Climate Change Impacts and Adaptation in a Hill Farming System of the Himalayan Region: Climatic Trends, Farmers’ Perceptions and Practices

Farming communities in the hills and mountains of the Himalayan region are some of the most vulnerable to the changing climate, owing to their specific biophysical and socioeconomic conditions. Understanding the observed parameters of the changing climate and the farmers’ perceptions of it, together with their coping approaches, is an important asset to making farming communities resilient. Therefore, this study aimed to explore the observed change in climatic variables; understand farmers’ perceptions of the changing climate; and document their adaptation approaches in farming systems in the mid-hills of the central Himalayas. Data on the observed change in climatic variables were obtained from the nearby meteorological stations and gridded regional products, and farmers’ perceptions and their adaptation practices were collected from household surveys and from the interviews of key informants. The analysis of temperature data revealed that there has been a clear warming trend. Winter temperatures are increasing faster than summer and annual temperatures, indicating a narrowing temperature range. Results on precipitation did not show a clear trend but exhibited large inter-annual variability. The standardized precipitation index (SPI) showed an increased frequency of droughts in recent years. Farmers’ perceptions of the changing climate are coherent with the observed changes in climatic parameters. These changes may have a substantial impact on agriculture and the livelihood of the people in the study area. The farmers are adapting to climate change by altering their farming systems and practices. Location-specific adaptation approaches used by farmers are valuable assets for community resilience

Climate Change Impacts and Adaptation in a Hill Farming System of the Himalayan Region: Climatic Trends, Farmers’ Perceptions and Practices

Farming communities in the hills and mountains of the Himalayan region are some of the most vulnerable to the changing climate, owing to their specific biophysical and socioeconomic conditions. Understanding the observed parameters of the changing climate and the farmers’ perceptions of it, together with their coping approaches, is an important asset to making farming communities resilient. Therefore, this study aimed to explore the observed change in climatic variables; understand farmers’ perceptions of the changing climate; and document their adaptation approaches in farming systems in the mid-hills of the central Himalayas. Data on the observed change in climatic variables were obtained from the nearby meteorological stations and gridded regional products, and farmers’ perceptions and their adaptation practices were collected from household surveys and from the interviews of key informants. The analysis of temperature data revealed that there has been a clear warming trend. Winter temperatures are increasing faster than summer and annual temperatures, indicating a narrowing temperature range. Results on precipitation did not show a clear trend but exhibited large inter-annual variability. The standardized precipitation index (SPI) showed an increased frequency of droughts in recent years. Farmers’ perceptions of the changing climate are coherent with the observed changes in climatic parameters. These changes may have a substantial impact on agriculture and the livelihood of the people in the study area. The farmers are adapting to climate change by altering their farming systems and practices. Location-specific adaptation approaches used by farmers are valuable assets for community resilience

家畜排泄物コンポスト水抽出液で種子処理した飼料作物の生育反応における種間ならびに指標間差異

家畜排泄物コンポストの作物生育阻害効果の検定方法について検討した。7種の飼料作物(トウモロコシ、ソルガム、イタリアンライグラス、シコクビエ、アカクローバー、アルファルファ、ダイズ)とコマツナの種子発芽と初期生育に及ぼす14種の家畜排泄物コンポストの阻害効果を室内実験で比較した。阻害効果の指標として、処理後72時間の発芽率、草丈、根長、新鮮重、乾物重を測定した。コンポストの阻害効果は検定値物や指標間で異なり、単一の植物種の特定の測定指標でコンポストの阻害効果を判定することは困難であった。これらの結果は、コンポスト中の毒性成分とその作用が植物種間で異なりうることを示しており、阻害物質の同定とそれらの阻害作用機構を明らかにすることが必要である。Experiments were conducted to find the best assay method to evaluate the inhibitory effects of animal-waste composts on crop growth. The inhibitory effects of 14 kinds of animal-waste composts on seed germination and seedling growth of 7 forage crops (corn, sorghum, Italian ryegrass, African millet, red clover, alfalfa and soybean) and Komatsuna (Brassica rapa L) were tested under laboratory conditions. The parameters measured were seed germination rate and root length, shoot length, fresh weight and dry weight of 72 h old seedlings. The inhibitory effects of animal-waste composts varied among the test plant species and parameters. It is difficult to evaluate the inhibitory effects of a given compost by using a given parameter of a single plant. These results indicate that toxic substances in composts and their activity differ among the crop plant species. The necessity to identify the causal substances and to clarify their mode of action in plant growth is also indicated

Increased rate of potassium fertilizer at the time of heading enhances the quality of direct seeded rice

Abstract Background Potassium (K) is not easily assimilated into organic matter but helps to improve rice quality. Paddy yield and its quality depend on the correct time of fertilization and harvesting (days after flowering) in the field. Methods Changes in the grain quality of (Oryza sativa L.) were studied in a field experiment over two dry seasons using three rates of muriate of potash (MOP; 60% K2O) as 12.5, 25 and 37.5 kg/ha applied at the time of heading (7 weeks after planting—WAP). Paddy samples were harvested during 25, 30 (control), 35 and 40 days after 50% flowering (DAFF). Grain yield and physico-chemical characteristics of grain were studied after harvesting. Results The impact of seasons and treatments’ interactions was not statistically significant (P > 0.05) and, hence, data were averaged over two seasons. Length, breadth, true density and bulk density of rice grains were the highest with 37.5 kg MOP/ha applied at heading and harvested at 30–35 DAFF. Crude protein (6.24%) and crude fat (2.61%) contents in grains were the highest when harvested at 40 DAFF and 35–40 DAFF, respectively. Amylose content decreased with increased MOP rates at the time of heading and delayed paddy harvest. The highest average paddy yield (APY; 6.85 t/ha), head rice yield (HRY; 65%) and total rice milling yield (TMY; 67%) were recorded with 37.5 kg MOP/ha applied at heading of rice plant and paddy harvested at 35 DAFF. The APY, HRY and TMY were also 13.8, 7.7 and 5.9% higher, respectively, compared to the control. Applying K fertilizer at a rate 50% more (18.75 kg K/ha) than the recommended rate at the time of heading (7 WAP) and harvesting paddy at optimum maturity (35 DAFF), which is 5 days later than the recommendation, increase the yield and grain quality of direct seeded rice. Harvesting later than 35 DAFF resulted in a 10.5% loss of HRY (P < 0.05). Conclusions The present study showed that K fertilizer applied at the rate of 37.5 kg MOP/ha at the time of heading 50% higher than the recommended rate is the best among K fertilizer treatments to obtain the highest HRY

Distribution of Exchangeable Magnesium in Lowland Rice-Cultivated Soils of Sri Lanka as Affected by the Differences in Climate, Soil, and Water Source

Magnesium (Mg) is an essential macronutrient for plants. Even though Sri Lankans consume rice as the staple food, the Mg status in Sri Lankan paddy soils as affected by its climate, soils, and water sources used are not well understood. This study was conducted to (i) determine the distribution of exchangeable Mg (ex-Mg) concentration, and (ii) examine the interactive effects of agro-climatic zones (ACZs), soil order, and water source in determining the ex-Mg concentra-tion in lowland paddy fields of Sri Lanka. A total of 9,038 soil samples representing six ACZs, six soil orders, and three water sources were collected using a stratified random sampling approach. The ex-Mg concentration was determined after extracting in 0.01 M CaCl2 and detected using inductively coupled plasma-mass spectrometry. The range of ex-Mg was within 0.01-1,610 mg kg-1, with a mean of 210.4 mg kg-1. From the tested soil samples, 66% were Mg-deficient (730 mg kg-1). Among the ACZ, the Dry zone Low country had the highest ex-Mg concentration (p<0.05). Among the soil orders tested, Vertisols had the highest and Histosols had the lowest ex-Mg concentration (p<0.05). Irrigated rice fields had higher ex-Mg than the rainfed systems (p<0.05). Soil ex-Mg concentration was positively correlated with soil pH (p<0.05) and crop productivity (p<0.05). As most rice-growing soils of Sri Lanka are Mg-deficient, it is important to implement strategies specific to ACZs, soil orders, and water sources to improve the soil-Mg status

Population genetics and evolutionary history of the wild rice species Oryza rufipogon and O-nivara in Sri Lanka

Genetic diversity and population genetic structure of the wild rice species Oryza rufipogon and O. nivara in Sri Lanka were studied using 33 microsatellite markers. A total of 315 individuals of 11 natural populations collected from the wet, intermediate, and dry zones of the country were used in the study. We found a moderate to high level of genetic diversity at the population level, with the polymorphic loci (P) ranging from 60.6% to 100% (average 81.8%) and the expected heterozygosity (H-E) varying from 0.294 to 0.481 (average 0.369). A significant genetic differentiation between species and strong genetic structure within species were also observed. Based on species distribution modeling, we detected the dynamics of the preferred habitats for the two species in Sri Lanka and demonstrated that both O. rufipogon and O. nivara populations have expanded substantially since the last internal glacial. In addition, we showed that the geographical distribution of the two species corresponded to the climate zones and identified a few of key environmental variables that contribute to the distribution of the two species, implying the potential mechanism for ecological adaptation of these two species in Sri Lanka. These studies provided important insights into the population genetics and evolution of these wild species in Sri Lanka and are of great significance to the in situ conservation and utilization of these wild resources in genetic improvement of rice