The Role of Terraced Paddy Fields and Its Critical Issues in Sustaining a Mountainous Tropical Monsoon Rural Community: Case Study of Malasari Village, Bogor Regency, Indonesia

Terraced paddy fields play an important role not only in the food production function, but also in flooding control, water source recharge, and soil erosion and landslide prevention in mountainous area. Abandonment has been occurring in many countries due to natural condition climate, low-productive, less economic condition, depopulation, aging, and poor work efficiency. However, the terraced fields in Malasari village, Bogor Regency are relatively sustained and constantly maintained by traditional local farmers. Therefore, this study aims to seek keys to how to maintain of the terraced paddy fields by local farmers in Malasari village. The survey was conducted from October 2019 to January 2020 on Malasari village (6°40’S and 106°31’E) by using primary and secondary data with a sample of 28 households. Questionnaire survey was conducted to elicit primary data on farmer’s basic information. Verification of land cover in Malasari village was carried out by visual interpretation land cover in images obtained from drone image in 2019. The terraced paddy fields have been maintained by local farmers contentiously. Two factors are discovered maintained the terraced paddy fields, namely: (1) the local wisdom technique is an act that has direct influences on the physical structure of terraced paddy fields for maintaining, especially land management which is plowing and making levee are playing an important role, and (2) social capital is an act that has indirect influences on the terraced paddy fields. These factors interact with each other to maintain the terraced paddy fields

Effects of clearcutting and girdling on soil respiration and fluxes of dissolved organic carbon and nitrogen in a Japanese cedar plantation

Impacts of forest management practices on soil carbon (C) and nitrogen (N) dynamics remain under debate due to complex interactions between belowground biogeochemical processes. To optimize practices that minimize soil C and N losses, we investigated the effects of management practices on soil C and N fluxes, including the leaching of dissolved organic C (DOC) and N, by comparing clearcutting, stem girdling (removal of the bark and phloem tissue), and control treatments in a Japanese cedar plantation. Canopy opening by clearcutting is hypothesized to have a greater effect on soil C loss and the leaching of nitrate-N relative to girdling. Results showed that clearcutting increased soil heterotrophic respiration (organic matter decomposition) and lead to a loss of soil organic C (2.9–3.7 Mg C ha⁻¹ yr⁻¹). Higher litter inputs from girdled tree dieback caused an increase in DOC fluxes from the organic horizon, whereas the loss of fresh litter inputs decreased DOC fluxes from the organic horizon following clearcutting. Clearcutting increased nitrate-N leaching by 3.3–4.8 kg N ha⁻¹ yr⁻¹ due to the loss of plant N uptake and the increased mineralization of soil organic matter, but high C/N ratios in dissolved organic matter limited nitrate leaching in the girdled treatment. Effects of forest management practices on soil C loss and nitrate leaching loss could be variable, but the slash application in clearcutting and the slow dieback in stem girdling could mitigate soil C loss and nitrate leaching loss

Disentangling the pedogenic factors controlling active Al and Fe concentrations in soils of the Cameroon volcanic line

Active Al, Fe and Si (i.e., oxalate extractable fraction: Alo, Feo, Sio) strongly affect soil physical, chemical and biological properties. This study examined the pedogenic factors affecting Alo, Feo and Sio contents across a soil weathering sequence in the Cameroon volcanic line. We investigated the B horizon (∼50-cm depth) from 26 soils formed in basaltic materials at different elevations (110–2570 m) incorporating a wide range of temperature (14–27 °C) and precipitation (1520–3130 mm). The weathering sequence ranged from weakly weathered Andisols in the southwest region grading to strongly weathered Oxisols on the central highlands. We assumed pyrophosphate extractable Al/Fe (Alp/Fep) as organo-Al/Fe complexes, and Sio, (Alo − Alp) and (Feo − Fep) as short-range-order (SRO) minerals. Factor analysis of climatic (e.g., temperature and precipitation/leaching metrics) and soil geochemical properties (e.g., weathering indices) identified three independent factors representing temperature/dry season intensity, weathering degree and precipitation/leaching as the primary determinants of Alo, Feo and Sio concentrations. Organo-metal complexes (Alp and Fep) were negatively correlated with the temperature/dry season intensity factor, whereas the SRO mineral phases (Sio, Alo − Alp and Feo − Fep) were negatively correlated with weathering degree. The precipitation/leaching factor positively correlated with Alo, Feo and Sio. Our analysis infers that low temperature promotes the formation and preservation of organo-Al/Fe complexes, whereas weathering degree is more critical for SRO minerals. Further, increased weathering and a drier climate enhance the formation of crystalline clay minerals at the expense of SRO minerals. Allophanic materials (Sio) were evident (Sio: 9–43 g kg⁻¹) only in weakly weathered soils. However, low allophanic contents were found in more highly weathered soils (Sio: 2–7 g kg⁻¹) accompanied by high Alp and Fep, suggesting the importance of volcanic parent materials as a direct source of Al and Fe via weathering for the formation of organo-metal complexes. In sum, we clarified the discriminatory effects of climatic factors and degree of weathering in regulating the composition of the active Al, Fe and Si fractions along the Cameroon volcanic line

Farmers’ perspectives as determinants for adoption of conservation agriculture practices in Indo-Gangetic Plains of India

Understanding the farmer's perspective has traditionally been critical to influencing the adoption and out-scaling of CA-based climate-resilient practices. The objective of this study was to investigate the biophysical, socio-economic, and technical constraints in the adoption of CA by farmers in the Western- and Eastern-IGP, i.e., Karnal, Haryana, and Samastipur, Bihar, respectively. A pre-tested structured questionnaire was administered to 50 households practicing CA in Western- and Eastern-IGP. Smallholder farmers (<2 ha of landholding) in Karnal are 10% and Samastipur 66%. About 46% and 8% of households test soil periodically in Karnal and Samastipur, respectively. Results of PCA suggest economic profitability and soil health as core components from the farmer's motivational perspective in Karnal and Samastipur, respectively. Promotion and scaling up of CA technologies should be targeted per site-specific requirements, emphasizing biophysical resource availability, socio-economic constraints, and future impacts of such technology

京都府北部の天然林下における土壌生成過程に関する研究

本文データは平成22年度国立国会図書館の学位論文(博士)のデジタル化実施により作成された画像ファイルを基にpdf変換したものである京都大学0048新制・課程博士博士(農学)甲第5467号農博第767号新制||農||656(附属図書館)学位論文||H5||N2591(農学部図書室)UT51-93-J522京都大学大学院農学研究科農芸化学専攻(主査)教授 久馬 一剛, 教授 古川 久雄, 教授 岩坪 五郎学位規則第4条第1項該当Doctor of Agricultural ScienceKyoto UniversityDFA

Production of indigenous alcoholic beverages in a rural village of Cameroon

In this study, the indigenous alcoholic beverages in a rural village of Cameroon were investigated. The technique for producing alcoholic beverages in the village was observed, and the concentrations of ethanol, glucose and lactic acid and the pH values during the course of production were measured using portable devices at the field site. Eight different kinds of alcoholic beverage (palm wine, palm spirits, raffia wine, cassava spirits, maize turbid beer, maize spirits, plantain wine and plantain spirits) were produced and consumed in the village. Of these beverages, palm wine, made from palm sap, was the most important alcoholic beverage in a villager's daily life. In addition, starch-based alcoholic beverages were distilled rather than drunk directly. As germinated maize, which has a relatively low amylase activity, was used as an amylase source in production, starch-based alcoholic beverages might need to be distilled to enhance the ethanol concentration. During the course of production, the pH was reduced using local techniques, which proved to be effective in preventing bacterial contamination

Management of wood resources: A dilemma between conservation and livelihoods in a rural district in the Aral region

This study focused on black saxaul (Haloxylon aphyllum) and tamarisk (Tamarix hispida), which are economically and environmentally important trees in one of the most arid parts of the Aral region. Black saxaul is the main local fuelwood species. However, its extraction was banned after it became critically endangered in the 1990s. Planting this species is now regarded as essential for rehabilitating the Aralkum Desert in light of the Aral Sea crisis. Tamarisk is another fuelwood species that supports local livelihoods. We administered questionnaires among residents in Karateren district and conducted interviews with some residents and with policymakers responsible for regulating forest management. The findings revealed a significantly higher preference for black saxaul than for tamarisk among residents, with a high potential demand for the former. Moreover, some residents observed a decrease in tamarisk biomass, which could accelerate as a result of constant population growth in the study district. We recommend conducting an assessment of logging sites and establishing a feedback system involving local communities to develop risk management that can address future shortages in wood supplies and over logging. Political decision making should also consider the uneven preferences of residents of this region for fuelwood species

The fate of caesium-137 in a soil environment controlled by immobilization on clay minerals

Caesium-137 (137Cs), with its high release rate and long half life, is the most important longterm contributor to environmental contamination of all the radionuclides released by the accident at the Fukushima Dai-ichi nuclear power plant in March 2011. There have been many surveys of the fate of 137Cs in terrestrial environments, especially after the atmospheric nuclear tests of the 1950s and 60s and the Chernobyl accident in 1986. Previous surveys revealed that most of the 137Cs deposited on land remains in the surface soil for decades and that 137Cs rarely exchanges with other cations (atoms that have lost an electron to become positively charged). The immobilization of 137Cs in soil is mostly ascribed to selective adsorption on clay minerals, particularly on illitic minerals. 137Cs is irreversibly retained at the fringe of the layered structure of illitic minerals, called the frayed-edge site, with much higher selectivity than other cations. Comparison of the radiocaesium interception potential (RIP) between soils and clay minerals indicates that the difference in the frayed-edge site capacity is largely dependent on the degree of weathering and the degree of hydroxy-Al interlayering in illitic minerals. Here we investigate the difference in the RIP values between mineral soils to predict the level of contamination of crops grown in 137Cs contaminated fields