming manipulation. Eighteen peat cores indicated that the bog has been accumulating carbon for over 11,000 years, to yield 176±40 kg C m−2 to 225±58 cm of peat depth. Estimated peat basal ages ranged from 5100 to 11,100 cal BP. The long-term apparent rate of carbon accumulation over the entire peat profile was 22±2 kg C m−2 yr−1. Plot location within the study area did not affect carbon accumulation rates, but estimated basal ages were younger in profiles from plots closer to the bog lagg and farther from the bog outlet. In addition, carbon accumulation varied considerably over time. Early Holocene net carbon accumulation rates were 30±6 g C m−2 yr−1. Around 3300 calendar BP, net carbon accumulation rates dropped to 15±8 g C m−2 yr−1 until the last century when net accumulation rates increased again to 74±57 g C m−2 yr−1. During this period of low accumulation, regional droughts may have lowered the water table, allowing for enhanced aerobic decomposition and making the bog more susceptible to fire. These results suggest that experimental warming treatments, as well as a future warmer climate may reduce net carbon accumulation in peat in this and other southern boreal peatlands. Furthermore, our we caution against historical interpretations extrapolated from one or a few peat cores.