Paddy and Water Environment最新文献

The concept of agricultural and rural multifunctionality expands the public’s understanding of the diverse roles of agriculture and rural areas. However, the establishment of the concept burdens governments with a complicated issue related to formulating an agricultural and rural policy, as the public could have diverse views on the functions that should be promoted via the policy. This study applies case 1 best–worst scaling to measure the relative importance of agricultural and rural multifunctionality in Japan. Sixteen functions, including the primary function of agriculture (agricultural commodity output), were addressed. The results show that, on average, agricultural commodity output was prioritized most, followed by disaster prevention-related, water-related, and biological conservation functions. The clustering results demonstrate that the individuals were divided into seven classes and that the relative importance of functions among the seven classes differed significantly. The heterogeneity in the relative importance of functions among the public indicates that social consensus on weighting multifunctional roles in agricultural and rural policies cannot be reached easily.

The "eco-craft trail" is firmly grounded in the principles of nature-based solutions (NBS), which advocate for the preservation of ecology. It adopts a site-specific intervention approach that considers natural and cultural contexts to restore trail facilities while prioritizing the protection of the natural environment and the preservation of cultural and historical characteristics. Moreover, it aimed to engage local communities in local affairs or by convening volunteers on a working holiday. However, there has been less focus on the divergence in context-specific knowledge between local residents and outsider participants in NBS events, as well as the identified implications for rural governance. This paper aims to address these theoretical gaps by examining a case study of eco-craft trail maintenance through a participatory action process. Our study involved conducting participatory action research, including in-depth interviews with 17 participants, to explore the rural governance in Pinglin before and after eco-craft trail maintenance events. The research revealed that local residents in Pinglin demonstrate a significant level of commitment to environmental conservation and exhibit a strong sense of attachment to their local community. Within the framework of multi-stakeholder collaboration, our study found that local individuals, as opposed to outsider volunteers, display a reluctance to deviate from their established work habits. This phenomenon, referred to as tshiú-lōo in Taiwanese, embodies a collective body memory rooted in customary knowledge and physical skills unique to the local community. This paper suggests that the maintenance of eco-craft trails cannot solely rely on government resources. Instead, it necessitates comprehensive training and preparation to effectively integrate local residents with outsider volunteers in collaborative efforts. Recommendations for enhancing multi-stakeholder collaboration are essential for advancing environmental conservation, rural governance, and facilitating sustainable transformation.

Kinmen, primarily reliant on rain-fed agriculture, faces persistent water shortages. This study investigates the potential of Kinmen Kaoliang Liquor Inc. (KKL) effluent, diluted with Houlong River (HR) water, to address water scarcity and assess its impact on sorghum yields, as well as the accumulations of macroelements (P, K, Ca, Mg, Na) and heavy metals in soils and plants. Results indicate that sorghum yields (2733.33 kg/ha) were optimal for the 40% KKL treatment, followed by the 80%, 60%, 20% KKL treatment, with the control treatment using HR water yielding the lowest. Macroelements exhibited distinct distributions in various plant parts. The distribution of P and Mg was highest in the leaves and grains, followed by the stems and roots for different KKL treatments. The order of Ca concentration was leaves > roots and stems > grain, while that of Na was roots > stems > leaves > grains. However, the distribution of K varied between the 20% and 40% KKL treatments (stems and leaves > roots > grains) and the 60% and 80% KKL treatments (roots > stems > leaves > grains). The findings emphasize the importance of understanding the intricate relationships among various elements within plant physiological processes. The macroelement mass balance in water-plants-soils revealed a decline in P and Mg portions stored in plants with higher KKL treatments, while Ca, K and Na portions varied across KKL treatments. In summary, considering sorghum yields and macroelement accumulation in plants and soils, the 40% KKL treatment is recommended for irrigation as an effective solution for water scarcity in Kinmen.

The number of cases of damage to reservoirs due to debris flows has increased. In this study, granular material was released down the slope in a flume model to observe the debris flow morphology in a reservoir and to examine the impact pressure on a model dam embankment. The model flume had a slope angle of 30°, slope section width of 300 mm, and reservoir section width of 800 mm, and a model embankment with pressure and water pressure gauges was installed. Several experiments were conducted by varying the grain size of the granular materials to 3, 6 mm, mixed, and initial water storage levels. Observations from a high-speed camera indicate that when the debris flow enters the reservoir, the momentum rapidly decreases immediately after inflow. However, a solitary wave was generated, with heights reaching up to 2.5 times the initial water level. Additionally, during the impact of the debris flow on the model embankment, a large impact pressure was instantaneously generated. The magnitude and frequency of the occurrence tended to be more pronounced when the grain size was large. Additionally, the instantaneous impact pressure reached approximately twice the average impact pressure. However, with the exception of instantaneous large impact pressures, the existing equations used in the design of Sabo dams and coefficients with a specific range proposed in previous studies can be used to successfully calculate the impact pressure acting on the embankment in relation to the velocity.

The intensifying impacts of climate change have led to widespread water scarcity across numerous countries. In response, many countries are suspending access to water supplies as part of their drought management strategies. This paper identifies the causal effect of losing access to irrigated water on farmland prices. Using population-based administrative data on farmland transactions from 2014 to 2015, we apply the difference-in-differences and event study methods to estimate the impact of supply-side policies restricting access to irrigated water on farmland prices using the case of Taiwan as an illustration. Farmers that lost access to irrigated water sold their farmland for lower prices during the policy’s rollout and the month following its implementation. High-quality farmland or farmland with the option of non-farm development is not affected by this policy. Altogether, these results imply that monetary payments in lieu of irrigated water can largely compensate farmers from losing access to this natural resource.

The Tanjero River in Sulaimani City exhibits severe pollution, prompting a comprehensive water quality analysis. Physical and chemical characteristics were conducted to evaluate their contribution to contamination levels. The primary objectives of this study were to assess the degree of water quality deterioration and to evaluate the purification capacity of the river. Utilizing the Thomas graphical method, the maximum concentration of organic mass entering from the city’s wastewater leading to oxygen depletion was observed in location 2, with the ultimate biochemical oxygen demand L_o 214.89 mg L⁻¹ which exceeds the allowed limit with a deoxygenation rate k₁ of 0.52 d⁻¹. Furthermore, the Streeter-Phelps model was employed to assess the river’s behavior under continuous flow conditions, focusing on dissolved oxygen deficits and reaeration dynamics. The results demonstrated that the DO values of the river water were less than the common minimum DO required for aquatic life 4 mg L⁻¹. The maximum deficit of dissolved oxygen for the water river was too high 20.31 mg L⁻¹ based on t_c = 1.46 d, and the reaeration rate constant k₂ is 1.58 d⁻¹. Dissolved oxygen deficiencies were observed to be markedly elevated beyond location 2, indicating a constrained self-purification capability of the river and presenting a significant risk to aquatic life. This research is crucial for an international audience as it underscores the global challenges urban rivers face in managing organic pollution and maintaining ecological balance. It highlights the need for effective wastewater management practices and global strategies. Therefore, establishing a wastewater treatment facility in the city is suggested as an effective and feasible measure to prevent further deterioration of the river’s water quality.

A field experiment was conducted to investigate suitable irrigation methods for cultivating four types of vegetable crops in sodic soil with alkaline irrigation water. The experiment employed a split-plot design, with drip, sprinkler, and furrow irrigation methods applied to main plots, while the cultivation of cluster beans, bhendi, vegetable cowpeas, and onions took place in subplots. Both drip and sprinkler irrigations proved more efficient than furrow irrigation, resulting in significant yield increases. Specifically, drip irrigation led to yields of 4120, 5160, 9264, and 4019 kg ha⁻¹ for cluster beans, bhendi, vegetable cowpeas, and onions, respectively, in sodic soil with alkaline irrigation water. This represented a yield increase of 43%, 34%, 71%, and 49%, respectively, compared to furrow irrigation. Post-harvest soil samples were collected and analyzed to assess the impact of irrigation methods on soil sodicity, revealing substantial reductions in electrical conductivity and exchangeable sodium percentage with drip irrigation. Additionally, drip irrigation was found to be effective in mitigating soil sodicity compared to sprinkler and furrow irrigation methods. The study also identified sodicity build-up as a critical factor influencing soil microbial populations and enzyme activities in sodic soil and alkaline irrigation water environments. Consequently, based on these findings, drip irrigation is recommended as the preferred method for cultivating vegetable crops in such environments.

To improve rice yields while conserving water and minimizing environmental impact, a lysimeter experiment was conducted at Bangladesh Agricultural University’s field irrigation laboratory in Mymensingh. This study, spanning 2018–2020, aimed to measure the water footprint (WF) of the Aman-Boro-Aman rotation, considering green water footprint (GWF; rainwater) and blue water footprint (BWF; irrigation water), with a focus on climate change implications. Various irrigation methods, including rainfed and several interval-based irrigations (I9D–irrigation applied after nine days of ponded water disappearance, I6D, I3D, I3D + NP–I3D with no percolation allowed, and I1D), were evaluated. Results showed rainfed treatments had higher GWF (1155–1575 L/kg) due to reliance on inconsistent rainfall, while irrigated ones had lower GWF (375–1084 L/kg) but increased BWF, notably I1D with the highest BWF (2675 L/kg). This contrast highlights significant water usage differences among irrigation methods. The total water footprint (TWF) varied, with rainfed methods showing 1460–1960 L/kg and I1D the highest at 3603 L/kg. The consumptive water footprint ranged from 734 L/kg (I3D + NP) to 1097 L/kg (rainfed), indicating the efficiency of no-percolation strategies in water conservation. This also led to improved nutrient availability, resulting in higher plant height and rice yield. Seasonal variations in TWF were also observed, with the Aman season showing greater variability than the Boro season due to differences in rainfall and irrigation practices. The study underscores the importance of managing irrigation frequency, timing, and percolation for optimizing rice water footprints under changing climatic conditions.

Properly managed microsprinkler irrigation of rice is an efficient and viable alternative to traditional flood irrigation methods for enhancing crop and water productivity in water-scarce regions. Field experiments were conducted for two consecutive summer seasons (February to June) of 2017 and 2018 on sandy loam soil with three levels of irrigation, viz., the ratios of crop evapotranspiration (ETc) were 1.25, 1.0 and 0.75, and a microsprinkler, including surface irrigation, was used to evaluate the growth parameters, yield attributes, yield, crop water productivity (CWP), root-zone soil water dynamics and nutrient utilization of aerobic rice. The results showed that microsprinkler irrigation at 1.25 ETc resulted in the maximum plant height, dry matter yield, leaf area index, number of effective tillers m⁻², number of panicles m⁻², number of filled grains panicle⁻¹, relative leaf water content, 1000-grain weight, grain yield (3.76 t ha⁻¹), straw yield (5.15 t ha⁻¹), harvest index, chlorophyll content and grain nutrient uptake. The highest CWP (0.92 kg m⁻³) was found under microsprinkler irrigation at 1.0 ETc, while under deficit irrigation at 0.75 ETc, the microsprinkler exhibited greater root length, root volume and water savings than did surface irrigation. Greater soil water contents and root-zone soil water storage and depletion at all growth stages were recorded under microsprinkler irrigation at 1.25 ETc. A strong second-degree polynomial relationship was detected between grain yield and the amount of irrigation water. The optimal irrigation requirement for aerobic rice grown in the Indo-Gangetic Plains of Eastern India was estimated to be 325 mm to maximize yield and water utilization.

Rice cultivation in Tamil Nadu, a southern state of India, is a vital component of its agricultural landscape and economy. It holds historical significance and contributes significantly to the state's food security. Green manuring–system of rice intensification (SRI)–blackgram (rice fallow pulses) cropping system is novel, and this integrated system appears to be holistic and sustainable approach, combining innovative farming techniques to optimize yields, improve soil health, and minimize environmental impacts. To evaluate this, field demonstrations were conducted at a farmer's field through the National Pulses Research Centre, Vamban, Pudukkottai, Tamil Nadu, within the kharif rabi and summer seasons of 2019–20 under the Tamil Nadu Irrigated Agriculture Modernization project. The experimental site was medium deep clay with soil pH of 8.51, EC of 0.26 d S m⁻¹, low in available nitrogen (212.02 kg ha⁻¹), high in P₂O₅ (23.24 kg ha⁻¹), and medium in K₂O (300.46 kg ha⁻¹). Initially, farmers were given the awareness about the improved production technologies (IPT), and then, demonstration was conducted in 50 hectares with 92 locations of Ponnaniyar sub-basin. The demonstration results showed that the improved practice of SRI recorded higher plant height and other yield attributes. Notably, the SRI cultivation method exhibited a range of yields from 7580 to 9400 kg ha⁻¹ of rice across various locations, with the highest recorded at Avoor village. Concurrently, within the IPT framework for the GM–SRI–Rice fallow pulses cropping system, the recorded yields for Rice fallow Blackgram ranged from 590 to 730 kg ha⁻¹. Comparative analysis indicated a remarkable 39.9 percent enhancement in system productivity through the adoption of IPT practices compared to conventional farmer practices. Moreover, the IPT framework showcased significantly higher water productivity, recording 0.7087 kg ha⁻¹ m⁻³ compared to the conventional method, which yielded 0.2512 kg ha⁻¹ m⁻³. Soil nutrient observations highlighted that these cropping systems positively impacted soil fertility parameters, compared to the initial available nutrient status. This augmentation in soil fertility could be attributed to the incorporation of green manures. Consequently, the green manure–system of rice intensification–rice fallow pulses crop sequences emerged as more productive and sustainable option, displaying the potential to enhance soil productivity and fertility status compared to conventional rice–blackgram/groundnut cropping sequences. These systems present promising alternatives for farmers within the Ponnaniyar sub-basin area of Tamil Nadu.